Effect of immobilized cell-binding peptides on chitosan membranes for osteoblastic differentiation of mesenchymal stem cells

Two cell-binding domains from FGF-2 (fibroblast growth factor-2) were shown to increase cell attachment and osteoblastic differentiation. Two synthetic peptides derived from FGF-2, namely residues 36-41 (F36; PDGRVD) and 77-83 (F77; KEDGRLL), were prepared and their N-termini further modified for ease of surface immobilization. Chitosan membranes were used in the present study as mechanical supportive biomaterials for peptide immobilization. Peptides could be stably immobilized on to the surface of chitosan membranes. The adhesion of mesenchymal stem cells to the peptide (F36 and F77)-immobilized chitosan membrane was increased in a dose-dependent manner and completely inhibited by soluble RGD (Arg-Gly-Asp) and anti-integrin antibody, indicating the existence of an interaction between F36/F77 and integrin. Peptide-immobilized chitosan supported human bone-marrow-derived mesenchymal-stem-cell differentiation into osteoblastic cells, as demonstrated by alkaline phosphate expression and mineralization. Taken together, the identified peptide-immobilized chitosan membranes were able to support cell adhesion and osteoblastic differentiation; thus these peptides might be useful as bioactive agents for osteoblastic differentiation and surface-modification tools in bone regenerative therapy.