Bone regeneration produced in rat femur defects by polymer capsules containing recombinant human bone morphogenetic protein-2

Purpose: This study examines the effect of polymer capsules containing recombinant human bone morphogenetic protein-2 (rhBMP-2) on bone regeneration in a large segmental bone defect in the rat. Materials and Methods: Poly(DL-lactide-co-glycolide) (PLGA) capsules containing 3 mu g of rhBMP-2 were implanted in a 5-mm segmental femoral defect in rats, and the femurs were harvested at 4 and 8 weeks after implantation and observed by radiographically and microscopically. Results: At 8 weeks after implantation, union of bone was found radiographically and histologically in the femoral defects implanted with the rhBMP-2/PLGA capsules. In contrast, the control animals did not show bridging of the defect. Conclusions: This study provides evidence that use of rhBMP-2/PLGA capsules is a promising delivery system to regenerate bone.