U.S. patent application number 11/112879 was filed with the patent office on 2005-11-24 for compositions for treatment with glucagon-like peptide, and methods of making and using the same.
Invention is credited to Bolotin, Elijah M..
Application Number | 20050260259 11/112879 |
Document ID | / |
Family ID | 35428848 |
Filed Date | 2005-11-24 |
United States Patent
Application |
20050260259 |
Kind Code |
A1 |
Bolotin, Elijah M. |
November 24, 2005 |
Compositions for treatment with glucagon-like peptide, and methods
of making and using the same
Abstract
In part, the present invention is directed to compositions
comprising a carrier with a metal binding domain, a metal ion, and
GLP-1.
Inventors: |
Bolotin, Elijah M.; (Buffalo
Grove, IL) |
Correspondence
Address: |
FOLEY HOAG, LLP
PATENT GROUP, WORLD TRADE CENTER WEST
155 SEAPORT BLVD
BOSTON
MA
02110
US
|
Family ID: |
35428848 |
Appl. No.: |
11/112879 |
Filed: |
April 22, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60564710 |
Apr 23, 2004 |
|
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|
Current U.S.
Class: |
424/450 ;
514/11.7; 514/6.9 |
Current CPC
Class: |
A61K 47/645 20170801;
A61K 9/0019 20130101; A61K 38/26 20130101; A61K 47/60 20170801;
A61K 47/42 20130101; A61K 47/34 20130101; A61K 47/10 20130101 |
Class at
Publication: |
424/450 ;
514/006 |
International
Class: |
A61K 038/16; A61K
009/127 |
Claims
We claim:
1. A biocompatible composition comprising: a carrier with a metal
binding domain (MBD), a metal ion chelated to the metal binding
domain of the carrier, and glucagon-like peptide-1 (GLP-1) with a
MBD chelated to the metal ion, wherein after administration of the
composition to a patient, GLP-1 is released from the carrier.
2. The composition of claim 1, wherein the carrier is one of the
following: polymer, micelle, reverse micelle, liposome, emulsion,
hydrogel, microparticle, nanoparticle, microsphere, or solid
surface.
3. The composition of claim 1, wherein the carrier is a
polymer.
4. The composition of claim 1, wherein the carrier is a polymer
having a molecular mass ranging from about 100 to about 100,000,000
daltons.
5. The composition of claim 1, wherein the carrier is a polymer
having a molecular mass ranging from about 10,000 to about 250,000
daltons.
6. The composition of claim 1, wherein the carrier comprises a poly
amino acid.
7. The composition of claim 1, wherein the carrier comprises
poly-lysine.
8. The composition of claim 1, wherein the carrier comprises
poly(ethyleneglycol).
9. The composition of claim 1, wherein the carrier comprises a
protective sidechain.
10. The composition of claim 9, wherein the protective side chain
comprises poly(ethylene glycol).
11. The composition of claim 9, wherein the protective side chain
comprises alkoxy poly(ethyleneglycol).
12. The composition of claim 9, wherein the protective side chain
comprises methoxy poly(ethyleneglycol) (MPEG).
13. The composition of claim 1, wherein the metal binding domain
comprises a nitrogen containing poly carboxylic acid.
14. The composition of claim 1, wherein the metal binding domain
comprises one or more of the following:
N-(hydroxy-ethyl)ethylenediaminetriacetic acid; nitrilotriacetic
acid (NTA); ethylene-bis(oxyethylene-nitrilo)tetra- acetic acid;
1,4,7,10-tetraazacyclodo-decane-N,N',N",N'"-tetraacetic acid;
1,4,7,10-tetraaza-cyclododecane-N,N',N"-triacetic acid;
1,4,7-tris(carboxymethyl)-10-(2'-hydroxypropyl)-1,4,7,10-tetraazocyclodec-
ane; 1,4,7-triazacyclonane-N,N',N"-triacetic acid;
1,4,8,11-tetraazacyclot- etra-decane-N,N',N",N'"-tetraacetic acid;
diethylenetriamine-pentaacetic acid (DTPA); ethylenedicysteine;
bis(aminoethanethiol)carboxylic acid;
triethylenetetraamine-hexaacetic acid; ethylenediamine-tetraacetic
acid (EDTA); 1,2-diaminocyclohexane-N,N,N',N'-tetraacetic acid; or
polypeptide.
15. The composition of the claim 14, wherein the polypeptide has
the formula: (AxHy)p where A is any amino acid residue, H is
histidine, x is an integer from 0-6; y is an integer from 1-6; and
p is an integer from 1-6.
16. The composition of claim 1, wherein the metal ion is a
transition metal ion.
17. The composition of claim 1, wherein the metal ion is one or
more of the following: Zn.sup.2+, Ni.sup.2+, Co.sup.2+, Fe.sup.2+,
Mn.sup.2+, or Cu.sup.2+.
18. The composition of claim 1, wherein the metal ion is Zn.sup.2+
or Ni.sup.2+.
19. The composition of claim 9, wherein the carrier comprises
poly-L-lysine, the protective side chain comprises MPEG, the metal
binding domain comprises NTA, and the metal ion is Ni.sup.2+.
20. The composition of claim 9, wherein the carrier comprises
poly-L-lysine, the protective side chain comprises MPEG, the metal
binding domain comprises NTA, and the metal ion is Zn.sup.2+.
21. A pharmaceutical composition comprising the composition of
claim 1.
22. The pharmaceutical composition of claim 22, wherein the
pharmaceutical composition is an injectable composition.
Description
RELATED APPLICATIONS
[0001] This application claims the benefit of priority to U.S.
Provisional Patent Application Ser. No. 60/564,710, filed Apr. 23,
2004.
INTRODUCTION
[0002] The development of new drugs, formulations and other systems
for administration of physiologically active peptides and proteins
and other therapeutics and materials is driven by the need to
provide these peptides or proteins or other materials to achieve
the desirable physiological effects. With respect to peptides and
proteins, many of them have been observed to be unstable in the
gastro-intestinal tract and therefore may need to be stabilized or
protected or delivered via systemic circulation. In addition,
peptides and proteins that have low molecular masses tend to have
short biological half-lives due to their efficient removal from
systemic circulation via kidneys. For example, a fraction of these
peptides and proteins can also be removed via reticulo-endothelial
uptake due to recognition by monocyte/macrophages or as a result of
opsonization by complement components. Many peptides and proteins
can also lose their activity in vivo due to proteolysis (peptide
bond cleavage).
[0003] In part to circumvent these undesirable effects, a drug
delivery system may be used. There are several drug delivery
strategies that can be useful for peptide and protein delivery in
vivo. First, a continuous systemic infusion of drug via a pump can
be employed. This strategy is proven efficient in clinical practice
but may be impractical for outpatients requiring high levels of
mobility, associated disadvantages of quality of life and potential
intravenous (I.V.) line infections.
[0004] Second, peptides and proteins can be included in an
implantable pump comprised of a capsule with a membrane allowing
diffusion of the drug, for example, at a desirable release rate.
Due to limited volume of these capsules, peptides and proteins are
often used in a concentrated formulation, which leads to a loss of
solubility due to aggregation and potential loss of specific
activity. In most cases, the drug is usually released into the
extracellular space and distributed in lymphatics. Overall
concentration of peptide or protein may be affected by local lymph
node activity and the efficacy of lymph node drainage of the
implantation site. There is also a potential of host reaction to
capsule material but in general, this side effect is
infrequent.
[0005] Third, the drug release system can be made biodegradable as
a result of encapsulation or inclusion into degradable drug
delivery vehicles or carriers, e.g. polymeric matrices, particles
or membrane vesicles (liposomes). These delivery systems are
usually either implantable or injectable. Implantable drug delivery
systems are often placed under the epidermis where the components
of the system are usually slowly degraded as a result of biological
activity of surrounding cells (i.e. as a result of the release of
enzymes degrading chemical bonds that hold these implants
together).
[0006] One example of treatment with a peptide that is currently
rendered ineffective due to proteolysis is treatment with
glucagon-like peptides such as glucagon-like peptide 1 (GLP-1) and
glucagon-like peptide 2 (GLP-2). In particular, treatment that
involves proteolysis protected GLP-1 would be beneficial for the
treatment of diabetes.
[0007] Diabetes is a disease in which the body does not produce or
properly use insulin, a hormone that regulates blood sugar.
Diabetes is the third most common disease and fourth leading cause
of death in North America with an estimated 18.2 million (6.3% of
the population) affected in the United States. The annual economic
cost of diabetes in the US is estimated to be as much as $100
billion, making the disease an important clinical and public health
problem.
[0008] There are two major types of diabetes: Type 1, (5-10% of
diabetics) in which the immune system attacks the insulin-producing
beta cells of the pancreas and Type 2 in which individuals develop
resistance to insulin. Untreated diabetics are affected by a myriad
of complications including eye, kidney, nerve and cardiovascular
disease. The goal of diabetes treatment is to regulate blood sugar
levels and prevent hyperglycemia. While high blood sugar can be
controlled in Type II diabetes by lifestyle changes and oral
anti-hyperglycemic agents, the only standard treatment for Type I
diabetes, however, is strict control of blood glucose levels by
insulin therapy by injection, with the associated risk of serious
hypoglycemic events. More recently, the transplantation of
insulin-producing pancreatic islet cells has been shown to be
highly effective in reversing diabetes in Type I patients. The
success of this therapy however depends on effective
immunosuppression to prevent the rejection of the transplanted
islets by the autoimmune response of the patient, though reports of
sustained tolerance to the transplant have been reported.
[0009] The recent finding that islet cells can be regenerated in
diabetic animals by GLP-1 has raised the exciting possibility of a
new approach for a cure that avoids the need for transplantation of
islets and its associated complications. GLP-1 may offer an
attractive alternative to islet transplantation, circumventing the
complications associated with surgery or portal vein administration
of islet cells. However, this treatment still suffers from a short
half life for GLP-1 due to proteolysis.
[0010] New therapies are still desperately needed to relieve
patients with diabetes from the neuropathy, nephropathy and
retinopathy associated with the current standard of treatment,
injected insulin. An attractive new treatment presented herein is a
drug delivery system that overcomes the problems presented
above.
[0011] In part, the present invention is directed towards novel
drug delivery systems, and methods of making and using the
same.
SUMMARY OF INVENTION
[0012] In part, the present invention is directed to the use of
metal bridges to connect a carrier and GLP-1. In certain instances,
the subject compositions provide a means of achieving sustained
release of the active agent after administration to a patient. In
certain instances, the release may be designed to be other than
sustained. As used herein, a "metal bridge" comprises the metal
binding domain (MBD) of the carrier, the MBD of the active agent,
and the metal that is chelated to both of them. It may be the case
that the metal bridge may comprise more than a single metal ion
(i.e., multiple metal ions) with bridging ligands, provided that
the MBDs of the carrier and active agent are capable of being
connected through the metal ions and bridging ligand. It may be in
the case of GLP-1 that an MBD is not necessary.
[0013] In part, the present invention is directed to a drug
delivery system involving a polymeric carrier to which a drug may
associate via a metal ion. It has been observed that polymeric
carriers bearing chelated metal ion can bind biologically active
peptides and proteins in the absence or presence of plasma
proteins. The subject compositions, and methods of making and using
the same, may achieve a number of desirable results and features,
one or more of which (if any) may be present in any particular
embodiment of the present invention: 1) protecting peptides and
proteins and other associated drugs from the interaction with other
macromolecules and cells; 2) decreasing undesirable immunogenicity
of the carrier or peptide/protein/drug; 3) prolonging biological
half-life of peptides and proteins and drugs in vivo (e.g. for
decreasing glomerular filtration in kidneys, decreasing kidney and
liver uptake, decreasing macrophage uptake etc); 4) stabilizing
peptides/proteins/drugs by complexation with metal ion and carrier.
One potential advantage of the metal binding domain of the present
invention is to afford labile binding with peptides and proteins
and other drugs which are capable of forming coordination bonds
with metal ions (e.g., Zn and Ni). In many instances, coordinate
bonding affords reversible dissociation of the peptide or protein
or drug from the polymeric carrier. It may be possible to affect
the dissociation rate by modulating with competitive ligands for
the metal ion, such as imidazole or nitrilotriacetic acid
(NTA).
[0014] In certain embodiments, the present invention may not
require the use of a MBD with GLP-1, in so much as certain carriers
associate with GLP-1 in the absence of a MBD.
[0015] In certain embodiments, the present invention relates to a
biocompatible composition comprising: (i) a carrier with a metal
binding domain (MBD); (ii) a metal ion chelated to the MBD; and
(iii) an active agent with a MBD chelated to the metal ion, wherein
after administration of the composition to a patient, the active
agent is released in a sustained manner. It is understood that not
all of the active agents in a sample of the composition will
necessarily be attached to the carrier through the metal ion, but
that some portion of the active agent may be combined with the
carrier. Likewise, it is understood that not all of the metal
binding domains attached to the carrier will chelate a metal ion,
and that not all of the metal ions bound to a metal binding domain
will form a coordinate bond with an active agent.
[0016] In a further embodiment, the present invention relates to
the composition described above wherein the carrier is one of the
following: polymer, micelle, reverse micelle, liposome, emulsion,
hydrogel, microparticle, nanoparticle, microsphere, colloid or
solid surface. In a further embodiment, the carrier is a
biocompatible polymer. In a further embodiment, the carrier is a
polymer having a molecular weight ranging from about 100 to about
1,000,000 daltons. In a further embodiment, the carrier is a
polymer having a molecular weight ranging from about 10,000 to
about 250,000 daltons. In a further embodiment, the carrier
comprises a poly amino acid. In a further embodiment, the carrier
comprises poly-lysine.
[0017] In a further embodiment, the present invention relates to
the above described composition wherein the carrier comprises
protective side chains. In a further embodiment, the protective
side chain comprises poly(ethylene glycol). In a further
embodiment, the protective side chain comprises alkoxy
poly(ethylene glycol). In a further embodiment, the protective side
chain comprises methoxy poly(ethylene glycol) (MPEG).
[0018] In a further embodiment, the present invention relates to
the above described composition wherein the metal binding domain
comprises a nitrogen containing poly carboxylic acid. In a further
embodiment, the metal binding domain comprises one or more of the
following moieties: N-(hydroxy-ethyl)ethylenediaminetriacetic acid;
nitrilotriacetic acid (NTA);
ethylene-bis(oxyethylene-nitrilo)tetraacetic acid;
1,4,7,10-tetraazacyclodo-decane-N,N',N",N'"-tetraacetic acid;
1,4,7,10-tetraaza-cyclododecane-N,N',N"-triacetic acid;
1,4,7-tris(carboxymethyl)-10-(2'-hydroxypropyl)-1,4,7,10-tetraarocyclodec-
ane; 1,4,7-triazacyclonane-N,N',N"-triacetic acid;
1,4,8,11-tetraazacyclot- etra-decane-N,N',N",N'"-tetraacetic acid;
diethylenetriamine-pentaacetic acid (DTPA); ethylenedicysteine;
bis(aminoethanethiol)carboxylic acid;
triethylenetetraamine-hexaacetic acid; ethylenediamine-tetraacetic
acid (EDTA); 1,2-diaminocyclohexane-N,N,N',N'-tetraacetic acid; or
polypeptide. In a further embodiment, the polypeptide in the metal
binding domain has the formula: (AxHy)p where A is any amino acid
residue, H is histidine, x is an integer from 0-6; y is an integer
from 1-6; and p is an integer from 1-6.
[0019] In a further embodiment, the present invention relates to
the above described composition wherein the metal ion is a
transition metal ion. In a further embodiment, the metal ion is one
or more of the following: Zn.sup.2+, Ni.sup.2+, Co.sup.2+,
Fe.sup.2+, Mn.sup.2+, or Cu.sup.2+.
[0020] In a further embodiment, the present invention relates to
the above described composition wherein the active agent is one of
the following: a diagnostic, targeting moiety, or therapeutic
agent. In a further embodiment, the present invention relates to
the above described composition wherein more than one type of
active agent forms a coordinate bond with the metal binding domain
of the polymeric carrier. In a further embodiment, the active agent
is a therapeutic agent comprising a protein, peptide,
peptidomimetic, deoxyribonucleic acid, ribonucleic acid,
oligonucleotide, other nucleic acid, oligosaccharide, antibody or
proteoglycan.
[0021] In a further embodiment, the present invention relates to
the above described composition wherein the carrier comprises
poly-L-lysine, the protective side chain comprises MPEG, the metal
binding domain comprises NTA, the metal ion is Ni.sup.2+, and the
active agent is GLP-1.
[0022] In a further embodiment, the present invention relates to
the above described composition wherein the carrier comprises
poly-L-lysine, the protective side chain comprises MPEG, the metal
binding domain comprises NTA, the metal ion is Zn.sup.2+, and the
active agent is GLP-1.
[0023] In another embodiment, the present invention relates to a
pharmaceutical composition comprising any of the above described
compositions. In a further embodiment, the pharmaceutical
composition is an injectable composition.
[0024] In another embodiment, the present invention relates to a
composition comprising: a carrier with a metal binding domain
(MBD), a metal ion chelated to the MBD of the carrier, one or more
protective side chains covalently bonded to the carrier, and an
active agent with a MBD chelated to the metal ion. In a further
embodiment, the carrier comprises a polymer. In a further
embodiment, the protective sidechain comprises poly(ethylene
glycol). In a further embodiment, the protective sidechain
comprises alkoxy poly(ethyleneglycol). In a further embodiment, the
protective sidechain comprises methoxy poly(ethyleneglycol) (MPEG).
In a further embodiment, the active agent is a therapeutic agent.
In a further embodiment, the active agent is a peptide or
protein.
[0025] The present invention provides a number of methods of making
the subject compositions. Examples of such methods include those
described in the Exemplification below.
[0026] In another embodiment, the present invention relates to a
method of treatment, comprising administering any of the above
described compositions. In a further embodiment, the present
invention relates to a method of treating diabetes, obesity,
Alzheimer's, or cardiovascular problems comprising administering
any of the above described compositions.
[0027] In another embodiment, the present invention relates to a
kit comprising a composition comprising: (i) a carrier with a MBD;
(ii) a metal ion chelated to the MBD of the carrier; and (iii) an
active agent with a MBD chelated to the metal ion. Uses for such
kits include, for example, therapeutic applications. Such kits may
have a variety of uses, including, for example, imaging, targeting,
diagnosis, therapy, vaccination, and other applications.
[0028] In another aspect, the compositions of the present invention
may be used in the manufacture of a medicament for any number of
uses, including for example treating any disease or other treatable
condition of a patient. In still other aspects, the present
invention is directed to a method for formulating biocompatible
compositions of the present invention in a pharmaceutically
acceptable carrier.
[0029] These embodiments of the present invention, other
embodiments, and their features and characteristics, will be
apparent from the description, drawings and claims that follow.
BRIEF DESCRIPTION OF DRAWINGS
[0030] FIG. 1 depicts a graph showing the binding of hrGH to
polymers in the presence of Zn and Ni cations. Size-separation on
Centricon YM-100 membrane suggests that approximately 1 mg of rhGH
binds to 100 mg of MPEGs-PL-ZnNTA.
[0031] FIG. 2 depicts a chromatogram showing elution profiles of
.sup.125I-labled rhGH (squares) and rhGH complex with
MPEGs-PL-ZnNTA (circles) on SEC-5 size-exclusion HPLC column. The
profile of time-dependent elution shows that a fraction of the
complex of labeled hormone with MPEGs-PL-ZnNTA elutes earlier than
the free hormone suggesting a complex formation.
[0032] FIG. 3 depicts a bar-graph showing histidine tagged-GFP
binding yields after separation of complexes with MPEGs-PL-NTA (Ni
or Zn salts), MPEGs-PL or MPEGs-PL-succinate in the presence or
absence of blood plasma. The graph shows that complex formation
with metal salts of MPEGs-PL-NTA is equally possible in the
presence or absence of bulk protein of plasma.
[0033] FIG. 4 depicts a bar graph showing the levels of GFP in
plasma of animals injected with a histidine tagged-GFP (control);
and complexes of histidine tagged-GFP with MPEGs-PL-ZnNTA and
MPEGs-PL-NiNTA. The graph shows significantly higher in vivo levels
of GFP in blood in the case of Ni-complex suggesting prolonged
circulation of histidine tagged-GFP bound to MPEGs-PL-NiNTA
carrier.
[0034] FIG. 5 depicts N-terminal cleavage at the Ala2 position by
dipeptidyl peptidase IV (DPP-IV) in GLP-1 amide.
[0035] FIG. 6 depicts a protected graft copolymer (PGC) nanocarrier
with PharmaIn reversible binding (PRB) (reversible binding that
comprises a metal ion bridge).
[0036] FIG. 7 depicts an example of binding isotherm for the
interaction. ITC is a true in-solution method.
DETAILED DESCRIPTION OF INVENTION
[0037] Definitions
[0038] For convenience, before further description of the present
invention, certain terms employed in the specification, examples
and appended claims are collected here. These definitions should be
read in light of the remainder of the disclosure and understood as
by a person of skill in the art. Unless defined otherwise, all
technical and scientific terms used herein have the same meaning as
commonly understood by a person of ordinary skill in the art.
[0039] The articles "a" and "an" are used to refer to one or to
more than one (i.e., to at least one) of the grammatical object of
the article. By way of example, "an element" means one element or
more than one element.
[0040] The term "plurality" means more than one.
[0041] The terms "comprise" and "comprising" are used in the
inclusive, open sense, meaning that additional elements may be
included.
