title: In situ accelerated degradation of polyoxyethylene/poly(epsilon-caprolactone) multiblock copolymer by moderate thermal treatment.
abstract: Alternating amphiphilic multiblock copolymers, consisting of polyoxyethylene (POE) and poly(epsilon-caprolactone) (PCL) of various lengths, were synthesized by a polycondensation reaction between dicarboxylated PEG and dihydroxyl PCL. The polymer formed a physical hydrogel by PCL crystallization. For in vitro hydrolysis in phosphate-buffered saline solution, the change of molecular weight depended on the composing block length of POE. The polymer with longer POE showed a faster decline in molecular weight. The mass remaining at the end of two weeks at 25 degrees C was more than 95 w%. However, when the swollen hydrogels were exposed to temperatures slightly above PCL melting point for 30 min, the degradation rate was accelerated and the mass remaining dropped to less than 10 wt% in one week. In vivo degradation after hydrogel implantation, the polymer degraded as under in vitro. However, the implant irradiated with infrared (IR) accelerated its degradation similar to a treatment with elevated temperature.
authors.affiliation: Center for Biomaterials and Biotechnology, Department of Materials Science and Engineering, Kwangju Institute of Science and Technology, 1 Oryong-dong, Buk-gu, Gwangju 500-712, South Korea.
authors.forename: Jong-Ho
authors.initials: JH
authors.lastname: Kim
authors.forename: Sang K
authors.initials: SK
authors.lastname: Park
authors.forename: You Han
authors.initials: YH
authors.lastname: Bae
mesh_terms: D002152:Calorimetry, Differential Scanning; D006358:Hot Temperature; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D008970:Molecular Weight; D011091:Polyesters / Q000737:chemistry*; D020959:Polyethylene / Q000737:chemistry*
chemical_list: D011091:Polyesters; C016240:polycaprolactone; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D020959:Polyethylene