U.S. patent application number 16/416503 was filed with the patent office on 2019-09-05 for biological adhesives and sealants and methods of using the same.
The applicant listed for this patent is SEALANTIS LTD.. Invention is credited to Havazelet BIANCO-PELED, Ohad KIMHI, Ronit LANGZAM-SINAI, Rina LEV, Charles MILGROM.
Application Number | 20190269820 16/416503 |
Document ID | / |
Family ID | 54392228 |
Filed Date | 2019-09-05 |
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United States Patent
Application |
20190269820 |
Kind Code |
A1 |
KIMHI; Ohad ; et
al. |
September 5, 2019 |
BIOLOGICAL ADHESIVES AND SEALANTS AND METHODS OF USING THE SAME
Abstract
This invention provides a kit for making an adhesive and/or a
sealant which includes: a first composition of alginate and a
multivalent cation salt at a concentration ratio (mg/ml) of 30:1 to
1:60, and a second composition of alginate and a buffer, wherein
the buffer has a pH value of between 2 to 7. The invention also
provides a method for making a sealant or an adhesive, by
contacting the first composition and the second composition.
Inventors: |
KIMHI; Ohad; (Kiryat Yam,
IL) ; LANGZAM-SINAI; Ronit; (Kiryat Tivon, IL)
; BIANCO-PELED; Havazelet; (Tivon Mail, IL) ;
MILGROM; Charles; (Moshav Aminadav, IL) ; LEV;
Rina; (Haifa, IL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SEALANTIS LTD. |
Haifa |
|
IL |
|
|
Family ID: |
54392228 |
Appl. No.: |
16/416503 |
Filed: |
May 20, 2019 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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15309257 |
Nov 7, 2016 |
10293079 |
|
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PCT/IL2015/050473 |
May 5, 2015 |
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16416503 |
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61988463 |
May 5, 2014 |
|
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62074724 |
Nov 4, 2014 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61L 24/0031 20130101;
A61L 24/02 20130101; A61L 24/08 20130101; A61L 2300/802 20130101;
A61L 2300/232 20130101; A61L 24/08 20130101; A61L 2300/412
20130101; A61L 24/0015 20130101; A61L 2300/424 20130101; C08L 5/04
20130101 |
International
Class: |
A61L 24/08 20060101
A61L024/08; A61L 24/00 20060101 A61L024/00; A61L 24/02 20060101
A61L024/02 |
Claims
1. A kit comprising: a first component and a second component, said
first component comprises a crosslinkable polysaccharide and a
multivalent cation salt at a concentration ratio (mg/ml) of 30:1 to
1:60, said second component comprises a crosslinkable
polysaccharide and a buffering agent, said buffering agent has a pH
value of between 2 to 7 and comprises an acid and its acid addition
salt.
2. The kit of claim 1, wherein said crosslinkable polysaccharide is
alginate.
3. The kit of claim 1, wherein said crosslinkable polysaccharide
and said multivalent cation salt are at a concentration ratio
(mg/ml) of 1:1 to 1:4.
4. The kit of claim 1, wherein said multivalent cation salt is
selected from: a calcium salt selected from the group comprising:
CaCO.sub.3, (C.sub.17H.sub.35COO).sub.2Ca,
CaNa.sub.2P.sub.2O.sub.7, Ca.sub.2P.sub.2O.sub.7, or any
combination thereof; a multivalent cation salt present at a
concentration of 20 to 40 mg/ml within said first component; and a
particle size between 0.1 microns and 150 microns.
5. The kit of claim 1, wherein said crosslinkable polysaccharide is
present at a concentration of 5 to 100 mg/ml within said first
component and crosslinkable polysaccharide is present at a
concentration of 5 to 100 mg/ml within said second component.
6. The kit of claim 1, wherein said buffering agent has a
concentration selected from: a buffering agent having a
concentration of between 1 to 2000 mM and a buffering agent having
a concentration of 100 to 500 mM.
7. The kit of claim 1, wherein said buffering agent is selected
from a buffering agent having a pH value of between 4 to 5 and a
buffering agent comprises acetic acid and sodium acetate salt.
8. The kit of claim 1, wherein the concentration of said
multivalent cation salt in said first component is 1.5 to 10 times
higher than the stoichiometric ratio of said buffering agent having
a concentration of between 100 to 500 mM.
9. The kit of claim 1, wherein said multivalent cation salt is
CaCO.sub.3 at a concentration of 20 to 40 mg/ml, said crosslinkable
polysaccharide is present at a concentration of 10 to 30 mg/ml in
said first component, said crosslinkable polysaccharide is present
at a concentration of 10 to 30 mg/ml in said second component, said
buffering agent is buffer acetate having a pH value between 4 to 5
and a concentration of between 150 to 300 mM.
10. The kit of claim 1, further comprising an instruction manual,
optionally wherein said instruction manual provides instruction
with respect to quantities of said first component and said second
component to be applied, further optionally wherein said
instruction manual provides a spectrum of gelation time, wherein
said gelation time is affected by the particle size of said calcium
salt, the particular calcium salt, the type of buffering agent, the
pH value of said buffering agent, or any combination thereof.
11. The kit of claim 1, wherein the combination of said first
component and/or said second component have a viscosity of between
100 cP and 100000 cP.
12. A method for forming a sealant, comprising contacting a first
composition and a second composition, wherein said first
composition comprises a crosslinkable polysaccharide and a
multivalent cation salt at a concentration ratio (mg/ml) of 30:1 to
1:60, said second composition comprises a crosslinkable
polysaccharide and a buffer, said buffer has a pH value of between
2 to 7 and comprises an acid and its acid addition salt, thereby
forming a sealant.
13. The method of claim 12, wherein said crosslinkable
polysaccharide and said multivalent cation salt are at a
concentration ratio (mg/ml) of 1:1 to 1:4 or wherein said
crosslinkable polysaccharide is present at a concentration of 5 to
100 mg/ml within said first composition and said crosslinkable
polysaccharide is present at a concentration of 5 to 100 mg/ml in
said second composition, optionally wherein said crosslinkable
polysaccharide is alginate.
14. The method of claim 12, wherein said multivalent cation salt is
selected from: a calcium salt selected from the group comprising:
CaCO.sub.3, (C.sub.17H.sub.35COO).sub.2Ca,
CaNa.sub.2P.sub.2O.sub.7, Ca.sub.2P.sub.2O.sub.7, or any
combination thereof; a multivalent cation salt present at a
concentration of 20 to 40 mg/ml within said first component; a
particle size between 0.1 microns and 150 microns; and a
multivalent cation salt having a concentration in said first
composition of 1.5 to 10 times higher than the stoichiometric ratio
of said buffer having a concentration of between 100 to 500 mM.
15. The method of claim 12, wherein said buffer is selected from: a
buffer has a concentration of between 1 to 2000 mM; a buffer having
a pH value of between 4 to 5; and a buffer having comprising acetic
acid and sodium acetate salt.
16. The method of claim 12, wherein said multivalent cation salt is
calcium salt is CaCO.sub.3 at a concentration of 20 to 40 mg/ml,
said crosslinkable polysaccharide is present at a concentration of
10 to 30 mg/ml in said first composition, said crosslinkable
polysaccharide is present at a concentration of 10 to 30 mg/ml in
said second composition, said buffer is buffer acetate having a pH
value between 4 to 5 and a concentration of between 150 to 500
mM.
17. The method of claim 12, wherein said forming a sealant further
comprises controlling gelation time, wherein said pH value of less
than 4.5 increases gelation time, wherein smaller particle size of
said bivalent cation salt decreases gelation time or wherein said
forming a sealant is forming a sealant having a viscosity of
between 100 cP and 100000 cP.
18. A method for securing or holding a graft in a target site, the
method comprising the step of: (a) providing a first composition
and a second composition, said first composition comprises a
crosslinkable polysaccharide and a multivalent cation salt at a
concentration ratio (mg/ml) of 30:1 to 1:60, said second
composition comprises a crosslinkable polysaccharide and a buffer,
said buffer has a pH value of between 2 to 7 and comprises an acid
and its acid addition salt, (b) applying said first composition and
said second composition to a graft situated at the target site,
thereby securing or holding said graft at the target site.
19. The method of claim 18, further comprising mixing said first
composition and said second composition prior to step (b).
Description
RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 15/309,257 filed on Nov. 7, 2016, which is a
National Phase of PCT Patent Application No. PCT/IL2015/050473
having International filing date of May 5, 2015, which claims the
benefit of priority of U.S. Patent Application Nos. 61/988,463
filed on May 5, 2014 and 62/074,724 filed on Nov. 4, 2014. The
contents of the above applications are all incorporated by
reference as if fully set forth herein in their entirety.
FIELD OF INVENTION
[0002] This invention is directed to, inter alia, biological
adhesives and sealants and methods of making and using the
same.
BACKGROUND OF THE INVENTION
Adhesives and Sealants
[0003] Surgical adhesives have been increasingly used to enhance or
at least partially replace traditional wound closure technologies
such as sutures and staples, offering improved sealing capabilities
and plugging of undesired leaks.
[0004] Despite recent developments and increased clinical demand,
most of the currently available products suffer from serious
drawbacks. One of the drawbacks is the short time-window available
for their proper application onto the treated site and another is
the short time they remain adhesive after application.
