title: Surface chemistry and biological responses to synthetic octacalcium phosphate.
abstract: Octacalcium phosphate (OCP) has been suggested as a precursor of biological apatite in bone, dentin, and cementum because its existence explains the nonstoichiometry of apatite crystals in their compositions. Synthetic inorganic calcium phosphate compounds have been used clinically to fill bone defects, and sintered hydroxyapatite (HA) and beta-tricalcium phosphate (beta-TCP), bone substitute materials, are known to be osteoconductive, with beta-TCP also being bioresorbable. Nonsintered synthetic OCP has been shown to enhance bone regeneration accompanied by conversion into hydrolyzed apatitic products in situ and biodegradation. The surfaces of the OCP implant and the converted apatite seem to be continuously exposed to biological constituents, such as extracellular matrices, inorganic biominerals, and cellular components. This article reviews the surface reaction of OCP implants and the biological responses, such as experimentally stimulated bone formation on synthetic OCP, the mechanism of OCP hydrolysis into apatite, and the adsorption of biomolecules onto OCP and the converted apatite, of particular interest in reactive bone induction with synthetic OCP implants.
authors.affiliation: Division of Craniofacial Function Engineering, CFE, Tohoku University Graduate School of Dentistry, 4-1 Seiryo-machi, Sendai 980-8575, Japan. suzuki-o@mail.tains.tohoku.ac.jp
authors.forename: Osamu
authors.initials: O
authors.lastname: Suzuki
authors.forename: Shinji
authors.initials: S
authors.lastname: Kamakura
authors.forename: Takenobu
authors.initials: T
authors.lastname: Katagiri
mesh_terms: D000327:Adsorption; D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry / Q000378:metabolism; D001861:Bone Regeneration; D018786:Bone Substitutes / Q000737:chemistry / Q000378:metabolism; D002130:Calcium Phosphates / Q000737:chemistry / Q000378:metabolism; D049109:Cell Proliferation; D004337:Drug Carriers; D016503:Drug Delivery Systems; D005109:Extracellular Matrix / Q000737:chemistry / Q000378:metabolism; D006882:Hydroxyapatites / Q000737:chemistry / Q000378:metabolism; D016348:Osseointegration; D019736:Prostheses and Implants; D013499:Surface Properties
chemical_list: D001672:Biocompatible Materials; D018786:Bone Substitutes; D002130:Calcium Phosphates; D004337:Drug Carriers; D006882:Hydroxyapatites; C022045:octacalcium phosphate