The fabrication process, compressive strength and biocompatibility of porous beta-tricalcium phosphate (beta-TCP) ceramic scaffolds reinforced with 45P(2)O(5)-22CaO-25Na(2)O-8MgO bioglass (beta-TCP/BG) were investigated for their suitability as bone engineering materials. Porous beta-TCP/BG scaffolds with macropore sizes of 200-500 muicrom were prepared by coating porous polyurethane template with beta-TCP/BG slurry. The beta-TCP/BG scaffolds showed interconnected porous structures and exhibited enhanced mechanical properties to those pure beta-TCP scaffolds. In order to assess the effects of chemical composition of this bioglass on the behavior of osteoblasts cultured in vitro, porous scaffolds were immersed in simulated body fluid (SBF) for 2 weeks, and original specimens (without soaked in SBF) seeded with MC3T3-E1 were cultured for the same period. The ability of inducing apatite crystals in simulated body fluid and the attachment of osteoblasts were examined. Results suggest that apatite agglomerates are formed on the surface of the beta-TCP/BG scaffolds and its Ca/P molar ratio is approximately 1.42. Controlling the crystallization from the beta-TCP/BG matrix could influence the releasing speed of inorganic ions and further adjust the microenvironment of the solution around the beta-TCP/BG, which could improve the interaction between osteoblasts and the scaffolds.

Unsintering macroporous calcium phosphate scaffolds with macropore sizes of 200∼400μm and hydroxyapatite nanofiber of in-situ growth were prepared by coating porous polyurethane templates with α-tricalcium phosphate bone cement (CPC) slurry, and their subsequent hydrolysis to calcium deficient hydroxyapatite (HAp) during the self-setting processes are presented. The effects of Sr2+ (SrNO3) on the nucleation, growth of the hydroxyapatite nanofiber and phase constitution were studied. The results show that the main component of the coating is HA after hydrolysis for 72h and the Sr2+ added could depress the growth of block or sheet HA crystal and promote the nanowhisker growth. This new processing technique can be used to improve the bioactivity of porous polymer template while maintaining its macroporous structure.

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