Comparison of cell viability on anorganic bone matrix with or without P-15 cell binding peptide.

Cell-extracellular cell matrix (ECM) interactions play a vital role in development including cytoskeletal structure, growth and differentiation. A 15 amino acid, non-RGD containing, peptide that is derived from type I collagen was tested for its ability to confer cell survival. Two routinely utilized bone graft materials, anorganic bone matrix (ABM) and ABM carrying the cell binding peptide P-15 were compared for cell viability and apoptosis. Anchorage-dependent human foreskin fibroblasts (HFF) or osteogenic MC3T3-E1 cells were seeded on ABM or ABM/P-15. After serum withdrawal, viability and level of apoptosis were significantly (p<0.05) improved for cells on ABM/P-15 compared to cells on ABM. Scanning electron microscopy confirmed large, spread cells on ABM/P-15 and smaller cells with apoptotic cellular blebs on ABM. In addition, viable cell attachment was significantly greater on cells cultured on ABM/P-15 compared with demineralized freeze-dried bone allograft. This is the first report that the P-15 cell binding peptide, when complexed with ABM, promotes cell survival. The P-15 peptide may modulate cell number and tissue structure by the enhancement of viable cell attachment and via the regulation of apoptosis.