The preparation and the ability of the morselized bone in repairing bone defects

Objective To explore the degradation characteristics of the composite of calcium polyphosphate fiber(cPPF),calcium phosphate cement(CPC),micromorselized bone in vitro and the ability in repairing bone defoem in vivo.Methods A blend method was developed to prepare the composite of diameter was observed by scanning electron microscope.In vitro,the composite was put into PBS(pH 7.4);the PH value,weight and biomechanics of them were determined during the degradation.In vivo,the effect was observed by gross,X-ray,histopathologieal,scanning eleetron microscopic and dynamic examinations 2,4,8,12 weeks after operation.Results In vitro,scaning electron microscopy revealed that the pore diameter 0f CPPF/CPC/micromorselized bone composite was 100-400 μm,the porosity was 72.1%,while the CPC/micromorselized bone composite was 50-300 μm,the porosity was 58.2%.During degradation,the pH values of both the two composite were kept steady at the end of 12th week.The weight of CPPF/CPC/micmmorselized bone was slighdy decreased within 4 weeks,then decreased obviously and remained 50%of its prime weight at the end of the 12th week:while the weight of CPC/mieromorselized bone was slightly decreased within 6 weeks,then decreased obviously and remained 70% of its prime weight at the end of the 12th week.The prime biomechanieal strength was 9.28 Mpa in CPPF/CPC/micromorselized bone and 6.21 Mpa in CPC/micromorselized b0He respectively.There was significant difierence between them ( P＜0.05 ).The strength of CPPF/CPC/miemmorselized bone was decreased slowly within 4 weeks,then decreased obviously and was 0.18 Mpa at the end of 12th week:the strength of CPC/micromomelized bone was decreased symmetrically and was 0.24 Mpa at the end of 12 week.In vivo,the ability of CPPF/CPC/micromorselized bone in repairing bone defoct was better than the other groups.There was significant difierence between them ( P＜0.05).Conclusion The composite of CPPF/CPC/mieromorselized bone may be one of ideal scaffolds engineering for its good biocharacteristies in repairing bone defect in bone engineering. Key words: Calcium phosphate; Bone; Degradation; Bone defect