Inorganic material surfaces made bioactive by immobilizing growth factors for hard tissue engineering

Medical and dental titanium has become the fundamental material in clinical use, in applications from surgical instruments and orthopedic rods to pins and plates. Besides titanium, various inorganic materials have been used in tissue engineering because of their unique mechanical properties. However, inorganic materials have no specific biological activities. The immobilization of growth factors on these materials is expected to add various biological functionalities that can regulate cell destinies, including not only adhesion but also cell growth or differentiation at the interface between these inorganic materials and biological tissues. This review discusses recent progress in the immobilization of growth factors on inorganic materials, including the methods and applications used for hard tissue engineering.