Inorganic materials used as rhBMP-2 delivery vehicles include β-TCP, which has rhBMP-2-binding activity and which is a useful carrier of rhBMP-2 because of its osteoconductivity and its rapid resorption in the body [5]. One study reported that it recovered a bone defect faster than an autologous bone graft due to carrier characteristics that aided the sustained release of rhBMP-2 in the bone defect [16].