Biological activity of rhBMP-2 released from PLGA microspheres

Human recombinant bone morphogenetic protein-2 (rhBMP-2) has been proven ef fective ill stimulating the regeneration of bone in both skeletal and extra skeletal locations. Through encapsulation within, and release from, biodegr adable poly(DL-lactic-co-glycolic acid) (PLGA) microspheres, a proven vehic le for sustained delivery of various proteins, the local concentrations of rhBMP-2 could be maintained at optimal levels to stimulate bone regeneratio n and remodeling at the site of healing irt diverse clinical settings. Thus the purpose of this work was to investigate the encapsulation of rhBMP-2 i n PLGA microspheres and its biologic activity upon release. Using in vitro tests in simulated body fluids, the effect of rhBMP-2 released from PLGA mi crospheres upon osteoblast cell cultures was found to be statistically simi lar to the effect produced by positive controls consisting of nonencapsulat ed aqueous rhBMP-2 in simulated body fluids. This clarifies an important st ep in skeletal tissue engineering strategies aimed at the use of encapsulat ed rhBMP-2 to stimulate bone regeneration and remodeling.