U.S. patent application number 12/610857 was filed with the patent office on 2010-11-04 for mechanism-based targeted pancreatic beta cell imaging and therapy.
Invention is credited to Ali Azhdarinia, Jerry Bryant, Saady Kohanim, Chang-Sok Oh, David J. Yang, Dong-Fang Yu.
Application Number | 20100278731 12/610857 |
Document ID | / |
Family ID | 34375381 |
Filed Date | 2010-11-04 |
United States Patent
Application |
20100278731 |
Kind Code |
A1 |
Yang; David J. ; et
al. |
November 4, 2010 |
Mechanism-Based Targeted Pancreatic Beta Cell Imaging and
Therapy
Abstract
Compositions for imaging pancreatic beta cells comprise
chelator-antidiabetic agent conjugates and optionally chelated
metals.
Inventors: |
Yang; David J.; (Sugar Land,
TX) ; Oh; Chang-Sok; (Houston, TX) ; Kohanim;
Saady; (Sugar Land, TX) ; Yu; Dong-Fang;
(Pearland, TX) ; Azhdarinia; Ali; (Houston,
TX) ; Bryant; Jerry; (Houston, TX) |
Correspondence
Address: |
VINSON & ELKINS, L.L.P.
FIRST CITY TOWER, 1001 FANNIN STREET, SUITE 2500
HOUSTON
TX
77002-6760
US
|
Family ID: |
34375381 |
Appl. No.: |
12/610857 |
Filed: |
November 2, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10942615 |
Sep 16, 2004 |
7611693 |
|
|
12610857 |
|
|
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60503683 |
Sep 17, 2003 |
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Current U.S.
Class: |
424/1.65 ;
424/9.3 |
Current CPC
Class: |
A61K 51/0497 20130101;
A61P 1/18 20180101; A61P 5/48 20180101; A61P 43/00 20180101; A61P
3/10 20180101 |
Class at
Publication: |
424/1.65 ;
424/9.3 |
International
Class: |
A61K 51/04 20060101
A61K051/04; A61K 49/10 20060101 A61K049/10 |
Claims
1. A composition for imaging a pancreas comprising an antidiabetic
agent, a chelator and a chelated metal ion.
2. The composition of claim 1, wherein the metal ion is effective
for contrast enhanced imaging when the composition is administered
to a mammal during use.
3. The composition of claim 1, wherein the chelator is
diethylenetriamine pentaacetic acid (DTPA), ethylene diamine
tetra-acetic acid (EDTA), cyclohexyl 1,2-diamine tetra-acetic acid
(CDTA), ethyleneglycol-0, 0'bis
(2-aminoethyl)-N,N,N',N'-tetra-acetic acid (EGTA),
N,N-bis(hydroxybenzyl)-ethylenediamine-N,N'-diacetic acid (HEED),
triethylene tetramine hexa-acetic acid (TTHA),
1,4,7,10-tetraazacyclododecane-N,N',N'',N'''-tetraacetic acid
(DOTA), hydroxyethyldiamine triacetic acid (HEDTA),
1,4,8,11-tetra-azacyclo-tetradecane-N,N',N'',N'''-tetra-acetic acid
(TETA), dimercaptosuccinic acid (DMSA), triglycinbenzoyl thiol
(MAG-3) and methylenebisphophonate (MDP).
4. The composition of claim 1, wherein the chelator is DTPA.
5. The composition of claim 1, wherein the antidiabetic agent binds
preferentially to beta cells of the pancreas.
6. The composition of claim 1, wherein the antidiabetic agent binds
preferentially to the pancreatic beta cell sulphonylurea receptor
SUR-1, angiotensin II receptor, or bradykinin receptor.
7. The composition of claim 1, wherein the antidiabetic agent is
nateglinide, glipizide, glyburide, or glimepiride.
8. The composition of claim 1, wherein the metal ion is a
radionuclide.
9. The composition of claim 1, wherein the metal ion is a beta
emitter.
10. The composition of claim 1, wherein the metal ion is a gamma
emitter.
11. The composition of claim 1, wherein the metal ion is Tc-99m,
Cu-60-64, Gd, Ho-166, or Re-187, 188.
12. The composition of claim 1, further defined as
.sup.99mTc-DTPA-nateglinide, .sup.99mTc-DTPA glipizide,
.sup.99mTc-DTPA-glyburide or .sup.99mTc-DTPA-glimepiride.
13. A method of treating a pancreatic disease comprising
administering to a subject in need thereof a composition comprising
an antidiabetic agent, a chelator and a chelated metal ion, wherein
the metal ion is a beta emitter.
14. The method of claim 13, wherein the chelated metal ion is
.sup.188Re .sup.90Y or .sup.166Ho.
