Substrate-immobilized bone morphogenic protein-7 peptides on titanium surface support the expression of extracellular matrix proteins

Abstract

Bone regeneration is an attractive area of research within tissue engineering because of the demanding clinical requirements of bone repair. It is widely recognized that various osteogenic growth factors, such as bone morphogenic protein (BMP), transforming growth factors β1 (TGF-β1), and basic fibroblast growth factor, regulate the proliferation and differentiation of osteogenic cells and enhance bone formation 1) . Thus if one can accelerate bone regeneration using osteogenic growth factors in a suitable manner, this regeneration technology will provide a new clinical procedure to promote bone repair and be a substitute for autogenous and allogenous bone grafts or biomaterial implants.1) BMPs, with their potential to promote bone formation in vivo, have been used for bone regeneration to repair bone injuries and defects 2) . The current DNA technologies have enable the production of enough recombinant human BMPs for basic and applied research. BMP-2 and BMP-7 have already been clinically applied to accelerate bone regeneration, both in fracture healing and spinal fusion 3) . On the other hand, recombinant osteogenic protein 1 and partially purified osteogenic protein preparations have been shown to enhance the osseointegration around dental implants 4,5) . Osteoblast differentiation and mineralization have been demonstrated on titanium, glass, and hydroxyapatite-coated implant surface 6,7) . Using various methods, including immunocytochemical analysis and electron microscopy, no significant differences have been observed between implant surface coatings and mineralization in tissue culture. Thus, more recent experimental strat-