Objective The composite membrane was made by recombinant human bone morphogenetic protein-2 （rhBMP-2）, collagen（Co）, polylactic-co-glycolic acid（PLGA）. To observe the ectopic bone formation and evaluate the capability of rhBMP-2/Co/PLGA complex membrane. Methods 48 male Kunming adult mice were divided into two groups randomly: Co/PLGA complex membrane group and rhBMP -2/Co/PLGA complex membrane group. After etherized, an incision was made on the outer muscle and two groups of complex membranes were implanted into the right side hind limb muscle pouch. 8 mice from each group were sacrificed at 7, 14, 28 d. The hind limbs were removed, examined by soft X-ray, HE staining and light microscope examination. Results Wounds healed well, no infections and rejections were observed. In the Co/PLGA group, partial implanted membrane degradated and absorbed at 7 d. The membrane collagen fiber appeared loose at 14 d. The membrane lost its intact to disrupted at 28 d. No ectopic bone formation was found. In the rhBMP-2/Co/PLGA group, ectopic bone formation was found by eye, soft Xray and histological examinations. The rhBMP-2/Co/PLGA complex membrane degraded slower than Co/PLGA complex membrane. Conclusion Co/PLGA can provide a carrier for rhBMP-2 to have stronger effect of biological activity.
