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In vitro degradation of polylactide and poly(lactide‐ co ‐glycolide) microspheres
Author(s) -
Zhu JiaHuei,
Shen ZhengRong,
Wu LanTing,
Yang ShiLin
Publication year - 1991
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.1991.070431117
Subject(s) - plga , gel permeation chromatography , lactide , glycolic acid , copolymer , polymer chemistry , materials science , degradation (telecommunications) , solvent , scanning electron microscope , polyester , nuclear chemistry , polymerization , lactic acid , chemical engineering , chemistry , polymer , organic chemistry , composite material , nanoparticle , nanotechnology , telecommunications , biology , bacteria , computer science , engineering , genetics
Polyactide (PLA) and poly(lactide‐ co ‐glycolide) (PLGA) were prepared by bulk ring‐opening polymerization of lactide or lactide/glycolide using stannous octoate as initiator. PLA and PLGA microspheres with an average diameter of 65–100 μm were prepared by a solvent evaporation process. An in vitro degradation test of different molecular weight PLA and of different composition PLGA were carried out in pH 7.4 buffer solution at 37°C in the form of microspheres. Quantitatively, the degree of degradation was monitored by gel permeation chromatography (GPC), by measurement of mass loss and determination of lactic/glycolic acid in degradation medium, and qualitatively, by observing the morphological changes of microspheres with a scanning electron microscope (SEM). The decrease in weight average molecular weight ( M w ) for PLA with higher molecular weight is faster at the first degradation stage; afterward, the tendency of M w to decrease for PLA with different molecular weight is almost the same. PLGA degrades much faster than does PLA, and the degradation rate is significantly enhanced with the increase of glycolic acid (GA) content in copolymers.