Preparation and assessment of heterotopic osteoinduction of beta-TCP/rhBMP-2 composite

OBJECTIVE: To search for ideal bone graft substitute. METHODS: The beta TCP/rhBMP-2 composite was constructed by combining beta-Tricalcium phosphat (beta-TCP) that was prepared by the authors with recombinant human morphogenetic protein-2 (rhBMP-2) and was implanted into the muscle pouches in the thigh of mice. beta-TCP alone was implanted on the opposite side as controls. At intervals of 1,3,7,14 and 28 days after the implantation, the specimens were obtained, and histologic study and alkaline phosphatase assay (7,14,28 days) were performed. RESULTS: There was a large amount of cartilage and bone formation within the composite, increasing with time; whereas there was no new bone formation where beta-TCP alone was implanted. Besides, the levels of alkaline phosphatase in the beta-TCP/rhBMP-2 implants also were increasing with time and were higher than those in controls. CONCLUSIONS: The results indicate that beta-TCP/rhBMP-2 composite possesses heterotopic osteoinductive potential.