15. The method of claim 13, wherein the pancreatic disease is
diabetes, pancreatitis, hyperinsulinemia or insulinoma.
16. A method of imaging a mammalian pancreas comprising
administering to the mammal a composition comprising an
antidiabetic agent, a chelator and a chelated metal ion, and
detecting an image of the pancreas.
17. The method of claim 16, wherein the image is a gamma image a
PET image, or an MRI image.
18. The method of claim 16 wherein the composition comprises
.sup.99mTc-DTPA-nateglinide.
19-38. (canceled)
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is filed as a divisional of U.S. Ser. No.
10/942,615 filed Sep. 16, 2004, which claims priority to U.S. Ser.
No. 60/503,683 filed Sep. 17, 2003.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] N/A
BACKGROUND OF THE INVENTION
[0003] In the United States, approximately 16 million people (6
percent of the population) suffer from diabetes mellitus. Every
year, about 800,000 new cases are diagnosed and another 6 million
people remain unaware that they have the disease. Diabetes mellitus
kills about 193,000 U.S. residents each year, and it is the seventh
leading cause of all deaths and the sixth leading cause of all
deaths caused by disease. There is a steady rise in children
developing type 2 diabetes. In Canada, more than 2.2 million
residents (7 percent of the population) have diabetes mellitus, and
the disease contributes to more than 25,000 deaths a year.
[0004] Adenocarcinoma of the pancreas is the fifth most common
cause of cancer death in the United States. In the U.S., almost
45,000 people become affected with pancreatic cancer every year.
Cancer most often occurs in the pancreatic head and often leads to
biliary obstruction with a clinical presentation of painless
jaundice. The 5 year survival rate for resectable patients is about
10% with a median survival of 12 to 18 months. Unresectable
patients live about 6 months. Both diseases are associated with
pancreatic function. Also, risk for pancreatic cancer is increased
in adult-onset diabetics.
[0005] In the pancreas, the Islets of Langerhans are composed of
four cell types, each of which synthesizes and secrets a distinct
polypeptide hormone: insulin in the beta cell (60%), glucagon in
the alpha cell (25%), somatostatin in the D cell (10%), and
pancreatic polypeptide in the F cell (5%). Beta cells are the major
type of cells in the pancreas. Certain nutrients and growth factors
can stimulate pancreatic beta-cell growth. However, the appropriate
mitogenic signaling pathways in beta-cells have been relatively
undefined. This failure to define these important signaling
pathways is due at least in part to a lack of effective imaging
technologies.
[0006] The current status of imaging in pancreatic diseases has
been recently reviewed by Kaira et al. Journal of Computer Assisted
Tomography 26:661-675. The reviewed technologies include CT, MRI,
EUS and PET scans.
SUMMARY
[0007] The present disclosure addresses at least in part some
deficiencies in the prior art by providing novel DTPA-antidiabetic
conjugates useful for imaging beta-cell function. Through binding
of radiolabeled conjugates, such as .sup.99mTc-DTPA-antidiabetic
conjugates, for example, to pancreatic beta receptors, detectable
by gamma scintigraphy, pancreatic function is monitored. Four
DTPA-antidiabetic conjugates have been synthesized and evaluated.
Animal studies have shown that DTPA-nateglinide and DTPA-glipizide
are able to selectively image pancreatic beta cells with no acute
toxicity at the given doses. These agents are labeled with isotopes
in order to assess beta cell function in diabetic or insulinoma
patients both pre- and post-treatment. These compositions and
methods are useful to provide early diagnosis as well as monitoring
of response of pancreatic disease during treatment.
[0008] The present invention may be described in certain
embodiments therefore as a composition comprising an antidiabetic
agent, a chelator and a chelated metal ion. It is further
understood that the composition may be a prodrug comprising an
antidiabetic agent conjugated to a chelator to which a metal may be
added. In such an embodiment, various metals may be added to the
composition as appropriate for different diagnostic or therapeutic
applications or for different types of imaging as described herein.
The use of compositions comprising metals or metal ions in the in
vivo imaging of mammalian tissues or organs including human organs
is well known in the art, and any of such uses of an appropriate
metal for a particular type of detection is contemplated by the
present disclosure.