[0042] The term "including" is used to mean "including but not
limited to". "Including" and "including but not limited to" are
used interchangeably.
[0043] The term "Glucagon-like Peptide-1", "GLP-1", or "GLP-1
amide" is art recognized, and is an intestinal hormone that
increases insulin secretion. This definition includes derivatives
and fragments thereof that have substantially the same biological
effect as naturally occurring GLP-1. GLP-1 may be isolated or
synthetically prepared. Derivatives and fragments may also be
isolated or synthetically prepared.
[0044] The term "backbone polymer" is art-recognized and refers to
any linear or branched polymer or copolymer from which pendant side
chains may be chemically linked.
[0045] The term "carrier" refers to any substance capable of
supporting a metal binding domain which in turn chelate at least
one metal ion which in turn coordinates at least one active
agent.
[0046] The term "protective side chain" is art recognized and
refers to any side chain chemical moiety chemically linked to the
backbone polymer or other type of carrier that is capable of
providing protection for a therapeutic agent also associated with
the backbone polymer or other type of carrier. In some instances,
the protective side chain is capable of protecting the therapeutic
agent through sterics. In certain embodiments, the protective side
chain is linear or branched polymer or copolymer.
[0047] The term "chemically linked" is art-recognized and refers to
two atoms or chemical moieties bonded together through either a
covalent, ionic, or hydrogen bond.
[0048] The term "metal binding domain" is art-recognized and refers
to any conformational arrangement of several chemical groups that
is capable of forming a complex between the metal ion and the
chemical groups by coordinate bonds.
[0049] The term "chelated" is art-recognized and refers to a metal
ion coordinated with a Lewis Base of a chemical moiety. In certain
instances, when the moiety would be deemed a bidentate ligand, the
metal ion and the moiety form a ring.
[0050] The term "chelating group" is art-recognized and refers to a
molecule, often an organic one, and often a Lewis base, having two
or more unshared electron pairs available for donation to a metal
ion. The metal ion is usually coordinated by two or more electron
pairs to the chelating agent. The terms, "bidentate chelating
agent", "tridentate chelating agent", and "tetradentate chelating
agent" are art-recognized and refer to chelating agents having,
respectively, two, three, and four electron pairs readily available
for simultaneous donation to a metal ion coordinated by the
chelating agent. Usually, the electron pairs of a chelating agent
forms coordinate bonds with a single metal ion; however, in certain
examples, a chelating agent may form coordinate bonds with more
than one metal ion, with a variety of binding modes being
possible.
[0051] The term "non-liposomic carrier" refers to carriers that do
not have the properties of liposomes. It is understood by those
ordinarily skilled in the art that liposomes are vesicles with an
internal cavity and an external surface, and further that the
location of a MBD in either the internal or external portion would
effect the properties of the compositions of the present invention.
For example, in certain applications an external MBD would be
desirable for the slow release of a therapeutic agent.
[0052] The term "biocompatible composition" as used herein means
that the composition in question, upon implantation in a subject,
does not elicit a detrimental response sufficient to result in the
rejection of the composition or to render it inoperable, for
example through degradation. To determine whether any subject
composition is biocompatible, it may be necessary to conduct a
toxicity analysis. Such assays are well known in the art. One
non-limiting example of such an assay for analyzing a composition
of the present invention would be performed with live carcinoma
cells, such as GT3TKB tumor cells, in the following manner: various
amounts of subject compositions are placed in 96-well tissue
culture plates and seeded with human gastric carcinoma cells
(GT3TKB) at 104/well density. The degraded products are incubated
with the GT3TKB cells for 48 hours. The results of the assay may be
plotted as % relative growth versus amount of compositions in the
tissue-culture well. In addition, compositions of the present
invention may also be evaluated by well-known in vivo tests, such
as subcutaneous implantations in rats to confirm that they do not
cause significant levels of irritation or inflammation at the
subcutaneous implantation sites.
[0053] The term "treating" is art recognized and includes
preventing a disease, disorder or condition from occurring in a
patient which may be predisposed to the disease, disorder and/or
condition but has not yet been diagnosed as having it; inhibiting
the disease, disorder or condition, e.g., impeding its progress;
and relieving the disease, disorder or condition, e.g., causing
regression of the disease, disorder and/or condition. Treating the
disease or condition includes ameliorating at least one symptom of
the particular disease or condition, even if the underlying
pathophysiology is not affected. Treating includes, without
limitation, use of the subject compositions with a diagnostic for
diagnostic purposes as well as a targeting moiety or an
antigen.
[0054] The term "active agent" includes without limitation,
therapeutic agents, diagnostics, targeting moieties, and
antigens.
[0055] The term "therapeutic agent" is art-recognized and refers to
any chemical moiety that is a biologically, physiologically, or
pharmacologically active substance that acts locally or
systemically in a subject. Examples of therapeutic agents, also
referred to as "drugs", are described in well-known literature
references such as the Merck Index, the Physicians Desk Reference,
and The Pharmacological Basis of Therapeutics, and they include,
without limitation, medicaments; vitamins; mineral supplements;
substances used for the treatment, prevention, diagnosis, cure or
mitigation of a disease or illness; substances which affect the
structure or function of the body; or pro-drugs, which become
biologically active or more active after they have been placed in a
physiological environment. Various forms of a therapeutic agent may
be used which are capable of being released from the subject
composition into adjacent tissues or fluids upon administration to
a subject. Examples include steroids and esters of steroids (e.g.,
estrogen, progesterone, testosterone, androsterone, cholesterol,
norethindrone, digoxigenin, cholic acid, deoxycholic acid, and
chenodeoxycholic acid), boron-containing compounds (e.g.,
carborane), chemotherapeutic nucleotides, drugs (e.g., antibiotics,
antivirals, antifingals), enediynes (e.g., calicheamicins,
esperamicins, dynemicin, neocarzinostatin chromophore, and
kedarcidin chromophore), heavy metal complexes (e.g., cisplatin),
hormone antagonists (e.g., tamoxifen), non-specific (non-antibody)
proteins (e.g., sugar oligomers), oligonucleotides (e.g., antisense
oligonucleotides that bind to a target nucleic acid sequence (e.g.,
mRNA sequence)), peptides, proteins, antibodies, photodynamic
agents (e.g., rhodamine 123), radionuclides (e.g., I-131, Re-186,
Re-188, Y-90, Bi-212, At-211, Sr-89, Ho-166, Sm-153, Cu-67 and
Cu-64), toxins (e.g., ricin), and transcription-based
pharmaceuticals.
[0056] A "diagnostic" or "diagnostic agent" is any chemical moiety
that may be used for diagnosis. For example, diagnostic agents
include imaging agents containing radioisotopes such as indium or
technetium; contrasting agents containing iodine or gadolinium;
enzymes such as horse radish peroxidase, GFP, alkaline phosphatase,
or .alpha.-galactosidase; fluorescent substances such as europium
derivatives; luminescent substances such as N-methylacrydium
derivatives or the like.
[0057] "Diagnosis" is intended to encompass diagnostic, prognostic,
and screening methods.
[0058] The term "targeting moiety" refers to any molecular
structure which assists the construct in localizing to a particular
target area, entering a target cell(s), and/or binding to a target
receptor. For example, lipids (including cationic, neutral, and
steroidal lipids, virosomes, and liposomes), antibodies, lectins,
ligands, sugars, steroids, hormones, nutrients, and proteins may
serve as targeting moieties.
[0059] A "target" shall mean a site to which targeted constructs
bind. A target may be either in vivo or in vitro. In certain
embodiments, a target may be a tumor (e.g., tumors of the brain,
lung (small cell and non-small cell), ovary, prostate, breast and
colon as well as other carcinomas and sarcomas). In other
embodiments, a target may be a site of infection (e.g., by
bacteria, viruses (e.g., HIV, herpes, hepatitis) and pathogenic
fungi (Candida sp.). In still other embodiments, a target may refer
to a molecular structure to which a targeting moiety binds, such as
a hapten, epitope, receptor, dsDNA fragment, carbohydrate or
enzyme. Additionally, a target may be a type of tissue, e.g.,
neuronal tissue, intestinal tissue, pancreatic tissue etc.
[0060] The term "antigen" refers to any molecule or compound that
specifically binds to an antigen binding site.
[0061] The term "antigen binding site" refers to a region of an
antibody construct that specifically binds an epitope on an
antigen.
[0062] The term "antibody" is art-recognized and intended to
include whole antibodies, e.g., of any isotype (IgG, IgA, IgM, IgE,
etc.), and includes fragments thereof which are also specifically
reactive with a vertebrate, e.g., mammalian, protein. Antibodies
may be fragmented using conventional techniques and the fragments
screened for utility in the same manner as described above for
whole antibodies. Thus, the term includes segments of
proteolytically-cleaved or recombinantly-prepared portions of an
antibody molecule that are capable of selectively reacting with a
certain protein. The subject invention may include polyclonal,
monoclonal or other purified preparations of antibodies and
recombinant antibodies.
[0063] The phrases "systemic administration," "administered
systemically," "peripheral administration" and "administered
peripherally" are art-recognized, and include the administration of
a subject composition or other material at a site remote from the
disease being treated. Administration of a subject composition
directly into, onto or in the vicinity of a lesion of the disease
being treated, even if the composition is subsequently distributed
systemically, may be termed "local" or "topical" or "regional"
administration, other than directly into the central nervous
system, e.g., by subcutaneous administration, such that it enters
the patient's system and, thus, is subject to metabolism and other
like processes.
[0064] The phrase "therapeutically effective amount" is an
art-recognized term. In certain embodiments, the term refers to an
amount of the therapeutic agent that, when bridged through a metal
ion to a carrier of the present invention, produces some desired
effect at a reasonable benefit/risk ratio applicable to any medical
treatment. In certain embodiments, the term refers to that amount
necessary or sufficient to eliminate, reduce or maintain (e.g.,
prevent the spread of) a tumor or other target of a particular
therapeutic regimen. The effective amount may vary depending on
such factors as the disease or condition being treated, the
particular targeted constructs being administered, the size of the
subject or the severity of the disease or condition. One of
ordinary skill in the art may empirically determine the effective
amount of a particular compound without necessitating undue
experimentation. In certain embodiments, the term refers to that
amount necessary or sufficient for a use of the subject
compositions described herein.
[0065] The term "naturally-occurring", as applied to an object,
refers to the fact that an object may be found in nature. For
example, a carrier that may be isolated from a source in nature and
which has not been intentionally modified by man in the laboratory
is naturally-occurring.
[0066] The term "porous particles" refers to particles having a
total mass density less than about 0.4 g/cm.sup.3. The mean
diameter of the particles can range, for example, from about 100 nm
to 15 .mu.m, or larger depending on factors such as particle
composition.
[0067] The term "ligand" is art-recognized and refers to a species
that interacts in some fashion with another species. In one
example, a ligand may be a Lewis base that is capable of forming a
coordinate bond with a Lewis Acid. In other examples, a ligand is a
species, often organic, that forms a coordinate bond with a metal
ion. Ligands, when coordinated to a metal ion, may have a variety
of binding modes know to those of skill in the art, which include,
for example, terminal (i.e., bound to a single metal ion) and
bridging (i.e., one atom of the Lewis base bound to more than one
metal ion).
[0068] The terms "labile" and "non-labile" are art-recognized and
are usually used in this context in reference to a ligand bonded to
a metal ion. Without intending to limit or modify the definition
for the term as it is known in the art, a labile ligand may be
understood to be a ligand whose bond to the metal ion is expected
to break under certain circumstances.
[0069] The term "cis" is art-recognized and refers to the
arrangement of two atoms or groups around a central metal atom such
that the atoms or groups are next to each other.
[0070] The term "trans" is art-recognized and refers to the
arrangement of two atoms or groups around a central metal atom such
that the atoms or groups are not next to each other and are on
opposite sides of the central metal atom.
[0071] The terms "Lewis acid" and "Lewis acidic" are art-recognized
and refer to chemical moieties which can accept a pair of electrons
from a Lewis base as defined above.
[0072] The terms "Lewis base" and "Lewis basic" are art-recognized
and generally refer to a chemical moiety capable of donating a pair
of electrons under certain reaction conditions. It may be possible
to characterize a Lewis base as donating a single electron in
certain complexes, depending on the identity of the Lewis base and
the metal ion, but for most purposes, however, a Lewis base is best
understood as a two electron donor. Examples of Lewis basic
moieties include uncharged compounds such as alcohols, thiols, and
amines, and charged moieties such as alkoxides, thiolates,
carbanions, and a variety of other organic anions. In certain
examples, a Lewis base may consist of a single atom, such as oxide
(O.sup.2-). In certain, less common circumstances, a Lewis base or
ligand may be positively charged. A Lewis base, when coordinated to
a metal ion, is often referred to as a ligand. Further description
of ligands relevant to the present invention is presented
herein.
[0073] The term "covalent bond" is art-recognized and refers to a
bond between two atoms where electrons are attracted
electrostatically to both nuclei of the two atoms, and the net
effect of increased electron density between the nuclei
counterbalances the internuclear repulsion. The term covalent bond
includes coordinate bonds when the bond is with a metal ion.
[0074] The term "coordination" is art-recognized and refers to an
interaction in which one multi-electron pair donor coordinatively
bonds (is "coordinated") to one metal ion.
[0075] The term "coordinate bond" is art-recognized and refers to
an interaction between an electron pair donor and a coordination
site on a metal ion leading to an attractive force between the
electron pair donor and the metal ion. The use of this term is not
intended to be limiting, in so much as certain coordinate bonds may
also be classified as having more or less covalent character (if
not entirely covalent character) depending on the nature of the
metal ion and the electron pair donor.
[0076] The term "coordination site" is art-recognized and refers to
a point on a metal ion that can accept an electron pair donated,
for example, by a liquid or chelating agent.
[0077] The term "free coordination site" is art-recognized and
refers to a coordination site on a metal ion that is vacant or
occupied by a species that is weakly donating. Such species is
readily displaced by another species, such as a Lewis base.
[0078] The term "coordination number" is art-recognized and refers
to the number of coordination sites on a metal ion that are
available for accepting an electron pair.
[0079] The term "coordination geometry" is art-recognized and
refers to the manner in which coordination sites and free
coordination sites are spatially arranged around a metal ion. Some
examples of coordination geometry include octahedral, square
planar, trigonal, trigonal biplanar and others known to those of
skill in the art.
[0080] The term "complex" is art-recognized and refers to a
compound formed by the union of one or more electron-rich and
electron-poor molecules or atoms capable of independent existence
with one or more electronically poor molecules or atoms, each of
which is also capable of independent existence. A "coordination
complex" is one type of a complex, in which there is a coordinate
bond between a metal ion and an electron pair donor. A transition
metal complex is a coordination complex in which the metal ion is a
transition metal ion. In general, the terms "compound,"
"composition," "agent" and the like discussed herein include
complexes, coordination complexes and transition metal complexes.
As a general matter, the teachings of Advanced Inorganic Chemistry
by Cotton and Wilkinson are referenced as supplementing the
definitions herein in regard to coordination complexes and related
matters.
[0081] In certain circumstances, a coordination complex may be
understood to be composed of its constitutive components. For
example, a coordination complex may have the following components:
(i) one or more metal ions, which may or may not be the same atom,
have the same charge, coordination number or coordination geometry
and the like; and (ii) one or more Lewis bases that form coordinate
bonds with the metal ion(s). Examples of such Lewis bases include
chelating agents and ligands. Examples of such chelating agents and
ligands include the metal binding domains and therapeutic agents of
the present invention.
[0082] If a transitional metal complex is charged, in that the
transition metal ion and any Lewis bases, in the aggregate, are not
neutral, then such a complex will usually have one or more
counterions to form a neutral compound. Such counterions may or may
not be considered part of the coordination complex depending on how
the term coordination complex is used. Counterions generally do not
form coordinate bonds to the metal ion, although they may be
associated, often in the solid state, with the metal ion or Lewis
bases that make up the coordination complex. Some examples of
counterions include monoanions such as nitrate, chloride,
tetrafluoroborate, hexafluorophosphate, and monocarboxylates having
the general formula RCOO.sup.-, and dianions such as sulfate. In
some cases, coordination complexes themselves may serve as
counterions to another coordination complex, as in Magnus (green)
salt [Pt(NH.sub.3).sub.4].sup.- 2+[PtCl.sub.4].sup.2-.
[0083] The same chemical moiety may be either a ligand or a
counterion to a coordination complex. For example, the anionic
ligand chloride may be either coordinately bound to a metal ion or
may act as a counterion without any need for bond formation. The
exact form observed for chloride in any coordination complex will
depend on a variety of factors, including theoretical
considerations, such as kinetic versus thermodynamic effects, and
the actual synthetic procedures utilized to make the coordination
complex, such as the extent of reaction, acidity, concentration of
chloride. These considerations are applicable to other counterions
as well.
[0084] Additionally, a coordination complex may be solvated.
Solvation refers to molecules, usually of solvent and often water,
that associate with the coordination complex in the solid state.
Again, as for counterions, such solvation molecules may or may not
be considered part of the coordination complex depending on how the
term coordination complex is used.
[0085] The term "hrGH" is art-recognized and refers to human
recombinant growth hormone.
[0086] The term "tether" is art-recognized and refers to, as used
herein, a chemical linking moiety between a metal ion center and
another chemical moiety, often a therapeutic agent. As such, the
tether may be considered part of the chemical moiety (e.g.,
therapeutic agent).
[0087] When used with respect to an active agent, the term
"sustained release" or "released in a sustained manner" is
art-recognized. For example, a subject composition which releases
an active agent over time may exhibit sustained release
characteristics, in contrast to a bolus type administration in
which the entire amount of the active agent is made biologically
available at one time. This sustained release may result in
prolonged delivery of effective amounts of the particular active
agent.
[0088] The term "therapeutic effect" is art-recognized and refers
to a local or systemic effect in animals, particularly mammals, and
more particularly humans caused by a pharmacologically active
substance. The term thus means any substance intended for use in
the diagnosis, cure, mitigation, treatment or prevention of disease
or in the enhancement of desirable physical or mental development
and/or conditions in an animal or human. The phrase
"therapeutically-effective amount" means that amount of such a
substance that produces some desired local or systemic effect at a
reasonable benefit/risk ratio applicable to any treatment. The
therapeutically effective amount of such substance will vary
depending upon the subject and disease condition being treated, the
weight and age of the subject, the severity of the disease
condition, the manner of administration and the like, which can
readily be determined by one of ordinary skill in the art. For
example, certain compounds of the present invention, such as the
subject coordination complex, may be administered in a sufficient
amount to produce a at a reasonable benefit/risk ratio applicable
to such treatment.
[0089] The terms "combinatorial library" or "library" are
art-recognized and refer to a plurality of compounds, which may be
termed "members," synthesized or otherwise prepared from one or
more starting materials by employing either the same or different
reactants or reaction conditions at each reaction in the library.
There are a number of other terms of relevance to combinatorial
libraries (as well as other technologies). The term "identifier
tag" is art-recognized and refers to a means for recording a step
in a series of reactions used in the synthesis of a chemical
library. The term "immobilized" is art-recognized and, when used
with respect to a species, refers to a condition in which the
species is attached to a surface with an attractive force stronger
than attractive forces that are present in the intended environment
of use of the surface, and that act on the species. The term "solid
support" is art-recognized and refers to a material which is an
insoluble matrix, and may (optionally) have a rigid or semi-rigid
surface. The term "linker" is art-recognized and refers to a
molecule or group of molecules connecting a support, including a
solid support or polymeric support, and a combinatorial library
member. The term "polymeric support" is art-recognized and refers
to a soluble or insoluble polymer to which a chemical moiety can be
covalently bonded by reaction with a functional group of the
polymeric support. The term "functional group of a polymeric
support" is art-recognized and refers to a chemical moiety of a
polymeric support that can react with an chemical moiety to form a
polymer-supported amino ester.
[0090] The term "synthetic" is art-recognized and refers to
production by in vitro chemical or enzymatic synthesis.
[0091] The term "meso compound" is art-recognized and refers to a
chemical compound which has at least two chiral centers but is
achiral due to a plane or point of symmetry.
[0092] The term "chiral" is art-recognized and refers to molecules
which have the property of non-superimposability of the mirror
image partner, while the term "achiral" refers to molecules which
are superimposable on their mirror image partner. A "prochiral
molecule" is a molecule which has the potential to be converted to
a chiral molecule in a particular process.
[0093] The term "stereoisomers" is art-recognized and refers to
compounds which have identical chemical constitution, but differ
with regard to the arrangement of the atoms or groups in space. In
particular, "enantiomers" refer to two stereoisomers of a compound
which are non-superimposable mirror images of one another.
"Diastereomers", on the other hand, refers to stereoisomers with
two or more centers of dissymmetry and whose molecules are not
mirror images of one another.
[0094] Furthermore, a "stereoselective process" is one which
produces a particular stereoisomer of a reaction product in
preference to other possible stereoisomers of that product. An
"enantioselective process" is one which favors production of one of
the two possible enantiomers of a reaction product.
[0095] The term "regioisomers" is art-recognized and refers to
compounds which have the same molecular formula but differ in the
connectivity of the atoms. Accordingly, a "regioselective process"
is one which favors the production of a particular regioisomer over
others, e.g., the reaction produces a statistically significant
increase in the yield of a certain regioisomer.
[0096] The term "epimers" is art-recognized and refers to molecules
with identical chemical constitution and containing more than one
stereocenter, but which differ in configuration at only one of
these stereocenters.
