Synergistic Effect of rhBMP-2 and osteopontin Derived Peptides Grafted to a Hydrogel Substrate on Osteogenesis of Marrow Stroma

INTRODUCTION Osteogenic differentiation and mineralization of bone marrow stromal (BMS) cells depends on the cells’ interactions with bioactive peptides associated with the matrix proteins. Multiple bioactive peptides in the bone ECM, interact with progenitor BMS cells to initiate the cascade of chemotaxis, differentiation, and mineralization. The peptide KIPKASSVPTELSAISTLYL (hereafter referred to as the BMP peptide), corresponding to residues 73-92 of the knuckle epitope of recombinant human bone morphogenetic protein (rhBMP-2), is implicated in osteogenic differentiation of BMS cells. It has also been demonstrated that the osteopontin-derived peptide SVVYGLR (hereafter referred to as the OP peptide) has as potent activity for tube formation by endothelial cells as vascular endothelial growth factor (VEGF), which is known to be the strongest angiogenic factor. The objective of this work was to determine synergistic effect of osteogenic BMP peptide and vasculogenic OP peptide, grafted to an inert hydrogel substrate, on vascularized osteogenesis of BMS cells.