CHITOSAN AND POLYETHYLENE GLYCOL COPOLYMERS AND METHODS AND DEVICES FOR USING SAME FOR SEALING A VASCULAR PUNCTURE
A sealant is provided for sealing a puncture through tissue that comprises an elongate first section including a proximal end, a distal end, and a cross-section sized for delivery into a puncture through tissue, and a second section extending from the distal end of the first section. The first section may be formed from a freeze-dried hydrogel that expands when exposed to physiological fluid within a puncture. The first section comprises chitosan and at least one additional polymer. The second section may be formed from a solid mass of non-freeze-dried, non-cross-linked hydrogel precursors. The precursors are in an unreactive state until exposed to an aqueous physiological environment, whereupon the precursors undergo in-situ crosslinking with one another to provide an adhesive layer bonded to the first section. The second section may further comprise chitosan. Apparatus and methods for delivering the sealant into a puncture through tissue are also provided.
1 - 41 . (canceled)
42 . A vascular sealant comprising
a first elongated section with a proximal and distal end comprising a copolymer with
a biodegradable polysaccharide having hemostatic and/or procoagulative properties, and a mixture of amine modified polyethylene glycol (PEG) and ester modified PEG polymers,
wherein the polysaccharide is covalently bound to the mixture of PEG polymers; and
a second section extending from the distal end of the first section comprising non-cross-linked precursors of amine modified PEG and ester modified PEG.
43 . The vascular sealant of claim 42 , wherein the biodegradable polysaccharide is deacetylated chitin.
44 . The vascular sealant of claim 42 , wherein the biodegradable polysaccharide is chitosan.
45 . The vascular sealant of claim 42 , wherein the copolymer in the first section forms a hydrogel.
46 . The vascular sealant of claim 42 , wherein amine modified PEG and ester modified PEG are present in a molar ratio of between 4:1 and 1:4.
47 . The vascular sealant of claim 42 , wherein amine modified PEG and ester modified PEG are present in a ratio of equivalent active groups between a range from about 0.1 to about 5.
48 . The vascular sealant of claim 42 , wherein the copolymer is freeze-dried.
49 . The vascular sealant of claim 43 , wherein the chitin is at least partially deacetlyated.
50 . The vascular sealant of claim 49 , wherein the chitin has a degree of deacetylation of at least 60%.
51 . The vascular sealant of claim 42 , wherein the polysaccharide is chitosan having a molecular weight between about 10 kilodaltons and about 600 kilodaltons.
52 . The vascular sealant of claim 43 , wherein the chitosan is selected from free chitosan, chitosan chloride, chitosan glutamate, chitosan acetate, chitosan dicarboxylic acid salts, chitosan adipate, chitosan succinate, chitosan fumarate, or combinations thereof.
53 . The vascular sealant of claim 42 , wherein the first section comprises between about 0.1% and about 30% (by weight) chitosan.
54 . The vascular sealant of claim 42 , wherein the second section extends from a distal end of the first section.
55 . The vascular sealant of claim 42 , wherein the amine modified PEG and ester modified PEG are in equimolar amounts.
56 . The vascular sealant of claim 42 , wherein the first elongated section is sized for delivery into a puncture through tissue.
57 . A polymer composition comprising chitosan and a mixture of amine modified PEG and ester modified PEG polymers,
wherein the mixture comprises equimolar quantities of the amine modified PEG and the ester modified PEG polymers; and
wherein the composition forms a partially cross-linked mesh network.
58 . The polymer composition of claim 57 , wherein amine modified PEG and ester modified PEG polymers are present in a ratio of equivalent active groups between a range from about 0.1 to about 5.
59 . The polymer composition of claim 57 , wherein the chitosan has a molecular weight between about 10 kilodaltons and about 600 kilodaltons.
60 . The polymer composition of claim 57 , wherein the chitosan is selected from free chitosan, chitosan chloride, chitosan glutamate, chitosan acetate, chitosan dicarboxylic acid salts, chitosan adipate, chitosan succinate, chitosan fumarate, or combinations thereof.
61 . A method for producing a two section porous polymer sealant comprising
producing a first section by
combining chitosan with an equimolar mixture of amine modified PEG and ester modified PEG polymers to form a hydrogel,
wherein chitosan and the amine modified PEG and ester modified PEG polymers are covalently bound and form a porous hydrogel material; and
freeze drying the hydrogel; and
producing a second section by
applying non-cross-linked precursors of the amine modified PEG and the ester modified PEG polymers to an end of the first section.