[0005] United States Application Publication No. US2005069589 to
Lowinger et al. describes a tissue adhesive sealant that includes a
cross-linkable protein in a solution, that when combined with a
cross-linking agent solution including an aldehyde and amino acid
containing species reactive with the aldehyde, cross-links to form
a seal.
[0006] The sealant is stated to be highly suitable for bonding
tissue alone or in combination with a patch. Such a system may not
be easy to use as it may limit the time-window for application of
the adhesive.
[0007] International Application Publication No. WO2010146582 is
directed to reinforced multi component adhesives that include an
uncured and curable spreadable composition of matter, and a
biocompatible inert reinforcing agent including at least one curing
agent, wherein the uncured composition applied to a surface is
characterized as capable of curing after adding the reinforcing
agent to the uncured composition, and wherein the cured composition
together with the added reinforcing agent is configured to have
improved mechanical support and strength. Following placement of
the fibrous component containing the curing-agent, curing process
begins spontaneously. The method and system of WO2010146582
provides the ability to control the time of application of the
adhesive since the second step of applying the reinforcing agent is
fully controlled by the caregiver, and curing occurs only once this
second step is practiced.
[0008] However, a drawback of this method may be that curing often
occurs immediately upon application of the reinforcing agent. As an
example, if the curable composition contains albumin and the
reinforcing agent contains gluteraldehyde, the crosslinking
reaction will be initiated immediately after creating contact
between albumin and gluteraldehyde. As a result, the caregiver
cannot improve or alter the positioning of the reinforcing agent on
the surface once applied.
[0009] United States Application Publication No. US2010303891
describes a biocompatible layer that specifically delays the
release of NO as an agent.
[0010] U.S. Pat. No. 6,124,373 describes a method for controlling
the gelling point of a bone cement containing poly(polypropylene
fumarate), a cross-linking monomer, an initiator, an inorganic
filler, and a radical initiator. The gelling point is controlled by
varying the molecular weight of the poly(polypropylene fumarate)
while maintaining the weight average molecular weight (Mw) of the
poly(polypropylene fumarate) above 2000 and the polydispersity
index of the poly(polypropylene fumarate) below 2.
[0011] United States Application Publication No. US2003175327
describes haemostatic compositions useful to promote hemostasis at
active bleeding wound sites. The haemostatic compositions typically
include an article containing cellulose, e.g., cotton gauze, and a
polysaccharide covalently linked to the cellulose, or a
polysaccharide ionically cross-linked and in association with the
article. Obviously, the compositions have to be capable of
immediate action upon application at the bleeding site, rather than
controlled action after application, and thus the compositions are
prepared ex-situ and ready for use in final form well before
needed. Some of the compositions include cross-linked dextran beads
that incorporate cations such as Ca.sup.2+. The incorporated
cations serve to promote haemostasis. The polysaccharides also
serve to establish haemostasis, by size-excluding coagulation
components. Additional materials may be added to make the
composition adhesive.
[0012] Canadian Patent No. CA2670429 describes a gelling sealant
for a medical device, the gelling sealant including: a viscoelastic
material exhibiting a first viscosity during introduction into a
body cavity; and a second viscosity after dwelling within the body
cavity for a predetermined amount of time, the body cavity is
adjacent to a medical device adapted to occlude at least a portion
of the body cavity; wherein the viscoelastic material provides
enhanced impermeability to the portion of the body cavity occluded
by the medical device. The gelling sealant may thicken and then
adhere to the inner surfaces of the body cavity after dwelling
within the body cavity for a predetermined amount of time.
Thickening results from crosslinks is described as being initiated
by: mixing two components that are physically separated until
combined in situ, or a prevalent condition in the physiological
environment, such as temperature, pH, ionic strength, etc., and the
cross-linking reaction rate and final viscosity are described as
being dependent upon the concentration of cations in the
solution.
[0013] Similarly, United States Application Publication No.
US2002022676, describes in situ crosslinkable biodegradable polymer
compositions which include poly(propylene fumarate) (PPF),
poly(ethylene glycol)-dimethacrylate (PEG-DMA), and optionally,
beta-tricalcium phosphate)beta-TCP), and a method for controlling
the crosslinking characteristics of the compositions, including the
optimal crosslinking temperature and the gel point, as well as the
properties of the cross linked compositions such as the compressive
strength and modulus and the water holding capacity. The gelling
point and temperature are controlled by the amount of PEG in the
composites.
Adhesion Barriers
[0014] Postoperative stiffness is one of the most common
complications of shoulder surgery and is associated with pain,
formation of adhesions, and limitation in motion. The
pathophysiology of the stiffness complication is likely to be
attributable to formation of adhesions primarily developing between
the deltoid muscle and the underlying rotator cuff, in the
extra-articular space. These occur frequently in cases of open
anterior surgical approach to the shoulder (i.e., open reduction
and internal fixation of shoulder fractures, Latarjet procedures,
hemi- or total shoulder arthroplasties), and to a less extent in
arthroscopic rotator cuff repairs or arthroscopic shoulder
stabilizations (i.e., Bankart procedures). If the adhesion area is
very small, physical therapy may be effective in "breaking" of
adhesions. It is not effective, however, in the treatment of large
area adhesions. Adhesions may also occur in shoulder fractures not
treated surgically or secondary to blunt shoulder trauma. Other
joints such as the elbow and knee can be similarly affected.
Up-to-date, none of commercial adhesion prevention products,
currently used in pelvic and abdominal surgeries, are available for
adhesion prevention after rotator cuff repair surgeries, open
reduction and internal fixation of shoulder fractures, Latarjet
procedures, hemi- or total shoulders, arthroscopic Bankart
procedures, blunt shoulder trauma, non surgically treated, shoulder
fractures, elbow trauma or trauma or surgery about the knee.
[0015] A possible solution to prevent the formation of
post-operative adhesions is the use of a mechanical barrier to
prevent contact between the damaged muscle layers, and enable
tissue healing with minimal scar formation. Currently, there is a
range of adhesion prevention products, such as Interceed (J&J),
Seprafilm etc., used in pelvic and abdominal surgical procedures
(Ahmad G, et al. Cochrane Database Syst Rev. 2008 Apr. 16;
(2)).
[0016] The use of alginate as a promising biomaterial in terms of
adhesion prevention has been recently proposed (Chaturvedi A A, et
al. Br J Surg. 2013 June; 100(7):904-10; Chaturvedi A. A., et al. J
Surg Res. 2014 Jun. 4. pii: S0022-4804(14)00548-4). In animal
models, alginate gels have been reported to attenuate postoperative
intraperitoneal adhesions following caecal abrasion (Chaturvedi
2013, ibid.) and repair of colon anastomoses (Chaturvedi 2014,
ibid.). However, none of the aforementioned materials have been
designed and used for adhesion prevention after rotator cuff repair
surgeries, open shoulder surgery, blunt shoulder trauma, shoulder
fractures, elbow trauma or trauma or surgeries about the knee.
[0017] U.S. Pat. No. 5,266,326 describes a method of modifying
salts of alginic acid in situ, to form an insoluble gel, for
prevention and treatment of various intra-articular and
extra-articular (spine) complications.
[0018] U.S. Pat. No. 6,693,089 describes a method of reducing
adhesion at a site of trauma, which includes forming a film from an
alginate solution, contacting the film with a cross-linking
solution to form a cross-linked mechanically stable sheet, and
placing at least a portion of the sheet at the site of trauma. U.S.
Pat. No. 6,693,089 further relates to an anti-adhesion barrier
including a sheet of ionically cross-linked alginate having a
thickness in a range of 0.25 mm to 10 mm.
[0019] International Application Publication No. WO 2010/117266
relates to a dispensing system that can be used to introduce a
gel-forming fluid into or onto the body that will produce a
homogeneous gel in situ.
SUMMARY OF THE INVENTION
[0020] In one embodiment, the present invention provides a kit
comprising: a first component and a second component, wherein the
first component comprises alginate and a multivalent cation salt at
a concentration ratio (mg/ml) of 30:1 to 1:60, wherein the second
component comprises alginate and a buffer or a buffering agent,
wherein the buffer or buffering agent has a pH value of between 2
to 7 and comprises an acid and its acid addition salt. In some
embodiments, the kit further comprises an instruction manual. In
some embodiments, the alginate and the bivalent cation salt are at
a concentration ratio (mg/ml) of 3:1 to 1:6. In some embodiments,
the alginate and the multivalent cation salt are at a concentration
ratio (mg/ml) of 1:1 to 1:4. In some embodiments, the buffer has a
pH value of between 4 to 5. In some embodiments, the buffer is
buffer acetate. In some embodiments, the concentration of the
multivalent cation salt in the first component is 1.5 to 10 times
higher than the stoichiometric ratio of the buffer (the salt within
the buffer) having a concentration of between 1 to 2000 mM or
alternatively 100 to 500 mM. In some embodiments, the multivalent
cation salt has a particle size of between 0.1 microns and 150
microns.
[0021] In another embodiment, the present invention further
provides a method for forming an adhesive and/or sealant,
comprising contacting a first composition and a second composition,
wherein the first composition comprises alginate and a multivalent
cation salt at a concentration ratio (mg/ml) of 30:1 to 1:60,
wherein the second composition comprises alginate and a buffer,
wherein the buffer has a pH value of between 2 to 7 and comprises
an acid and its acid addition salt, thereby forming a sealant.