[0009] The compositions of the present disclosure may include,
therefore, metals appropriate for contrast enhanced imaging or for
scintigraphic imaging PET, MRI, or even CT imaging. The metal may
be a radionuclide, including beta or gamma emitters, or it may be a
magnetic or paramagnetic metal ion as needed. Preferred metals and
metal ions for use in the described compositions and methods
include, but are not limited to ions and isotopes of iron,
manganese, chromium, copper, nickel, gadolinium, erbium, europium,
dysprosium, holmium, gallium, germanium, cobalt, calcium, rubidium,
yttrium, technetium, ruthenium, rhenium, indium, iridium, platinum,
thallium, samarium, or boron, and most preferred metal ions for
imaging include technetium (Tc-99m), gallium (Ga-67, 68), copper
(Cu-60-64), gadolinium (Gd), holmium (Ho-166), or holmium (Re-187,
188); preferred metal ions for therapeutics include isotopes of
yttrium, rhenium, copper and holmium.
[0010] The chelators of the disclosed compositions may be any
appropriate chelators known in the art, including, but not limited
to diethylenetriamine pentaacetic acid (DTPA), ethylene diamine
tetra-acetic acid (EDTA), cyclohexyl 1,2-diamine tetra-acetic acid
(CDTA), dimercaptosuccinic acid (DMSA), triglycinbenzoyl thiol
(MAG-3), methylenebisphophonate (MDP), ethyleneglycol-0, 0'bis
(2-aminoethyl)-N,N,N',N'-tetra-acetic acid (EGTA),
N,N-bis(hydroxybenzyl)-ethylenediamine-N,N'-diacetic acid (HBED),
triethylene tetramine hexa-acetic acid (TTHA),
1,4,7,10-tetraazacyclododecane-N,N',N'',N'''-tetraacetic acid
(DOTA), hydroxyethyldiamine triacetic acid (HEDTA), or
1,4,8,11-tetra-azacyclo-tetradecane-N,N,N'',N'''-tetra-acetic acid
(TETA). In the most preferred embodiments the chelator is DTPA.
[0011] The antidiabetic agents of the disclosed inventions may be
any antidiabetic drugs known in the art, or any compounds that bind
to or associate preferentially with beta cells of the pancreas. The
most preferred agents are those that bind to a surface receptor on
beta cells, including various sulphonylurea receptors such as
SUR-1, SUR2A and SUR2B as well as other receptors such as the GLP-1
receptor or the somatostatin receptor. Preferred antidiabetic
agents include nateglinide, L-nateglinide, repaglinide,
tolbutamide, glibenclamide, Amaryl, glipizide, glyburide,
gliclazide, glimepiride, and most preferably nateglinide,
glipizide, glyburide, or glimepiride.
[0012] In certain embodiments the compositions of the present
inventions may include any of the mentioned compounds or elements
in any combination, and preferably include
.sup.99mTc-DTPA-nateglinide, .sup.99mTc-DTPA glipizide,
.sup.99mTc-DTPA-glyburide or .sup.99mTc-DTPA-glimepiride for gamma
imaging.
[0013] In certain embodiments, the present invention may be
described as a method of treating a pancreatic disease comprising
administering to a subject in need thereof a composition comprising
an antidiabetic agent a chelator and a chelated metal ion, wherein
the metal ion is a beta emitter. A subject in need thereof may
include any animal or human subject that has, or is subject to
developing a pancreatic disease including, but not limited to
diabetes, pancreatitis, hyperinsulinemia or insulinoma. Subjects
may be identified by various methods known in the clinical arts,
including monitoring glucose tolerance, insulin resistance, blood
insulin levels, blood glucose levels, major histocompatibility
complex typing, certain antibodies, weight gain or loss, obesity,
or even family history and genetic profiles.
[0014] Compositions as described herein are useful in a number of
applications, both diagnostic, prognostic and therapeutic. As such,
certain embodiments of the invention may be described as methods of
imaging a mammalian pancreas comprising administering to the mammal
a composition comprising an antidiabetic agent, a chelator and a
chelated metal ion and detecting an image of the pancreas. As
described, the image may be a gamma image, a PET image, an MRI
image, or other types of images known in the art.
[0015] Exemplary methods include methods of monitoring pancreatic
beta cell mass or morphology in a mammal, useful for monitoring the
condition of the pancreas in a susceptible subject prior to onset
of a pancreatic disease, or monitoring progress of a disease, or
even methods of monitoring the outcome of certain therapies during
treatment or management of a pancreatic disease. The methods of the
inventions may be used therefore to monitor beta cell mass, cell
number, function, or lymphocyte infiltration into the beta cell
mass.
[0016] Throughout this disclosure, unless the context dictates
otherwise, the word "comprise" or variations such as "comprises" or
"comprising," is understood to mean "includes, but is not limited
to" such that other elements that are not explicitly mentioned may
also be included. Further, unless the context dictates otherwise,
use of the term "a" or "the" may mean a singular object or element,
or it may mean a plurality, or one or more of such objects or
elements.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The following drawings form part of the present
specification and are included to further demonstrate certain
aspects of the present invention. The invention may be better
understood by reference to one or more of these drawings in
combination with the detailed description of specific embodiments
presented herein.
