Bone Rebuilding Enhancement Induced by rhBMP-2 solution in Animal Model

Objectives: The aim of our study was to investigate the efficacy of human recombinant bone morphogenetic protein (rhBMP-2) solution on osseogenesis in a rabbit femur model. RhBMP-2 can be produced by human recombinant technique and has a pivotal role in the regulation of bone induction, maintenance, and repair. Regarding osseogenesis, it can enhance ossification and improve the quality of newly formed bone. Methods: RhBMP-2 was prepared in E.coli and purified to homogeneity with the objective of production of a very high grade pure protein species. In vivo experiments were performed in rabbit femur models with 4 weeks of healing period. A 3.3 mm diameter bone wound was prepared in the proximal third of both femurs. On the test side rhBMP-2 solution in concentration of 90 µl rhBMP-2/ml was placed into the bone wound while on the control side the same amount of sterile buffered physiological solution was inserted into the wound. Sacrificing the animals after four weeks of healing period the bone segments were embedded and cut without decalcification using the Exact cutting and grinding system. Results: The measure of osseogenesis was evaluated by histomorphometry. The bone formation in the control bone wound was compared with the rhBMP-2 treated wound by perarea measurement. In the test side where rhBMP-2 solution was inserted, the bony closure of the bone-wound was completed totally, while on the control side the prepared bone wound was filled partially with newly formed bone. Conclusion: Our results proved that the ossification of the rhBMP-2 treated bone wound was significantly enhanced (3 times) as compared to the control site where natural bone healing occurred. The demonstrated efficacy of the rhBMP-2 is of great importance concerning their biomedical applications. Supports: Hungarian-German Intergovernmental Cooperation Program (Project no: D-18/02, GVOP-3.2.1.-2004-04-0408/3.0 Project funded by the Hungarian Ministry of Economy and the EC.