title: In vitro degradation of nanoparticles prepared from polymers based on DL-lactide, glycolide and poly(ethylene oxide).
abstract: Nanoparticles of poly(DL-lactic acid) (PDLLA), poly(DL-lactic-co-glycolic acid) (PLGA) and poly(ethylene oxide)-PLGA diblock copolymer (PEO-PLGA) were prepared by the salting-out method. The in vitro degradation of PDLLA, PLGA and PEO-PLGA nanoparticles in PBS (pH 7.4) at 37 degrees C was studied. The particle size, molecular weight of the polymers and the amount of lactic and glycolic acids formed were followed in time. PDLLA nanoparticles gradually degraded over a period of 2 years and retain their size during that period. A faster degradation was observed for PLGA nanoparticles, which was nearly complete after 10 weeks. PLGA nanoparticles retained their size during that period. In PEO-PLGA nanoparticles, the ester bond connecting the PEO and the PLGA segments was preferentially cleaved, which led to a relatively fast decrease in molecular weight and to (partial) aggregation, as multimodal size distributions were observed. PEO-PLGA nanoparticles were almost completely degraded within 8 weeks.
authors.affiliation: Department of Polymer Chemistry and Biomaterials, Institute for Biomedical Technology, Faculty of Science and Technology, Twente University, P.O. Box 217, 7500 AE Enschede, The Netherlands.
authors.forename: Miechel L T
authors.initials: ML
authors.lastname: Zweers
authors.forename: Gerard H M
authors.initials: GH
authors.lastname: Engbers
authors.forename: Dirk W
authors.initials: DW
authors.lastname: Grijpma
authors.forename: Jan
authors.initials: J
authors.lastname: Feijen
mesh_terms: D000465:Algorithms; D004339:Drug Compounding; D004355:Drug Stability; D005079:Excipients / Q000737:chemistry*; D019344:Lactic Acid / Q000737:chemistry; D008863:Microspheres; D008970:Molecular Weight; D010316:Particle Size; D011091:Polyesters / Q000737:chemistry*; D011092:Polyethylene Glycols / Q000737:chemistry*; D011100:Polyglycolic Acid / Q000737:chemistry*; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011108:Polymers / Q000737:chemistry
chemical_list: D005079:Excipients; D011091:Polyesters; D011108:Polymers; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D011092:Polyethylene Glycols; C033616:poly(lactide)