[0022] In another embodiment, the present invention further
provides a method for preventing, inhibiting, or reducing fibrosis,
scarring, and/or adhesion in a target site, the method comprising
the step of: (a) providing a first composition and a second
composition, said first composition comprises a crosslinkable
polysaccharide and a multivalent cation salt at a concentration
ratio (mg/ml) of 30:1 to 1:60, said second composition comprises a
crosslinkable polysaccharide and a buffer, said buffer has a pH
value of between 2 to 7 and comprises an acid and its acid addition
salt, (b) applying said first composition and said second
composition to the target site thereby forming an adhesion barrier
in situ, wherein said adhesion barrier adheres to said target
site.
[0023] In another embodiment, the present invention further
provides a sealant or an adhesion barrier produced by mixing a
first composition comprising alginate and a bivalent cation salt at
a concentration ratio (mg/ml) of 30:1 to 1:60 and a second
composition comprising alginate and a buffer, wherein the buffer
has a pH value of between 2 to 7 and comprises an acid and its acid
addition salt.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] FIG. 1 is a bar graph showing the burst pressure of the
double liquid sealant using acetic acid or buffer acetate.
[0025] FIG. 2 is a graph showing the burst pressure and strain at
break of the double liquid sealant using buffer acetate at
different pH values.
[0026] FIG. 3 is a graph showing the burst pressure of the double
liquid sealant using buffer acetate at different
concentrations.
[0027] FIG. 4 is a graph showing the burst pressure of the double
liquid sealant with various concentrations of CaCO.sub.3.
[0028] FIG. 5 illustrates the measurement of shoulder full range of
motion.
[0029] FIGS. 6A-6C depict the effect of alginate adhesion barrier
on passive shoulder mechanics in rat.
[0030] FIG. 7 shows histological evidence of alginate adhesion
barrier in rat shoulder.
DETAILED DESCRIPTION OF THE INVENTION
[0031] In one embodiment, the present invention provides at least
two distinct, separate, components (e.g., compositions of matter)
that upon contact form a bio-absorbable adhesive. The adhesive, in
some embodiments, may be adapted for internal use and be capable of
adhering to wet as well as dry surfaces and tissues. In another
embodiment, the adhesive is utilized as an integument curing agent.
"Integument" according to the present invention is any layer that
protects a tissue or an organ. "Integument" according to additional
embodiments, is any layer or tissue that surrounds another tissue.
In another embodiment, "integument" is skin, connective tissue, or
mucous.
[0032] The present invention provides kits, methods and
compositions based on extensive research that resulted in
unexpected results. Specifically, the present invention provides
that actuating/triggering a multivalent cation within a composition
comprising alginate with a buffer (the second composition) results
in a superior sealant with respect to the sealant's physical
properties, the ability to control the crosslinking-gelation of the
pre-sealant, and with respect to its uniformity. A pre-sealant,
according to some embodiments, is a composition comprising alginate
and an inactive multivalent cation. An inactive multivalent cation
according to some embodiments is in the form of a salt of a
multivalent cation such as a calcium salt. An inactive multivalent
cation according to some embodiments cannot activate
crosslinking/gelation of alginate. An inactive multivalent cation
according to some embodiments is insoluble in a composition
comprising alginate. The buffer of the invention activates the
inactive multivalent cation upon contacting it.
[0033] In another embodiment, the present invention provides
unexpected means for controlling gelation/crosslinking time. In
another embodiment, the present invention provides unexpected means
for controlling the physical properties of the adhesive of the
invention. Physical properties of the adhesive, according to an
embodiment of the invention, include but are not limited to burst
pressure and the strain of break.
[0034] In another embodiment, unexpected means for controlling
gelation/crosslinking time and unexpected means for controlling the
physical properties of the adhesive (a crosslinked gel) include but
are not limited to: the particle size of the salt of the
multivalent cation, the identity of the salt of the multivalent
cation, the type of buffer, the buffer's pH value, the
concentration of acid within the buffer, the concentration of the
salt of the multivalent cation, the concentration of alginate, the
ratio between the salt of the multivalent cation and the salt
and/or acid within the buffer, or any combinations thereof.
[0035] In another embodiment, the present invention provides two
liquid compositions: the first includes alginate and an inactive
multivalent cation salt (e.g., calcium salt) such as but not
limited to CaCO.sub.3, the second includes alginate and buffer such
as but not limited to acetate. In another embodiment, liquid is
aqueous. In one embodiment, the present invention provides two
water based compositions.
[0036] In one embodiment, the present invention provides a kit
comprising: a first component (e.g., composition), a second
component (e.g., composition), and optionally an instruction
manual, wherein first component comprises alginate and a calcium
salt (inactive), and wherein the second component comprises
alginate and a buffer.
[0037] One skilled in the art will appreciate that the first
component and/or the second component may each take a form of a
composition, or alternatively may be stored in separate containers,
e.g., a double-chambered syringe, suitable for mixing two or more
ingredients so as to form a composition. Accordingly, the terms
"first component" and "second component" are used herein
interchangeably with "first composition" and "second compositions",
respectively.
[0038] One skilled in the art will appreciate that many suitable
double-chambered syringes may be used for storing the ingredients
of the adhesive of the invention prior to mixing and applying at a
target site.
[0039] In one embodiment, the alginate and multivalent cation salt
of the first component form a composition. In another embodiment,
the alginate and multivalent cation salt of the first component are
stored in separate containers. In another embodiment, the alginate
and buffer or buffering agent of the second component form a
composition. In another embodiment, the alginate and buffer or
buffering agent of the second component are stored in separate
containers.
[0040] In another embodiment, the buffer or buffering agent
comprises an acid and its acid addition salt. In another
embodiment, the buffer has a pH value of between 2 to 7. In another
embodiment, the buffer has a pH value of between 3.5 to 6. In
another embodiment, the buffer has a pH value of between 4 to 6. In
another embodiment, the buffer has a pH value of between 4 to 5. In
another embodiment, the buffer has a pH value of between 4.4 to
4.6. In another embodiment, the buffer has a pH value of 4.5.
[0041] In some embodiments, the first composition comprises
alginate and a calcium salt at a concentration ratio (mg/ml) of 4:1
to 1:8. In some embodiments, the first composition comprises
alginate and a calcium salt at a concentration ratio (mg/ml) of 2:1
to 1:4. In some embodiments, the first composition comprises
alginate and a calcium salt at a concentration ratio (mg/ml) of 1:1
to 1:4. In some embodiments, the first composition comprises
alginate and a calcium salt at a concentration ratio (mg/ml) of 1:1
to 1:3. In some embodiments, the first composition comprises
alginate and a calcium salt at a concentration ratio (mg/ml) of 1:1
to 1:2.
[0042] In another embodiment, a crosslinkable polysaccharide is any
polysaccharide that can be crosslinked. In another embodiment, a
crosslinkable polysaccharide is any polysaccharide that can be
crosslinked by a soluble divalent cation. In another embodiment, a
crosslinkable polysaccharide is gelatin. In another embodiment, a
crosslinkable polysaccharide is pectin. Cross linking (gelation) of
crosslinkable polysaccharides such as but not limited to:
alginates, is based on their affinity toward multivalent cations
and their ability to bind those ions selectively and cooperatively,
a process which leads to the formation of ionically cross linked
alginate gels.
[0043] In some embodiments, alginate is Protanal LF 200 S (FMC
Biopolymers) with G content of approximately 70% or Protanal HF 120
RBS with G content of approximately 50% (FMC Biopolymers). In some
embodiments, alginate is any alginate known to one of average skill
in the art.
[0044] In some embodiments, said multivalent cation salt is a
bivalent cation salt. In another embodiment, the term "bivalent
cation" is synonymous with the term "divalent cation". None
limiting examples of bivalent cations include Pb.sup.2+, Cu.sup.2+,
Cd.sup.2+, Ba.sup.2+, Sr.sup.2+, Co.sup.2+, Ni.sup.2+, Zn.sup.2+ or
Mn.sup.2+. None limiting examples of trivalent cations include
Al.sup.3+ or Fe.sup.3+.
[0045] In some embodiments, said bivalent cation salt is calcium
salt. In some embodiments, calcium salt is CaCO.sub.3. In some
embodiments, calcium salt is (C.sub.17H.sub.35COO).sub.2Ca. In some
embodiments, calcium salt is CaCO.sub.3. In some embodiments,
calcium salt is CaNa.sub.2P.sub.2O.sub.7. In some embodiments,
calcium salt is Ca.sub.2P.sub.2O.sub.7. In another embodiment,
calcium salt is any combination of CaCO.sub.3,
(C.sub.17H.sub.35COO).sub.2Ca, CaNa.sub.2P.sub.2O.sub.7,
Ca.sub.2P.sub.2O.sub.7, wherein each possibility is a separate
embodiment of the present invention.
[0046] In some embodiments, said bivalent cation salt is barium
salt. In some embodiments, calcium salt is BaCO.sub.3.
