Delivery systems for bone morphogenetic proteins. A summary of experimental studies in primate models

The characterization and molecular cloning of the family of the bone morphogenetic proteins (BMPs) have laid the foundation for the cellular and molecular analysis of bone development and regeneration. A carrier substratum is required, however, to optimize osteogenic activity initiated by BMPs bound to the surface of the carrier. Native and recombinant human (rh) BMPs induce local endochondral bone formation in conjunction with the insoluble collagenous bone matrix, the inactive residue obtained after dissociative extraction of the matrix with chaotropic agents. While the cellular and molecular biology of BMPs and related members is advancing at a furious pace, progress in the formulation and implementation of novel delivery systems has been slow. The creation of inorganic nonimmunogenic carriers with defined geometries capable of delivering BMPs in the absence of the collagenous matrix is a crucial goal for skeletal reconstructionists and molecular biologists alike. Significant advances in skeletal reconstruction may be expected when novel carrier substrata are implemented for delivery of optimal doses of now available recombinant human BMPs.