Abstract: A novel BMP/α-TCP composite bone cement was developed by bone tissue engineering
approach. The releasing behavior of BMP from the composite was investigated in vitro through protein releasing testing, compressive
strength measurement and XRD analysis. With the help of histological study and X radiographic examination, the skull defect of rabbit was
repaired by the novel composite bone cement, and α-TCP bone cement was discussed as the control. Results in simulate body environment show
that the rules of BMP releasing from BMP/α-TCP composite agree with Higuchi equation, which indicate that BMP releasing accords with diffusion
model. The setting time of the bone cement is not influenced by the combination of BMP and α-TCP. After BMP releasing, the compressive
strength of materials increases with time, and the value reaches the level hardened pure α-TCP bone cement at fourth week. The crystalline
phase of materials is transferred into hydroxyapatite (HA) with time increasing. Animal experiments confirm the strong osteogenesis capacity of
the novel bone cement. Rabbit skull defect can be well healed with the materials in short period.

Key words: α-tricalcium phosphate （α-TCP）, bone morphogenetic protein （BMP）, bone cement, releasing kinetics, osteogenesis