[0047] In another embodiment, alginate is present at a
concentration of 5 to 100 mg/ml within the first composition. In
another embodiment, alginate is present at a concentration of 5 to
70 mg/ml within the first composition. In another embodiment,
alginate is present at a concentration of 10 to 60 mg/ml within the
first composition. In another embodiment, alginate is present at a
concentration of 10 to 40 mg/ml within the first composition. In
another embodiment, alginate is present at a concentration of 10 to
30 mg/ml within the first composition. In another embodiment,
alginate is present at a concentration of 15 to 25 mg/ml within the
first composition. In another embodiment, alginate is present at a
concentration of 20 mg/ml within the first composition.
[0048] In another embodiment, alginate is present at a
concentration of 5 to 100 mg/ml within the first composition. In
another embodiment, alginate is present at a concentration of 5 to
70 mg/ml within the second composition. In another embodiment,
alginate is present at a concentration of 10 to 60 mg/ml within the
second composition. In another embodiment, alginate is present at a
concentration of 10 to 40 mg/ml within the second composition. In
another embodiment, alginate is present at a concentration of 10 to
30 mg/ml within the second composition. In another embodiment,
alginate is present at a concentration of 15 to 35 mg/ml within the
second composition. In another embodiment, alginate is present at a
concentration of 20 mg/ml within the second composition. In another
embodiment, the concentration of alginate within the first
composition and within the second composition is the same.
[0049] In another embodiment, the viscosity of the first
composition and/or the second composition is between 100 cP and
100000 cP. In another embodiment, the viscosity of the first
composition and/or the second composition is between 100 cP and
10000 cP. In another embodiment, the viscosity of the first
composition and/or the second composition is between 100 cP and
1000 cP. In another embodiment, the viscosity of the first
composition and/or the second composition is between 100 cP and 800
cP. In another embodiment, the viscosity of the first composition
and/or the second composition is between 200 cP and 800 cP. In
another embodiment, the viscosity of the first composition and/or
the second composition is between 300 cP and 700 cP. In another
embodiment, the viscosity of the first composition and/or the
second composition is between 5000 cP and 100000 cP. In another
embodiment, the viscosity of the first composition and/or the
second composition is between 1000 cP and 70000 cP. In another
embodiment, the viscosity of the first composition and/or the
second composition is between 30000 cP and 80000 cP. In another
embodiment, the viscosity of the first composition and/or the
second composition is between 800 cP and 8000 cP. In another
embodiment, the viscosity of the first composition and/or the
second composition is between 1000 cP and 5000 cP.
[0050] In another embodiment, alginate is substituted with any
water miscible cross-linkable polymer. In another embodiment, water
miscible cross-linkable polymer is a naturally existing form of a
carbohydrate. In another embodiment, water miscible cross-linkable
polymer is synthetically prepared form of carbohydrate and a salt
of a polysaccharide.
[0051] In another embodiment, water miscible cross-linkable polymer
is a hydrophilic polymer selected from one of more of: polyethylene
glycol, polyvinyl alcohol, alginate, collagen and dextran, and
combinations thereof.
[0052] In another embodiment, alginate is present at a
concentration of 5 to 50 mg/ml within the second composition. In
another embodiment, alginate is present at a concentration of 10 to
40 mg/ml within the second composition. In another embodiment,
alginate is present at a concentration of 10 to 30 mg/ml within the
second composition. In another embodiment, alginate is present at a
concentration of 15 to 25 mg/ml within the second composition. In
another embodiment, alginate is present at a concentration of 20
mg/ml within the second composition.
[0053] In another embodiment, the salt of the multivalent cation is
present at a concentration of 10 to 50 mg/ml within the first
composition. In another embodiment, the salt of the multivalent
cation is present at a concentration of 20 to 40 mg/ml within the
first composition. In another embodiment, the salt of the
multivalent cation is present at a concentration of 25 to 35 mg/ml
within the first composition. In another embodiment, the salt of
the multivalent cation is present at a concentration of 30 mg/ml
within the first composition.
[0054] As used herein the terms "buffer" and "buffering agent" are
used interchangeably, and refer to any compound and/or combination
of compounds (e.g., in solid or liquid state), which will maintain
the pH of the composition at a desired range. In another
embodiment, the buffer has a pH value of between 3 to 6. In another
embodiment, the buffer has a pH value of between 4 to 5. In another
embodiment, the buffer has a pH value of between 4.2 to 4.8. In
another embodiment, the buffer has a pH value of between 4.4 to
4.6.
[0055] In another embodiment, the buffer has a concentration of
between 1 to 2000 mM. In another embodiment, the buffer has a
concentration of between 1 to 1500 mM. In another embodiment, the
buffer has a concentration of between 1 to 1000 mM. In another
embodiment, the buffer has a concentration of between 1 to 500 mM.
In another embodiment, the buffer has a concentration of between 50
to 500 mM. In another embodiment, the buffer has a concentration of
between 100 to 500 mM. In another embodiment, the buffer has a
concentration of between 150 to 400 mM. In another embodiment, the
buffer has a concentration of between 200 to 400 mM. In another
embodiment, the buffer has a concentration of between 250 to 300
mM. In another embodiment, the buffer has a concentration of 300
mM. In another embodiment, the buffer has a concentration of
between 200 to 600 mM. In another embodiment, the buffer has a
concentration of between 300 to 500 mM. In another embodiment, the
buffer has a concentration of 400 mM.
[0056] In another embodiment, the buffer comprises 0.2 to 10% (by
volume) acid. In another embodiment, the buffer comprises 0.2 to 9%
(by volume) acid. In another embodiment, the buffer comprises 0.2
to 8% (by volume) acid. In another embodiment, the buffer comprises
0.2 to 7% (by volume) acid. In another embodiment, the buffer
comprises 0.2 to 6% (by volume) acid. In another embodiment, the
buffer comprises 0.2 to 5% (by volume) acid. In another embodiment,
the buffer comprises 0.2 to 4% (by volume) acid. In another
embodiment, the buffer comprises 0.2 to 3% (by volume) acid. In
another embodiment, the buffer comprises 0.2 to 2% (by volume)
acid. In another embodiment, the buffer comprises 1.5%-2% (by
volume) acid. In another embodiment, the buffer comprises 0.2 to 1%
(by volume) acid. In another embodiment, the buffer comprises 0.4
to 0.8% (by volume) acid. In another embodiment, the buffer
comprises 0.4 to 0.6% (by volume) acid. In another embodiment, the
buffer comprises 0.5% (by volume) acid. In another embodiment, the
buffer comprises 1.7% (by volume) acid. In another embodiment, the
acid is acetic acid. In another embodiment, the buffer comprises
sodium acetate salt.
[0057] In another embodiment, the concentration of the multivalent
cation salt (e.g., calcium salt) in the first composition is higher
than the stoichiometric ratio of the buffer (or salt within the
buffer) having a concentration of between 100 to 500 mM. In another
embodiment, the concentration of the multivalent cation salt in the
first composition is 1.5 to 10 times higher than the stoichiometric
ratio of the buffer having a concentration of between 100 to 500
mM. In another embodiment, the concentration of the multivalent
cation salt in the first composition is 1.5 to 8 times higher than
the stoichiometric ratio of the buffer having a concentration of
between 200 to 400 mM. In another embodiment, the concentration of
the multivalent cation salt in the first composition is 1.5 to 5
times higher than the stoichiometric ratio of the buffer having a
concentration of between 250 to 350 mM.
[0058] In another embodiment, the multivalent cation salt (e.g.,
calcium salt) has a particle size between 0.1 microns and 250
microns. In another embodiment, the multivalent cation salt (e.g.,
calcium salt) has a particle size between 0.1 microns and 150
microns. In another embodiment, the multivalent cation salt has a
particle size between 0.1 microns and 100 microns. In another
embodiment, the multivalent cation salt has a particle size between
0.1 microns and 50 microns. In another embodiment, the multivalent
cation salt (e.g., calcium salt) has a particle size smaller than
50 microns. In another embodiment, multivalent cation salt has a
particle size between 1 microns and 40 microns. In another
embodiment, the multivalent cation salt has a particle size between
1 microns and 30 microns.
[0059] In another embodiment, calcium salt is CaCO.sub.3 at a
concentration of 20 to 40 mg/ml, alginate is present at a
concentration of 10 to 30 mg/ml, the buffer is buffer acetate
having a pH value between 4.4 to 4.6 and a concentration of between
1 to 500 mM. In another embodiment, calcium salt is CaCO.sub.3 at a
concentration of 20 to 40 mg/ml, alginate is present at a
concentration of 10 to 30 mg/ml, the buffer is buffer acetate
having a pH value between 4.4 to 4.6 and a concentration of between
100 to 400 mM.
[0060] In another embodiment, the instruction manual provides
instructions with respect to quantities of the first composition
and the second composition to be applied. In another embodiment,
the instruction manual provides a spectrum of gelation time,
wherein the gelation time is provided as any one of a function of
the particle size of the calcium salt, the particular calcium salt
to be used, the pH value of the buffer, or any combination
thereof.
[0061] In another embodiment, the second composition is contacted
with the first composition by spraying, dripping, or wetting the
pre-gel (the second composition) with the second composition. In
another embodiment, the pre-gel hardens (crooslinked) with time due
to the dissolution of the multivalent salt.
