Inorganic silica hybrid octacalcium phosphate bone substitute: Harmonics to acceleration in biological metabolism and its curing process

Previously, assembling and developing a compatible bone remodeling process had been a dogma for bone substitute fabrication. However, considering patients who use such bone substitutes, such as elderly people, the major problem is poor bone remodeling, which has been a significant disadvantage limiting active intervention. Therefore, in this study, we introduced a new concept for bone substitutes, namely, a continuous up-regulating bone remodeling process using implanted materials for a rapid curing process. Using an ionic insertion method, inorganic silica, and a viability-controlled factor for bone remodeling, we fabricated octacalcium phosphate (OCP) with silica (OCP-silica) blocks as bone substitutes. The fabricated OCP-silica blocks consisted of hieratical silica and OCP structures at an atomic scale. In vivo experimental results indicated that these OCP-silica blocks enhanced bone remodeling and almost completely replaced all bone tissues in only 3 months compared with existing bone replacement-type bone substitutes.