[0097] The term "ED.sub.50" is art-recognized and refers to the
dose of a drug or other compound or coordination complex which
produces 50% of its maximum response or effect, or alternatively,
the dose which produces a pre-determined response in 50% of test
subjects or preparations.
[0098] The term "LD.sub.50" is art-recognized and refers to the
dose of a drug or other compound or coordination complex which is
lethal in 50% of test subjects.
[0099] The term "therapeutic index" is art-recognized and refers to
the therapeutic index of a drug or other compound or coordination
complex defined as LD.sub.50/ED.sub.50.
[0100] The term "agonist" is art-recognized and refers to a
compound or coordination complex that mimics the action of natural
transmitter or, when the natural transmitter is not known, causes
changes at the receptor complex in the absence of other receptor
ligands.
[0101] The term "antagonist" is art-recognized and refers to a
compound or coordination complex that binds to a receptor site, but
does not cause any physiological changes unless another receptor
ligand is present.
[0102] The term "competitive antagonist" is art-recognized and
refers to a compound or coordination complex that binds to a
receptor site; its effects may be overcome by increased
concentration of the agonist.
[0103] The term "partial agonist" is art-recognized and refers to a
compound or coordination complex that binds to a receptor site but
does not produce the maximal effect regardless of its
concentration.
[0104] The term "aliphatic" is art-recognized and refers to a
linear, branched, cyclic alkane, alkene, or alkyne. In certain
embodiments, aliphatic groups in the present invention are linear
or branched and have from 1 to about 20 carbon atoms.
[0105] The term "alkyl" is art-recognized, and includes saturated
aliphatic groups, including straight-chain alkyl groups,
branched-chain alkyl groups, cycloalkyl (alicyclic) groups, alkyl
substituted cycloalkyl groups, and cycloalkyl substituted alkyl
groups. In certain embodiments, a straight chain or branched chain
alkyl has about 30 or fewer carbon atoms in its backbone (e.g.,
C.sub.1-C.sub.30 for straight chain, C.sub.3-C.sub.30 for branched
chain), and alternatively, about 20 or fewer. Likewise, cycloalkyls
have from about 3 to about 10 carbon atoms in their ring structure,
and alternatively about 5, 6 or 7 carbons in the ring structure.
The term "alkyl" is also defined to include halosubstituted
alkyls.
[0106] Moreover, the term "alkyl" (or "lower alkyl") includes
"substituted alkyls", which refers to alkyl moieties having
substituents replacing a hydrogen on one or more carbons of the
hydrocarbon backbone. Such substituents may include, for example, a
hydroxyl, a carbonyl (such as a carboxyl, an alkoxycarbonyl, a
formyl, or an acyl), a thiocarbonyl (such as a thioester, a
thioacetate, or a thioformate), an alkoxyl, a phosphoryl, a
phosphonate, a phosphinate, an amino, an amido, an amidine, an
imine, a cyano, a nitro, an azido, a sulfhydryl, an alkylthio, a
sulfate, a sulfonate, a sulfamoyl, a sulfonamido, a sulfonyl, a
heterocyclyl, an aralkyl, or an aromatic or heteroaromatic moiety.
It will be understood by those skilled in the art that the moieties
substituted on the hydrocarbon chain may themselves be substituted,
if appropriate. For instance, the substituents of a substituted
alkyl may include substituted and unsubstituted forms of amino,
azido, imino, amido, phosphoryl (including phosphonate and
phosphinate), sulfonyl (including sulfate, sulfonamido, sulfamoyl
and sulfonate), and silyl groups, as well as ethers, alkylthios,
carbonyls (including ketones, aldehydes, carboxylates, and esters),
--CN and the like. Exemplary substituted alkyls are described
below. Cycloalkyls may be further substituted with alkyls,
alkenyls, alkoxys, alkylthios, aminoalkyls, carbonyl-substituted
alkyls, --CN, and the like.
[0107] The term "aralkyl" is art-recognized and refers to an alkyl
group substituted with an aryl group (e.g., an aromatic or
heteroaromatic group).
[0108] The terms "alkenyl" and "alkynyl" are art-recognized and
refer to unsaturated aliphatic groups analogous in length and
possible substitution to the alkyls described above, but that
contain at least one double or triple bond respectively.
[0109] Unless the number of carbons is otherwise specified, "lower
alkyl" refers to an alkyl group, as defined above, but having from
one to about ten carbons, alternatively from one to about six
carbon atoms in its backbone structure. Likewise, "lower alkenyl"
and "lower alkynyl" have similar chain lengths.
[0110] The term "heteroatom" is art-recognized and refers to an
atom of any element other than carbon or hydrogen. Illustrative
heteroatoms include boron, nitrogen, oxygen, phosphorus, sulfur and
selenium.
[0111] The term "aryl" is art-recognized and refers to 5-, 6- and
7-membered single-ring aromatic groups that may include from zero
to four heteroatoms, for example, benzene, pyrrole, furan,
thiophene, imidazole, oxazole, thiazole, triazole, pyrazole,
pyridine, pyrazine, pyridazine and pyrimidine, and the like. Those
aryl groups having heteroatoms in the ring structure may also be
referred to as "aryl heterocycles" or "heteroaromatics." The
aromatic ring may be substituted at one or more ring positions with
such substituents as described above, for example, halogen, azide,
alkyl, aralkyl, alkenyl, alkynyl, cycloalkyl, hydroxyl, alkoxyl,
amino, nitro, sulfhydryl, imino, amido, phosphonate, phosphinate,
carbonyl, carboxyl, silyl, ether, alkylthio, sulfonyl, sulfonamido,
ketone, aldehyde, ester, heterocyclyl, aromatic or heteroaromatic
moieties, --CF.sub.3, --CN, or the like. The term "aryl" also
includes polycyclic ring systems having two or more cyclic rings in
which two or more carbons are common to two adjoining rings (the
rings are "fused rings") wherein at least one of the rings is
aromatic, e.g., the other cyclic rings may be cycloalkyls,
cycloalkenyls, cycloalkynyls, aryls and/or heterocyclyls.
[0112] The terms ortho, meta and para are art-recognized and refer
to 1,2-, 1,3- and 1,4-disubstituted benzenes, respectively. For
example, the names 1,2-dimethylbenzene and ortho-dimethylbenzene
are synonymous.
[0113] The terms "heterocyclyl" or "heterocyclic group" are
art-recognized and refer to 3- to about 10-membered ring
structures, alternatively 3- to about 7-membered rings, whose ring
structures include one to four heteroatoms. Heterocycles may also
be polycycles. Heterocyclyl groups include, for example, thiophene,
thianthrene, furan, pyran, isobenzofuran, chromene, xanthene,
phenoxanthene, pyrrole, imidazole, pyrazole, isothiazole,
isoxazole, pyridine, pyrazine, pyrimidine, pyridazine, indolizine,
isoindole, indole, indazole, purine, quinolizine, isoquinoline,
quinoline, phthalazine, naphthyridine, quinoxaline, quinazoline,
cinnoline, pteridine, carbazole, carboline, phenanthridine,
acridine, pyrimidine, phenanthroline, phenazine, phenarsazine,
phenothiazine, furazan, phenoxazine, pyrrolidine, oxolane,
thiolane, oxazole, piperidine, piperazine, morpholine, lactones,
lactams such as azetidinones and pyrrolidinones, sultams, sultones,
and the like. The heterocyclic ring may be substituted at one or
more positions with such substituents as described above, as for
example, halogen, alkyl, aralkyl, alkenyl, alkynyl, cycloalkyl,
hydroxyl, amino, nitro, sulfhydryl, imino, amido, phosphonate,
phosphinate, carbonyl, carboxyl, silyl, ether, alkylthio, sulfonyl,
ketone, aldehyde, ester, a heterocyclyl, an aromatic or
heteroaromatic moiety, --CF.sub.3, --CN, or the like.
[0114] The terms "polycyclyl" or "polycyclic group" are
art-recognized and refer to two or more rings (e.g., cycloalkyls,
cycloalkenyls, cycloalkynyls, aryls and/or heterocyclyls) in which
two or more carbons are common to two adjoining rings, e.g., the
rings are "fused rings". Rings that are joined through non-adjacent
atoms are termed "bridged" rings. Each of the rings of the
polycycle may be substituted with such substituents as described
above, as for example, halogen, alkyl, aralkyl, alkenyl, alkynyl,
cycloalkyl, hydroxyl, amino, nitro, sulfhydryl, imino, amido,
phosphonate, phosphinate, carbonyl, carboxyl, silyl, ether,
alkylthio, sulfonyl, ketone, aldehyde, ester, a heterocyclyl, an
aromatic or heteroaromatic moiety, --CF.sub.3, --CN, or the
like.
[0115] The term "carbocycle" is art-recognized and refers to an
aromatic or non-aromatic ring in which each atom of the ring is
carbon.
[0116] The term "nitro" is art-recognized and refers to --NO.sub.2;
the term "halogen" is art-recognized and refers to --F, --Cl, --Br
or --I; the term "sulfhydryl" is art-recognized and refers to --SH;
the term "hydroxyl" means --OH; and the term "sulfonyl" is
art-recognized and refers to --SO.sub.2.sup.-. "Halide" designates
the corresponding anion of the halogens, and "pseudohalide" has the
definition set forth on 560 of "Advanced Inorganic Chemistry" by
Cotton and Wilkinson.
[0117] The terms "amine" and "amino" are art-recognized and refer
to both unsubstituted and substituted amines, e.g., a moiety that
may be represented by the general formulas: 1
[0118] wherein R50, R51 and R52 each independently represent a
hydrogen, an alkyl, an alkenyl, --(CH.sub.2).sub.m--R61, or R50 and
R51, taken together with the N atom to which they are attached
complete a heterocycle having from 4 to 8 atoms in the ring
structure; R61 represents an aryl, a cycloalkyl, a cycloalkenyl, a
heterocycle or a polycycle; and m is zero or an integer in the
range of 1 to 8. In certain embodiments, only one of R50 or R51 may
be a carbonyl, e.g., R50, R51 and the nitrogen together do not form
an imide. In other embodiments, R50 and R51 (and optionally R52)
each independently represent a hydrogen, an alkyl, an alkenyl, or
--(CH.sub.2).sub.m--R61. Thus, the term "alkylamine" includes an
amine group, as defined above, having a substituted or
unsubstituted alkyl attached thereto, i.e., at least one of R50 and
R51 is an alkyl group.
[0119] The term "ammine" is art-recognized are refers to a compound
containing an ammonia moiety or moieties coordinated to a metal
ion. The term "ammonia" is art-recognized an refers to an amine
group substituted with hydrogens.
[0120] The term "acylamino" is art-recognized and refers to a
moiety that may be represented by the general formula: 2
[0121] wherein R50 is as defined above, and R54 represents a
hydrogen, an alkyl, an alkenyl or --(CH.sub.2).sub.m--R61, where m
and R61 are as defined above.
[0122] The term "amido" is art recognized as an amino-substituted
carbonyl and includes a moiety that may be represented by the
general formula: 3
[0123] wherein R50 and R51 are as defined above. Certain
embodiments of the amide in the present invention will not include
imides which may be unstable.
[0124] The term "alkylthio" refers to an alkyl group, as defined
above, having a sulfur radical attached thereto. In certain
embodiments, the "alkylthio" moiety is represented by one of
--S-alkyl, --S-alkenyl, --S-alkynyl, and
--S--(CH.sub.2).sub.m--R61, wherein m and R61 are defined above.
Representative alkylthio groups include methylthio, ethyl thio, and
the like.
[0125] The term "carbonyl" is art recognized and includes such
moieties as may be represented by the general formulas: 4
[0126] wherein X50 is a bond or represents an oxygen or a sulfur,
and R55 and R56 represents a hydrogen, an alkyl, an alkenyl,
--(CH.sub.2).sub.m--R61 or a pharmaceutically acceptable salt, R56
represents a hydrogen, an alkyl, an alkenyl or
--(CH.sub.2).sub.m--R61, where m and R61 are defined above. Where
X50 is an oxygen and R55 or R56 is not hydrogen, the formula
represents an "ester". Where X50 is an oxygen, and R55 is as
defined above, the moiety is referred to herein as a carboxyl
group, and particularly when R55 is a hydrogen, the formula
represents a "carboxylic acid". Where X50 is an oxygen, and R56 is
hydrogen, the formula represents a "formate". In general, where the
oxygen atom of the above formula is replaced by sulfur, the formula
represents a "thiolcarbonyl" group. Where X50 is a sulfur and R55
or R56 is not hydrogen, the formula represents a "thiolester."
Where X50 is a sulfur and R55 is hydrogen, the formula represents a
"thiolcarboxylic acid." Where X50 is a sulfur and R56 is hydrogen,
the formula represents a "thiolformate." On the other hand, where
X50 is a bond, and R55 is not hydrogen, the above formula
represents a "ketone" group. Where X50 is a bond, and R55 is
hydrogen, the above formula represents an "aldehyde" group.
[0127] The terms "alkoxyl" or "alkoxy" are art-recognized and refer
to an alkyl group, as defined above, having an oxygen radical
attached thereto. Representative alkoxyl groups include methoxy,
ethoxy, propyloxy, tert-butoxy and the like. An "ether" is two
hydrocarbons covalently linked by an oxygen. Accordingly, the
substituent of an alkyl that renders that alkyl an ether is or
resembles an alkoxyl, such as may be represented by one of
--O-alkyl, --O-alkenyl, --O-alkynyl, --O--(CH.sub.2).sub.m--R61,
where m and R61 are described above.
[0128] The term "sulfonate" is art recognized and refers to a
moiety that may be represented by the general formula: 5
[0129] in which R57 is an electron pair, hydrogen, alkyl,
cycloalkyl, or aryl.
[0130] The term "sulfate" is art recognized and includes a moiety
that may be represented by the general formula: 6
[0131] in which R57 is as defined above.
[0132] The term "sulfonamido" is art recognized and includes a
moiety that may be represented by the general formula: 7
[0133] in which R50 and R56 are as defined above.
[0134] The term "sulfamoyl" is art-recognized and refers to a
moiety that may be represented by the general formula: 8
[0135] in which R50 and R51 are as defined above.
[0136] The term "sulfonyl" is art-recognized and refers to a moiety
that may be represented by the general formula: 9
[0137] in which R58 is one of the following: hydrogen, alkyl,
alkenyl, alkynyl, cycloalkyl, heterocyclyl, aryl or heteroaryl.
[0138] The term "sulfoxido" is art-recognized and refers to a
moiety that may be represented by the general formula: 10
[0139] in which R58 is defined above.
[0140] The term "phosphoryl" is art-recognized and may in general
be represented by the formula: 11
[0141] wherein Q50 represents S or O, and R59 represents hydrogen,
a lower alkyl or an aryl. When used to substitute, e.g., an alkyl,
the phosphoryl group of the phosphorylalkyl may be represented by
the general formulas: 12
[0142] wherein Q50 and R59, each independently, are defined above,
and Q51 represents O, S or N. When Q50 is S, the phosphoryl moiety
is a "phosphorothioate".
[0143] The term "phosphoramidite" is art-recognized and may be
represented in the general formulas: 13
[0144] wherein Q51, R50, R51 and R59 are as defined above.
[0145] The term "phosphonamidite" is art-recognized and may be
represented in the general formulas: 14
[0146] wherein Q51, R50, R51 and R59 are as defined above, and R60
represents a lower alkyl or an aryl.
[0147] Analogous substitutions may be made to alkenyl and alkynyl
groups to produce, for example, aminoalkenyls, aminoalkynyls,
amidoalkenyls, amidoalkynyls, iminoalkenyls, iminoalkynyls,
thioalkenyls, thioalkynyls, carbonyl-substituted alkenyls or
alkynyls.
[0148] The definition of each expression, e.g. alkyl, m, n, and the
like, when it occurs more than once in any structure, is intended
to be independent of its definition elsewhere in the same
structure.
[0149] The term "selenoalkyl" is art-recognized and refers to an
alkyl group having a substituted seleno group attached thereto.
Exemplary "selenoethers" which may be substituted on the alkyl are
selected from one of --Se-alkyl, --Se-alkenyl, --Se-alkynyl, and
--Se--(CH.sub.2).sub.m--R61, m and R61 being defined above.
[0150] The terms triflyl, tosyl, mesyl, and nonaflyl are
art-recognized and refer to trifluoromethanesulfonyl,
p-toluenesulfonyl, methanesulfonyl, and nonafluorobutanesulfonyl
groups, respectively. The terms triflate, tosylate, mesylate, and
nonaflate are art-recognized and refer to trifluoromethanesulfonate
ester, p-toluenesulfonate ester, methanesulfonate ester, and
nonafluorobutanesulfonate ester functional groups and molecules
that contain said groups, respectively.
[0151] The abbreviations Me, Et, Ph, Tf, Nf, Ts, and Ms represent
methyl, ethyl, phenyl, trifluoromethanesulfonyl,
nonafluorobutanesulfonyl, p-toluenesulfonyl and methanesulfonyl,
respectively. A more comprehensive list of the abbreviations
utilized by organic chemists of ordinary skill in the art appears
in the first issue of each volume of the Journal of Organic
Chemistry; this list is typically presented in a table entitled
Standard List of Abbreviations.
[0152] Certain compounds of the present invention may exist in
particular geometric or stereoisomeric forms. In addition, polymers
of the present invention may also be optically active. The present
invention contemplates all such compounds, including cis- and
trans-isomers, R- and S-enantiomers, diastereomers, (D)-isomers,
(L)-isomers, the racemic mixtures thereof, and other mixtures
thereof, as falling within the scope of the invention. Additional
asymmetric carbon atoms may be present in a substituent such as an
alkyl group. All such isomers, as well as mixtures thereof, are
intended to be included in this invention.
[0153] If, for instance, a particular enantiomer of compound of the
present invention is desired, it may be prepared by asymmetric
synthesis, or by derivation with a chiral auxiliary, where the
resulting diastereomeric mixture is separated and the auxiliary
group cleaved to provide the pure desired enantiomers.
Alternatively, where the molecule contains a basic functional
group, such as amino, or an acidic functional group, such as
carboxyl, diastereomeric salts are formed with an appropriate
optically-active acid or base, followed by resolution of the
diastereomers thus formed by fractional crystallization or
chromatographic means well known in the art, and subsequent
recovery of the pure enantiomers.
[0154] It will be understood that "substitution" or "substituted
with" includes the implicit proviso that such substitution is in
accordance with permitted valence of the substituted atom and the
substituent, and that the substitution results in a stable
compound, e.g., which does not spontaneously undergo transformation
such as by rearrangement, cyclization, elimination, or other
reaction.
[0155] The term "substituted" is also contemplated to include all
permissible substituents of organic compounds. In a broad aspect,
the permissible substituents include acyclic and cyclic, branched
and unbranched, carbocyclic and heterocyclic, aromatic and
nonaromatic substituents of organic compounds. Illustrative
substituents include, for example, those described herein above.
The permissible substituents may be one or more and the same or
different for appropriate organic compounds. For purposes of this
invention, the heteroatoms such as nitrogen may have hydrogen
substituents and/or any permissible substituents of organic
compounds described herein which satisfy the valences of the
heteroatoms. This invention is not intended to be limited in any
manner by the permissible substituents of organic compounds.
[0156] For purposes of this invention, the chemical elements are
identified in accordance with the Periodic Table of the Elements,
CAS version, Handbook of Chemistry and Physics, 67th Ed., 1986-87,
inside cover. Also for purposes of this invention, the term
"hydrocarbon" is contemplated to include all permissible compounds
having at least one hydrogen and one carbon atom. In a broad
aspect, the permissible hydrocarbons include acyclic and cyclic,
branched and unbranched, carbocyclic and heterocyclic, aromatic and
nonaromatic organic compounds that may be substituted or
unsubstituted.
[0157] The term "protecting group" is art-recognized and refers to
temporary substituents that protect a potentially reactive
functional group from undesired chemical transformations. Examples
of such protecting groups include esters of carboxylic acids, silyl
ethers of alcohols, and acetals and ketals of aldehydes and
ketones, respectively. The field of protecting group chemistry has
been reviewed by Greene and Wuts in Protective Groups in Organic
Synthesis (2.sup.nd ed., Wiley: New York, 1991).
[0158] The term "hydroxyl-protecting group" is art-recognized and
refers to those groups intended to protect a hydrozyl group against
undesirable reactions during synthetic procedures and includes, for
example, benzyl or other suitable esters or ethers groups known in
the art.
[0159] The term "carboxyl-protecting group" is art-recognized and
refers to those groups intended to protect a carboxylic acid group,
such as the C-terminus of an amino acid or peptide or an acidic or
hydroxyl azepine ring substituent, against undesirable reactions
during synthetic procedures and includes. Examples for protecting
groups for carboxyl groups involve, for example, benzyl ester,
cyclohexyl ester, 4-nitrobenzyl ester, t-butyl ester,
4-pyridylmethyl ester, and the like.
