Synthesis, characterization, thermal stability, and in vitro and in vivo degradation study of polycaprolactone and polyglycolide block copolymers

Abstract

Biodegradable polymer materials are attractive in various biomedical applications. Herein, we report a block aliphatic copolymer, polycaprolactone-<i>block</i>-polyglycolide (PCL-<i>b</i>-PGA, denoted as PCLGA), and explored the polymer composition effect on the thermal and degradation behaviors. Three copolymers with different PCL/PGA weight ratios were obtained by a two-step ring opening polymerization. The chemical structures and compositions of copolymers were studied by NMR and FT-IR. The thermal behaviors were investigated by DSC and TGA. The <i>in vitro</i> degradation in phosphate buffer saline and <i>in vivo</i> degradation as an implant in rats were evaluated and the hygroscopic rate and polymer weight loss changes were monitored in an eight-week period. PCLGA with a higher PCL composition showed a slower degradation <i>in vitro</i> and <i>in vivo</i>. These PCLGAs with different degradation rates could be used as biomedical implants for potential application in drug delivery and tissue repair.