Preparation and characterisation of composites based on biodegradable polymers for "in vivo" application

Poly(L-lactic) acid (PLLA), polycaprolactone (PCL), three different copolym ers based on poly(L-lactic) acid and polyglycolic acid (PLLA-co-PGA), and t heir composites with hydroxyapatite obtained from bovine bone (ossein), wer e tested in order to have information on the thermal, morphological, mechan ical and biochemical properties in view of their use as biocompatible/biode gradable materials. Ossein, which is essentially a biological hydroxyapatit e, was found to improve the modulus and increase the hydrophilicity of the polymeric substrate. In addition, the size of the ossein particles was foun d to be critical for the improvement of mechanical properties. Finally, pre liminary results on the in vitro biocompatibility of selected blends carrie d out by using primary cultures of human osteoblasts showed that the presen ce of hydroxyapatite stimulates a more positive cellular response. (C) 2000 Elsevier Science Ltd. All rights reserved.