[0160] The term "amino-blocking group" is art-recognized and refers
to a group which will prevent an amino group from participating in
a reaction carried out on some other functional group, but which
can be removed from the amine when desired. Such groups are
discussed by in Ch. 7 of Greene and Wuts, cited above, and by
Barton, Protective Groups in Organic Chemistry ch. 2 (McOmie, ed.,
Plenum Press, New York, 1973). Examples of suitable groups include
acyl protecting groups such as, to illustrate, formyl, dansyl,
acetyl, benzoyl, trifluoroacetyl, succinyl, methoxysuccinyl, benzyl
and substituted benzyl such as 3,4-dimethoxybenzyl, o-nitrobenzyl,
and triphenylmethyl; those of the formula --COOR where R includes
such groups as methyl, ethyl, propyl, isopropyl,
2,2,2-trichloroethyl, 1-methyl-1-phenylethyl, isobutyl, t-butyl,
t-amyl, vinyl, allyl, phenyl, benzyl, p-nitrobenzyl, o-nitrobenzyl,
and 2,4-dichlorobenzyl; acyl groups and substituted acyl such as
formyl, acetyl, chloroacetyl, dichloroacetyl, trichloroacetyl,
trifluoroacetyl, benzoyl, and p-methoxybenzoyl; and other groups
such as methanesulfonyl, p-toluenesulfonyl, p-bromobenzenesulfonyl,
p-nitrophenylethyl, and p-toluenesulfonyl-aminocarbonyl. Preferred
amino-blocking groups are benzyl (--CH.sub.2C.sub.6H.sub.5), acyl
[C(O)R1] or SiR1.sub.3 where R1 is C.sub.1-C.sub.4 alkyl,
halomethyl, or 2-halo-substituted-(C.sub.2-C.sub.4 alkoxy),
aromatic urethane protecting groups as, for example,
carbonylbenzyloxy (Cbz); and aliphatic urethane protecting groups
such as t-butyloxycarbonyl (Boc) or 9-fluorenylmethoxycarbonyl
(FMOC).
[0161] The definition of each expression, e.g. lower alkyl, m, n, p
and the like, when it occurs more than once in any structure, is
intended to be independent of its definition elsewhere in the same
structure.
[0162] The term "electron-withdrawing group" is art-recognized, and
refers to the tendency of a substituent to attract valence
electrons from neighboring atoms, i.e., the substituent is
electronegative with respect to neighboring atoms. A quantification
of the level of electron-withdrawing capability is given by the
Hammett sigma (.sigma.) constant. This well known constant is
described in many references, for instance, March, Advanced Organic
Chemistry 251-59 (McGraw Hill Book Company: New York, 1977). The
Hammett constant values are generally negative for electron
donating groups (.sigma.(P)=-0.66 for NH.sub.2) and positive for
electron withdrawing groups (.sigma.(P)=0.78 for a nitro group),
.sigma.(P) indicating para substitution. Exemplary
electron-withdrawing groups include nitro, acyl, formyl, sulfonyl,
trifluoromethyl, cyano, chloride, and the like. Exemplary
electron-donating groups include amino, methoxy, and the like.
[0163] The term "amino acid" is art-recognized and refers to all
compounds, whether natural or synthetic, which include both an
amino functionality and an acid functionality, including amino acid
analogs and derivatives.
[0164] The terms "amino acid residue" and "peptide residue" are
art-recognized and refer to an amino acid or peptide molecule
without the --OH of its carboxyl group.
[0165] The term "amino acid residue" further includes analogs,
derivatives and congeners of any specific amino acid referred to
herein, as well as C-terminal or N-terminal protected amino acid
derivatives (e.g. modified with an N-terminal or C-terminal
protecting group).
[0166] The names of the natural amino acids are abbreviated herein
in accordance with the recommendations of IUPAC-IUB.
[0167] A "reversed" or "retro" peptide sequence as disclosed herein
refers to that part of an overall sequence of covalently-bonded
amino acid residues (or analogs or mimetics thereof) wherein the
normal carboxyl-to amino direction of peptide bond formation in the
amino acid backbone has been reversed such that, reading in the
conventional left-to-right direction, the amino portion of the
peptide bond precedes (rather than follows) the carbonyl portion.
See, generally, Goodman et al. Accounts of Chem. Res. 12:423
(1979).
[0168] The reversed orientation peptides described herein include
(a) those wherein one or more amino-terminal residues are converted
to a reversed ("rev") orientation (thus yielding a second "carboxyl
terminus" at the left-most portion of the molecule), and (b) those
wherein one or more carboxyl-terminal residues are converted to a
reversed ("rev") orientation (yielding a second "amino terminus" at
the right-most portion of the molecule). A peptide (amide) bond
cannot be formed at the interface between a normal orientation
residue and a reverse orientation residue.
[0169] Therefore, certain reversed peptide compounds of the
invention may be formed by utilizing an appropriate amino acid
mimetic moiety to link the two adjacent portions of the sequences
depicted above utilizing a reversed peptide (reversed amide)
bond.
[0170] The reversed direction of bonding in such compounds will
generally, in addition, require inversion of the enantiomeric
configuration of the reversed amino acid residues in order to
maintain a spatial orientation of side chains that is similar to
that of the non-reversed peptide. The configuration of amino acids
in the reversed portion of the peptides is usually (D), and the
configuration of the non-reversed portion is usually (L). Opposite
or mixed configurations are acceptable when appropriate to optimize
a binding activity.
[0171] The term "nucleic acid" is art-recognized and refers to
polynucleotides such as deoxyribonucleic acid (DNA), and, where
appropriate, ribonucleic acid (RNA). The term should also be
understood to include, as equivalents, analogs of either RNA or DNA
made from nucleotide analogs, and, as applicable to the embodiment
being described, single-stranded (such as sense or antisense) and
double-stranded polynucleotides.
[0172] An "imaging agent" shall mean a composition capable of
generating a detectable image upon binding with a target and shall
include radionuclides (e.g., In-111, Tc-99m, I-123, I-125 F-18,
Ga-67, Ga-680); for Positron Emission Tomography (PET) and Single
Photon Emission Tomography (SPECT), unpair spin atoms and free
radicals (e.g., Fe, lanthanides, and Gd); and contrast agents
(e.g., chelated (DTPA) manganese) for Magnetic Resonance Imaging
(MRI). Imaging agents are discussed in greater detail below.
[0173] The term "small molecule" is art-recognized and refers to a
composition which has a molecular weight of less than about 2000
amu, or less than about 1000 amu, and even less than about 500 amu.
Small molecules may be, for example, nucleic acids, peptides,
polypeptides, peptide nucleic acids, peptidomimetics,
carbohydrates, lipids or other organic (carbon containing) or
inorganic molecules. Many pharmaceutical companies have extensive
libraries of chemical and/or biological mixtures, often fungal,
bacterial, or algal extracts, which can be screened with any of the
assays of the invention. The term "small organic molecule" refers
to a small molecule that is often identified as being an organic or
medicinal compound, and does not include molecules that are
exclusively nucleic acids, peptides or polypeptides.
[0174] The term "modulation" is art-recognized and refers to up
regulation (i.e., activation or stimulation), down regulation
(i.e., inhibition or suppression) of a response, or the two in
combination or apart.
[0175] The term "prophylactic" or "therapeutic" treatment is
art-recognized and refers to administration to the host of one or
more of the subject compositions. If it is administered prior to
clinical manifestation of the unwanted condition (e.g., disease or
other unwanted state of the host animal) then the treatment is
prophylactic, i.e., it protects the host against developing the
unwanted condition, whereas if administered after manifestation of
the unwanted condition, the treatment is therapeutic (i.e., it is
intended to diminish, ameliorate or maintain the existing unwanted
condition or side effects therefrom).
[0176] A "patient," "subject" or "host" to be treated by the
subject method may mean either a human or non-human animal.
[0177] The term "mammal" is known in the art, and exemplary mammals
include humans, primates, bovines, porcines, canines, felines, and
rodents (e.g., mice and rats).
[0178] The term "bioavailable" is art-recognized and refers to a
form of the subject invention that allows for it, or a portion of
the amount administered, to be absorbed by, incorporated to, or
otherwise physiologically available to a subject or patient to whom
it is administered.
[0179] The term "pharmaceutically-acceptable salts" is
art-recognized and refers to the relatively non-toxic, inorganic
and organic acid addition salts of compounds, including, for
example, coordination complexes of the present invention.
[0180] The term "pharmaceutically acceptable carrier" is
art-recognized and refers to a pharmaceutically-acceptable
material, composition or vehicle, such as a liquid or solid filler,
diluent, excipient, solvent or encapsulating material, involved in
carrying or transporting any supplement or composition, or
component thereof, from one organ, or portion of the body, to
another organ, or portion of the body. Each carrier must be
"acceptable" in the sense of being compatible with the other
ingredients of the supplement and not injurious to the patient.
Some examples of materials which may serve as pharmaceutically
acceptable carriers include: (1) sugars, such as lactose, glucose
and sucrose; (2) starches, such as corn starch and potato starch;
(3) cellulose, and its derivatives, such as sodium carboxymethyl
cellulose, ethyl cellulose and cellulose acetate; (4) powdered
tragacanth; (5) malt; (6) gelatin; (7) talc; (8) excipients, such
as cocoa butter and suppository waxes; (9) oils, such as peanut
oil, cottonseed oil, safflower oil, sesame oil, olive oil, corn oil
and soybean oil; (10) glycols, such as propylene glycol; (11)
polyols, such as glycerin, sorbitol, mannitol and polyethylene
glycol; (12) esters, such as ethyl oleate and ethyl laurate; (13)
agar; (14) buffering agents, such as magnesium hydroxide and
aluminum hydroxide; (15) alginic acid; (16) pyrogen-free water;
(17) isotonic saline; (18) Ringer's solution; (19) ethyl alcohol;
(20) phosphate buffer solutions; and (21) other non-toxic
compatible substances employed in pharmaceutical formulations.
[0181] The terms "systemic administration," "administered
systemically," "peripheral administration" and "administered
peripherally" are art-recognized and refer to the administration of
a subject supplement, composition, therapeutic or other material
other than directly into the central nervous system, such that it
enters the patient's system and, thus, is subject to metabolism and
other like processes, for example, subcutaneous administration.
[0182] The terms "parenteral administration" and "administered
parenterally" are art-recognized and refer to modes of
administration other than enteral and topical administration,
usually by injection, and includes, without limitation,
intravenous, intramuscular, intraarterial, intrathecal,
intracapsular, intraorbital, intracardiac, intradermal,
intraperitoneal, transtracheal, subcutaneous, subcuticular,
intra-articulare, subcapsular, subarachnoid, intraspinal, and
intrastemal injection and infusion.
[0183] Contemplated equivalents of the compounds described herein
include compounds which otherwise correspond thereto, and which
have the same general properties thereof (such as other
coordination complexes comprising tethered therapeutic agents),
wherein one or more simple variations of substituents are made
which do not adversely affect the characteristics of the compounds
of interest. In general, the compounds of the present invention may
be prepared by the methods illustrated in the general reaction
schema as, for example, described below, or by modifications
thereof, using readily available starting materials, reagents and
conventional synthesis procedures. In these reactions, it is also
possible to make use of variants which are in themselves known, but
are not mentioned here.
[0184] General Introduction
[0185] In part, the present invention relates to a carrier with a
metal binding domain, a metal ion chelated to the metal binding
domain, and GLP-1 with a metal binding domain coordinated to the
metal ion. By way of a further embodiment, the carrier may contain
protective side chains. By way of a further embodiment GLP-1 may
bind to a carrier by a means other than through its MBD.
[0186] The carrier compositions of the present invention include
polymers and co-polymers of linear or branched structure or
conjugates thereof, micelles, emulsions, colloids and solid
surfaces, where the polymers may in addition self-organize in
supramolecular structures including at least two polymers. The
copolymers include as one of the main polymeric elements a backbone
carrier that contains metal binding domains where said domains
comprise chelating groups covalently attached to the monomeric
units of the backbone element or comprised of non-modified
monomeric units that are spontaneously folding with the formation
of metal-binding domains.
[0187] In one example, a composition of the present invention
comprises the backbone linear polyamino acid with degree of
polymerization in the range of 2-10,000 to which independently and
covalently linked are methoxypolyethylene glycol (mPEG) protective
chains with a mass of 300-6000 D and chelating groups, where said
chains and chelating groups are independently linked to the
backbone. In another example, the degree of polymerization is in
the range of 100-1,000. In still another example, the degree of
polymerization is in the range of 100 to 300. The metal binding
domains of the present invention may include polycarboxylic acids
containing nitrogen where at least one of carboxylic groups may be
utilized for covalent linking of the chelate to the carrier
backbone polymer component of the composition of the invention. The
addition of said metal ions to chelates included in the carrier
compositions of the invention either at room temperature or at
elevated temperatures results in the formation of coordinate
complexes (metal-chelates). These metal-chelate complexes bind to
the metal binding domain of peptide or protein, added either in a
purified state or in the presence of bulk protein or blood plasma
proteins, with the formation of drug-delivery compositions
containing coordinate complexes formed between the metal-chelate
and peptides or proteins. The amino acid sequence of peptides or
proteins of the invention may include one or more histidines or
cysteines which increase the stability of the complex formed
between the peptide or protein and metal-chelate complexes bound to
compositions of the invention.
[0188] For the purpose of delivery of peptides and proteins to
their receptors on cells or other molecular targets in the body
with the goal of providing medicinal, therapeutic, targeting or
diagnostic effects, the bond between the metal-chelate and peptide
or protein is chosen to allow dissociation of the peptide or
protein from the metal-chelate bound to the carrier composition.
The dissociation of the bond between metal-chelate and peptide or
protein can be accelerated by the administration of competing
compounds (histidine, imidazole).
[0189] For the purpose of stabilization and better
distribution/dissolutio- n of peptides and proteins, and other
biologically active molecules in water and organic solvent(s) based
environment of formulations and drug delivery systems, the
described composition of association of polymer, chelate-metal, and
bound peptide or protein allow significant increase in stability,
solubility and distribution of the active molecule.
[0190] Carrier
[0191] The carrier of the present invention may be any substance
capable of supporting at least one metal binding domain which in
turn chelates a metal ion which in turn coordinates active agents.
Non-limiting examples of carriers include polymers and copolymers,
micelles, reverse micelles, liposomes, microspheres, emulsions,
hydrogels, microparticles, nanoparticles, colloids and solid
surfaces. In one aspect, the carrier is biocompatible.
[0192] (i) Polymers and Co-Polymers
[0193] In certain embodiments, the polymers or co-polymers of the
subject compositions, e.g., which include repetitive elements shown
in any of the subject formulas, have molecular weights ranging from
about 2000 or less to about 1,000,000 or more daltons, or
alternatively about 10,000, 20,000, 30,000, 40,000, or 50,000
daltons, more particularly at least about 100,000 daltons, and even
more specifically at least about 250,000 daltons or even at least
500,000 daltons. Number-average molecular weight (Mn) may also vary
widely, but generally fall in the range of about 1,000 to about
200,000 daltons, or even from about 1,000 to about 100,000 daltons
or even from about 1,000 to about 50,000 daltons. In one
embodiment, Mn varies between about 8,000 and 45,000 daltons.
Within a given sample of a subject polymer, a wide range of
molecular weights may be present. For example, molecules within the
sample may have molecular weights which differ by a factor of 2, 5,
10, 20, 50, 100, or more, or which differ from the average
molecular weight by a factor of 2, 5, 10, 20, 50, 100, or more.
[0194] One method to determine molecular weight is by gel
permeation chromatography ("GPC"), e.g., mixed bed columns,
CH.sub.2Cl.sub.2 solvent, light scattering detector, and off-line
dn/dc. Other methods are known in the art.
[0195] In certain embodiments, the intrinsic viscosities of the
polymers generally vary from about 0.01 to about 2.0 dL/g in
chloroform at 40.degree. C., alternatively from about 0.01 to about
1.0 dL/g and, occasionally, from about 0.01 to about 0.5 dL/g.
[0196] The glass transition temperature (Tg) of the subject
polymers may vary widely, and depend on a variety of factors, such
as the degree of branching in the polymer components, the relative
proportion of phosphorous-containing monomer used to make the
polymer, and the like. When the article of the invention is a rigid
solid, the Tg is often within the range of from about -10.degree.
C. to about 80.degree. C., particularly between about 0 and
50.degree. C. and, even more particularly between about 25.degree.
C. to about 35.degree. C. In other embodiments, the Tg is low
enough to keep the composition of the invention flowable at body
temperature. Then, the glass transition temperature of the polymer
used in the invention is usually about 0 to about 37.degree. C., or
alternatively from about 0 to about 25.degree. C.
[0197] In other embodiments, the polymer composition of the
invention may be a flexible or flowable material. When the polymer
used is itself flowable, the polymer composition of the invention,
even when viscous, need not include a biocompatible solvent to be
flowable, although trace or residual amounts of biocompatible
solvents may still be present.
[0198] A flexible polymer may be used in the fabrication of a solid
article. Flexibility involves having the capacity to be repeatedly
bent and restored to its original shape. Solid articles made from
flexible polymers are adapted for placement in anatomic areas where
they will encounter the motion of adjacent organs or body walls. A
flexible solid article can thus be sufficiently deformed by those
moving tissues that it does not cause tissue damage. Flexibility is
particularly advantageous where a solid article might be dislodged
from its original position and thereby encounter an unanticipated
moving structure; flexibility may allow the solid article to bend
out of the way of the moving structure instead of injuring it. Such
a flexible article might be suitable for covering pulsatile vessels
such as the carotid artery in the neck, or for covering more
delicate structures in the neck like the jugular vein that may also
be affected by local movements. Similarly, a flexible solid article
may be used to protect nerves exposed during a neck dissection such
as the spinal accessory nerve, wherein the flexibility of the solid
article may permit it to bend or deform when encountering motion
rather than eroding into or damaging the nerve. Use of a solid
carrier according to the present invention in the aforesaid ways
may allow less extensive dissections to be carried out with
surgical preservation of structures important to function. Solid
articles may be configured as three-dimensional structures suitable
for implantation in specific anatomic areas. Solid articles may be
formed as films, meshes, sheets, tubes, or any other shape
appropriate to the dimensions and functional requirements of the
particular anatomic area. Physical properties of polymers may be
adjusted to attain a desirable degree of flexibility by
modification of the chemical components and crosslinking thereof,
using methods familiar to practitioners of ordinary skill in the
art.
[0199] Examples of polymeric carriers include carboxylated or
carboxymethylated linear poly-1-lysine (PL) or poly-D-lysine;
carboxylated or carboxymethylated
poly-alfa,beta-(2-aminoethyl)-D,L-aspar- tamide; poly-1-aspartic
acid; poly-glutamic acid, copolymers of histidine with positively
or negatively charged aminoacids, carboxylated
polyethyleneimines,i.e. polyethylene imines reacted with
derivatives of carbonic acids; natural saccharides or products
chemically derived thereof, bearing carboxylic groups, which may be
exemplified by: galacturonic acid, glucuronic acid, mannuronic
acid, hyaluronic acid, pectic acid, neuraminic acid, alginic acid,
carrageenan; oxidized dextrans; aminated, e.g. containing linked
aminogroups, polysaccharides or oligosaccharides, linear or
branched; carboxylated, carboxymethylated, sulfated or
phosphorylated polysaccharides or oligosaccharides, e.g.reacted
with derivatives of carbonic, dicarbonic, sulfuric, aminosulfuric,
phosphoric acids with resultant linking of carboxylic,
aminocarboxylic, carboxymethyl, sulfuric, amino or phosphate
groups. Such olygosaccharides may be obtained by chemical
alteration of e.g., dextran, mannan, xylan, pullulan, cellulose,
chytosan, agarose, fucoidan, galactan, arabinan, fructan, fucan,
chitin, pustulan, levan or pectin. In addition these poly- or
oligosachharides may be represented by heteropolymers or
homopolymers of monosaccharides such as glucose, galactose,
mannose, galactose, deoxyglucose, ribose, deoxyribose, arabinose,
fucose, xylose, xylulose, ribulose, polyamidoamine, linear or
branched; polyacrylic acid; polyalcohols,e.g.polyvinylalcohol an
polyxylitol, to which carboxylic or aminogroups are chemically
linked. The molecular weight of a polyaminoacid is preferably
larger than 1000 and smaller than 100000. Polyamino acids with
narrow molecular weight (MW) distribution are preferred to those
with broad MW distribution. Polyamino acids are linked with peptide
bonds. Polyaminoacids are prepared by chemical synthesis or by
recombinant techniques, such as genetic engineering. For additional
examples of polymers suitable for use in the present invention see
U.S. Pat. Nos. 6,509,323; 6,492,560; 6,468,532; 6,521,736;
6,348,069; 5,871,710; and 6,051,549. In another embodiment, the
polymer acting as the carrier may be poly(ethylene glycol) (PEG)
with functional groups at the far-end making up the metal binding
domain to which the metal ion coordinates and in turn coordinates
the active agent. Schematically the embodiment may be represented
by the following: PEG-MBD-Metal-MBD-Active agent. Alternatively,
PEG may be functionalized along its backbone allowing
MBD-Metal-MBD-Active agent moieties to be pendant to the backbone.
This functionalization may also allow pendant protective chains as
well.
[0200] (ii) Micelles, Reverse Micelles, Liposomes and
Microspheres
[0201] Amphipathic compounds that contain both hydrophobic and
hydrophilic domains are typically organized into vesicular
structures such as liposomes, micellar, or reverse micellar
structures. Liposomes can contain an aqueous volume that is
entirely enclosed by a membrane composed of lipid molecules
(usually phospholipids). Micelles and reverse micelles are
microscopic vesicles that contain amphipathic molecules but do not
contain an aqueous volume that is entirely enclosed by a membrane.
