Fabrication of Apatite-Hyaluronic Acid Hybrids

Apatite-polymer hybrids have been attractive as novel bone-bonding bioactive bone substitutes with mechanical performances analogous to those of natural bone. It is shown that carboxyl group (COOH) can induce the apatite nucleation in an environment of simulated body fluid (SBF). In the present study, we fabricated porous hyaluronic acid gels abundant in COOH group and investigated their apatite formation ability in SBF. Hyaluronic acid has been attractive for boneand cartilagerepairing materials due to high biological compatibility. We attempted the preparation of bioactive organic-inorganic hybrids from Hyaluronic acid. It has been attractive for boneand cartilage-repairing materials due to high biological compatibility. It is known that divinyl sulfone is a candidate of cross-linker to bridge the hydroxyl groups. The hydroxyl group of hyaluronic acid side chains were bridged by divinyl sulfone. Porous hyaluronic acid gels stable in aqueous environment were obtained by appropriate crosslinking. They formed the apatite on their surfaces in SBF, when they were priorly treated with CaCl2 aqueous solution. In addition, trehalose, a kind of disaccharide, is found to increase the pore size of the porous hyaluronic acid. This suggests that the pore size and porosity can be controlled by addition of trehalose during fabrication of the scaffolds.