In situ gelation of PEG-PLGA-PEG triblock copolymer aqueous solutions and degradation thereof

J Biomed Mater Res. 2000 May;50(2):171-7. doi: 10.1002/(sici)1097-4636(200005)50:2<171::aid-jbm11>3.0.co;2-f.

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Biocompatible Materials*
  • Lactic Acid*
  • Polyethylene Glycols*
  • Polyglycolic Acid*
  • Polylactic Acid-Polyglycolic Acid Copolymer
  • Polymers*
  • Prostheses and Implants*
  • Prosthesis Implantation
  • Rats

Substances

  • Biocompatible Materials
  • Polymers
  • Polylactic Acid-Polyglycolic Acid Copolymer
  • Polyglycolic Acid
  • Lactic Acid
  • Polyethylene Glycols