Evaluation of bone regeneration with biphasic calcium phosphate substitute implanted with bone morphogenetic protein 2 and mesenchymal stem cells in a rabbit calvarial defect model.

OBJECTIVE

The aim of this study was to evaluate the in vivo osteogenic potential of biphasic calcium phosphate (BCP), bone morphogenetic protein 2 (BMP-2), and/or mesenchymal stem cell (MSC) composites by using a rabbit calvarial defect model.

STUDY DESIGN

Bone formation was assessed by using three different kinds of implants in rabbit calvarial defects, BCP alone, BCP/recombinant human (rh) BMP-2, and BCP/rhBMP-2/MSCs composite. The implants were harvested after 2 or 8 weeks, and the area of new bone formation was quantified by micro-computed tomography (micro-CT) and histologic studies.

RESULTS

The highest bone formation was achieved with the BCP/rhBMP-2/MSCs treatment, and it was significantly higher than that achieved with the empty or BCP-alone treatment. The quantity of new bone at 8 weeks was greater than at 4 weeks in each group. The relative density of osteocalcin immunoreactivity also increased during this interval.

CONCLUSIONS

These results indicate that the combination of BCP, rhBMP-2, and MSCs synergistically enhances osteogenic potential during the early healing period and could be used as a bone graft substitute.