In vitro and in vivo behavior of self-reinforced bioabsorbable polymer and self-reinforced bioabsorbable polymer/bioactive glass composites

The aim of this study was to investigate the in vitro and in vivo properties and degradation of (1) self-reinforced (SR) lactide copolymer, P(L/DL)LA 70:30, and (2) SR composites of the same polylactide and bioactive glass 13-93. The following three polymer and polymer-bioactive glass samples were studied: SR-PLA70, SR-PLA70 + BaG15s, and SR-PLA70 + BaG20c. In vitro behavior was studied in a phosphate-buffered saline for 87 weeks at 37 degrees +/- 1 degrees C and a pH of 7.4 +/- 0.2. In vivo behavior was studied by implanting the rods in the dorsal subcutaneous tissue of rats (SR-PLA70 + BaG20c) or rabbits (SR-PLA70 and SR-PLA70 + BaG15s) for 48 weeks. The degradation of the specimens was evaluated by measuring the changes in mechanical properties, crystallinity and molecular weight of polymer, water absorption, weight loss, and structural changes. Results showed that the addition of bioactive glass filler modified the degradation kinetics and material morphology.