[0018] FIG. 1 is a synthetic scheme of metal-(.sup.99mTc, Gd)
DTPA-NGN2.
[0019] FIG. 2 is .sup.1H-NMR spectrum of Nateglinide.
[0020] FIG. 3 is .sup.1H-NMR spectrum of NGN-Et.
[0021] FIG. 4 is .sup.1H-NMR spectrum of NGN-EA.
[0022] FIG. 5 is the Mass Spectrum of NGN-EA.
[0023] FIG. 6 is .sup.1H-NMR spectrum of NGN2.
[0024] FIG. 7 is the Mass Spectrum of DTPA-NGN2.
[0025] FIG. 8 is a synthetic scheme of DTPA-GLP.
[0026] FIG. 9 is .sup.1H-NMR data of Glipizide.
[0027] FIG. 10 is .sup.1H-NMR spectrum of Glipizide.
[0028] FIG. 11 is .sup.13C-NMR data of Glipizide.
[0029] FIG. 12 is the .sup.13C-NMR spectrum of Glipizide.
[0030] FIG. 13 is .sup.1H-NMR data of DTPA-Glipizide.
[0031] FIG. 14 is .sup.1H-NMR spectrum of DTPA-Glipizide.
[0032] FIG. 15 is .sup.13C-NMR data of DTPA-Glipizide.
[0033] FIG. 16 is .sup.13C-NMR spectrum of DTPA-Glipizide.
[0034] FIG. 17 is the Mass Spectrum of DTPA-Glipizide.
[0035] FIG. 18 is a synthetic scheme for DTPA-Glyburide.
[0036] FIG. 19 is the .sup.1H-NMR data of Glyburide.
[0037] FIG. 20 is the .sup.1H-NMR spectrum of Glyburide.
[0038] FIG. 21 is the .sup.13C-NMR data of Glyburide.
[0039] FIG. 22 is the .sup.13C-NMR spectrum of Glyburide.
[0040] FIG. 23 is the .sup.1H-NMR data of DTPA-Glyburide.
[0041] FIG. 24 is the .sup.1H-NMR spectrum of DTPA-Glyburide.
[0042] FIG. 25 is the .sup.13C-NMR spectrum of DTPA-Glyburide.
[0043] FIG. 26 is a synthetic scheme for DTPA-GLMP.
[0044] FIG. 27 is .sup.1H-NMR data of GLMP.
[0045] FIG. 28 is a .sup.1H-NMR spectrum of GLMP.
[0046] FIG. 29 is .sup.13C-NMR data of GLMP.
[0047] FIG. 30 is a .sup.13C-NMR spectrum of GLMP.
[0048] FIG. 31 is .sup.1H-NMR data of DTPA-GLMP.
[0049] FIG. 32 is a .sup.1H-NMR spectrum of DTPA-GLMP.
[0050] FIG. 33 is .sup.13C-NMR data of DTPA-GLMP.
[0051] FIG. 34 is a .sup.13C-NMR spectrum of DTPA-GLMP.
[0052] FIG. 35 is ITLC data for Tc-DTPA-NGN2.
[0053] FIG. 36 is nuclear imaging of .sup.99mTc-DTPA-Nateglinide.
Mammary tumor-bearing rats were imaged with .sup.99mTc-DTPA (left
panel) and .sup.99mTc-DTPA-NGN2 (right panel) (300 .mu.Ci, i.v.).
Selected planar images of .sup.99mTc-DTPA-NGN2 are presented at 5
and 50 minutes post-injection. The arrow indicates the
pancreas.
[0054] FIG. 37 is an image of a mammary tumor-bearing rat imaged
with .sup.99mTc-DTPA-NGN2 (300 .mu.Ci, i.v.) Selected planar images
of .sup.99mTc-DTPA-NGN2 are presented at 50 minutes post-injection.
The arrow indicates the pancreas.
[0055] FIG. 38 is planar scintigraphy images of .sup.99mTc-DTPA in
13762 tumor-bearing rats (300 .mu.Ci/rat, i.v. injection).
[0056] FIG. 39 is planar scintigraphy images of .sup.99mTc-DTPA-NGN
(2) in 13762 tumor-bearing rats (300 .mu.Ci/rat, i.v.
injection).
[0057] FIG. 40 is planar scintigraphy images of .sup.99mTc-DTPA-NGN
(1) in 13762 tumor-bearing rats (300 .mu.Ci/rat, i.v.
injection).
