BMP releasing kinetics and osteogenesis capacity of BMP/α-tricalcium phosphate bone cement

A novel BMP/alpha-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 alpha-TCP bone cement was discussed as the control. Results in simulate body environment show that the rules of BMP releasing from BMP/alpha-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 alpha-TCP. After BMP releasing, the compressive strength of materials increases-with time, and the value reaches the level hardened pure alpha-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.