In micelles the hydrophilic part of the amphipathic compound is on
the outside (on the surface of the vesicle) whereas in reverse
micelles the hydrophobic part of the amphipathic compound is on the
outside. The reverse micelles thus contain a polar core that can
solubilize both water and macromolecules within the inverse
micelle. As the volume of the core aqueous pool increases the
aqueous environment begins to match the physical and chemical
characteristics of bulk water. The resulting inverse micelle can be
referred to as a microemulsion of water in oil.
[0202] In water, when a sufficient concentration of the two or more
components that make up a micelle is present, the components
spontaneously aggregate into thermodynamically stable polymeric
micelles. The micelle particles assume a microspheroidal shape and
possess, in essence, a double layer. The core "layer" forms by
virtue of the hydrophobic interactions between, for example,
hydrophobic polyesters. Similarly, the surface "layer" forms by
virtue of the corresponding hydrophilic interactions of a, for
example, hydrophilic polycation with water. A net positive charge
will exist around the surface of the micelle, since the hydrophilic
segment of the first component is a polycation.
[0203] Functional compounds having metal binding properties can be
easily introduced to the micelle by: (1) creating a third copolymer
component that bears the functional group and (2) coupling the
copolymer to the surface of a pre-assembled polymeric micelle.
Alternatively, a metal binding domain-bearing component can be
incorporated into a micelle at the time the micelle originally
forms. If so, then it may be preferable to use a copolymer wherein
the metal binding domain resides in the hydrophilic segment so that
it is exposed in the micelle surface layer. It is an advantage of
the present invention that the kind and content of the functional
group can be easily changed without limitation.
[0204] Micelles according to the present invention may comprise
biodegradable, biocompatible copolymers, resulting in
non-immunogenicity and non-toxicity. In one aspect copolymers
disclosed herein degrade into non-toxic, small molecules subject to
renal excretion and are inert during the required period of
treatment. Degradation may occur via simple hydrolytic and/or
enzymatic reaction. Degradation through simple hydrolysis may be
predominant when the backbone of a copolymer comprises ester bonds.
Enzymatic degradation may become significant in the presence of
certain organelles such as lyposomes. The degradation period can be
varied from days to months by using polymers of different kinds and
molecular weights. In one example, the present invention may use
biodegradable polyesters or polypeptides possessing safe and
biocompatible degradation pathways. In addition, the
highly-branched micellar structure of the present invention may
further reduce cytotoxicity since branched polycations such as
dendritic polyamidoamines are thought to be less cytotoxic than
linear polycations. Accordingly, the advantageous components and
structure of polymeric micelles according to the present invention
can be appreciated regarding reduced cytotoxicity. For additional
examples of micelles, reverse micelles, liposomes, and microspheres
suitable for the present invention see U.S. Pat. Nos. 6,338,859,
5,631,018; 6,162,462; 6,475,779; 6,521,211; and 6,443,898.
[0205] (iii) Emulsions and Hydrogels
[0206] Emulsions as the carrier in the present invention relate to
emulsions of an aqueous or an aqueous-organic continuous phase and
an organic discontinuous phase, the latter containing an organic
solvent which is not miscible with water. Hydrogels are similar and
refer to a type of gel in which the disperse phase has combined
with water to produce a semisolid material. The emulsions and
hydrogels used in the present invention may contain organic
compounds from the group of the reaction products of alkylene
oxides with compounds capable of being alkylated, such as, for
example, fatty alcohols, fatty amines, fatty acids, phenols,
alkylphenols, carboximides and resinic acids, preferably balsamic
resin and/or abietic acid.
[0207] Organic solvents which are not miscible with water include,
for example, aliphatic, cycloaliphatic or aromatic hydrocarbons or
the acetate-type solvents. Suitable as organic solvents are,
preferably, natural, fully- or semisynthetic compounds and, if
appropriate, mixtures of these solvents which are fully miscible or
soluble with the other compounds of the emulsion in the temperature
range of from 20 to 130.degree. C. In one embodiment, suitable
solvents are those from the group of the aliphatic, cycloaliphatic
or aromatic hydrocarbons which are liquid at room temperature,
including oils, such as, for example, mineral oils, paraffins,
isoparaffins, fully-synthetic oils such as silicon oils,
semisynthetic oils based on, for example, glycerides of unsaturated
fatty acids of medium chain length, essential oils, esters of
natural or synthetic, saturated or unsaturated fatty acids, for
example C.sub.8-C.sub.22-fatty acids, C.sub.8-C.sub.18-fatty acids,
especially preferably methyl esters of rapeseed oil or 2-ethylhexyl
laurate, alkylated aromatics and their mixtures, alkylated
alcohols, in particular fatty alcohols, linear, primary alcohols
obtained by hydroformylation, terpene hydrocarbons and
naphtene-type oils, such as, for example, Enerthene. Further
organic solvents include those from the group of the acetate-type
solvents such as, for example, 1,2-propanediol diacetate,
3-methyl-3-methoxybutyl acetate, ethyl acetate and the like. The
solvents can be employed individually or as mixtures with each
other.
[0208] The continuous aqueous or aqueous-organic phase of the
active-agent-containing emulsions or microemulsions according to
the present invention contain water, an organic solvent that is
soluble or miscible in water, and may also contain at least one
natural or synthetic surface-active agent which has a solubility of
>10 g/l, in particular >100 g/l in water (d) at 20.degree.
C., and, if appropriate, further adjuvants. Organic solvents which
are soluble or miscible in water have a solubility in water of
>5.0 g/l at 20.degree. C., in particular >15 g/l.
[0209] Examples of suitable organic solvents are: aliphatic
C.sub.1-C.sub.4-alcohols such as methanol, ethanol, isopropanol,
n-propanol, n-butanol, isobutanol or tert-butanol, aliphatic
ketones such as acetone, methyl ethyl ketone, methyl isobutyl
ketone or diacetone alcohol, polyols, such as ethylene glycol,
propylene glycol, butylene glycol, 1,4-butanediol, 1,5-pentanediol,
1,6-hexanediol, diethylene glycol, triethylene glycol,
trimethylolpropane, polyethylene glycol or polypropylene glycol
with a mean gram-molecular weight of 100 to 4000 g/mol or 200 to
1500 g/mol, or glycerol, monohydroxyethers, such as
monohydroxyalkyl ethers or mono-C.sub.1-C.sub.4-alkyl glycol ethers
such as ethylene glycol monoethyl ether, ethylene glycol monomethyl
ether, diethylene glycol monomethyl ether or diethylene
glycolmonoethyl ether, diethylene glycol monobutyl ether,
dipropylene glycol monoethyl ether, thiodiglycol, triethylene
glycol monomethyl ether or triethylene glycol monoethyl ether,
furthermore 2-pyrrolidone, N-methyl-2-pyrrolidone,
N-ethyl-pyrrolidone, N-vinylpyrrolidone, 1,3-dimethylimidazolidone,
dimethylacetamide and dimethyl formamide.
[0210] The amount of the solvents employed in the aqueous
continuous phase is in general less than 60% by weight or less than
40% by weight, based on the continuous phase.
[0211] Surface-active agents are understood as meaning emulsifiers,
wetters, dispersants, antifoams or solubilizers which are soluble
or fully soluble, in the aqueous phase. In particular, they can be
nonionic, anionic, cationic or amphoteric or of monomeric,
oligomeric or polymeric nature. The choice of the surface-active
agents is not limited in accordance with the present invention and
must be matched with the discontinuous phase to be stabilized with
regard to the desired type of emulsion (for example miniemulsion or
microemulsion) and the stability of the emulsion, in particular the
sedimentation and/or creaming of the disperse phase.
[0212] Examples of suitable surface-active agents include the
following: a) alkoxylation product which can be obtained by
ethylene-oxide-alkoxylat- ion or propylene-oxide-alkoxylation of
condensates of phenolic OH-containing aromatics with formaldehyde
and NH functional groups; b) inorganic salts which are soluble in
water, such as borates, carbonates, silicates, sulfates, sulfites,
selenates, chlorides, fluorides, phosphates, nitrates and
aluminates of the alkali metals and alkaline earth metals and other
metals and also ammonium; c) polymers composed of recurrent
succinyl units, in particular polyaspartic acid; d) nonionic or
ionically modified compounds form the group of the alkoxylates,
alkylolamides, esters, amine oxides and alkyl polyglycosides,
including reaction products of alkylene oxides with compounds
capable of being alkylated, such as, for example, fatty alcohols,
fatty amines, fatty acids, phenols, alkyl phenols, carboximides and
resinic acids. These are, for example, ethylene oxide adducts from
a class of the reaction products of ethylene oxide with: 1)
saturated and/or unsaturated fatty alcohols with 6 to 25 C atoms or
2) alkyl phenols with 4 to 12 C atoms in the alkyl radical or 3)
saturated and/or unsaturated fatty amines with 14 to 20 C atoms or
4) saturated and/or unsaturated fatty acids with 14 to 22 C atoms
or 5) hydrogenated and/or unhydrogenated resinic acids, or 6)
esterification and/or arylation products prepared from natural or
modified, optionally hydrogenated castor oil lipid bodies which, if
appropriate, are linked by esterification with dicarboxylic acids
to give recurrent structural units; e) ionic or nonionic compounds
from the group of the reaction products of alkylene oxide with
sorbitan ester, oxalkylated acetylene diols and acetylene glycols,
and oxalkylated phenols; f) ionic or nonionic polymeric
surface-active agents from the group of the homo- and copolymers,
graft and graft copolymers and random and linear block copolymers.
Examples of such suitable polymeric surface-active agents include
polyethylene oxides, polypropylene oxides, polyoxymethylenes,
polytrimethylene oxides, polyvinyl methyl ethers, polyethylene
imines, polyacrylic acid, polyaryl amides, polymethacrylic acids,
polymethacrylamides, poly-N,N-dimethyl-acrylamides,
poly-N-isopropyl acrylamides, poly-N-acrylglycinamides,
poly-N-methacryl-glycinamides, polyvinyloxazolidones,
polyvinylmethyloxazolidones; g) anionic surface-active agents such
as, for example, alkyl sulfates, ether sulfates, ether
carboxylates, phosphate esters, sulfosuccinate amides, paraffin
sulfonates, olefin sulfonates, sarcosinates, isothionates and
taurates; h) anionic surface-active agents from the group of what
is known as dispersants, in particular condensates which can be
obtained by reacting naphthols with alkanols, subjecting alkylene
oxide to an addition reaction and at least partially converting the
terminal hydroxyl groups into sulfo groups or monoesters of maleic
acid, phthalic acid or succinic acid, sulfosuccinic esters,
alkylbenzene sulfonates, and salts of the polyacrylic acids,
polyethylene sulfonic acids, polystyrene sulfonic acid,
polymethacrylic acids, polyphosphoric acids; i) lignin-type
compounds, especially lignosulfonates, for example those which have
been obtained by the sulfite or Kraft method. They include products
which are partially hydrolyzed, oxidized, propoxylated, sulfonated,
sulfomethylated or bisulfonated and which are fractionated by known
methods, for example according to the molecular weight or the
degree of sulfonation. Mixtures of sulfite and Kraft
lignosulfonates are also very effective. Suitable are
lignosulfonates with a mean molecular weight of greater than about
1,000 to 100,000, a content of active lignosulfonate of at least
80% and, a low content of polyvalent cations. The degree of
sulfonation can be varied within wide limits.
[0213] In another embodiment, the continuous aqueous phase can also
contain, in addition to the abovementioned surface-active agents,
water-soluble block or block copolymers; these block or block
copolymers include water-soluble block and block copolymers based
on ethylene oxide and/or propylene oxide and/or water-soluble block
and block copolymers of ethylene oxide and/or propylene oxide on
bifunctional amines. Block copolymers based on polystyrene and
polyalkylene oxide, poly(meth)acrylates and polyalkylene oxide and
also poly(meth)acrylates and poly(meth)acrylic acids are also
suitable.
[0214] In addition, the continuous aqueous phase can also contain
further customary adjuvants such as, for example, water-soluble
wetters, antifoams and/or preservatives.
[0215] Emulsion types of the present invention which may be
mentioned are: macroemulsion: contains droplets >2 .mu.m
(microscopic); miniemulsion: droplet diameter 0.1 to 2 .mu.m,
turbid; and microemulsion: droplet diameter <0.1 .mu.m;
transparent. For additional examples of emulstions and hydrogels
suitable for the present invention see U.S. Pat. Nos. 6,458,373 and
6,124,273.
[0216] (iv) Nanoparticles and Microparticles
[0217] Examples of nanoparticles and microparticles that can be
used as a carrier in the present invention are include porous
particles having a mass density less than 1.0 g/cm.sup.3, or less
than about 0.4 g/cm.sup.3. The porous structure permits, for
example, deep lung delivery of relatively large diameter
therapeutic aerosols, for example greater than 5 .mu.m in mean
diameter.
[0218] The porous particles preferably are biodegradable and
biocompatible, and optionally are capable of biodegrading at a
controlled rate for delivery of a drug. The porous particles may be
made of any material which is capable of forming a porous particle
having a mass density less than about 0.4 g/cm.sup.3. Both
inorganic and organic materials can be used. For example, ceramics
may be used. Other non-polymeric materials may be used which are
capable of forming porous particles as defined herein.
[0219] The particles may be formed from any biocompatible, and
preferably biodegradable polymer, copolymer, or blend, which is
capable of forming porous particles having a density less than
about 0.4 g/cm.sup.3.
[0220] Surface eroding polymers such as polyanhydrides may be used
to form the porous particles. For example, polyanhydrides such as
poly[(p-carboxyphenoxy)-hexane anhydride] ("PCPH") may be used.
Biodegradable polyanhydrides are described, for example, in U.S.
Pat. No. 4,857,311.
[0221] In another embodiment, bulk eroding polymers such as those
based on polyesters including poly(hydroxy acids) can be used. For
example, polyglycolic acid ("PGA") or polylactic acid ("PLA") or
copolymers thereof may be used to form the porous particles,
wherein the polyester has incorporated therein a charged or
functionalizable group such as an amino acid as described
below.
[0222] Other polymers include polyamides, polycarbonates,
polyalkylenes such as polyethylene, polypropylene, poly(ethylene
glycol), poly(ethylene oxide), poly(ethylene terephthalate), poly
vinyl compounds such as polyvinyl alcohols, polyvinyl ethers, and
polyvinyl esters, polymers of acrylic and methacrylic acids,
celluloses, polysaccharides, and peptides or proteins, or
copolymers or blends thereof which are capable of forming porous
particles with a mass density less than about 0.4 g/cm.sup.3.
Polymers may be selected with or modified to have the appropriate
stability and degradation rates in vivo for different controlled
drug delivery applications.
[0223] As another example, the porous particles may be formed from
functionalized polyester graft coppolymers, as described in Hrkach
et al., Macromolecules, 28:4736-4739 (1995); and Hrkach et al.,
"Poly(L-Lactic acid-co-amino acid) Graft Copolymers: A Class of
Functional Biodegradable Biomaterials" in Hydrogel and
Biodegradable Polymers for Bioapplications, ACS Symposium Series
No. 627, Raphael M. Ottenbrite et al., Eds., American Chemical
Society, Chapter 8, pp. 93-101, 1996, the disclosures of which are
incorporated herein by reference. The functionalized graft
copolymers are copolymers of polyesters, such as poly(glycolic
acid) or poly(lactic acid), and another polymer including
functionalizable or ionizable groups, such as a poly(amino acid).
In another embodiment, comb-like graft copolymers are used which
include a linear polyester backbone having amino acids incorporated
therein, and poly(amino acid) side chains which extend from the
amino acid groups in the polyester backbone. The polyesters may be
polymers of .alpha.-hydroxy acids such as lactic acid, glycolic
acid, hydroxybutyric acid and valeric acid, or derivatives or
combinations thereof. The inclusion of ionizable side chains, such
as polylysine, in the polymer has been found to enable the
formation of more highly porous particles, using techniques for
making microparticles known in the art, such as solvent
evaporation. Other ionizable groups, such as amino or carboxyl
groups, may be incorporated, covalently or noncovalently, into the
polymer to enhance porosity. For example, polyaniline could be
incorporated into the polymer.
[0224] An exemplary polyester graft copolymer, which may be used to
form porous polymeric particles is the graft copolymer, poly(lactic
acid-co-lysine-graft-lysine) ("PLAL-Lys"), which has a polyester
backbone consisting of poly(L-lactic acid-co-Z-L-lysine) (PLAL),
and grafted lysine chains. PLAL-Lys is a comb-like graft copolymer
having a backbone composition, for example, of 98 mol % lactic acid
and 2 mol % lysine and poly(lysine) side chains extending from the
lysine sites of the backbone.
[0225] The use of the poly(lactic acid) copolymer is advantageous
since it biodegrades into lactic acid and lysine, which can be
processed by the body. The existing backbone lysine groups are used
as initiating sites for the growth of poly(amino acid) side
chains.
[0226] In the synthesis, the graft copolymers may be tailored to
optimize different characteristic of the porous particle including:
i) interactions between the agent to be delivered and the copolymer
to provide stabilization of the agent and retention of activity
upon delivery; ii) rate of polymer degradation and, thereby, rate
of drug release profiles; iii) surface characteristics and
targeting capabilities via chemical modification; and iv) particle
porosity. For additional examples of nanoparticles and
microparticles suitable for the present invention see U.S. Pat.
Nos. 6,447,753 and 6,274,175.
[0227] (v) Solid Surface
[0228] In certain embodiments, the carrier used in the present
invention may be a solid support, e.g., a polymer bead or a resin,
e.g., a Wang resin. Supports can be solids having a degree of
rigidity such as silicon, plastic, and the like. Support can also
be flexible materials such as plastic or otherwise synthetic
materials (such as nylon), materials made of natural polymers (such
as cellulose or silk) or derivatives thereof (such as
nitrocellulose) and the like. In certain embodiments the support is
a porous material which can be rigid or flexible, intermeshed
fibers including woven fabrics, and the like. In some embodiments,
the solid support is a bead or pellet, which can be porous.
[0229] Another option for creating a solid support with reactive
sites is to directly derivatize the solid support so that it can be
coupled to a compound. The chemistry used to do this can be the
same or similar to that used to derivatize controlled pore glass
(cpg) beads and polymer beads. Typically, the first step in this
process is to create hydroxyl groups (if they do not already exist
on the support) or amino groups on the support. If hydroxyl groups
exist or are created, they are typically converted to amino groups,
for instance by reacting them with gamma-aminopropyl triethoxy
silane. MBDs can be added to the amino groups with cyclic acid
anhydrides, activated esters, reactions with polymerized alkylene
oxides and other methods known to the art.
[0230] Another method to increase the reactive surface area of a
solid support is to create columnar structures of silicon monoxide,
for instance by thermal evaporation of SiO.sub.x. Another such
method is to insert into the reaction cells fabrics, such as
non-woven glass or plastic (preferably fiberglass or polypropylene
fiber) fabrics and plasma treating the fabric to create reactive
sites. Still another method uses spin-on glass, which creates a
thin film of nearly stoichiometric SiO.sub.2 from a sil-sesquioxane
ladder polymer structure by thermal oxidation. Sol-gel processing
creates thin films of glass-like composition from organometallic
starting materials by first forming a polymeric organometallic
structure in mixed alcohol plus water and then careful drying and
baking. When the sol-gel system is dried above the critical
temperature and pressure of the solution, an aerogel results.
Aerogels have chemical compositions that are similar to glasses
(e.g. SiO.sub.2) but have extremely porous microstructures. Their
densities are comparably low, in some cases having only about one
to about three percent solid composition, the balance being
air.
[0231] Protective Side Chains
[0232] Examples of Protective Chains include poly(ethylene glycol),
which may be esterified by dicarboxylic acid to form a
poly(ethylene glycol) monoester; methoxy poly(ethylene glycol)
(MPEG) or a copolymer of poly(ethylene glycol) and poly(propylene
glycol) preferably in a form of an ester with dicarboxylic acid;
poly(ethylene glycol)-diacid; poly(ethylene glycol) monoamine;
methoxy poly(ethylene glycol) monoamine; methoxy poly(ethylene
glycol) hydrazide; methoxy poly(ethylene glycol) imidazolide
block-copolymer of poly (ethylene glycol) and one or several
polymers represented by polyaminoacid, poly-lactide-glycolide
co-polymer, polysaccharide, polyamidoamine, polyethyleneimine or
polynucleotide (see polymeric carrier) where these blocks are
preferably alternated to give a preferably linear block-copolymer.
Overall molecular weight of a protective chain is preferentially
larger than 300 but preferably not exceeding 10,000. A protective
chain or chains are linked to the polymeric carrier by preferably a
single linkage.
[0233] Metal Binding Domain
[0234] In general, the metal binding domains used in the present
invention contain a Lewis base fragment that is contemplated to
encompass numerous chemical moieties having a variety of
structural, chemical and other characteristics capable of forming
coordination bonds with a metal ion. The types of functional groups
capable of forming coordinate complexes with metal ions are too
numerous to categorize here, and are known to those of skill in the
art. For example, such moieties will generally include functional
groups capable of interaction with a metal center, e.g.,
heteroatoms such as nitrogen, oxygen, sulfur, and phosphorus.
[0235] Metal cations are almost always Lewis acidic and are
therefore able to bind various moieties that may serve as Lewis
bases. In general, a moiety serving as a Lewis base will be a
strongly acidic group, e.g., with a pKa less than about 7, and more
preferably less than 5, which may produce a conjugate base that,
under the appropriate conditions, is a strong enough Lewis base to
donate an electron pair to a metal ion to form a coordinate bond.