[0058] FIG. 41 is images of breast tumor bearing rats imaged with
.sup.99mTc-DTPA (left panel), .sup.99mTc-DTPA-NGN2 (middle panel)
and .sup.99mTc-DTPA-NGN2with a blocking dose of 4 mg/kg NGN2 (right
panel) (300 .mu.Ci, i.v.). Selected planar images are shown at 150
minutes post-injection.
[0059] FIG. 42 is images of breast tumor bearing rats imaged with
.sup.99mTc-DTPA (left panel), .sup.99mTc-DTPA-NGN2 (middle panel)
and .sup.99Tc-DTPA-NGN2 with a blocking dose of 4 mg/kg NGN2 (right
panel) (300 .mu.Ci, i.v.). Selected planar images are shown at 150
minutes post-injection. The arrow indicates the pancreas.
[0060] FIG. 43 is planar scintigraphy images of .sup.99mTc-DTPA and
.sup.99mTc-DTPA-Glipizide (GLUCOTROL) in rats (300 .mu.Ci/rat, i.v.
injection) at 5 minutes post injection.
[0061] FIG. 44 is planar scintigraphy images of .sup.99mTc-DTPA and
.sup.99mTc-DTPA-Glipizide (GLUCOTROL) in rats (300 .mu.Ci/rat, i.v.
injection) at 15 minutes post injection.
[0062] FIG. 45 is planar scintigraphy images of .sup.99mTc-DTPA in
VX2 tumor-bearing rabbits (1 mCi/rabbit, i.v. injection).
[0063] FIG. 46 is planar scintigraphy images of .sup.99mTc-DTPA-NGN
in VX2 tumor-bearing rabbits (1 mCi/rabbit, i.v. injection). P
indicates the pancreas.
[0064] FIG. 47 is a graphical representation comparing pancreas
uptake for .sup.99mTc-DTPA and .sup.99mTc-DTPA-NGN in breast
tumor-bearing rats (n=3/time interval, 20 .mu.Ci, IV, p=0.11, 0.05,
and 0.01).
[0065] FIG. 48 is a graphical representation of pancreas to muscle
count density ratio of .sup.99mTc-DTPA and .sup.99mTc-NGN in breast
tumor bearing rats (n=3/time interval, 20 .mu.Ci/rat, IV, p=0.19,
0.19, and 0.029).
DETAILED DESCRIPTION
[0066] The present disclosure provides compositions and methods to
improve the diagnosis and treatment of pancreatic associated
diseases including, but not limited to diabetes, pancreatitis,
insulinoma, adenocarcinoma, islet cell tumor, islet hypertrophy in
diabetics and hyperinsulinemia based on the discovery of
compositions and methods for the imaging of beta cells in vivo as
well as the delivery of agents of therapeutic value specifically to
pancreatic beta cells.
[0067] This disclosure is based on the development of compositions
and methods for mechanism-based targeting of beta-cells for imaging
and therapeutic purposes. In preferred embodiments, the disclosed
compositions include an antidiabetic agent, a chelator, and
optionally a chelated metal ion. The present inventors have
successfully demonstrated scintigraphic visualization of the
pancreas in rat and rabbit animal models using such compositions,
including .sup.99mTc-DTPA-nateglinide (NON) and
.sup.99mTc-DTPA-glipizide.
[0068] The antidiabetic agents of the present disclosure are
preferably agents that preferentially interact with or bind to
specific receptors on the pancreatic beta cells. Such agents may
bind to the sulphonylurea receptors, including SUR1, SUR2A and
SUR2B, GLP-1 receptor, somatostatin receptor, angiotensin II
receptor, and/or bradykinin receptor. Preferred agents include, but
are not limited to nateglinide, L-nateglinide, repaglinide,
tolbutamide, glibenclamide, Amaryl, glipizide, glyburide,
gliclazide, and glimepiride.
[0069] In certain preferred embodiments, the chelator of the
disclosed compositions is diethylenetriamine pentaacetic acid
(DTPA). Other chelators may also be used in the practice of the
disclosure, including but not limited to ethylene diamine
tetra-acetic acid (EDTA), cyclohexyl 1,2-diamine tetra-acetic acid
(CDTA), ethyleneglycol-0, 0'bis
(2-aminoethyl)-N,N,N',N'-tetra-acetic acid (EGTA),
N,N-bis(hydroxybenzyl)-ethylenediamine-N,N'-diatetic acid (HBED),
triethylene tetramine hexa-acetic acid (TTHA),
1,4,7,10-tetraazacyclododecane-N,N',N'',N'''-tetraacetic acid
(DOTA), hydroxyethyldiamine triacetic acid (HEDTA),
1,4,8,11-tetra-azacyclo-tetradecane-N,N',N'',N'''-tetra-acetic acid
(TETA) dimercaptosuccinic acid (DMSA), triglycinbenzoyl thiol
(MAG-3) and methylenebisphophonate (MDP). The preferred metal ions
for imaging include technetium (Tc-99m), gallium (Ga-67, 68),
copper (Cu-60-64), gadolinium (Gd), holmium (Ho-166), or holmium
(Re-187, 188); preferred metal ions for therapeutics include
yttrium, rhenium, copper and holmium.
