Bone Response of Gelatin Composite Including the Apatite Prepared from an Amino Acid Calcium Complex

Abstract

The composite of apatite from calcium-asparatic acid (Asp) complex and gelatin was prepared and evaluated the bone response after the implantation into the cortical bone of rabbit tibiae. Four kinds of porous materials were employed in the present study. Namely, Gelatin: 3 wt % gelatin gel, Gelatin-Arg: 3 wt % gelatin-arginine (Arg) gel, CAP-Gelatin: L-Asparatic acid-Ca(OH)₂-H₃PO₄ and 3 wt % gelatin gel, CAP-Gelatin-Arg: L-Asparatic acid-Ca(OH)₂-H₃PO₄ and 3 wt % gelatin gel-Arg. These samples were freeze-dried and were sterilized with ethylene-oxide gas. Afterwards, four porous materials were implanted into the cortical bone defects of rabbit tibiae. After the 12 weeks of implantation, bone responses were evaluated by the observation of non-decalcified thin sections.The histological appearances of Gelatin implantation promoted the limited bone formation and the space of bone defects was still present. Degradation residue of gelatin was observed close to the new bone. For Gelatin-Arg implantaion, greater degree of bone formation was observed compared with Gelatin implantation. CAP-Gelatin and CAP-Gelatin-Arg implantation showed the partial new bone formation in the bone defects. Greater amount of degradation residue was observed in the space of bone defects rather than Gelatin and Gelatin-Arg implantation. Apatite particle and degraded gelatin could be observed inside the space of bone defects. It is suggested that degraded gelatin influenced the bone formation.