Biopolymer system for tissue sealing
A tissue sealant for use in surgical and medical procedures for sealing the tissues of a living mammal is provided. The tissue sealant comprises a hydrogel which is formed by gelation of a premix disposed on the tissue to be sealed. The premix comprises alkylated chitosan or a gelatin, and a polybasic carboxylic acid or an oxidized polysaccharide, in an aqueous medium. The premix can also include a dehydrating reagent, a carboxyl activating reagent, or both. A specific use of the tissue sealant is in the repair of the dura mater after brain surgery to prevent leakage of cerebrospinal fluid. The tissue sealant may include a therapeutic or protective agent such as an antibiotic or an anti-inflammatory drug.
1. A method of sealing a disrupted biological tissue in need thereof in a living mammal, the method comprising applying to the disrupted biological tissue a biocompatible, biodegradable composition produced by mixing a first solution comprising an acrylated chitosan with a second solution comprising oxidized dextran to produce a mixture comprising from about 1% to about 10% by weight of the acrylated chitosan, wherein the acrylated chitosan has a degree of substitution of a chitosan backbone with acrylate groups in the range of from about 0.25 to about 0.5,
such that, when the mixture is applied to the disrupted biological tissue, the mixture forms a hydrogel within a minute after mixing thereby sealing the biological tissue.
2. The method of claim 1 wherein the biological tissue comprises a meninx of a nervous system organ.
3. The method of claim 2 wherein the nervous system organ comprises brain or spinal cord.
4. The method of claim 1 wherein sealing comprises adhesively sealing.
5. The method of claim 1 wherein the biological tissue comprises blood vessels or musculature.
6. The method of claim 1 wherein the biological tissue comprises the annulus of an intervertebral disk.
7. The method of claim 1 wherein the biological tissue comprises cartilage or bone.
8. The method of claim 1 wherein the biological tissue comprises neural tissue or dermal tissue.
9. The method of claim 8 comprising sealing any laceration, cut, abrasion, or disruption of the dermal tissue.
10. The method of claim 1 comprising adhesively sealing the disrupted biological tissue against leakage of a biological fluid.
11. The method of claim 10 wherein the biological fluid is cerebrospinal fluid.
12. The method of claim 1 comprising reinforcement of a sutured biological tissue.
13. The method of claim 1 comprising holding portions of disrupted biological tissue in mutual proximity.
14. The method of claim 1 comprising filling in a void resulting from tissue removal.
15. The method of claim 1 , wherein the composition further comprises a dye material or a radio-opaque material.
16. The method of claim 1 , wherein the composition further comprises a therapeutic or protective agent.
17. The method of claim 1 , wherein the acrylated chitosan concentration is about 3% to about 7% by weight.
18. The method of claim 1 , wherein the mixture comprises about 5% by weight of the acrylated chitosan.
19. The method of claim 1 , wherein the first solution comprises from about 1% to about 10% acrylated chitosan.
20. The method of claim 1 , wherein the degree of substitution of the acrylated chitosan is in the range from about 0.25 to about 0.45.
21. The method of claim 1 , wherein the degree of substitution of the acrylated chitosan is about 0.5.