[0062] In some embodiments, the present invention further provides
a method for forming an adhesive/sealant, comprising contacting a
first composition and a second composition, wherein the first
composition comprises alginate and an inactive multivalent salt
(inability to crosslink the alginate) at a concentration ratio
(mg/ml) of 2:1 to 1:4, the second composition comprises alginate
and a buffer, wherein the buffer has a pH value of between 3.5 to 6
and comprises an acid and its acid addition salt. In another
embodiment, the identities of the constituents, concentrations,
ratios, pH values, particle size, and amounts to be used according
to the methods of the present invention are coherent with the kits
as provided herein.
[0063] In some embodiments the adhesive/sealant is 10 microns to 8
mm thick. In another embodiment, the sealant is 100 microns to 1 mm
thick. In another embodiment, the sealant is 50 microns to 500
microns thick. In another embodiment, the sealant is 200 microns to
500 microns thick. In another embodiment, the adhesive/sealant is
up to 1 cm thick. One skilled in the art will appreciate that
thickens of the adhesive/sealant depends, inter alia, on the mode
of administration and the target site of the sealant/adhesive.
[0064] In another embodiment, forming a sealant further comprises
controlling gelation time, wherein a pH value of the buffer of less
than 4.5 increases gelation time and wherein smaller particle size
of the calcium salt decreases gelation time.
[0065] In another embodiment, further provided herein is an
adhesive/sealant produced or formed by contacting and/or mixing a
first composition comprising alginate and a multivalent cation salt
(e.g., calcium salt) at a concentration ratio (mg/ml) of 2:1 to 1:4
and a second composition comprising alginate and a buffer, wherein
the buffer has a pH value of between 3.5 to 6 and comprises an acid
and its acid addition salt.
[0066] The ability to control crosslinking according to the present
invention is crucial for any medical use as the practitioner can
control gelation/crosslinking rate according to the medical
procedure being formed. In another embodiment, the ability to set
crosslinking rate according to the present invention is crucial for
any medical use as the practitioner can set the crosslinking rate
suitable for the medical procedure being formed.
[0067] In another embodiment, it is important that the
concentration of the salt of the multivalent cation (which is
insoluble in the first liquid composition) is higher than its
stoichiometry with the buffer. In another embodiment, a
concentration of the salt of the multivalent cation higher than its
stoichiometry with the buffer results in a stronger sealant. In
another embodiment, a concentration of the salt of the multivalent
cation higher than its stoichiometry with the buffer results in
favorable sealant physical properties. In another embodiment,
elevating the concentration of the salt of the multivalent cation
beyond its stoichiometry with the buffer, results in a
transparent/lucent adhesive/sealant (a property that can assist the
caregiver with respect to visualizing the area where the
adhesive/sealant is present).
[0068] In another embodiment, the second composition further
comprises a surfactant that further solubilizes the salt of the
multivalent cation (which is insoluble in the first liquid
composition). In another embodiment, the surfactant is a
biocompatible surfactant. In another embodiment, the surfactant is
non-toxic in the concentration of the surfactant utilized.
[0069] Optionally, colorant or other components for controlling
physical/chemical properties of the pre-gel (salts, preservatives,
etc.) can be provided to any of the components of the adhesive.
[0070] In some embodiments, the present invention further provides
that a method for forming a sealant (also synonymous with tissue
adhesive) includes a method of producing a tissue adhesive that
adheres to biological surfaces. In some embodiments, the
adhesive/sealant becomes inert after curing (the result of the
crosslinking and gelation process). In some embodiments, the
present invention further provides that a method for forming an
adhesive/sealant includes a method of in situ application (to a
subject) of the first and second compositions as described herein.
In another embodiment, the first composition is a pre-gel. In
another embodiment, the "first composition" is synonymous with
"pre-gel".
[0071] In another embodiment, a method as described herein
includes: applying an uncured pre-gel to a bodily surface and
subsequently contacting the uncured pre-gel with the second
composition which allows the uncured pre-gel to cure (crosslink)
and to become increasingly adhesive to the bodily surface.
[0072] In another embodiment, the present invention further
provides a first composition and a second composition for forming
an adhesive and/or sealant, wherein the first composition comprises
alginate and a multivalent cation salt at a concentration ratio
(mg/ml) of 30:1 to 1:60, and wherein the second composition
comprises alginate and a buffer, wherein the buffer has a pH value
of between 2 to 7 and comprises an acid and its acid addition salt.
In one embodiment, said adhesive and/or sealant is formed upon
contacting said first composition and said second composition.
[0073] According to some embodiments of the present invention, the
uncured pre-gel is the source of cross-linking agents (multivalent
cations). The multivalent cations and salts comprising the same
are, in some embodiments, in a water-insoluble inactive form, such
that as long as there no actuation/triggering (by the second
composition comprising alginate and a buffer) of the inactive form
no crosslinking can occur.
[0074] In some embodiments, the buffer within the second
composition is the trigger factor. In another embodiment, the term
"triggering" refers to the ability of the buffer to release a
cross-linking agent from its insoluble form, such that the cross
linking agent causes the uncured pre-gel to cure. In another
embodiment, as a result of gaining cohesive strength the
adhesive/sealant resulting from the addition of the second
composition to the first composition is strongly bound/adhered to a
bodily or a biological surface.
[0075] In one embodiment, the adhesive is used for securing/holding
a graft, e.g., a bone graft, artificial bone graft or a bone
healing promoter, in place for a pre-determined time.
[0076] In another embodiment, the present invention further
provides a method for securing or holding a graft in a target site,
the method comprising the step of: (a) providing a first
composition and a second composition, said first composition
comprises a crosslinkable polysaccharide and a multivalent cation
salt at a concentration ratio (mg/ml) of 30:1 to 1:60, said second
composition comprises a crosslinkable polysaccharide and a buffer,
said buffer has a pH value of between 2 to 7 and comprises an acid
and its acid addition salt, (b) applying said first composition and
said second composition to a graft situated at the target site,
thereby securing or holding said graft at the target site.
[0077] In another embodiment, the present invention further
provides a first composition and a second composition for forming
an adhesion barrier in situ, said first composition comprises a
crosslinkable polysaccharide and a multivalent cation salt at a
concentration ratio (mg/ml) of 30:1 to 1:60, said second
composition comprises a crosslinkable polysaccharide and a buffer,
said buffer has a pH value of between 2 to 7 and comprises an acid
and its acid addition salt. In one embodiment, said adhesion
barrier prevents, inhibits, or reduces fibrosis, scarring, and/or
adhesion in a target site.
[0078] In some embodiments of the invention, a solid support is
further integrated with the sealant/adhesive by adding it to the
first composition prior to curing (the addition of the second
composition), to provide additional mechanical strength to the
sealant/adhesive.
[0079] In another embodiment, the sealant is a surgical multi
component adhesive suitable for internal use in a subject. The
adhesive, in some embodiment, is bio-absorbable. In another
embodiment, the adhesive/sealant is absorbed into the body of the
patient within a period of 3 days to 6 months. In another
embodiment, the adhesive/sealant is absorbed into the body of the
patient within a period of 1 to 18 weeks. In another embodiment,
the adhesive/sealant is absorbed into the body of the patient
within a period of 2 to 12 weeks.
[0080] According to one embodiment, a multi component adhesive is
provided that comprises: 1. An uncured pre-gel including a solution
of cross-linkable polysaccharide, such as alginate. The pre-gel may
be lightly cross-linked, yet it is still substantially fluid and
easily administrable to a surface. 2. A second composition carrying
a triggering buffer which activates-solubilizes the previously
insoluble bivalent cation salt present within the uncured pre-gel
(first composition). In another embodiment, the first composition
is a dry uncured pre-gel including a dehydrated solution of
cross-linkable polysaccharide, such as alginate.
[0081] Optionally, pharmaceutical substances such as antibacterial
compounds, antiseptic compounds, drugs, anti-oxidants, growth
factors, therapeutic proteins/peptides or other therapeutic
molecules for wound healing, anti-cancer, anti-arrhythmia, etc. are
incorporated within the first composition and/or second composition
so as to be released from the adhesive/sealant within the area to
be treated.
[0082] In some embodiments, the second composition is contacted
with the first composition at a site to be sealed/adhered. In some
embodiments, contacting the second and the first composition is
embedding, mixing, blending or even laying the second composition
on top of the first composition.
[0083] In another embodiment, a layer of pre-gel is spread or
applied on the tissue or the bodily surface and the second
composition is then contacted with the layer of the pre-gel. In
another embodiment, the pre-gel hardens (being crosslinked) due to
the de-novo solubilization of the multivalent salt.
The Application of the Sealant
[0084] Several methods are used to apply sealant in the site that
requires tissue repair or tissue sealing. (1) A layer of a liquid
pre-gel (comprising an inactive form of a crosslinking agent, for
example insoluble salt of multivalent ions (e.g. CaCO.sub.3 or
CaEGTA)) is spread on the bodily surface, and then the second
composition is contacted with the pre-gel thus forming a sealant.
(2) A layer of a dry pre-gel is placed on the bodily surface, and
then the second composition is contacted with the pre-gel thus
forming an adhesive/sealant. In some embodiments, liquids, such as
saline, are further applied to the site. The caregiver, in some
embodiments, uses a particular buffer and/or particular multivalent
salt for controlling the time period for hardening (curing,
crosslinking) process which renders the combination of the first
composition and the second composition as an adhesive/sealant. In
another embodiment, once the pre-gel is cured (crosslinked), it
loses its adherence capability thus acts as a barrier/sealant.