[0070] Metal chelators useful in this disclosure include those
which contain cationic, basic and basic-amine groups and which
chelate metals and metal ions, transition elements and ions, and
lanthanide series elements and ions. It will be apparent to those
skilled in the art that essentially any single atomic element or
ion amenable to chelation by a cationic, basic and amine-containing
chelator, may also be useful in this disclosure.
[0071] Aqueous compositions of the present inventions comprise an
effective amount of the described compositions dissolved and/or
dispersed in a pharmaceutically acceptable carrier and/or aqueous
medium. The phrases "pharmaceutically and/or pharmacologically
acceptable" refer to molecular entities and/or compositions that do
not produce an adverse, allergic and/or otherwise untoward reaction
when administered to an animal, and/or a human, as appropriate.
[0072] As used herein, "pharmaceutically acceptable carrier"
includes any and/or all solvents, dispersion media, coatings,
antibacterial and/or antifungal agents, isotonic and/or absorption
delaying agents and/or the like. The use of such media and/or
agents for pharmaceutical active substances is well known in the
art. Except insofar as any conventional media and/or agent is
incompatible with the active ingredient, its use in the
compositions is contemplated. Supplementary active ingredients can
also be incorporated into the compositions.
[0073] Aqueous carriers may include water, alcoholic/aqueous
solutions, saline solutions, parenteral vehicles such as sodium
chloride, Ringer's dextrose, etc. Intravenous vehicles may include
fluid and nutrient replenishers. Preservatives may include
antimicrobial agents, anti-oxidants, chelating agents and inert
gases. The pH and exact concentration of the various components in
the pharmaceutical are adjusted according to well known
parameters.
[0074] For purposes of this disclosure, preferred metal ions are
generally those known in the art to be useful for imaging
techniques including, but not limited to gamma scintigraphy,
magnetic resonance, positron emission tomography, and computed
tomography. Metal ions useful for chelation in paramagnetic T1-Type
MRI contrast agent compositions and uses may include divalent and
trivalent cations of metals selected from iron, manganese,
chromium, copper, nickel, gadolinium, erbium, europium, dysprosium
and holmium. Chelated metal ions generally useful for radionuclide
imaging and in radiotherapeutic compositions and uses, may include
metals selected from gallium, germanium, cobalt, calcium, rubidium,
yttrium, technetium, ruthenium, rhenium, indium, iridium, platinum,
thallium and samarium. Metal ions useful in neutron-capture
radiation therapy may include boron and others with large nuclear
cross sections. Metal ions useful in Ultrasound contrast and X-Ray
contrast compositions and uses may, provided they achieve adequate
site concentrations, include any of the metal ions listed above,
and in particular, may include metal ions of atomic number at least
equal to that of iron.
[0075] The compositions may be provided "cold" (without a
radioisotope label) or they may be provided with a label. Various
radioactive labels may be used, as suited to a particular
application. For example, a .sup.99mTc label may be preferred for
gamma imaging, .sup.61Cu-- for PET imaging, gadolinium for MRI and
.sup.188Re (.sup.166Ho--) for internal radiotherapeutic
applications.
[0076] The following examples are included to demonstrate preferred
embodiments of the invention. It should be appreciated by those of
skill in the art that the techniques disclosed in the examples
which follow represent techniques discovered by the inventor to
function well in the practice of the invention, and thus can be
considered to constitute preferred modes for its practice. However,
those of skill in the art should, in light of the present
disclosure, appreciate that many changes can be made in the
specific embodiments which are disclosed and still obtain a like or
similar result without departing from the spirit and scope of the
invention.
EXAMPLE 1
Synthesis of DTPA-Nateglinide (DTPA-NGN)
[0077] DTPA-nateglinide was synthesized in a two-step manner. The
synthetic scheme is shown in FIG. 1.
Step 1. Synthesis of Aminoethyl Amide Analogue of Nateglinide
[0078] Nateglinide (3.1742 g, 10 mmol) was dissolved in 20 mL of
ethyl alcohol. Thionyl Chloride (5.1 mL, 70 mmol) was added
dropwise to the solution. The reaction mixture was stirred
overnight and the solvent was evaporated at reduced pressure. FIGS.
