Osteoformin accelerates fresh fracture healing in rats.

PURPOSE: Negatively charged resins have been shown to stimulate bone repair. In previous studies, the negatively charged polypeptide polyaspartate, which has been named Osteoformin, has been shown to stimulate osteoblast differentiation in vitro. The objective of the current study was to investigate the potential effect of Osteoformin on experimental femoral fracture healing in vivo. MATERIALS AND METHODS: Thirty-six male Sprague-Dawley rats were used. The femurs of anesthetized rats were stabilized with intramedullary pins and subjected to closed midshaft transverse facture by bending to failure. In experimental rats, fracture sites were injected with 100 microg of Osteoformin dissolved in 0.1 mL phosphate buffered saline (PBS) at day 1 and day 7 after surgery; in controls groups, fracture sites received 0.1 mL PBS at the intervals indicated above. Between 2 and 4 weeks after fracture, the animals were sacrificed and the healing femurs were removed for radiographic and histologic analysis. RESULTS: Osteoformin decreased the healing time of fresh fractures in rats, as indicated by histologic and radiographic assessments. CONCLUSION: The results of this study show that Osteoformin improves femoral fracture healing in rats.