The degree of this Lewis acid-to-Lewis base interaction is a
function not only of the particular metal ion, but also of the
coordinating moiety itself, because the latter may vary in the
degree of basicity as well as in size and steric accessibility.
[0236] Exemplary Lewis basic moieties which may be included in the
metal binding domain include: amines (primary, secondary, and
tertiary) and aromatic amines, amino groups, amido groups, nitro
groups, nitroso groups, amino alcohols, nitriles, imino groups,
isonitriles, cyanates, isocyanates, phosphates, phosphonates,
phosphites, phosphines, phosphine oxides, phosphorothioates,
phosphoramidates, phosphonamidites, hydroxyls, carbonyls (e.g.,
carboxyl, ester and formyl groups), aldehydes, ketones, ethers,
carbamoyl groups, thiols, sulfides, thiocarbonyls (e.g.,
thiolcarboxyl, thiolester and thiolformyl groups), thioethers,
mercaptans, sulfonic acids, sulfoxides, sulfates, sulfonates,
sulfones, sulfonamides, sulfamoyls and sulfinyls.
[0237] Illustrative of suitable metal binding domains include those
chemical moieties containing at least one Lewis basic nitrogen,
sulfur, phosphorous or oxygen atom or a combination of such
nitrogen, sulfur, phosphorous and oxygen atoms. The carbon atoms of
such moiety may be part of an aliphatic, cycloaliphatic or aromatic
moiety. In addition to the organic Lewis base functionality, such
moieties may also contain other atoms and/or groups as
substituents, such as alkyl, aryl and halogen substituents.
[0238] Further examples of Lewis base functionalities suitable for
use in the metal binding domains include the following chemical
moieties: amines, particularly alkylamines and arylamines,
including methylamine, diphenylamine, trimethylamine,
triethylamine, N,N-dimethylaniline, methyldiphenylaniline,
pyridine, aniline, morpholine, N-methylmorpholine, pyrrolidine,
N-methylpyrrolidine, piperidine, N-methylpiperidine,
cyclohexylamine, n-butylamine, dimethyloxazoline, imidazole,
N-methylimidazole, N,N-dimethylethanolamine,
N,N-diethylethanolimine, N,N-dipropylethanolamine,
N,N-dibutylethanolamine, N,N-dimethylisopropanolamine,
N,N-diethylisopropanolamine, N,N-dipropylisopropanolamine,
N,N-dibutylisopropanolamine, N-methyldiethanolamine,
N-ethyldiethanolamine, N-propyldiethanolamine,
N-butyldiethanolamine, N-methyldiisopropanolamine,
N-ethyldiisopropanolamine, N-propyldiisopropanolamine,
N-butyldiisopropanolamine, triethylamine, triisopropanolamine,
tri-s-butanolamine and the like; amides, such as
N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone,
hexamethylphosphoric acid triamide and the like; sulfoxide
compounds, such as dimethylsulfoxide and the like; ethers such as
dimethyl ether, diethyl ether, tetrahydrofuran, dioxane and the
like; thioethers such as dimethylsulfide, diethyl thioether,
tetrahydrothiophene and the like; esters of phosphoric acid, such
as trimethyl phosphate, triethylphosphate, tributyl phosphate and
the like; esters of boric acid, such as trimethyl borate and the
like; esters of carboxylic acids, such as ethyl acetate, butyl
acetate, ethyl benzoate and the like; esters of carbonic acid, such
as ethylene carbonate and the like; phosphines including di- and
trialkylphosphines, such as tributylphosphine, triethylphosphine,
triphenylphosphine, diphenylphosphine and the like; and
monohydroxylic and polyhydroxylicalcohols of from 1 to 30 carbon
atoms such as methyl alcohol, ethyl alcohol, n-propyl alcohol,
isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, tert-butyl
alcohol, n-pentyl alcohol, isopentyl alcohol, 2-methyl-1-butyl
alcohol, 2-methyl-2-butyl alcohol, n-hexyl alcohol, n-heptyl
alcohol, n-octyl alcohol, isooctyl alcohol, 2-ethylhexyl alcohol,
n-nonyl alcohol, n-decyl alcohol, 1,5-pentanediol, 1,6-hexanediol,
allyl alcohol, crotyl alcohol, 3-hexene-1-ol, citronellol,
cyclopentanol, cyclohexanol, salicyl alcohol, benzyl alcohol,
phenethyl alcohol, cinnamyl alcohol, and the like; and heterocyclic
compounds, including pyridine and the like.
[0239] Other suitable structural moieties that may be included in
the metal binding domains include the following Lewis base
functionalities: arsine, stilbines, thioethers, selenoethers,
teluroethers, thioketones, imines, phosphinimine, pyridines,
pyrazoles, imidazoles, furans, oxazoles, oxazolines, thiophenes,
thiazoles, isoxazoles, isothrazoles, amides, alkoxy, aryoxy,
selenol, tellurol, siloxy, pyrazoylborates, carboxylate, acyl,
amidates, triflates, thiocarboxylate and the like.
[0240] Other suitable ligand fragments for use in the metal binding
domains include structural moieties that are bidentate ligands,
including diimines, pyridylimines, diamines, imineamines,
iminethioether, iminephosphines, bisoxazoline, bisphosphineimines,
diphosphines, phosphineamine, salen and other alkoxy imine ligands,
amidoamines, imidothioether fragments and alkoxyamide fragments,
and combinations of the above ligands.
[0241] Still other suitable fragments for use in the metal binding
domains include ligand fragments that are tridentate ligands,
including 2,5-diiminopyridyl ligands, tripyridyl moieties,
triimidazoyl moieties, tris pyrazoyl moieties, and combinations of
the above ligands.
[0242] Other suitable ligand fragments may consist of amino acids
or be formed of oligopeptides and the like.
[0243] Because the Lewis basic groups function as the coordination
site or sites for the metal cation, in certain embodiments, it may
be preferable that the deformability of the electron shells of the
Lewis basic groups and the metal cations be approximately similar.
Such a relationship often results in a more stable coordination
bond. For instance, sulfur groups may be desirable as the Lewis
basic groups when the metal cation is a heavy metal. Some examples
include the oligopeptides such as glutathione and cysteine,
mercapto ethanol amine, dithiothreitol, amines and peptides
containing sulfur and the like. Nitrogen containing groups may be
employed as the Lewis basic groups when smaller metal ions are the
metal. Alternatively, for those applications in which a less stable
coordination bond is desired, it may be desirable that the
deformability be dissimilar.
[0244] Further examples of chelating groups which act as the metal
binding domain and can be chemically linked the carrier include
1,4,7,10-tetraazacyclododecane-N,N',N",N'"-tetraacetic acid;
1,4,7,10-tetraaza-cyclododecane-N,N',N"-triacetic acid;
1,4,7-tris(carboxymethyl)-10-(2'-hydroxypropyl)-1,4,7,10-tetraazocyclodec-
ane, 1,4,7-triazacyclonane-N,N',N"-triacetic acid; and
1,4,8,11-tetraazacyclotetra-decane-N,N',N",N'"-tetraacetic acid;
diethylenetriamine-pentaacetic acid (DTPA);
triethylenetetraamine-hexaace- tic acid;
ethylenediamine-tetraacetic acid (EDTA); EGTA;
1,2-diaminocyclohexane-N,N,N',N'-tetraacetic acid but preferably
N-(hydroxyethyl)ethylenediaminetriacetic acid; nitrilotriacetic
acid (NTA); and ethylene-bis(oxyethylene-nitrilo)tetraacetic acid,
histidine, cysteine, oligoaspartic acid, oligoglutamic acid,
S-acetyl mercaptoacetate and meractoacetyltriglycine.
[0245] Metal Ion
[0246] The present invention contemplates the use of a variety of
different metal ions. The metal ion may be selected from those that
have usually two, three, four, five, six, seven or more
coordination sites. A non-limiting list of metal ions for which the
present invention may be employed (including exemplary and
non-limiting oxidation states for them) includes Co.sup.3+,
Cr.sup.3+, Hg.sup.2+, Pd.sup.2+, Pt.sup.2+, Pd.sup.4+, Pt.sup.4+,
Rh.sup.3+, Ir.sup.3+, Ru.sup.3+, Co.sup.2+, Ni.sup.2+, Cu.sup.2+,
Zn.sup.2+, Cd.sup.2+, Pb.sup.2+, Mn.sup.2+, Fe.sup.3+, Fe.sup.2+,
Tc, Au.sup.3+, Au.sup.+, Ag.sup.+, Cu.sup.+, MoO.sub.2.sup.2+,
Ti.sup.3+, Ti.sup.4+, CH.sub.3Hg.sup.+, and Y.sup.+3. In another
embodiment, the non-limiting list of metal ions for which the
present invention may be employed includes Zn.sup.2+, Ni.sup.2+,
Co.sup.2+, Fe.sup.2+, Mn.sup.2+, and Cu.sup.2+. The metal ion
contained in the metal bridge between the carrier and the active
agent may have a therapeutic use itself, but it cannot serve as the
active agent.
[0247] Active Agent
[0248] An active agent of the present invention is envisioned to be
GLP-1 comprising a metal binding domain, naturally occurring within
the peptide chain or otherwise, capable of coordinating to a metal
ion, thus completing a bridge between the active agent and the
carrier. It is envisioned that such an complex will increase the
half life of GLP-1 in vivo. GLP-1 activity is rapidly inhibited as
a result of the N-terminal cleavage at Ala2 position by dipeptidyl
peptidase IV (DPP-IV) in the blood stream (See FIG. 5). The
cleavage limits GLP-1 half-life to 2-6 minutes, which is considered
seriously limiting to its therapeutic potential. A number of GLP-1
analogues are in development that resist the effects of DPP-IV.
Some of these have been shown to normalize fasting and postprandial
blood glucose in diabetic animal models as well as in humans.
However, the effects of long term systemic administration of these
non-native peptides are unknown. Side effects of sustained
administration of these analogues appear to include
gastrointestinal and cardiovascular side effects, and doses have to
be carefully controlled to prevent hypoglycemic episodes. Though
not documented by clinical trials, there is also the potential for
the development of antibodies to these non-native analogues after
long-term treatment. An additional potential problem with sustained
release analogues is the potential for down-regulation of the GLP-1
receptor, as has been seen with agonists of a closely homologous
receptor, PTH.
[0249] As an alternative approach to GLP-1 analogues with extended
half-lives, small molecule inhibitors of DPP-IV are in development
that offer the advantage of being orally available. However, these
inhibitors have the potential for other side effects given the
importance of DPP-IV in the cleavage of other molecules important
for immune function.
[0250] The present invention overcomes these problems by protecting
the natural form of GLP-1 making it a potentially effective
treatment for diabetes. The present invention benefits from the
positioning of the N-terminal His in GLP-1 inside the protective
side chains on the carrier via the MBD. Such positioning of the
peptide would hide the peptidase sensitive area of the peptide from
DPP-IV through steric interactions. Additionally, GLP-1 would
target the pancreas once it has coordinated to the carrier with a
passive targeting/enhanced permeability retention (EPR) effect.
GLP-2 is very similar in chemical structure and sensitivity to
peptidases, but with different mechanism of action. Using the same
MBD/protective side chain approach it would be possible to
stabilize and prolong circulation time, which is very beneficial.
Different therapeutic agents may be combined with GLP-1 or GLP-2.
For example, GLP-1 can be combined with immunosuppressants such as
tacrolimus for treatment of type 1 diabetes.
[0251] GLPs can also be stabilized by attachment to the carrier via
MBD for oral/mucosal administration and for other forms of
administration as is, or in combination with other delivery systems
such as emulsions, micelles, reversed micelles, polymerized
reversed micelles, liposomes, hydrogels, microparticles, and
nanoparticles. For example, GLP-1 may be attached via a MBD to a
polymer forming reverse micelles. Attachment via a MBD would
increase shelf life stability and solubility of the peptides like
GLPs, especially amide derivatives. Combinations of these peptides
with PEG based drug delivery carriers would also decrease
immunogenecity, especially for chronic administration, and
especially with the MBD approach (the structure would remain
intact).
[0252] (i) GLP-1 and Type 2 Diabetes
[0253] GLP-1 amide is a potent intestinal hormone that increases
insulin secretion. Believed to be released in response to a meal,
GLP-1 is believed to stimulate insulin secretion from pancreatic
beta cells, inhibit the release of the hormone glucagon (which
functions as an insulin antagonist), and delay gastric emptying. By
interacting with the GLP-1 receptor on pancreatic islet cells,
GLP-1 leads to a cascade of signaling reactions resulting in an
increased exocytosis of insulin-containing granules in a strictly
glucose-dependent manner (at glucose concentrations >4.5 mM).
Additionally, it is believed that GLP-1 strongly enhances all steps
of insulin biosynthesis including transcription of the insulin
gene. The transcription of other genes essential for beta cell
function (glucokinase and Glut-2) is also increased in response to
GLP-1 treatment. Given these effects of GLP-1, there is
considerable interest in this peptide as a potential therapeutic
agent that could stimulate insulin release in Type 2 diabetics with
functional beta cells.
[0254] (ii) GLP-1 and Type I Diabetes
[0255] The observation that GLP-1 not only increases the
proliferation of beta cells and prevents their apoptosis, but also
stimulates their neogenesis, inducing the differentiation of new
beta cells from ductal progenitor cells, has led to interest in
this peptide for a possible cure for Type 1 diabetes. Indeed, the
importance of GLP-1 in islet generation is seen in mice lacking the
GLP-1 receptor, which have islets with fewer beta cells and
abnormal glucose tolerance. The regeneration of islet cells and
increase in pancreatic beta cell mass has been demonstrated in
animal models by GLP-1 and other agonists of the GLP-1 receptor
and, further, GLP-1 has been shown to attenuate the development of
diabetes after partial pancreatectomy. Therefore, GLP-1 treatment
can potentially regenerate destructed islets in Type 1
diabetics.
[0256] "PEGylation" of GLP-1 is the direct bonding of GLP-1 to PEG
and may result in loss of activity. GLP-1 coordinated to a carrier
with protecting side chains according to the present invention,
however, may result in a stable, long circulating alternative to
PEGylation. A coordinated GLP-1 of the present invention may act as
a cryoprotectant and macromolecular stabilizer preserving GLP-1 in
solution as well as during the lyophilization and reconstitution
process. It also may allow removal of albumin from freeze-dried
formulations.
[0257] GLP-1 naturally contains at least one MBD, which may be used
for binding to the carriers described above. GLP-1, therefore,
supplies an MBD naturally such that there is no need to provide one
synthetically. Alternatively, GLP-1 may bind to a carrier through
other means besides an MBD. As non-limiting examples, binding may
occur through both covalent and non-covalent interactions such as
hydrophobic, hydrogen bonding, Van de Waals attractions, or
electrostatic interactions. When GLP-1 is bound to the carrier
through non-covalent interactions, the complex may be in the form
of colloidal particles less than 0.05 microns. GLP-1 may be located
between the side chains on the carrier and/or on the side chain
surface. When the protective side chains are PEG a pegylated
carrier is formed. This pegylated carrier is a non-limiting example
of a protected graft copolymer (PGC) delivery system. As used
herein, PGC refers to a carrier comprising protective graft
copolymers or polymers.
[0258] Importantly, GLP-1 has an N-terminal histidine residue (see
FIG. 5), which contributes to its zinc binding properties making it
a candidate for coupling via PRB, reversible binding comprising a
metal ion. The proposed GLP-1 formulation is expected to not only
increase the circulation time, protect GLP-1 from DPP-IV and
control release, but also target delivery to the pancreas as well
as supply longer shelf-life stability.
[0259] GLP-1 may be loaded by co-lyophilization with a PGC or other
carrier through reconstitution with water or normal saline
solution, or by simple incubation of a GLP-1 solution with a PGC or
other carrier solution, or by reconstitution of a "lyophilized
cake" of GLP-1 with a solution of a PGC or other carrier.
[0260] Coordinated GLP-1 according to the present invention may
result in longer circulating, more stable GLP-1 which may be more
conveniently administered (for example, quicker administrations
such as through bolus instead of infusion, and less frequent
administrations, e.g. once a week instead of every day are
possible). Often chronic administration of GLP-1 may be
immunogenic. PGC based formulations generally result in less
immunogenicity than PEG based delivery systems so GLP-1 is expected
to be less immunogenic in compositions of the present
inventions.
[0261] Targeting Moieties
[0262] The role of a targeting moiety is to place the compositions
of the present invention in close proximity to a target within a
patient's body. In this manner, it is envisioned that the present
invention can utilize more than one type of active agent. For
instance, one type of active agent could be a targeting moiety
while another type of active agent could be a diagnostic label or
therapeutic agent. Conceivably, three types of active agents could
be coordinated to the carrier through a metal ion bridge.
[0263] Examples of targeting moieties include: (i) cells including
smooth muscle cells, leukocytes, B-lymphocytes, T-lymphocytes,
monocytes, macrophages, foam cells, platelets, granulocytes,
neutophilis, heme, porphoryns, and phthalocyanines; (ii)
chemotactic proteins and peptides including monocyte chemotactic
protein 1 (MCP-1), N-formyl-methionyl-leuc- yl-phenalanine; (iii)
colony stimulating factors including GM-CSF, CSF-1, and receptors
and antibodies thereto; and platelet factor 4; (iv) growth factors
including TGF-.beta. and VEGF; (v) adhesive cell-surface
glycoproteins including E-selectin, VCAM-1, and VCAM1.beta.; (vi)
carbohydrates including .sup.11C-deoxy-D-glucose, and
.sup.18F-2-fluorodeoxy-D-glucose; (vii) components of a vascular
inflammatory response including C1, C1q, C1r, C1s, C2, C3, C3a,
C3b, C4, C4C2, C4C2C3b, C5a, C5b and C5a; (viii) interleukins
including IL-1, IL-1.alpha., IL-1.beta., IL-2, IL-3, IL-6, IL-7,
and IL-8; (ix) interferons including interferon .alpha. and
interferon .gamma.; (x) tumor necrosis factor TNF-.alpha.; and (xi)
lipids including liposomes, polyethylene glycol coated liposomes,
cholesterol, esters of cholesterol, lipoproteins including LDL,
HDL, oxidized LDL, and lipid receptors.
[0264] Sustained Release
[0265] If a subject biocompatible composition is formulated with an
active agent, release of such an active agent for a sustained or
extended period as compared to the release from an isotonic saline
solution generally results. Such release profile may result in
prolonged delivery (over, say 1 to about 4,000 hours, or
alternatively about 4 to about 1500 hours) of effective amounts
(e.g., about 0.00001 mg/kg/hour to about 10 mg/kg/hour) of the
active agent or any other material associated with the
biocompatible composition.
[0266] A variety of factors may affect the desired rate of
dissociation of the active agent of the subject invention, the
desired softness and flexibility of the biocompatible composition,
rate and extent of active agent release. Some of such factors
include: the selection of various coordinating groups on the metal
ion, or, when the carrier is a polymer, the enantiomeric or
diastereomeric purity of the monomeric subunits, homogeneity of
subunits found in the polymer, and the length of the polymer. For
instance, the present invention contemplates heteropolymers with
varying linkages, and/or the inclusion of other monomeric elements
in the polymer, in order to control, for example, the rate of
active agent release of the subject compostion.
[0267] To illustrate further, a wide range of dissociation rates
may be obtained by adjusting the hydrophobicities of the backbones
or side chains of the polymers while still maintaining sufficient
biodegradability for the use intended for any such polymer. Such a
result may be achieved by varying the various functional groups of
the polymer. For example, the combination of a hydrophobic backbone
and a hydrophilic metal ion containing bridges between the carrier
and active agent produces heterogeneous release because
dissociation is encouraged whereas water penetration is
resisted.
[0268] One protocol generally accepted in the field that may be
used to determine the release rate of any active agent or other
material attached to the carrier through a metal ion bridge of the
present invention involves dissociation of any such active agent or
other material in a 0.1 M PBS solution (pH 7.4) at 37.degree. C.,
an assay known in the art. For purposes of the present invention,
the term "PBS protocol" is used herein to refer to such
protocol.
[0269] In certain instances, the release rates of different polymer
systems of the present invention may be compared by subjecting them
to such a protocol. In certain instances, it may be necessary to
process polymeric systems in the same fashion to allow direct and
relatively accurate comparisons of different systems to be made.
Such comparisons may indicate that any one polymeric system
releases the active agent at a rate from about 2 or less to about
1000 or more times faster than another polymeric system.
Alternatively, a comparison may reveal a rate difference of about
3, 5, 7, 10, 25, 50, 100, 250, 500 or 750. Even higher rate
differences are contemplated by the present invention and release
rate protocols.
[0270] In certain embodiments, when formulated in a certain manner,
the release rate for polymer systems of the present invention may
present as mono- or bi-phasic. Release of any material incorporated
into the polymer carrier, which may be provided as a microsphere,
may be characterized in certain instances by an initial increased
release rate, which may release from about 5 to about 50% or more
of the active agent or alternatively about 10, 15, 20, 25, 30 or
40%, followed by a release rate of lesser magnitude.
[0271] The release rate of the active agent may also be
characterized by the amount of such material released per day per
mg of carrier. For example, in certain embodiments, when the
carrier is a polymer, the release rate may vary from about 1 ng or
less of active agent per day per mg of polymeric system to about
5000 or more ng/day/mg. Alternatively, the release rate may be
about 10, 25, 50, 75, 100, 125, 150, 175, 200, 250, 300, 350, 400,
450, 500, 600, 700, 800 or 900 ng/day/mg. In still other
embodiments, the release rate of the active agent may be 10,000
ng/day/mg or even higher. In certain instances, active agents
characterized by such release rate protocols may include
therapeutic agents, antigens, diagnostics, targeting moieties and
other substances.
