A biocompatible tissue-bonding adhesive composition having a polyol of functionality N. The polyol being terminated has at least one polyisocyanate in solution with at least (N−1)% of the solution having free polyisocyanate. N may be in the range 1.5-8. The polyol may be a branched polypropylene/polyethylene oxide copolymer.
1. A method for covalent bonding of tissue, which comprises:
providing a cyanate-terminated hydrophilic prepolymer comprising:
a copolymer comprising polyether monomers and from 10% to 30% of propylene oxide monomers;
from 23 to 39 wt. % of at least one polyisocyanate selected from the group consisting of 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, and isophorone diisocyanate; and
from 1 to 5 wt. % of trimethylolpropane;
wherein the prepolymer is a liquid, water-soluble, and comprises from 1.5 to 5% free polyisocyanate content; and
applying said prepolymer to tissue such that said prepolymer forms a bond with such tissue.
2. The method of claim 1 , further comprising dissolving the prepolymer in water at a prepolymer to water ratio of 10:1 to 20:1.
3. The method of claim 1 wherein the prepolymer has a viscosity less than 20,000 cps.
4. The method of claim 1 wherein the prepolymer has a viscosity less than 10,000 cps.
5. The method of claim 1 wherein the prepolymer has a solid to liquid transition temperature of less than 20° C.
6. The method of claim 1 wherein the copolymer of polyether monomers comprises PE/PO in a ratio of 80:20.
7. The method of claim 1 wherein the copolymer of polyether monomers is a random copolymer.
8. The method of claim 1 wherein the copolymer of polyether monomers is a block copolymer.
9. The method of claim 1 wherein the prepolymer bonds to tissue in less than 120 seconds.
10. The method of claim 1 wherein the copolymer has a molecular weight of from 800 to 5,000.