| Due to their excellent biocompatibility, similarity to inorganic components of bone, bone conductivity and chemical binding with bone, the bio-ceramics have been payed more and more attentions from material and medical experts. Among them, the HA/β-TCP biphasic calcium phosphate have been more widely used owing to their biodegradation, bioactivity and osteogenic activity. The wet synthesizing method was applied to prepare the biphasic calcium phosphate ceramic powder using the raw materials of calcium carbonate (CaCO3) and phosphoric acid (H3PO4). The porous biphasic calcium phosphate ceramic scaffold was prepared via the steps including the impregnating into the porous foam carrier of the biphasic calcium phosphate ceramic slurry and sintering of the scaffold. Specially, the polyurethane porous foam carrier was reformed by laser cutting molding technology. Moreover, the obtained porous biphasic calcium phosphate scaffolds were combined with gelatin, silica and calcium sulfate, respectively, to get porous (SiO2, gelatin, CaSO4)/biphasic calcium phosphate scaffolds. The composition, structure and the properties of the porous scaffolds were investigated and the results were shown as following.(1) The biphasic calcium phosphate ceramic powders were obtained by wet synthesizing method, using the raw materials of calcium carbonate (CaCO3) and phosphoric acid (H3PO4). The biphasic calcium phosphate ceramic powder was composed with two phase, which are respectively named β-TCP and HAP. The main phase of the powder is β-TCP (accounts for 81.6 wt%). The grain size of the powder was between 0.2-20μm. The cytotoxicity tests showed the biphasic calcium phosphate ceramic powder had no cytotoxic effect.(2) The porous biphasic calcium phosphate ceramic scaffold was prepared by impregnating into the porous foam carrier of the biphasic calcium phosphate ceramic slurry and sintering of the scaffold. The composition of the scaffold was HA and β-TCP, similar to the powder. The main phase of the scaffold was β-TCP, account for79.3%,73.1% and 71.7%, respectively, due to the different density of the polyurethane porous foam carrier. The pore structure of the scaffold contained straight-through holes with the diameter of 0.9-1.0mm and three-dimensional irregular through-holes with the diameter of 200-800μm,200-500μm and 100-500μm, respectively, according to the different density of the polyurethane porous foam carrier. The porous scaffolds exhibited 0.1-0.4MPa of compressive strength, and the compressive strength increased with the decreasing of the density of the density of the polyurethane porous foam carrier. The cytotoxicity tests showed the biphasic calcium phosphate scaffolds was no cytotoxic effect.(3) The porous silica/biphasic calcium phosphate scaffolds were fabricated via the steps including soaking in the silica gel and sintering. The porous gelatin/biphasic calcium phosphate scaffolds were prepared by the steps including soaking in gelatin solution (count for 4wt%) and cross-linking with glutaraldehyde. The porous CaSO4/ biphasic calcium phosphate scaffolds were obtained by infusion of calcium sulfate into the pores of the biphasic calcium phosphate scaffolds. The pore structure of the silica/ biphasic calcium phosphate scaffolds and gelatin/biphasic calcium phosphate scaffolds contained straight-through holes and three-dimensional irregular through-holes. The size of the straight-through holes of the above scaffolds was 700-900μm. The diameters of three-dimensional irregular through-holes of silica/biphasic calcium phosphate scaffolds were 300-500μm,200-350μm and 100-300μm, respectively. The diameters of three-dimensional irregular through-holes of gelatin/biphasic calcium phosphate scaffolds were 300-500μm,300-500μm and 300-400μm, respectively. The in vitro degradation experiments revealed that the whole three scaffold exhibited excellent bioactivity according to the depositing of the hydroxyapatite. Three kinds of porous scaffolds exhibited 0.7-1.6MPa,0.8-1.2MPa and 0.7-1.6MPa of compressive strength, respectively. The degradation rate decreased with the increasing of the density of the density of the polyurethane porous foam carrier. Specially, The degradation period of the porous CaSO4/biphasic calcium phosphate scaffolds was about 90days. The cytotoxicity tests showed the whole three scaffolds had no cytotoxic effect.
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