ELABORATION AND EVALUATION OF A COMPOSITE BONE SUBSTITUTE BASED ON beta-TCP/DCPD AND PHBV, PRELIMINARY RESULTS

International audienceObjective: In the present study, we investigate the biological performance of a calcium phosphate ceramics (CPC) bone substitute combined with poly-hydroxybutyrate-co-hydroxyvalerate (PHBV). Materials and Methods: A particulate CPC [45% beta-tricalcium phosphate (beta-TCP) and 55% of dihydrated dicalcium phosphate (DCPD)] was incorporated into a biodegradable copolymer PHBV. Two series of the composite, 1 and 2, with CPC-PHBV weight ratios of (40%-60% and 60%-40%), respectively, were prepared using chloroform for dissolving the polymer and a pressure molding process for shaping the composite samples. After particle size analysis, the two composites were characterized by scanning electron microscopy (SEM) and energy dispersive spectrometry (EDS). In a second step, a 10mm bony segmental defect created in the tibias of 20 New Zealand White Rabbits was filled randomly with either composite 1 for group 1 or composite 2 for group 2. There were 10 animals in each group. Clinical, radiological and histological assessments were then carried out to evaluate the biological properties of developed CPC-PHBV composites. Results: For both variants of the developed CPC-PHBV biocomposite, there was evidence of osseous consolidation within three months. An in vivo investigation revealed the biological properties of the biocomposite, namely, biocompatibility, bioactivity, biodegradability and osteoconductivity. The morphological characteristics, granule size and chemical composition, were indeed found to be favorable for osseous cell development. This study likewise showed lower mortality for the variant with weight ratio (40% CPC-60% PHBV). Conclusion: An in vivo investigation revealed that the new biomaterial composed of CPC and PHBV exhibits manifest osteoconductivity and bioactivity with better degradation kinetics than the CPC. Moreover, the variant with 40%CPC/60% PHBV appeared more resistant to infection than the 60%CPC/40% PHBV which is an indicator of biocompatibility