[0272] In another aspect, the rate of release of an active agent
from any carrier of the present invention may be presented as the
half-life of such material in the such matrix.
[0273] In addition to the embodiment involving protocols for in
vitro determination of release rates, in vivo protocols, whereby in
certain instances release rates of active agents from the carrier
may be determined in vivo, are also contemplated by the present
invention. Other assays useful for determining the release of
active agents from the carriers of the present invention may be
envisoned.
[0274] Dosages
[0275] The dosage of any compound of the present invention will
vary depending on the symptoms, age and body weight of the patient,
the nature and severity of the disorder to be treated or prevented,
the route of administration, and the form of the supplement. Any of
the subject formulations may be administered in a single dose or in
divided doses. Dosages for the compounds of the present invention
may be readily determined by techniques known to those of skill in
the art or as taught herein. Also, the present invention
contemplates mixtures of more than one subject compound, as well as
other therapeutic agents.
[0276] In certain embodiments, the dosage of the subject compounds
will generally be in the range of about 0.01 ng to about 10 g per
kg body weight, specifically in the range of about 1 ng to about
0.1 g per kg, and more specifically in the range of about 100 ng to
about 10 mg per kg.
[0277] An effective dose or amount, and any possible affects on the
timing of administration of the formulation, may need to be
identified for any particular compound of the present invention.
This may be accomplished by routine experiment as described herein,
using one or more groups of animals (preferably at least 5 animals
per group), or in human trials if appropriate. The effectiveness of
any compound and method of treatment or prevention may be assessed
by administering the supplement and assessing the effect of the
administration by measuring one or more indices associated with the
neoplasm of interest, and comparing the post-treatment values of
these indices to the values of the same indices prior to
treatment.
[0278] The precise time of administration and amount of any
particular compound that will yield the most effective treatment in
a given patient will depend upon the activity, pharmacokinetics,
and bioavailability of a particular compound, physiological
condition of the patient (including age, sex, disease type and
stage, general physical condition, responsiveness to a given dosage
and type of medication), route of administration, and the like. The
guidelines presented herein may be used to optimize the treatment,
e.g., determining the optimum time and/or amount of administration,
which will require no more than routine experimentation consisting
of monitoring the subject and adjusting the dosage and/or
timing.
[0279] While the subject is being treated, the health of the
patient may be monitored by measuring one or more of the relevant
indices at predetermined times during a 24-hour period. Treatment,
including supplement, amounts, times of administration and
formulation, may be optimized according to the results of such
monitoring. The patient may be periodically reevaluated to
determine the extent of improvement by measuring the same
parameters, the first such reevaluation typically occurring at the
end of four weeks from the onset of therapy, and subsequent
reevaluations occurring every four to eight weeks during therapy
and then every three months thereafter. Therapy may continue for
several months or even years, with a minimum of one month being a
typical length of therapy for humans. Adjustments to the amount(s)
of agent administered and possibly to the time of administration
may be made based on these reevaluations.
[0280] Treatment may be initiated with smaller dosages which are
less than the optimum dose of the compound. Thereafter, the dosage
may be increased by small increments until the optimum therapeutic
effect is attained.
[0281] The combined use of several compounds of the present
invention, or alternatively other chemotherapeutic agents, may
reduce the required dosage for any individual component because the
onset and duration of effect of the different components may be
complimentary. In such combined therapy, the different active
agents may be delivered together or separately, and simultaneously
or at different times within the day.
[0282] Toxicity and therapeutic efficacy of subject compounds may
be determined by standard pharmaceutical procedures in cell
cultures or experimental animals, e.g., for determining the
LD.sub.50 and the ED.sub.50. Compositions that exhibit large
therapeutic indices are preferred. Although compounds that exhibit
toxic side effects may be used, care should be taken to design a
delivery system that targets the compounds to the desired site in
order to reduce side effects.
[0283] The data obtained from the cell culture assays and animal
studies may be used in formulating a range of dosage for use in
humans. The dosage of any supplement, or alternatively of any
components therein, lies preferably within a range of circulating
concentrations that include the ED.sub.50 with little or no
toxicity. The dosage may vary within this range depending upon the
dosage form employed and the route of administration utilized. For
agents of the present invention, the therapeutically effective dose
may be estimated initially from cell culture assays. A dose may be
formulated in animal models to achieve a circulating plasma
concentration range that includes the IC.sub.50 (i.e., the
concentration of the test compound which achieves a half-maximal
inhibition of symptoms) as determined in cell culture. Such
information may be used to more accurately determine useful doses
in humans. Levels in plasma may be measured, for example, by high
performance liquid chromatography.
[0284] Formulation
[0285] The compounds of the present invention may be administered
by various means, depending on their intended use, as is well known
in the art. For example, if compounds of the present invention are
to be administered orally, they may be formulated as tablets,
capsules, granules, powders or syrups. Alternatively, formulations
of the present invention may be administered parenterally as
injections (intravenous, intramuscular or subcutaneous), drop
infusion preparations or suppositories. For application by the
ophthalmic mucous membrane route, compounds of the present
invention may be formulated as eyedrops or eye ointments. These
formulations may be prepared by conventional means, and, if
desired, the compounds may be mixed with any conventional additive,
such as an excipient, a binder, a disintegrating agent, a
lubricant, a corrigent, a solubilizing agent, a suspension aid, an
emulsifying agent or a coating agent.
[0286] In formulations of the subject invention, wetting agents,
emulsifiers and lubricants, such as sodium lauryl sulfate and
magnesium stearate, as well as coloring agents, release agents,
coating agents, sweetening, flavoring and perfuming agents,
preservatives and antioxidants may be present in the formulated
agents.
[0287] Subject compounds may be suitable for oral, nasal, topical
(including buccal and sublingual), rectal, vaginal, aerosol and/or
parenteral administration. The formulations may conveniently be
presented in unit dosage form and may be prepared by any methods
well known in the art of pharmacy. The amount of agent that may be
combined with a carrier material to produce a single dose vary
depending upon the subject being treated, and the particular mode
of administration.
[0288] Methods of preparing these formulations include the step of
bringing into association agents of the present invention with the
carrier and, optionally, one or more accessory ingredients. In
general, the formulations are prepared by uniformly and intimately
bringing into association agents with liquid carriers, or finely
divided solid carriers, or both, and then, if necessary, shaping
the product.
[0289] Formulations suitable for oral administration may be in the
form of capsules, cachets, pills, tablets, lozenges (using a
flavored basis, usually sucrose and acacia or tragacanth), powders,
granules, or as a solution or a suspension in an aqueous or
non-aqueous liquid, or as an oil-in-water or water-in-oil liquid
emulsion, or as an elixir or syrup, or as pastilles (using an inert
base, such as gelatin and glycerin, or sucrose and acacia), each
containing a predetermined amount of a compound thereof as an
active ingredient. Compounds of the present invention may also be
administered as a bolus, electuary, or paste.
[0290] In solid dosage forms for oral administration (capsules,
tablets, pills, dragees, powders, granules and the like), the
coordination complex thereof is mixed with one or more
pharmaceutically acceptable carriers, such as sodium citrate or
dicalcium phosphate, and/or any of the following: (1) fillers or
extenders, such as starches, lactose, sucrose, glucose, mannitol,
and/or silicic acid; (2) binders, such as, for example,
carboxymethylcellulose, alginates, gelatin, polyvinyl pyrrolidone,
sucrose and/or acacia; (3) humectants, such as glycerol; (4)
disintegrating agents, such as agar-agar, calcium carbonate, potato
or tapioca starch, alginic acid, certain silicates, and sodium
carbonate; (5) solution retarding agents, such as paraffin; (6)
absorption accelerators, such as quaternary ammonium compounds; (7)
wetting agents, such as, for example, acetyl alcohol and glycerol
monostearate; (8) absorbents, such as kaolin and bentonite clay;
(9) lubricants, such a talc, calcium stearate, magnesium stearate,
solid polyethylene glycols, sodium lauryl sulfate, and mixtures
thereof; and (10) coloring agents. In the case of capsules, tablets
and pills, the compositions may also comprise buffering agents.
Solid compositions of a similar type may also be employed as
fillers in soft and hard-filled gelatin capsules using such
excipients as lactose or milk sugars, as well as high molecular
weight polyethylene glycols and the like.
[0291] A tablet may be made by compression or molding, optionally
with one or more accessory ingredients. Compressed tablets may be
prepared using binder (for example, gelatin or hydroxypropylmethyl
cellulose), lubricant, inert diluent, preservative, disintegrant
(for example, sodium starch glycolate or cross-linked sodium
carboxymethyl cellulose), surface-active or dispersing agent.
Molded tablets may be made by molding in a suitable machine a
mixture of the supplement or components thereof moistened with an
inert liquid diluent. Tablets, and other solid dosage forms, such
as dragees, capsules, pills and granules, may optionally be scored
or prepared with coatings and shells, such as enteric coatings and
other coatings well known in the pharmaceutical-formulating
art.
[0292] Liquid dosage forms for oral administration include
pharmaceutically acceptable emulsions, microemulsions, solutions,
suspensions, syrups and elixirs. In addition to the compound, the
liquid dosage forms may contain inert diluents commonly used in the
art, such as, for example, water or other solvents, solubilizing
agents and emulsifiers, such as ethyl alcohol, isopropyl alcohol,
ethyl carbonate, ethyl acetate, benzyl alcohol, benzyl benzoate,
propylene glycol, 1,3-butylene glycol, oils (in particular,
cottonseed, groundnut, corn, germ, olive, castor and sesame oils),
glycerol, tetrahydrofuryl alcohol, polyethylene glycols and fatty
acid esters of sorbitan, and mixtures thereof.
[0293] Suspensions, in addition to compounds, may contain
suspending agents as, for example, ethoxylated isostearyl alcohols,
polyoxyethylene sorbitol and sorbitan esters, microcrystalline
cellulose, aluminum metahydroxide, bentonite, agar-agar and
tragacanth, and mixtures thereof.
[0294] Formulations for rectal or vaginal administration may be
presented as a suppository, which may be prepared by mixing a
coordination complex of the present invention with one or more
suitable non-irritating excipients or carriers comprising, for
example, cocoa butter, polyethylene glycol, a suppository wax or a
salicylate, and which is solid at room temperature, but liquid at
body temperature and, therefore, will melt in the body cavity and
release the active agent. Formulations which are suitable for
vaginal administration also include pessaries, tampons, creams,
gels, pastes, foams or spray formulations containing such carriers
as are known in the art to be appropriate.
[0295] Dosage forms for transdermal administration of a supplement
or component includes powders, sprays, ointments, pastes, creams,
lotions, gels, solutions, patches and inhalants. The active
component may be mixed under sterile conditions with a
pharmaceutically acceptable carrier, and with any preservatives,
buffers, or propellants which may be required. For transdermal
administration of transition metal complexes, the complexes may
include lipophilic and hydrophilic groups to achieve the desired
water solubility and transport properties.
[0296] The ointments, pastes, creams and gels may contain, in
addition to a supplement or components thereof, excipients, such as
animal and vegetable fats, oils, waxes, paraffins, starch,
tragacanth, cellulose derivatives, polyethylene glycols, silicones,
bentonites, silicic acid, talc and zinc oxide, or mixtures
thereof.
[0297] Powders and sprays may contain, in addition to a supplement
or components thereof, excipients such as lactose, talc, silicic
acid, aluminum hydroxide, calcium silicates and polyamide powder,
or mixtures of these substances. Sprays may additionally contain
customary propellants, such as chlorofluorohydrocarbons and
volatile unsubstituted hydrocarbons, such as butane and
propane.
[0298] Compounds of the present invention may alternatively be
administered by aerosol. This is accomplished by preparing an
aqueous aerosol, liposomal preparation or solid particles
containing the compound. A non-aqueous (e.g., fluorocarbon
propellant) suspension could be used. Sonic nebulizers may be used
because they minimize exposing the agent to shear, which may result
in degradation of the compound.
[0299] Ordinarily, an aqueous aerosol is made by formulating an
aqueous solution or suspension of the compound together with
conventional pharmaceutically acceptable carriers and stabilizers.
The carriers and stabilizers vary with the requirements of the
particular compound, but typically include non-ionic surfactants
(Tweens, Pluronics, or polyethylene glycol), innocuous proteins
like serum albumin, sorbitan esters, oleic acid, lecithin, amino
acids such as glycine, buffers, salts, sugars or sugar alcohols.
Aerosols generally are prepared from isotonic solutions.
[0300] Pharmaceutical compositions of this invention suitable for
parenteral administration comprise one or more components of a
supplement in combination with one or more
pharmaceutically-acceptable sterile isotonic aqueous or non-aqueous
solutions, dispersions, suspensions or emulsions, or sterile
powders which may be reconstituted into sterile injectable
solutions or dispersions just prior to use, which may contain
antioxidants, buffers, bacteriostats, solutes which render the
formulation isotonic with the blood of the intended recipient or
suspending or thickening agents.
[0301] Examples of suitable aqueous and non-aqueous carriers which
may be employed in the pharmaceutical compositions of the invention
include water, ethanol, polyols (such as glycerol, propylene
glycol, polyethylene glycol, and the like), and suitable mixtures
thereof, vegetable oils, such as olive oil, and injectable organic
esters, such as ethyl oleate. Proper fluidity may be maintained,
for example, by the use of coating materials, such as lecithin, by
the maintenance of the required particle size in the case of
dispersions, and by the use of surfactants.
[0302] Kits
[0303] This invention also provides kits for conveniently and
effectively implementing the methods of this invention. Such kits
comprise any of the compounds of the present invention or a
combination thereof, and a means for facilitating compliance with
methods of this invention. Such kits provide a convenient and
effective means for assuring that the subject to be treated takes
the appropriate active in the correct dosage in the correct manner.
The compliance means of such kits includes any means which
facilitates administering the actives according to a method of this
invention. Such compliance means include instructions, packaging,
and dispensing means, and combinations thereof. Kit components may
be packaged for either manual or partially or wholly automated
practice of the foregoing methods. In other embodiments involving
kits, this invention contemplates a kit including compositions of
the present invention, and optionally instructions for their
use.
EXEMPLIFICATION
[0304] The invention is further illustrated by the following
Examples. The Examples are provided for illustrative purposes only,
and are not to be construed as limiting the scope or content of the
invention in any way.
[0305] General-Vertebrate Animals
[0306] The use of animals is proposed to determine the PK and
accumulation of the GLP-1 formulation in the pancreas and to
demonstrate in vivo efficacy in islet regeneration. Rats are used
for these studies as they are a standard and accepted rodent
species for drug developmental studies. It will be more feasible to
view the pancreas of the rat by imaging studies versus the mouse
and hence rats have been chosen for both Examples 14 and 15. Animal
studies are required in Example 15 in order to verify whether the
hypothesis elaborated from in vitro studies is confirmed by in vivo
experiments.
[0307] Newborn Wistar rats will be used for the efficacy studies,
10/group x 5 groups (50 animals) with potentially an additional 10
animals if STZ treatment does not induce elevated glucose in all by
the second day. Total for Example 15=.about.60. For Example 14,
initially pilot studies with 3 rats per group and then repeat with
12 or less rats per group for validation and statistics will be
done. The groups are:
[0308] 1. MacroGd (for MRI), then for Nuclear
Imaging/PK/distribution studies:
[0309] 2. GLP-1 control high dose
[0310] 3. GLP-1 control low dose
[0311] 4. PGC-GLP-1 high dose
[0312] 5. PGC-GLP-1 low dose
[0313] 6. MacroTc (PGC alone) control high dose
[0314] 7. MacroTc (PGC alone) control low dose
[0315] So total initially for pilot, 7*3=21 rats, then for repeat
12*7=84 (or less)
[0316] Overall total for Example 14 is 21+84=105 rats or so.
[0317] Total rats for proposal =155.
[0318] For Example 15, animals will be housed at a constant
22.degree. C., with a fixed 12:12-h artificial light-dark cycle.
They will be fed with regular chow and studied at various months of
age, as described in the individual specific Examples. Their sera
will be analyzed to evaluate the effect of GLP-1 on glucose
tolerance. Tissues will be harvested to investigate the effect of
GLP-1 on beta cell augmentation. For Example 14 the animals will be
housed in an AAALAC International accredited facility. Animals will
be singly housed in polycarbonate cages with Anderson bed-o'cob
bedding (Heinold, Kankakee, Ill.) in a temperature (64-79.degree.
F.) and humidity (50.+-.20%) controlled room with a 14 hour
light/10 hour dark cycle. The cage size, 840 cm.sup.2 area and 20
cm height, is adequate to house rats at the upper weight range as
described in the Guide for the Care and Use of Laboratory Animals,
National Research Council, 1996. All animals will be routinely
transferred to clean cages with fresh bedding once weekly.
Certified Rodent Chow No. 5002 (PMI Feeds, Inc., St. Louis, Mo.),
powder form, will be provided ad libitum from arrival until
termination. For blood collection, the animals will be anesthetized
by carbon dioxide inhalation (70% CO.sub.2:30% O.sub.2), and blood
will be collected from the orbital sinus. No other pain or distress
are anticipated in the PK and tissue distribution study. Therefore
no analgesics or anaesthesia required.
[0319] Rats will be anesthetized with pentobarbital anesthesia (4
mg/100 g body wt i.p.) for the glucose tolerance test in Example
15. Blood samples will be drawn from the tail vein.
[0320] Animals will be humanely euthanized by CO.sub.2 asphyxiation
from CO.sub.2 tank. This method is accepted and classified by the
American Veterinary Medical Association.
Example 1
Synthesis of MPEG-PL
[0321] Poly-L-lysine, hydrobromide (Sigma, mol mass. 48000, d.p.
200), Ig was dissolved in 175 ml of 0.1 M Na.sub.2CO.sub.3, pH 8.7.
An aliquot of this solution was removed for NH.sub.2-groups
determination by TNBS titration (final concentration of
NH.sub.2-groups, 25 mM). Methoxy polyethylene glycol succinate
(MPEGS9.6 g, 1.9 mmol) was dissolved in 25 ml of water, degassed,
and N-hydroxy(sulfo)succinimide (500 mg, 2.3 mmol) was added,
followed by 1 g, 5 mmol of EDC in 2 ml of water. This solution was
incubated for 10 min at room temperature and added drop-wise to the
solution of poly-1-lysine, final pH 7.7. The mixture was incubated
for six hours. The product was purified using ultrafiltration on a
cartridge with a cut-off of 100 kD (UFP-100 A/G Technology) to
remove unconjugated MPEGS and other reactants.
Example 2
Synthesis of MPEG-PL-NTA
[0322] The product obtained as described in Example 1
(MPEGsuccinyl-poly-L-Lys (m.w. 340000) was succinylated using
10-fold molar excess of succinic anhydride over the concentration
of TNBS-reactive free aminogroups in the co-polymer in 0.5 M sodium
carbonate pH 8.0, 4 hours room temperature. Succinylated co-polymer
(MPEGs-PL-Suc) was purified using dialysis against water.
[0323] 100 mg Lyophilized MPEGs-PL-Suc was dissolved in 2 ml water
at 28 .mu.mol succinate/ml, treated with 30 mg ethyl-diaminopropyl
carbodiimide (EDC) in the presence of 20 mg Sulfo-NHS for 10 min at
room temperature. A solution of activated MPEGs-PL-Suc was added to
a solution of N_,N_-Bis(carboxymethyl)-L-lysine Hydrate (BCMLys) in
1 ml sodium bicarbonate, pH 8.7. Final pH 7.6, incubated 24 hours
at 4.degree. C. The resultant product MPEGs-PL-Suc-NTA was purified
using ultrafiltration on YM50 membrane (Amicon) by diluting to 100
ml and concentrating to 5 ml volume four times. A solution of
MPEGs-PL-Suc was used as a control in further experiments.
Example 3
Synthesis of MPEGs-PL-NiNTA
[0324] A solution of product MPEGs-PL-Suc-NTA was dialysed against
IL of 10 mM Ni acetate/20 mM citric acid, pH 6 for 24 hours at
4.degree. C. and purified by dialysing against 2 L water (2
changes). Binding of Ni was measured by spectrophotometry at 625 nm
using Ni-citrate as a standard.
Example 4
Synthesis of MPEGs-PL-ZnNTA
[0325] A solution of MPEGs-PL-Suc-NTA was dialysed against 1 L of
10 mM Zn acetate/20 mM citric acid, pH 6 for 24 hours at 4.degree.
C. and purified by dialysing against 2 L water (2 changes). Binding
of Zn was measured by using elemental analysis.
Example 5
Binding of rhGH to MPEGs-PL-Zn/NiNTA
[0326] 500 .mu.g rhGH were mixed with 40 .mu.l radioactively
labeled trace amounts of .sup.125I-rhGH (concentration -5 mg/ml).
Centricon YM100 was used to remove rhGH aggregates (flow-through
collected). Final [rhGH]=3.22 mg/ml. Various amounts of
MPEGs-PL-Zn/NiNTA were incubated with 20 .mu.g rhGH in a volume of
100 .mu.l. Unbound rhGH was removed on Centricon YM100.
