Osteogenesis in vitro and in vivo with hyaluronan and bone morphogenic protein-2

Hyaluronan (HA) has a positive effect on osteogenesis both in vitro and in vivo. Bone morphogenetic protein-2 (BMP-2) when added to HA sponges gives additional osteotropic benefits. In two in vitro studies, HA increased bone colony formation, demonstrating a positive effect on osteogenesis. One in vitro study examined embryonic osteogenesis starting with fetal mesenchymal cells. The second study examined adult osteogenesis using adult bone marrow osteogenic stem cells. In an in vivo study, recombinant human Bone Morphogenetic Protein-2 (rhBMP-2) saturated within a bioresorbable HA sponge carrier, was compared with an absorbable collagen sponge (ACS), also laced with rhBMP-2. A critical size defect was used in dogs to evaluate the effect of rhBMP-2, saturated in HA or ACS carrier sponges. The addition of BMP-2, as a bone enhancing osteogenic substrate, to HA very clearly increased both the volume and density in critical size bony defects, as compared to collagen sponges with and without rhBMP-2.