2 and 3 showed .sup.1H-NMR of nateglinide and its ester form.
[0079] Ethyl alcohol (20 mL) and ethylene diamine (3.4 mL, 50 mmol)
were added. The mixture was stirred overnight. The solvent was
evaporated at reduced pressure. The solid was dissolved in
chloroform (50 mL) and washed with water (2 .times.50 mL). The
chloroform layer was dried over anhydrous magnesium sulfate. The
solvent was filtered and evaporated at reduced pressure. Aminoethyl
amide analogue of nateglinide was obtained as a white solid (3.559
g, 99% yield). FIGS. 4 and 5 showed .sup.1HNMR and mass
spectrometry of aminoethyl amide analogue of nateglinide.
Step 2. Synthesis of DTPA-Nateglinide
[0080] Aminoethyl amide analogue of nateglinide (359.5 mg, 1.0
mmol) was dissolved in DMSO (anhydrous, 10 ml). DTPA-dianhydride
(178.7 mg, 0.5 mmol) and triethyl amine (279 uL, 2.0 mmol) were
added to the solution and the mixture was heated at 60.sup.BC for 4
hours. After cooling, water (8 mL) and 1N-sodium bicarbonate
solution (8 mL) were added. The mixture was stirred for 2 hours.
The aqueous phase was dialyzed with membrane (MW CO<500) for 2
days. DTPA-NGN (413.9 mg, 87.7% yield) as a white solid was
gathered after lyophilization. FIGS. 6 and 7 showed .sup.1H-NMR and
mass spectrometry of DTPA-Nateglinide.
EXAMPLE 2
Synthesis of DTPA-Glipizide (DTPA-GLP)
[0081] Glipizide (445.5 mg, 1.0 mmol) was dissolved in DMSO
(anhydrous, 10 ml).
[0082] Sodium amide (76.03 mg, 2.0 mmol) was then added. The
reaction mixture was stirred at room temperature for 10 min.
DTPA-dianhydride (357.32 mg, 1.0 mmol) was dissolved in DMSO
(anhydrous, 10 ml). Sodium amide (76.03 mg, 2.0 mmol) was then
added. The reaction mixture was stirred at room temperature for 10
min. DTPA-dianhydride (357.32 mg, 1.0 mmol) dissolved in 5 ml DMSO
(anhydrous) was added and the mixture was stirred for 4 hours. The
mixture was added with water (10 mL), followed by 1N-sodium
hydroxide solution (3 mL) and stirred for 2 hours. The solid was
filtered and washed with water. This recovered starting material
was 142.6 mg (32%) after drying under vacuum. The aqueous phase was
dialyzed with membrane (MW CO<500) for 2 days. DTPA-GLP (506.6
mg, ;61.7% yield) as a white solid was gathered after
lyophilization. The synthetic scheme is shown in FIG. 8. FIGS. 9-17
showed .sup.1H-, .sup.13C-NMR spectrum and assignment and mass
spectrometry of DTPA-glipizide.
EXAMPLE 3
Synthesis of DTPA-Glyburide (DTPA-GLB)
[0083] Glyburide (494.0 mg, 1.0 mmol) was dissolved in DMSO
(anhydrous, 5 ml). Sodium amide (195.0 mg, 5.0 mmol) was then
added. The reaction mixture was stirred at room temperature for 10
min. DTPA-dianhydride (357.32 mg, 1.0 mmol) dissolved in 5 ml DMSO
(anhydrous) was added and the mixture was stirred for 22 hours. The
dark green colored mixture was added with water (10 mL), followed
by 1N-sodium hydroxide solution (5 mL) and stirred for 2 hours. The
solid was filtered and washed with water. This recovered starting
material was 88.9 mg (18%) after drying under vacuum. The aqueous
phase was dialyzed with membrane (MW CO<500) for 2 days. DTPA-LB
(695.5 mg, 80% yield) as a white solid was gathered after
lyophilization. The synthetic scheme is shown in FIG. 18. FIGS.
19-25 showed .sup.1H-, .sup.13C-NMR spectrum and assignment of
glyburide and DTPA-glyburide.
EXAMPLE 4
Synthesis of DTPA-Glimepiride (DTPA-GLMP)
[0084] Glimepiride (490.6 mg, 1.0 mmol) was dissolved in DMSO
(anhydrous, 10 ml). Sodium amide (195.0 mg, 5.0 mmol) was then
added. The reaction mixture was stirred at room temperature for 10
min. DTPA-dianhydride (357.32 mg, 1.0 mmol) dissolved in 5 ml DMSO
(anhydrous) was added and the mixture was stirred for 18 hours. The
dark brown colored mixture was added with water (10 mL), followed
by 1N-sodium hydroxide solution (5 mL) and stirred for 2 hours. The
solid was filtered and washed with water. The aqueous phase was
dialyzed with membrane (MW CO<500) for 2 days. DTPA-GLMP (782.3
mg, 90.3% yield) was a white solid was gathered after
lyophilization. The synthetic scheme is shown in FIG. 27. FIGS.
