Preparation Of Porous Calcium Phosphate Bioceramic Scaffold For Bone Tissue Engineering And Its Performance

The calcium phosphate powders were prepared by direct precipitation and two steps neutralization. Then the powders were mixed with Al2O3-MgO -H3PO4 binder to prepare slurry, and the porous calcium phosphate bioceramic scaffold for bone tissue engineering was fabricated by organic foam impregnation. The morphology and performance of scaffolds was tested and characterized. The biocompatibility and cytotoxicity of scaffolds was studied in vitro. The composition of calcium phosphate powders was analyzed by XRD. The pure calcium phosphate was obtained using direct precipitation from Ca(OH)2 and H3PO4. The powders, which were prepared by two steps neutralization and using CaO,Ca(OH)2 and H3PO4 as precursors, were composite calcium phosphate. Based on the results of thermal gravity(TG) and differ scan caloric(DSC) of the two precipitates, the preparation technology of calcium phosphate powder was confirmed. The porous scaffolds for bone tissue engineering were produced using foam impregnation process with β-TCP and composite calcium phosphate as main materials. In this process, the influences of composition of the powders, sintering temperature, holding time at high temperature and percent of binder on intensity and porosity was studied. Experimental Results showed that the porous scaffolds, which were prepared by composite calcium phosphate, possess better properties. In the case of higher porosity, the intensity value of composite calcium phosphate scaffold was still greater than that of β-TCP scaffold.The fabricating press of porous calcium phosphate bioceramic scaffold was optimized. The scaffold was prepared by sintering at 950℃ for 2 h and non-liner heating, using the composite calcium phosphate powder as main material and binder content of 27 wt%. It has three dimensional open pore structure and the compressive intensity was 14.55 MPa, average porosity 78.73%, these will be satisfactory properties for bone tissue engineering.The cell activity of scaffold was measured by MTT method and no cell cytotoxicity was observed. With the co-culture of scaffold and cell, the good biocompatibility of the scaffold was defined.