Preparation Of Hydroxyapatite Powder And Porous Hydroxyapatite Scaffolds

Hydroxyapatite(HA) powder was prepared by sol-gel method with Ca(NO3 ).4H2O and P2O5 ethanol solution. This process was simple and reactants were cheap compared with other methods. The phase structures were studied by XRD. The results showed that 600℃ seemed to be the appropriate temperature to prepare the fine HA powder. The ageing of the sol influenced the purity greatly. The CaO phase was observed in the powder without ageing .The ageing could increase the stabilization of HA. Proportion of Ca/P influenced HA powder's structure and quality greatly. Proportion of Ca/P was controlled to be 1.67 was the key of preparation of pure HA powder. Concentration was also very important. The higher the concentration was, the lower the sinter temperature was needed. This process was simple and appropriate to produce HA powder in large quantities.In this study, we also reported two novel methods to prepare HA porous scaffolds. One was polymer sponge method, the other was integrating the gel-casting technique with polymer sponge method to prepare HA porous scaffolds. The pore morphology, size, and distribution of the scaffolds were characterized using a electron microscope. The scaffolds prepared by both methods have an open, uniform and interconnected porous structure with a pore size of 300μm-500μm. The later method could prepare HA porous scaffolds with improved mechanical strength compared with the former one.The porous biomaterial was proved to have a good compatible by vitro cellular assay. The osteoblast-like cells were attached and spread well throughout the porous scaffold. Compressive yield strength and the porosity of the open pores in the scaffold could be controlled by changing HA concentration .