Adhesion Barriers
[0085] In another embodiment, the present invention provides kits,
methods and compositions for forming an adhesion barrier used to
reduce adhesions in a target site, including but not limited to
traumatized tissue such as following surgery. The adhesion barrier
disclosed herein adheres to the target site in situ. In some
embodiments, said adhesion barrier separates said tissues during
the tissue healing process.
[0086] The present invention is based, in part, on the finding that
alginate-based formulations disclosed herein, can be used as
adhesion barriers, such as in traumatized tissue. As demonstrated
hereinbelow, the capability of alginate-based formulations of the
present invention to perform as adhesion barrier in reduction of
postoperative shoulder stiffness after surgical trauma was assessed
in a rat model. At completion of the experiments, passive shoulder
mechanics, based on angular range of motion (ROM) measurements,
were recorded on the operated shoulders in comparison with the
non-operated shoulder. None to minimal reduction in the total ROM
and negligible shoulder stiffness were found in alginate-treated
animals, as compared to control animals having restricted passive
ROM and notable shoulder stiffness, postoperatively.
[0087] In another embodiment, the present invention provides a
method for preventing, inhibiting or reducing fibrosis, scarring
and/or adhesion in a target site, the method comprising the step
of:
[0088] (a) providing a first composition and a second composition,
said first composition comprises a crosslinkable polysaccharide and
a bivalent cation salt at a concentration ratio (mg/ml) of 3:1 to
1:6, said second composition comprises a crosslinkable
polysaccharide and a buffer, said buffer has a pH value of between
2 to 7 and comprises an acid and its acid addition salt,
[0089] (b) applying said first composition and said second
composition to the target site, thereby forming, in situ, an
adhesion barrier adherent to said target site, thereby preventing,
inhibiting or reducing fibrosis, scarring and/or adhesion of said
traumatized tissues
[0090] In another embodiment, the method of the invention further
comprising the step of mixing said first composition and said
second composition prior to applying said compositions to the
traumatized tissue. According to some embodiments, said mixing step
initiates gelation or crosslinking of said first composition and
said second composition to an adhesive barrier.
[0091] In another embodiment, said target site is a surgical site.
In another embodiment, said target site is a post-operative
surgical site. In another embodiment, said fibrosis, scarring
and/or adhesion results from a surgical procedure. In another
embodiment, said fibrosis, scarring and/or adhesion results from
blunt trauma or a fracture.
[0092] Adhesions are known in the art as abnormal, fibrous bands of
scar tissue that can form inside the body as a result of the
healing process that often follows open or minimally invasive
surgical procedure including abdominal, gynecologic,
cardiothoracic, spinal, plastic, vascular, ENT, ophthalmologic,
urologic, neuro, or orthopedic surgery. Adhesions are typically
connective tissue structures that form between adjacent injured
areas within the body. Briefly, localized areas of injury trigger a
healing response that culminates in healing and scar tissue
formation. If scarring results in the formation of fibrous tissue
bands or adherence of adjacent anatomical structures (that should
normally be separate), adhesion formation is said to have
occurred.
[0093] Post-surgical adhesions are a consequence resulting when
injured or traumatized tissue surfaces, following incision,
cauterization, suturing or other mechanical means of trauma, fuse
together to form scar tissue. Adhesions can also occur in areas
that have undergone blunt trauma or in tissue surrounding
fractures. The mechanism of adhesion formation at a traumatized
area is based on secretion of a tissue exudate, which in turn
induces fibroblast proliferation and consequent formation of
collagenous adhesions. These adhesions scar-up the tissue and lead
to dysfunctional soft tissues.
[0094] Adhesion formation may occur following any surgery or
trauma, and is a source of considerable morbidity. For example,
postoperative intra-abdominal and pelvic adhesions are a leading
cause of infertility, chronic pelvic pain, and intestinal
obstruction. Adhesions forming in the tissue may also irritate
surrounding nerves and disrupt nerve transmissions, resulting in a
significant reduction of sensory or motor function.
[0095] In some embodiments, reducing adhesion includes a decrease
in adhesion formation and does not require complete alleviation of
adhesion signs or symptoms, and does not require a cure. In various
embodiments, reducing adhesion formation includes even a marginal
decrease in adhesion formation by for example at least 5%, 10%,
15%, 20%, 25%, 30%, 35%, 40%, 45% or higher decreases in adhesion
formation or compared to control.
[0096] "Reducing adhesions" refers to administering the first and
second compositions disclosed herein so as to cause a reduction in
the number of adhesions, extent of adhesions (e.g., area), and/or
severity of adhesions (e.g., thickness or resistance to mechanical
or chemical disruption) relative to the number, extent, and/or
severity of adhesions that would occur without such administration.
In various embodiments, reducing adhesions may be part of a
protocol and also include performing a procedure (e.g., subsequent
surgery to reduce adhesions). The compositions or procedure may
inhibit formation, or growth of adhesions following an adhesion
promoting stimulus, may inhibit progression of adhesions, and/or
may inhibit recurrence of adhesions following their spontaneous
regression or following mechanical or chemical disruption.
[0097] "Preventing adhesions" refers to administering the first and
second compositions prior to formation of adhesions in order to
reduce the likelihood that adhesions will form in response to a
particular insult, stimulus, or condition. In various embodiments,
preventing adhesions may be part of a protocol and also include
performing a procedure (e.g., surgery to reduce adhesions). It will
be appreciated that "preventing adhesions" does not require that
the likelihood of adhesion formation is reduced to zero. Instead,
"preventing adhesions" refers to a clinically significant reduction
in the likelihood of adhesion formation following a particular
insult or stimulus, e.g., a clinically significant reduction in the
incidence or number of adhesions in response to a particular
adhesion promoting insult, condition, or stimulus.
[0098] In various embodiments, the adhesion barrier can act as an
adhesion barrier that can be administered or applied to the target
tissue site before, during or after the surgery to reduce, prevent
or inhibit adhesions. In some embodiments, the adhesion barrier
creates a barrier that separates opposing tissue surfaces or
tissue-organ surfaces while injured or traumatized tissues heal. In
growth of scar tissue and the formation or reformation of adhesions
immediately adjacent to the adhesion barrier is thus prevented.
[0099] In another embodiment, said target site is a site of tissue
injury including, but not limited to, sites of incision, drying,
suturing, excision, abrasion, contusion, laceration, anastomosis,
manipulation, prosthetic surgery, curettage, orthopedic surgery,
neurosurgery, cardiovascular surgery, and plastic or reconstructive
surgery. Target sites are also here understood to include
neighboring undamaged tissue. In another embodiment, said target
site is an area that has been exposed to blunt trauma or the soft
tissue surrounding a fracture.
[0100] In some embodiment, the invention has application in various
surgical procedures. In another embodiment, said surgical procedure
is a gynecological surgical procedure (myomectomy via laparotomy or
laparoscopy). According to non-limiting embodiments, during removal
of a fibroid, an incision is made in the uterus, and a barrier can
be formed in between the uterus and the surrounding tissues to
prevent adhesion.
[0101] In another embodiment, said surgical procedure is abdominal
surgery. According to non-limiting embodiments, an adhesion barrier
can be used to prevent peritoneal adhesions and therefore prevent
intestinal obstruction.
[0102] In another embodiment, said surgical procedure is cardiac
surgery. According to non-limiting embodiments, a barrier can be
used to prevent post-operative adhesion after cardiac
procedures.
[0103] In another embodiment, said surgical procedure is
craniofacial surgery. According to non-limiting embodiments, a
barrier can protect the exposed cortex during craniotomy to prevent
the skull and the cortex from adhering.
[0104] In another embodiment, said surgical procedure is
musculoskeletal surgery. According to non-limiting embodiments, a
barrier can prevent adherence of a tendon and the surrounding
tissues.
[0105] In some embodiments, the adhesion barrier is biocompatible.
i.e., does not cause substantial tissue irritation or necrosis at
the target tissue site. It will be appreciated by those with skill
in the art that the first and second composition (forming the
adhesion barrier of the invention) can be administered to the
target site using a "cannula" or "needle", e.g., a syringe, a gun
drug delivery device, or any medical device. The cannula or needle
is typically designed to cause minimal physical and psychological
trauma to the patient. Cannulas or needles include tubes that may
be made from materials, such as for example, polyurethane,
polyurea, polyether(amide), PEBA, thermoplastic elastomeric olefin,
copolyester, and styrenic thermoplastic elastomer, steel, aluminum,
stainless steel, titanium, metal alloys with high non-ferrous metal
content and a low relative proportion of iron, carbon fiber, glass
fiber, plastics, ceramics or combinations thereof. The dimensions
of the hollow cannula or needle, among other things, will depend on
the site for implantation.
[0106] In one embodiment, the term "comprise", and variations
thereof such as "comprises", "comprising" and the like indicate
that the components listed are included, but not generally to the
exclusion of other components. In one embodiment, the term
"comprise", and variations thereof such as "comprises",
"comprising" and the like are substituted with the term "consist"
and all variation of "consist".
[0107] In one embodiment, the amount of a sealant to be applied
depends on the medical procedure that is being preformed, the
severity of the affliction, and the judgment of the caregiver.
