Effect of β-tricalcium phosphate addition on the in vitro degradation of self-reinforced poly-L,D-lactide

The composite containing 20 wt% of osteoconductive beta-tricalcium phosphate and 80 wt% of bioabsorbable Poly-L,D-lactide (LL/DD dimer ratio 96/4) was manufactured using twin-screw extruder and self-reinforcing technique. The self-reinforcing created the porous surface and increased the mechanical properties of the composites. The in vitro degradation behavior of the self-reinforced composite was investigated comparatively with plain self-reinforced matrix polymer. The samples studied were characterized determining the changes in mechanical properties, thermal properties, molecular weight, mass loss and water absorption in phosphate buffered saline at 37 degrees C for up to 104 weeks. The results showed that the presence of the beta-tricalcium phosphate modified the degradation of the matrix polymer. The degradation rate of the self-reinforced composites was slower than the degradation rate of the self-reinforced matrix polymer. (c) 2005 Elsevier Ltd. All rights reserved.