Membrane-retained GH-MPEGs-PL-Ni/ZnNTA complex was washed with 100
.mu.l PBS by centrifugation. Radioactivity in eluate and retentate
were determined separately using a gamma counter (see Table 1 and
FIG. 1):
1TABLE 1 Binding of labeled rhGH (20 .mu.g) to various amounts of
experimental and control copolymer complexes with Ni and Zn.
Sample, chelate The fraction of rGH .mu.g bound attached to
MPEG-PL- retained on YM100 minus Suc and carrier amount membrane
.mu.g bound background Membrane control 0.05 1.03 control sucNi, 1
mg 0.05 1.04 0.01 sucNi, 2 mg 0.06 1.29 0.25 ZnNTA, 1 mg 0.11 2.26
1.22 ZnNTA, 2 mg 0.25 5.05 4.02 NiNTA, 1 mg 0.10 2.05 1.01 NiNTA, 2
mg 0.23 4.63 3.60
[0327] Non-specific binding to YM100 membrane surface and binding
to succinylated control (compound I of Example 1) polymers were
similar. Ni and Zn complexes of MPEGs-PL-NTA showed 12 to 20-fold
higher binding (2 mg polymer in the incubation mixture):
Example 6
Size-Exclusion Analysis of rhGH Complex with MPEGs-PL-ZnNTA
[0328] MPEGs-PL-Zn NTA complex (100 .mu.l, 2 mg) was mixed with 100
.mu.g rhGH and analyzed on size-exclusion HPLC column (SEC-5,
Rainin). Fractions were collected and counted using a gamma-counter
(see FIG. 2). The formation of a complex between the co-polymer and
rhGH is evident from a change in elution pattern (fractions 11-14
contain higher molecular weight complex).
Example 7
Construction of His-Tagged Green Fluorescent Protein (GFP)
variant
[0329] CDNA encoding for humanized GFP isoform was excised from
BlueScriptGFP vector using compatible restriction sites. GFP
fragment was then subcloned into SalI-KpnI-restricted pHAT10 vector
(Clontech) to afford in-frame expression with His-tag (HAT.TM.)
from chicken lactate dehydrogenase (KNHLIHRVHKDDHAHAHRK) containing
six histidines. Subcloning was performed by ligating the purified
GFP fragment with linearized pHAT10 vector using T4 DNA ligase.
Ligation reactions were used for E. coli transformation. Several
colonies exhibiting bright green fluorescence under the UV light
were selected. Bacterial colonies were transferred into LB broth
and grown overnight in a volume of 5 ml. This starter culture was
then used for infecting 1 l of LB medium grown to the density of
0.8 at 600 nm and bacterial culture was centrifuged at 6000 g to
isolate bacterial mass. Bacteria were then lysed using B-PER buffer
(Pierce) in the presence of 1.times. protease inhibitors (with no
EDTA, Roche Biochemicals). Lysate was cleared by centrifugation at
16000.times.g (SS-34 Rotor, Sorvall) and the supernatant was
combined with washed, pre-equilibrated TALON.TM. resin (Clontech).
The mixture was agitated at 4.degree. C. overnight and washed
several times with loading buffer (50 mM phosphate, 300 mM NaCl pH
7). Histidine tagged-GFP product was eluted using 100 mM imidazole
in 45 mM Na-phosphate, 270 mM NaCl, pH 7). Fluorescent eluate was
dialyzed against PBS, pH 7 and analyzed by electrophoresis.
Example 8
Binding of Histidine Tagged-GFP to MPEG-PL-NTA and Control
Polymers
[0330] Complex formation between NTA-conjugated MPEG-PL copolymer
and histidine-tagged GFP was achieved by combining histidine
tagged-GFP and Ni.sup.2+ or Zn.sup.2+ salts of MPEG-PL-NTA or
MEPG-PL-succinate (control). After a 1 hour incubation the
complexes were placed in YM-50 membrane. Various amounts of
MPEGs-PLZn/NiNTA were incubated with 20 .mu.g rhGH in a volume of
100 .mu.l. Free non-bound histidine tagged-GFP was removed on
Centricon YM100. Membrane-retained MPEGs-PL-Ni/ZnNTA complex was
washed three times using 100 .mu.l PBS aliquots by centrifugation.
The fluorescence intensities in eluate and retentate were
determined using a fluorometer (excitation 475, emission 510
.mu.m). In some experiments, 100% mouse plasma was added to the
incubation mixtures and samples were processed as described
before.
2TABLE 2 Binding of histidine tagged-GFP (20 .mu.g) to 1 mg of
MPEG-PL-NTA and a control polymer. Sample % GFP bound GFP control
0.002 MPEG-PL-succinate control 0.003 MPEG-PL-ZnNTA 99.68
MPEG-PL-NiNTA 99.52
[0331] The obtained result shows that the binding of histidine
tagged-GFP to metal chelates linked to MPEG-PL co-polymer was
highly specific (Table 2) and that the association of HAT-GFP with
similar co-polymer bearing no NTA residues was close to the
background.
[0332] In the presence of plasma binding of histidine tagged-GFP
was also highly specific. Binding to NTA-linked co-polymers in the
presence of Ni and Zn cations was approximately the same in the
presence or in the absence of the plasma. The only detectable
non-specific binding levels were detectable in the case of
polycationic MPEGs-PL co-polymer (see FIG. 3) and this binding has
not been inhibitable by plasma.
Example 9
Distribution of Histidine Tagged-GFP and Histidine Tagged-GFP
Complexes with MPEGs-PL-NTA in vivo after Intravenous Injection
[0333] Pre-formed complexes of histidine tagged-GFP with
MPEGs-PL-NiNTA and MPEGs-PL-ZnNTA as well as control histidine
tagged-GFP were injected IV in the tail vein of anesthetized balb/c
mice (20 .mu.g histidine tagged-GFP mixed with 1 mg of co-polymer
or 20 .mu.g histidine tagged-GFP in a total volume of 0.1 ml, 2 per
group) and blood samples were drawn through a catheter inserted in
a contralateral tail vein. Blood samples (40 .mu.l) were
heparinized, centrifuged (3,000 g) and plasma samples were analyzed
for histidine tagged-GFP using fluorometry (excitation-475/emission
508 nm). Observed fluorescence intensity values were normalized for
injection dose using histidine tagged-GFP standard diluted in mouse
plasma. The blood volume was calculated as 7% of animal weight and
hematocrit--at 50% (see FIG. 4).
Example 10
Formulation and Determination of PGC-GLP-1 Complex Formation
Efficiency
[0334] Based on our preliminary results and known structure and
properties of GLP-1 it is expected that GLP-1 will bind to the
backbone of PGC via His and therefore be positioned in a way that
the chains of polyethylene glycol would protect the peptide from
DPP-IV degradation (see FIGS. 5 and 6).
[0335] The feasibility of radioiodination of GLP-1 to evaluate the
efficiency of binding to the carrier will be tested first.
Radioiodinated GLP-1 will be obtained by using sodium
[.sup.125I]iodide in the presence of Iodo-Gen (Pierce) at
approximately 0.01-0.05 mCi/.mu.g peptide followed by purification
on C18-reversed phase HPLC column using a gradient of acetonitrile
in 0.1% TFA. Due to the possibility of additional N-terminal
histidine radioiodination, reactions in the presence and in the
absence of trace amounts of Zn to protect the His residue will be
performed. The ability of the peptide to form a complex with ZnNTA
after the radioiodination will be tested by measuring the retention
of radioactivity on Zn-saturated NTA-column. Trace amounts of
radioiodinated GLP-1 will be mixed with cold GLP-1 followed by the
incubation with PGC-Zn (MPEGs-PL-ZnNTA) to determine complex
formation efficiency. Unbound GLP-1 will be removed using Microcon
YM100-ultrafiltration followed by the separate radioactivity
determination in the eluate and the retentate.
[0336] To demonstrate that binding of GLP-1 to the carrier is
mediated via histidine binding to the PRB linker, competition
studies with imidazole, evaluating the dissociation of
radioiodinated GLP-1 from the complex in the presence of either a
buffer or buffer containing imidazole will be carried out.
Example 11
Measurement of Dissociation Constant (K.sub.d) of PGC/PRB:GLP-1
Complex
[0337] The refolded N-terminal domain of the human GLP-1R was
reported to have a K.sub.d of 47 nM, as determined by surface
plasmon resonance, and 144 nM from isothermal titration calorimetry
(ITC).
[0338] ITC will be used to measure the dissociation constant of
PGC/PRB:GLP-1. ITC is a thermodynamic technique for monitoring any
chemical reaction initiated by the addition of a binding component,
and has become the method of choice for characterizing biomolecular
interactions. When substances bind, heat is either generated or
absorbed. Measurement of this heat allows accurate determination of
binding constant (K.sub.B) or dissociation constant (K.sub.d),
reaction stoichiometry (n), enthalpy (H) and entropy (S), providing
a complete thermodynamic profile of the molecular interaction in a
single experiment.
[0339] ITC is routinely used to study all types of binding
interactions, including: antigen-antibody, protein-ligand,
protein-protein, protein-DNA, protein-carbohydrate, DNA-drug, and
receptor-target.
[0340] In ITC, a syringe containing a "ligand" solution is titrated
into a cell containing a solution of the "macromolecule" at
constant temperature. When the ligand is injected into the cell,
the two materials interact, and heat is released or absorbed in
direct proportion to the amount of binding. As the macromolecule in
the cell becomes saturated with ligand, the heat signal diminishes
until only background heat of dilution is observed. The area
underneath each injection peak (see top panel of FIG. 7) is equal
to the total heat released for that injection. When this integrated
heat is plotted against the molar ratio of ligand added to
macromolecule in the cell, a complete binding isotherm for the
interaction is obtained (see bottom panel of FIG. 7). Experiments
performed with VP-ITC are entirely computer-controlled, including
injection parameters and mixing.
Example 12
Demonstration of the Effect of PGC/PRB:GLP-1 In Vitro in Model
Systems on Insulin Secretion, Expression of Glucose Sensor Genes
and Glucose Responsiveness of Beta Cells
[0341] The following experiments will be run to demonstrate that
PGC/PRB:GLP-1 behaves in an similar manner to native GLP-1 in vitro
with respect to increasing the insulin-responsiveness of beta
cells. The clonal rat pancreatic beta cell line INS-1 will be used
as a model since the effects of GLP-1 on the expression of glucose
sensor genes and glucose responsiveness on this cell line is well
documented. Cells will be incubated either alone, in the presence
of naked GLP-1 at 2, 10 or 50 nM, or in the presence of equivalent
molar concentrations of GLP-1 formulated in PRB/PBC.
[0342] Glucose Responsiveness--Insulin Synthesis and Secretion
[0343] To evaluate the effect of GLP-1 on the response of beta
cells to glucose, a glucose-induced insulin secretion test, will be
performed on INS-1 cells. After a 1, 3 and 5 day incubation with
GLP-1, each group of cells will be tested. At different time points
(0, 10, 20, 60 minutes) after glucose stimulation, an aliquot of
the culture medium, as well as the cell pellet, will be collected
and used to detect the intracellular content of insulin by R.I.A.
assay (LINCO Research Inc. St. Charles, Mo.). The insulin values
will be normalized for the total protein content obtained from the
cell pellet extracted with M-PER mammalian protein extraction
buffer (PIERCE, Rockford, Ill.) in the presence of the Halt.TM.
protease inhibitor cocktail (PIERCE).
[0344] Expression of Glucose Sensor Genes
[0345] The expression of insulin and two main regulators of the
glucose sensing machine of normal beta cells, the glucose
transporter GLUT-2, and the glucose phosphorylating enzyme
glucokinase, will be evaluated by RT PCR as described previously.
Briefly, total RNA will be isolated using the TRiazol-method
(Gibco-BRL), and treated with DNase (Amplification Grade,
Gibco/BRL) to remove any traces of contaminating genomic DNA. RNA
(2.5 .mu.g) will then be subjected to reverse transcription (RT
reagents; Promega; Madison, Wis.) and amplified by PCR with sense
and antisense primers to rat beta-specific genes. RT-PCR for
.beta.-actin will be used as a control for cDNA loading.
Example 13
Effect of GLP-1 on Neogenesis of Beta Islet Cells In Vitro
[0346] The rat pancreatic ductal cell line ARIP (ATCC) will be used
as a biological model to evaluate the effects of GLP-1 on the
trans-differentiation of ductal cells into insulin producing
cells.
[0347] Analysis of Expression of Beta-Cell Specific Genes
[0348] ARIP cells will be cultured in the presence of GLP-1 and
analyzed for the acquisition of .beta.-cell-specific gene
expression profile (GLUT-2, glucokinase and insulin).
Trans-differentiation will be monitored by RT-PCR after 24, 48 and
72 h of GLP-1 treatment. Based on previous studies, insulin mRNA
should be detectable after 48 h, GLUT-2 after 24 h and glucokinase
mRNA at 72 h. No RT-PCR products for insulin, GLUT-2 or glucokinase
should be detectable in non-GLP-1 treated cells. RT-PCR for P-actin
will be used as a control for cDNA loading.
[0349] Detection of Insulin Production by Immunofluorescence
Microscopy
[0350] The acquisition of insulin-secreting phenotype (marker of
beta cells) and loss of a protein marker of ARIP ductal epithelial
cells (cytotkeratin-20) will be evaluated by immunofluorescence
microscopy. Cells will be stained for insulin as described
previously. Briefly, ARIP cells will be grown in monocoated chamber
slides (Nange Nunc International; Naperville, Ill.) in the
presence, or absence, of GLP-1 (10 nM) or PGC/PRB:GLP-1 for 0, 12,
24, 48, or 72 hours. After washing in PBS, the cells will be fixed
with washed in PBS and permeabilized with 0.1% (vol/vol) of Triton
X-100. The cells will be sequentially incubated with 10% normal
blocking serum in PBS (Santacruz), overnight incubation with guinea
pig anti-porcine insulin antibody (Dako, Carpinteria, Calif.), or
with mouse anti-human cytokeratin 20 (Novocastra, Newcastle upon
Tyne, UK) at a dilution of 1:50, at 4.degree. C., in a humid
chamber. After washing, the cells will be incubated with
FITC-conjugated rabbit anti-guinea pig IgG (Dako) (1:40) for
insulin detection and FITC-conjugated goat anti-mouse IgG
(Chemicon, Temecula, Calif.) (1:50) for CK20 detection. Mounted
slides will be examined using a fluorescent microscope (Olympus
AX-70) and images captured by Apogee Digital Camera and processed
by the Image-Pro Computer software.
Example 14
Pharmacokinetics, Biodistribution (Accumulation in Pancreas) and
Stability of Complex In Vivo in a Rat Model of
Streptozotocin-Induced Diabetes
[0351] Evaluation of PGC-Based Imaging Agent Accumulation in
Pancreas by MR
[0352] Rats (Wistar, n=6) will be divided into two groups (n=3).
The first group will be treated with streptozotocin (160 mg/kg, 4-5
days before the experiment, via the tail vein and butylscopolamine
(0.5 mg/kg IP), to stop peristaltic movement of the intestine). The
other (n=3) will be injected with saline and used as a control.
Animals will be anesthetized with a mixture of ketamine/xylazine
intraperitoneally (80 mg/kg per 12 mg/kg) and magnetic resonance
imaging (MRI) will be performed using and 1.5T MRI scanner (Signa,
GE) using a 3-inch surface coil. A GdDTPA standard (500 .mu.M) in a
tube will be placed next to the animal. After the initial
anatomical T1 (SE 700/12 TR/TE, 90 degree flip angle)--and T2 (SE
3000/60 TR/TE, ms)--weighted images will be acquired, all animals
will be injected with PGC labeled with GdDTPA (MacroGd) at 0.05
mmol/kg intravenously. Serial coronal and axial images will be
acquired with 10 min intervals (two images at 10 and 20 min) to
allow distribution and early accumulation of PGC in pancreas. The
imaging will be repeated at 12 hours and the results will be
analyzed using normalized signal intensity values.
[0353] Radioactively-Labeled PGC:GLP-1 Pharmacokinetic and Pancreas
Accumulation Study
[0354] Wistar rats normal (n=12) and streptozotocin-treated (n=12)
will be used for bio-distribution studies. Animals will be
anesthetized with ketamine/xylazine as described above and injected
at t=0 via the tail vein with .sup.125I-labeled GLP-1/PGC complex
(10 .mu.g GLP-1/kg?). Lugol's solution in drinking water will be
supplied to prevent accumulation of dehalogenated iodine in the
thyroid. Animals will be sacrificed at 6 h (n=6 each group), 12 h
(n--6 each group) and 24 h (n=6 for each group) with a lethal
overdose of anaesthetic (pentobarbital 200 mg/kg, i. p.). Samples
of blood, brain, fat, heart, intestine, kidney, liver, lung, lymph
nodes, muscle, pancreas, spleen, stomach and thyroid will excised,
weighed and radioactivity measured using a well-type gamma counter.
The organ samples will be counted together, with decay correction,
and the dose in each sample will be calculated. Bio-distribution
results will be expressed as percentage of the injected dose (ID)
per gram of tissue (% ID/g) corrected for radioactive decay.
Example 15
Demonstration of Increase in Beta Cell Mass in a Rat Model of
Streptozotocin-Induced Diabetes
[0355] The currently accepted animal models for human Type 1
diabetes are the NOD mouse and the BB rat. These models of
spontaneous autoimmune diabetes mimic the human condition in that
they share many important immunological characteristics with the
human disease. However, there are no published reports of GLP-1R
agonists increasing beta cell mass in either of these models,
despite numerous publications in other animal models of diabetes.
This is likely due to the need for immunosuppression concomitant
with GLP-1 treatment in these models, to prevent destruction of
regenerated islets by the autoimmune system.
[0356] The efficacy of PGC/PRB:GLP-1 will be demonstrated in an
experimental model used to study the regeneration of B-cells is the
neonatal rat, with diabetes induced by streptozotocin (STZ) (n0-STZ
model). Injection of STZ to newborn rats results in damage to
.beta.-cells. After 3-5 days, .beta.-cell regeneration occurs
through differentiation from precursor cells and increased beta
cell proliferation and there is a rapid recovery from neonatal
diabetes. However, despite some regeneration, adult rats exhibit a
decreased .beta.-cell mass and chronic diabetes characterized by
glucose intolerance and low insulin response to glucose. As has
been demonstrated previously for Exenatide, whether PGC:PRB:GLP-1
can protect against diabetes in this model by augmenting beta cell
mass will be evaluated. Animal studies will examine the effect of
PGC/PRB:GLP-1 in an autoimmune model of Type 1 diabetes in
combination with immunosuppression.
[0357] To induce diabetes, newborns will be injected I.P with a
single dose of STZ (100 .mu.g/g). Glucose will be monitored on day
two and only animals with elevated blood glucose will be included
in the study. Five groups of animals will be studied: Non-STZ
treated, STZ treated, STZ treated with GLP-1, STZ treated with
carrier alone (PGC/PRB) and STZ treated with PGC/PRB:GLP-1. GLP-1
treatment or carrier will be administered by injection for 5 days
from day 2-6. The dose of GLP-1 will depend on PK data from
above.
[0358] Animals will be sacrificed on day 7 or at 2 months and blood
samples and pancreas taken. Insulin content of pancreas will be
determined by immunostaining and beta cell mass determined by
calculating the fraction of area of pancreas occupied by
insulin-positive beta cells multipled by the weight of the
pancreas.
[0359] Replication of beta cells will be determined by
5'-Bromo-2'-deoxyuridine (BrdU) treatment of animals one hour
before sacrifice (50 mg/kg bodywt i.p). Pancreatic sections will be
double stained for BrdU and insulin. The proportion of BrdU.sup.+
.beta.-cell nuclei to total .beta.-cell nuclei will represent the
percentage .beta.-cell replicative rate in a 1-h interval. In
addition to BrdU the sections should be stained for markers of
islets (insulin, glucagon, Som, PP), markers of neogenesis (PDX-1,
neug 3) and markers of ductal cells (CK19).
[0360] Animals will be tested for glucose tolerance by subjecting
fasted animals to IV (or IP for newborns) glucose (0.5 g glucose/kg
body wt). Blood samples will be immediately drawn from the tail
vein, after anesthesia, and plasma stored at -20.degree. C. Insulin
and glucose responses during the glucose tolerance tests will be
calculated as the incremental plasma insulin (pmol/l) values
integrated over the period (30 min) after the injection of glucose
I.P. and the corresponding incremental integrated plasma glucose
(mmol/l) values. The insulinogenic index represents the ratio of
these two parameters. The rate of glucose disappearance (K) was
calculated from the slope of the regression line obtained with the
log-transformed plasma glucose values between 10 and 30 min after
glucose administration.
REFERENCES
[0361] All publications and patents mentioned herein, including
those items listed below, are hereby incorporated by reference in
their entirety as if each individual publication or patent was
specifically and individually incorporated by reference. In case of
conflict, the present application, including any definitions
herein, will control.
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EQUIVALENTS
[0363] While specific embodiments of the subject invention have
been discussed, the above specification is illustrative and not
restrictive. Many variations of the invention will become apparent
to those skilled in the art upon review of this specification. The
full scope of the invention should be determined by reference to
the claims, along with their full scope of equivalents, and the
specification, along with such variations.
[0364] Unless otherwise indicated, all numbers expressing
quantities of ingredients, reaction conditions, and so forth used
in the specification and claims are to be understood as being
modified in all instances by the term "about." Accordingly, unless
indicated to the contrary, the numerical parameters set forth in
this specification and attached claims are approximations that may
vary depending upon the desired properties sought to be obtained by
the present invention.
* * * * *
References