Bioadhesive for tissue repair

Abstract

The invention provides a bioadhesive composition comprising a polysaccharide and an energy converter, wherein the energy converter is activated by non-UV light. The composition may be prepared by dissolving the polysaccharide and the energy converter in an aqueous acidic solution. The composition, in the form of a film or a gel, may be used for repairing a discontinuity in an area of tissue or for joining tissue.

1 - 36 . (canceled) 
     
     
         37 . A bioadhesive composition, comprising:
 a polysaccharide; and   an energy converter, the energy converter, when in use, is activated by non-UV light;   the composition being substantially insoluble in water and physiological fluids.   
     
     
         38 . The composition of  claim 37 , wherein the composition does not comprise a protein. 
     
     
         39 . The composition of  claim 37 , wherein, in use, the energy converter is not activated by UV light. 
     
     
         40 . The composition of  claim 37 , wherein the composition is in the form of a film or a gel. 
     
     
         41 . The composition of  claim 37 , wherein the polysaccharide is selected from the group consisting of a positively charged polysaccharide and a negatively charged polysaccharide. 
     
     
         42 . The composition of  claim 37 , wherein the polysaccharide is selected from the group consisting of aminopolysaccharides, chitosan, heparin sulfate, chondroitin sulfate, betaglucans, carrageenan, xantham gum, guar gum, locust bean gum, pectin, galactomannan, acidic polysaccharides, hyaluronic acid and alginate. 
     
     
         43 . The composition of  claim 37 , wherein the polysaccharide is chitosan or chitin. 
     
     
         44 . The composition of  claim 43 , wherein the chitosan has a degree of deacetylation in a range from 0 to about 90 weight %. 
     
     
         45 . The composition of  claim 44 , wherein the degree of deacetylation is greater than 90%. 
     
     
         46 . The composition of  claim 37 , wherein the polysaccharide is covalently linked to a photoreactive group. 
     
     
         47 . The composition of  claim 37 , wherein the energy converter is a light converter. 
     
     
         48 . The composition of  claim 37 , wherein, in use, the energy converter is activated by light of ≧wavelength 400 μm. 
     
     
         49 . The composition of  claim 37 , wherein the energy converter is selected from the group consisting of water, D 2 O, carboxylated camphorquinone, a genipin dye, squid ink, melanin, and indocyanine green. 
     
     
         50 . The composition of  claim 37 , in which the energy converter is capable of functioning as a cross-linker. 
     
     
         51 . The composition of  claim 37 , wherein the energy converter is a genipin dye. 
     
     
         52 . The composition of  claim 37 , wherein energy converter has a the concentration in the composition of about 0.01 to about 5 wt %, 
     
     
         53 . The composition of  claim 40 , wherein the composition is in the form of a film, and the film has a thickness of about 5 microns to about 5 mm. 
     
     
         54 . The composition of  claim 37 , further comprising one or more cross-linking agents. 
     
     
         55 . The composition of  claim 37 , further comprising one or more additives selected from the group consisting of therapeutic agents, bacteriostats, wound healing agents, antimicrobials, preservatives, antioxidants, antifungals and antibacterials. 
     
     
         56 . A process for preparing a light activatable bioadhesive composition, comprising:
 dissolving a polysaccharide and a light converter in an aqueous acidic solution;   wherein the composition does not comprise a protein; and   wherein, in use, the light converter is not activated by UV light.   
     
     
         57 . The process of  claim 56 , further comprising drying the composition to produce a light activatable bioadhesive film. 
     
     
         58 . The process of  claim 56 , further comprising impregnating or coating treating the composition with a therapeutic agent. 
     
     
         59 . The process of  claim 56 , further comprising adding a therapeutic agent to the aqueous acidic solution. 
     
     
         60 . The process of  claim 56 , wherein the polysaccharide is chitosan. 
     
     
         61 . The process of  claim 60 , further comprising dissolving the chitosan in the aqueous acidic solution at a concentration in the range of about 1% to about 20%. 
     
     
         62 . The process of  claim 56 , further comprising irradiating the composition with light source. 
     
     
         63 . The process of  claim 61 , wherein the light source is a laser. 
     
     
         64 . The process of  claim 62 , wherein the light has a wavelength of ≧400 nm. 
     
     
         65 . A method for repairing a discontinuity in an area of tissue, comprising:
 applying at least one light activatable bioadhesive film to a first area of tissue to be repaired, thereby partially or fully covering the first area of tissue to be repaired by the at least one film; and   irradiating the at least one film with non-UV light from a light source;
 wherein the film comprises a polysaccharide, and an energy converter activated by non-UV light and not activated by UV light; and
 wherein the film does not comprise a protein. 
 
   
     
     
         66 . The method of  claim 65 , further comprising applying a bioadhesive gel to either an second area of tissue near the first area of tissue to be repaired or to the bioadhesive film prior to contacting the first area of tissue to be repaired with the bioadhesive film;
 wherein the bioadhesive gel, comprises a polysaccharide, and an energy convener activated by non-UV light.   
     
     
         67 . A method for repairing a discontinuity in an area of tissue, comprising:
 applying a light activatable bioadhesive gel to a first area of tissue to be repaired, thereby partially or fully covering the first area of tissue to be repaired by the gel; and   irradiating the gel with non-UV light from a right source;
 wherein the gel comprises a polysaccharide, and an energy converter activated by non-UV light and not activated by UV light; and
 wherein the gel does not comprise a protein. 
 
   
     
     
         68 . A method of joining tissue, comprising:
 aligning and abutting edges of tissue to be joined;   applying at least one light activatable bioadhesive film or a light activatable bioadhesive gel to the edges to be joined, thereby partially or fully covering the edges to be joined; and   irradiating the film or the gel with non-UV light from a light source;
 wherein the film or gel comprises a polysaccharide, and an energy converter activated by non-UV light and not activated by UV light; and
 wherein the film and gel do not comprise a protein. 
 
   
     
     
         69 . A method of sealing a leak or tear in a tissue, comprising applying the composition according to  claim 37  to an area of tissue. 
     
     
         70 . A process for preparing a bioadhesive composition, comprising:
 combining a non-water-soluble polysaccharide, an acidic medium, and an energy converter, the energy converter when in use is not activated by UV light, to form a mixture; and   dehydrating the mixture to form the composition;   wherein the composition does not comprise a protein.   
     
     
         71 . A bioadhesive composition comprising a composition made by the process of  claim 70 . 
     
     
         72 . The bioadhesive composition according to  claim 71 , wherein the composition is selected from the group consisting of a solid composition and a gelled composition.