title: In situ gelation of PEG-PLGA-PEG triblock copolymer aqueous solutions and degradation thereof.
abstract: Aqueous solutions of poly(ethylene glycol-b-[DL-lactic acid-co-glycolic acid]-b-ethylene glycol) (PEG-PLGA-PEG) triblock copolymers form a free-flowing sol at room temperature and become a gel at body temperature. In this study, in situ gel formation was investigated in rats. Upon subcutaneous injection of 33 wt % aqueous solutions of PEG-PLGA-PEG triblock copolymer into rats, transparent gels were observed. The gel showed good mechanical strength and the integrity of gels persisted longer than 1 month. The gel underwent degradation by hydrolysis and turned opaque. Degradation study showed preferential mass loss of PEG-rich segment from the in situ formed gel. Number average molecular weight determined by gel permeation chromatography decreased from 3300 to 1900 and 30% mass loss was observed over 1 month.
authors.affiliation: Biomedical Polymers Research Building, Room 205, CCCD/Pharmaceutics, University of Utah, Salt Lake City, Utah 84112, USA.
authors.forename: B
authors.initials: B
authors.lastname: Jeong
authors.forename: Y H
authors.initials: YH
authors.lastname: Bae
authors.forename: S W
authors.initials: SW
authors.lastname: Kim
mesh_terms: D000818:Animals; D001672:Biocompatible Materials; D019344:Lactic Acid; D011092:Polyethylene Glycols; D011100:Polyglycolic Acid; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011108:Polymers; D019736:Prostheses and Implants; D019919:Prosthesis Implantation; D051381:Rats
chemical_list: D001672:Biocompatible Materials; D011108:Polymers; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D011092:Polyethylene Glycols