[0108] In one embodiment, the compositions for forming a sealant as
described herein are provided to the individual per se. In one
embodiment, a sealant as described herein can be provided to the
individual with a pharmaceutical composition. In one embodiment, a
pharmaceutical composition is mixed within a sealant as described
herein. In one embodiment, a sealant as described herein is a drug
carrier. In one embodiment, a sealant as described herein is an
extended release drug carrier.
[0109] In one embodiment, a sealant as described herein is a
"physiologically acceptable carrier" and/or a "pharmaceutically
acceptable carrier". In another embodiment, additional carriers
and/or polymers are incorporated into the sealant of the invention,
such as but not limited to: polyethylene glycol (PEG), a
biocompatible polymer with a wide range of solubility in both
organic and aqueous media.
[0110] In one embodiment, the first composition, the second
composition, or both further comprise an excipient. In some
embodiments, "excipient" refers to an inert substance added any of
the compositions described herein. In one embodiment, excipients
may include calcium carbonate, calcium phosphate, various sugars
and types of starch, cellulose derivatives, vegetable oils and
polyethylene glycols.
[0111] In some embodiments, compositions as described herein
include solutions or emulsions, which in some embodiments are
aqueous solutions or emulsions. In some embodiments, a composition
as described herein comprises from about 0.01% to about 10.0% w/v
of an active pharmaceutical ingredient.
[0112] Further, in another embodiment, a sealant as described
herein is used for administering, topically to body surfaces, an
active pharmaceutical ingredient.
[0113] In one embodiment, compositions of the present invention are
manufactured by processes well known in the art, e.g., by means of
conventional mixing, dissolving, entrapping or lyophilizing
processes.
[0114] The compositions also comprise, in some embodiments,
preservatives, such as benzalkonium chloride and thimerosal and the
like; chelating agents, such as edetate sodium and others; buffers
such as phosphate, citrate and acetate; tonicity agents such as
sodium chloride, potassium chloride, glycerin, mannitol and others;
antioxidants such as ascorbic acid, acetylcystine, sodium
metabisulfote and others; aromatic agents; viscosity adjustors,
such as polymers, including cellulose and derivatives thereof; and
polyvinyl alcohol and acid and bases to adjust the pH of these
aqueous compositions as needed. The compositions also comprise, in
some embodiments, local anesthetics or other actives.
[0115] In another embodiment, the sealant of the invention is used
as a controlled release system such as similarly to a transdermal
patch, or other modes of administration.
[0116] In some embodiments, at least two composition as described
herein are packed separately in kits. In some embodiments, each
composition may comprise sterile, pyrogen-free water.
[0117] In another embodiment, the combined mix of the first and/or
the second compositions is/are further dried and can be
hydrated.
EXAMPLES
Example 1: Sealant Made of Two Distinct Compositions
[0118] The double liquid sealant results from contacting two
components: the first included alginate (20 mg/ml) and CaCO.sub.3
(30 mg/ml), the second component included alginate (20 mg/ml) and
buffer acetate (acetic acid and sodium acetate salt) (pH 4.5 200
mM).
[0119] The Buffer:
[0120] FIG. 1 demonstrates the differences in the sealant
performance; when the second component of the sealant included
acetic acid 0.5% the burst pressure was surprisingly much lower
than with buffer acetate pH 4.5 200 mM. The pH of the solution
including acetic acid 0.5% was 4.2 and the pH of the buffer was
4.5, the pH values were similar and still, surprisingly, the
resulting sealants were very different. Moreover, it seems that the
actual use of a buffer and not an acid allowed the control over the
reaction end point and gelation). Thus the use of a buffer provides
controlled crosslinking. This feature is crucial when sealant is
prepared during a medical procedure. The caregiver has an obvious
interest in controlling the overall duration and rate of gelation
in accordance to other procedures that are being performed in
parallel at the site of the sealant or at a nearby locus.
[0121] FIG. 2 demonstrates the effect of the pH value of the buffer
on the burst pressure and the strain of break (critical physical
characteristics); higher values of pH yielded on one hand a more
flexible sealant and on the other hand an overall weaker
sealant.
[0122] The reason for this surprising effect is unknown. However,
the quantity of the acid in the buffer; as the pH value ascends the
acid quantity descends in the buffer, probably lead to a lower
dissociation of CaCO.sub.3 and finally to a weaker, softer,
controllable, more flexible gel.
[0123] FIG. 3 demonstrates the effect of the buffer concentration
on the burst pressure; higher concentrations of buffer yielded a
stronger sealant up to a limit. Above the limit the sealant became
brittle and thus the burst pressure values were significantly
lowered.
[0124] Salt Concentration:
[0125] the crucial issue in this parameter is that the salt
concentration must be in excess from the stoichiometric ratio of
the salt within the buffer. Otherwise the gel created was very soft
and ineffective. This fact was discovered in tension tests that
were conducted in order to find the optimal concentration of
CaCO.sub.3 while maintaining the second component at acetic acid
concentration of 0.5%. The concentration of CaCO.sub.3 according
the stoichiometric ratio was 4.37 mg/ml. However, the gels resulted
from concentrations of 3 mg/ml and 4.5 mg/ml were very weak and
could not be tested for strain at break because of their
mellowness.
[0126] The concentration of CaCO.sub.3 according the stoichiometric
ratio regarding buffer acetate pH 4.5 200 mM is 6.4 mg/ml. FIG. 4
shows that as long as the salt concentration within the first
composition/component is in access (according to the stoichiometry
with the buffer) the sealant is stronger and the burst pressure
values are higher thus resulting in superior sealants.
[0127] Particle Size of the Salt:
[0128] The particle size was found to be a very important parameter
that affected the reaction time (see Table 1). It was surprisingly
discovered that smaller particles enhanced gelation.
TABLE-US-00001 TABLE 1 Particle size Gel point (.mu.m) (sec) End of
gelation (min) 80-100 50 10 <40 20 2
[0129] Table 2 exhibits the results of curing tests conducted on a
double liquid composed of two components. The first component:
Alginate (20 mg/ml) and CaNa.sub.2P.sub.2O.sub.7 (10 mg\ml) in
water, second component: Alginate (20 mg/ml) and Acetic acid 0.5%
in water. The quality of the resulting gel in both cases was
similar i.e. the particle size affected only the gelation time.
Another interesting fact is that above a certain concentration the
gelation time was not affected any more by particle size, see Table
2.
TABLE-US-00002 TABLE 2 Particle size (.mu.m) Gel point (sec) End of
gelation (min) >100 5 5 <40 5 5
[0130] Further experiments were conducted on a double liquid
composed of the components wherein the first component included
Alginate (20 mg/ml) and CaNa.sub.2P.sub.2O.sub.7 (50 mg\ml) in
water, and the second component included Alginate (20 mg/ml) and
Acetic acid 0.5% in water. The quality of the gel created in both
cases was similar i.e. the particle size affected gelation time.
The quality of the gel created in both cases was similar.
[0131] Thus particle size variation is used according to the
present invention for controlling gelation time.
[0132] Salt Type:
[0133] Surprisingly the salt type was also found to be a parameter
which affects gelation time and the quality of the gel created (see
the table 3, below).
TABLE-US-00003 TABLE 3 Ca.sup.+2 concentration End of gelation Salt
(mg/ml) Gel point (sec) (min) 1 Ca-stearate 3.4 immediate immediate
gelation CaCO.sub.3 4 15 2 2 CaCO.sub.3 8 10 2
CaNa.sub.2P.sub.2O.sub.7 7.7 5 5 3 Ca.sub.2P.sub.2O.sub.7 2.92 no
gelation CaNa.sub.2P.sub.2O.sub.7 2.92 120 13
[0134] Table 3 shows the difference between salts in the gel
formation point and the gelation end point.
[0135] For Ca-stearate salt, gel formation was faster than for
CaCO.sub.3 salt, the gel created by Ca-stearate was also
surprisingly stronger than the gel created by CaCO.sub.3 salt.
[0136] For CaNa.sub.2P.sub.2O.sub.7 salt, gel formation was faster
than for CaCO.sub.3 salt, but the end point for gelation was faster
for CaCO.sub.3 salt. The gel created by CaCO.sub.3 salt was also
surprisingly stronger than the gel created by
CaNa.sub.2P.sub.2O.sub.7 salt.
[0137] As for Ca.sub.2P.sub.2O.sub.7 salt no gelation occurred in
the tested concentration while for CaNa.sub.2P.sub.2O.sub.7
gelation was apparent at the same concentration.
[0138] Buffer Type:
[0139] The type of buffer also affected gelation point and the
quality of the gel created (see Table 4, below).
TABLE-US-00004 TABLE 4 Salt Buffer type pH Gel point (sec) end of
gelation (min) CaCO.sub.3 Buffer citrate 4.27 20 12 CaCO.sub.3
Buffer acetate 4.5 10 2
[0140] Table 4 exhibits the difference in gel formation point and
in gelation end point, while the pH values of the buffers are
similar.
[0141] Also, the gel created by buffer citrate was firm and
flexible but contained bubbles while the gel created by buffer
acetate was stronger and was free of bubbles.
Example 2: Alginate-Based Formulations Useful for Orthopedic
Adhesion Barriers
[0142] Ten (10) female Sprague Dawley rats weighing 298 to 419
grams were used in the study. All animal procedures were approved
by the Institutional Animal Studies Committee.
