Patent ID: 8835492
Filing Date: 2014-09-16
Classification: C08G,C08L

Abstract:
1. A block copolymer formed of: (a) a copolymer block (A) of a polyethylene glycol and a biodegradable polyester polymer; and (b) a poly(β-amino ester) oligomer block (B), wherein the biodegradable polyester polymer is at least one polymer selected from the group consisting of polylactide, polyglycolide, polycaprolactone, poly(caprolactone-lactide) random copolymer, poly(caprolactone-glycolide) random copolymer, and poly(lactide-glycolide) random copolymer, wherein the copolymer block (A) has an acrylate group at a terminal end of the biodegradable polyester polymer; wherein the poly(β-amino ester) oligomer block (B) is coupled to only the biodegradable polyester polymer in the copolymer block (A) by a directed bond at the acrylate group terminal of the biodegradable polyester polymer; and wherein the block copolymer shows an reversible sol-gel transition by a change in temperature and pH, and forms a hydrogel by sol-gel transition at a pH ranging from 7.2 to 7.4 and maintains a sol state at a pH ranging from 6.0 to 7.2.