28-34 showed .sup.1H-, .sup.13C-NMR spectrum and assignment of
glimepiride and DTPA-glimepiride.
EXAMPLE 5
[0085] Radiolabel DTPA-antidiabetic conjugates
[0086] Radiosynthesis of.sup.99mTc-DTPA-antidiabetic agents were
achieved by adding the required amount of DTPA-antidiabetic agents
(5-10 mg) and tin (II) chloride (SnCl.sub.2, 100 .sub..mu.g) and
pertechnetate (Na.sup.99mTcO.sub.4, 5 mCi). Radiochemical purity
was assessed by radio-TLC (Bioscan, Washington, D.C.) using 1 M
ammonium acetate: methanol (4:1) as an eluant. High-performance
liquid chromatography (HPLC), equipped with a Nal detector and UV
detector (254 nm), was performed on a gel permeation column (Biosep
SEC-S3000, 7.8.times.300 mm, Phenomenex, Torrance Calif.) using a
flow rate of 1.0 ml/min. The eluant was 0.1% LiBr in phosphate
buffered saline (PBS 10 mM, pH=7.4). Radiochemical purity was
<96% for all four agents. Radio-TLC data of
.sup.99mTc-DTPA-nateglinide is shown in FIG. 35.
EXAMPLE 6
Scintigraphic Imaging:
[0087] Scintigraphic imaging in rodents was conducted as
follows:
[0088] Female Fischer 344 rates (150-175 g) (Harlan Sprague-Dawley,
Inc., Indianapolis, Ind.) were inoculated subcutaneously in the
right leg with breast cancer cells (10.sup.6 cells/rat) from the
13762 NF cell line (known as DMBA-induced breast cancer cell line).
Scintigraphic imaging was serially performed on day 14 after
inoculation. Planar images were obtained at 0.5, 1 and 2 hours
after injection of 300 .mu.Ci of .sup.99mTc-DTPA-NGN or
.sup.99mTc-DTPA-GLP via tail vein. Control groups were given
.sup.99mTc-DTPA. Imaging was conducted with a gamma camera from
Digirad (2020tc Imager, San Diego, Calif.) equipped with a
low-energy parallel-hole collimator. The field of view is 20
cm.times.20 cm with an edge of 1.3 cm. The intrinsic spatial
resolution is 3 mm and the matrix is 64.times.64. The system is
designed for a planar image with sensitivity of 56 counts/second
(cps)/MBq and spatial resolution of 7.6 mm. FIGS. 36-44 showed that
pancreas could be visualized with either
.sup.99mTc-DTPA-nateglinide (NGN) or .sup.99mTc-DTPA-glipizide in
normal rat and tumor-bearing rats.
[0089] Scintigraphic imaging in rabbits was conducted as
follows:
[0090] Male (n=4) New Zealand white rabbits (Raynichols Rabbitry,
Lumberton, Tex.) were inoculated with VX-2 cells (rabbit driven
mammary squamous cell carcinoma). At day 14 post-inoculation,
scintigraphic imaging studies were conducted with
.sup.99mTc-DTPA-NGN (1 mCi, iv). Computer outlined region of
interest was used to analyze target-to-nontarget ratios. FIGS. 45
and 46 showed that pancreas could be visualized with
.sup.99mTc-DTPA-nateglinide (NGN). FIGS. 47 and 48 showed that
pancreas uptake was higher than control groups.
[0091] In summary, the imaging data demonstrated that the pancreas
can be imaged with radiolabeled nateglinide and glipizide. Thus,
uptake changes in pancreas can be assessed using this specific
molecular marker.
[0092] All of the compositions and methods disclosed and claimed
herein can be made and executed without undue experimentation in
light of the present disclosure. While the compositions and methods
of this invention have been described in terms of preferred
embodiments, it will be apparent to those of skill in the art that
variations may be applied to the compositions and/or methods and in
the steps or in the sequence of steps of the methods described
herein without departing from the concept, spirit and scope of the
invention. More specifically, it will be apparent that certain
agents which are both chemically and physiologically related may be
substituted for the agents described herein while the same or
similar results would be achieved. All such similar substitutes and
modifications apparent to those skilled in the art are deemed to be
within the spirit, scope and concept of the invention as defined by
the appended claims.
* * * * *