[0143] The rats were randomly divided into 3 groups, according to
the following experimental scheme (Table 5):
TABLE-US-00005 TABLE 5 Study design and treatment arms # of
Treatment animal Group Saline physiological solution, 1 ml, ready
to use 3 Control Alginate-Barium containing formulation (Prototype
A), 2 ALG-A prepared aseptically in a separate set of components
packed in vials. The final working formulations are mixed and
filled in dual syringes (delivery system) in the OR, prior to use
Alginate-Calcium containing formulation (Prototype 5 ALG-B B),
prepared aseptically in a separate set of components packed in
vials. The final working formulations are mixed and filled in dual
syringes (delivery system) in the OR, prior to use
[0144] The alginate-barium containing formulation (also denoted
herein "ALG-A") comprised a first composition comprising alginate,
barium carbonate, and sodium carbonate, and a second composition
comprising alginate and acetate buffer.
[0145] The alginate-calcium containing formulation (also denoted
herein "ALG-B") comprised a first composition comprising alginate
and calcium carbonate, and a second composition comprising alginate
and acetate buffer.
[0146] An open approach to the rotator cuff and proximal humerus
was performed using a modified procedure described previously
(Peltz C D et al. J Shoulder Elbow Surg. 2012 July; 21(7):873-81;
Peltz C D et al. J Orthop Res. 2010 July; 28(7):841-5). Briefly,
animals were anesthetized using Isoflurane 1%-2% with an oxygen
carrier by nose cone, Ketamine 90 mg/kg/Xylazine 5 mg/kg IM/IP, and
Buprenorphine 0.05 mg/kg SC. After sterile preparation and draping,
a 2-cm vertical incision was made over the cranio-lateral aspect of
the scapula-humeral joint to expose the deltoid muscle in one of
the animal shoulders. The deltoid muscle was then split using the
Periost surgical tool to form a subacromial intramuscular pocket.
The supraspinatus (SSP) tendon, underlying the deltoid muscle was
kept attached to the greater tuberosity, at its original anatomic
position. After the approach of an open rotator cuff repair was
simulated, the internal surface of the deltoid muscle was scraped
repetitively using an RASP tool. Next, either test (alginate) or
control (saline) material was applied beneath the operative deltoid
muscle. After treatment, the muscle was repositioned at its
original anatomic position and closed by 3-4 interrupted sutures
(Prolene, 3/0). Finally, the skin was closed using Nylon 3/0
suture. The operated shoulders were immobilized in a flexion
position in a plaster cast for 10.+-.2 days. The contralateral
shoulders were left uninjured (non-operated) in all 3 groups.
Throughout follow-up (F/U) period, animals received postoperative
care, including analgesic (Buprenorphine 0.05 mg/kg SC, twice daily
for 3 days) and antibiotic (Ceporex 180 mg/kg SC, once daily, for 5
days) treatment, and were monitored for discomfort, distress, and
pain.
[0147] At the completion of the F/U period (Day 10.+-.2), passive
shoulder mechanics were examined in anesthetized animals
immediately after the immobilization bandage was removed. The full
flexion to full extension angular ranges of motion (ROM) were
measured on both operated and non-operated shoulders, using an
angle measuring tool. Total angular ROM was then calculated by
summing the full flexion and extension ranges. In addition, the
severity of the postoperative stiffness was graded using 0-3 scale
(0=None; 1=Mild; 2=Moderate; 3=Severe).
[0148] The data collected for passive shoulder mechanics
measurements in each animal are provided in Table 6.
TABLE-US-00006 TABLE 6 Passive Shoulder Mechanics Following Open
Surgical Approach to the Rotator Cuff and Proximal Humerus Total
ROM Flexion ROM Extension ROM % of Total Total ROM (degrees)
(degrees) (degrees) ROM Reduction Non- Non- Non- Treatment/
Reduction*** (degrees)** Operated operated Operated operated
Operated operated Animal 63% 85 50 135 60 75 -10 60 Control 1 52%
75 70 145 10 70 60 75 Control 2* 48% 55 60 115 65 55 -5 60 Control
0% 0 135 135 70 70 65 65 ALG-A 1 21% 25 95 120 70 60 25 60 ALG-A 2
4% 5 115 120 65 55 50 65 ALG-B 1 8% 10 115 125 60 65 55 60 ALG-B 2
0% 0 115 115 70 55 45 60 ALG-B 3 11% 15 125 140 70 70 55 70 ALG-B 4
0% 0 120 120 70 65 50 55 ALG-B 5 Control: Untreated shoulders;
ALG-A: Shoulders treated with Alginate-Barium containing
formulation; ALG-B: Shoulders treated with Alginate-Calcium
containing formulation. *In this animal the forelimb was
immobilized in extension position (instead of flexion) **Total ROM
Reduction (degrees) = Non-Operated ROM - Operated ROM ***% of Total
ROM reduction = (1 - Operated ROM/Non-Operated ROM) * 100%
[0149] In three control animals, the total mean ROM of the operated
shoulders was reduced by 71.7.+-.15.3 degrees (54%.+-.8%), as
compared to the non-operated shoulders. In all untreated animals,
the severity of the postoperative stiffness of the operated
shoulders was defined as severe.
[0150] In ALG-A group, one animal showed no change (0%) in the
total ROM of the operated vs. non-operated shoulders. No
post-operative stiffness of the operated shoulders was found in
this animal (Grade: 0). In another animal from the same group,
reduction of 25 degrees (21%) in the total ROM of the operated vs.
non-operated shoulders was recorded, and the postoperative
stiffness of the operated shoulder was graded as mild.
[0151] Five animals in ALG-B group showed total mean ROM reductions
of 6.0.+-.6.5 degrees (5%.+-.5%) on the operated vs. non-operated
shoulders. In these animals, postoperative stiffness of the
operated shoulders was identified as none to very mild.
[0152] Graphical presentation of the total, flexion and extension
ROM outcomes on operated versus non-operated shoulders in all
alginate treated and untreated animals are provided in FIG. 6.
[0153] In this study, an experimental model of the deltoid muscle
injury in the rat subacromial area with following limb
immobilization was used to imitate open proximal humerus surgery,
such an experimental procedure is commonly associated with
formation of postoperative adhesions, stiffness and restricted
mobility of the operated shoulder. In common clinical practice, the
key measures for assessment of the impairments in the shoulder
function and mobility deficits are shoulder range of motion (ROM)
(Kelley M J, et al. J Orthop Sports Phys Ther. 2013 May;
43(5):A1-31). In fact, in the present study the findings of notable
postoperative shoulder stiffness and restricted passive ROM
obtained in control animals support the applicability of the
experimental model for further evaluation of adhesion barrier
systems. In one of the control animals, the operated forelimb was
immobilized in opposite position (extension instead of flexion),
leading to the notable loss of the ROM in opposite direction, as
compared to another control animal. In agreement with Liu et al
(Chin Med J (Engl). 2011 December; 124(23):3939-44), the position
of forelimb fixation is highly correlated with the direction of the
shoulder immobility post-immobilization. Nevertheless, when
measuring the total ROM, by summing flexion and extension, the
shoulder mobility deficits were consistent in both control
animals.
[0154] In alginate-treated animals, as compared to controls,
preserved passive mobility and negligible shoulder stiffness were
noted post-operatively, indicating a potential ability of the
alginate material to prevent adhesion formation in the shoulder
tissues. Alginate gels have been previously suggested to reduce
adhesions after abdominal and colon surgeries in rat model
(Chaturvedi, 2013, ibid. and Chaturvedi, 2014, ibid). In these
studies the alginate gels were formed in the proximity, but were
not attached, to the peritoneal wall or colon; thus potentially
constituting a risk of the gel migration from the target
tissue.
[0155] The alginate formulations of the present invention adhere to
the target tissue area and are, therefore, more effective in
formation of a stable adhesion barrier (FIG. 7). This example
demonstrated the feasibility of two alginate formulations in
providing an adhesion barrier between the deltoid muscle and the
underlying rotator cuff and reduction of postoperative stiffness,
after an open surgical approach to the proximal humerus in a rat
model.
[0156] In the current series of experiments in rat, at Day 10
post-operation the histological findings demonstrate normal tissue
response, reflected by presence of fibrotic tissue at a moderate
extent and no tissue necrosis in the alginate-treated animals. In
addition, alginate material residues were observed in the tissue,
within the deltoid muscle layers at the operation site. More
extensive fibrotic reaction, which may reflect a higher extent of
post-operative adhesions, was noted in the control, untreated
animals (FIG. 7).
Example 3: The Mechanical Properties of the Adhesive
[0157] Alginate solution (68 mg/ml) was mixed with different
concentrations of inactive cross linker and trigger. The different
systems were tested for burst pressure on fresh swine colon. Burst
pressure of at least 75-200 mmHg was reached.
[0158] In order to estimate the effect of trigger concentration on
the mechanical properties of the adhesive, various buffer
concentrations in the alginate\trigger solution were tested.
Samples were tested for burst pressure on fresh swine colon.
[0159] The results showed that buffer concentrations in the range
of 100-700 mM can act as effective triggering compound with a burst
pressure of 25-220 mmHg.
* * * * *