BONE MORPHOGENETIC PROTEIN ENCAPSULATED WITH A BIODEGRADABLE AND BIOCOMPATIBLE POLYMER

To develop a controlled release system for bane morphogenetic protein (BMP), poly(DL-lactide-co-glycolide) (PLGA) capsules containing BMP we re prepared by an interfacial precipitation method using a water-in-oi l-in-water emulsion. The surface morphology, particle size distributio n, and hydrolytic degradation rate of the PLGA capsules were examined. The encapsulation yield and release rate of BMP in vitro were measure d using fluorescein isothiocyanate-labeled BMP. The amount of BMP rele ased from PLGA capsules increased between days 3 and 5. In addition, t he effectiveness of BMP encapsulated in PLGA to induce bone formation in vivo was also examined by subcutaneous implantation in rats. Comple te digestion of the capsules and new bone formation including bone mar row were identified by histologic examination of harvested tissues at 3 weeks after implantation. These results demonstrated that encapsulat ion of BMP with PLGA could be a promising method to induce bone in cli nics. (C) 1996 John Wiley & Sons, Inc.