Patent ID: 7642329

Claim:
An oligomeric lactide macromer based copolymer having a general formula [A (x) B (y) ] n wherein A is an oligomeric lactide macromer selected from the group consisting of oligo (lactide) acrylate and oligo (lactide) methacrylate and having a degree of polymerization of from 2 to 10; B is a basic monomer; selected from the group consisting of dimethyl amino ethyl methacrylate, dimethyl amino ethyl acrylate, diethyl amino ethyl methacrylate, diethyl amino ethyl acrylate, piperidine ethyl methacrylate and 2-tert-butyl amino ethyl methacrylate; x is from 1 to 4; y is from 3 to 7; and n is from 1 to 5, wherein a molecular weight of the oligomeric lactide macromer is from 500 to 1000, wherein the copolymer has a molecular weight of from 1000 to 5000, and wherein the copolymer is soluble in an aqueous medium at a pH of from 1.8 to 7.4.