Narrow Results

Hydroxyapatite is the well known bioactive ceramic used in medical and dental fields as blocks and particles, while chondroitin-sulfate is a dominant polysaccharide component of cartilage. Novel composite materials consisting of hydroxyapatite [Ca₁₀(PO₄)₆(OH)₂] and chondroitin-sulfate were synthesized by a coprecipitation method with a H₃PO₄ solution and a Ca(OH)₂ suspension, one of which contain chondroitin-sulfate, and were consolidated under a cold isostatic pressure. The composites were evaluated by X-ray diffractometry, Fourier transformed infrared spectroscopy and transmission electron microscopy. In the composites, hydroxyapatite nanocrystals contained calcium-deficiency and a small amount of carbonate ions like human bone minerals and their c-axes were aligned along chondroitin-sulfate molecules by a self-assembly mechanism.

Implants (hemitrochlea) were prepared from nacre (mother of pearl) and implanted in the knees of sheep. Cartilage formed at the endoarticular surfaces of the implant, and new endochondral bone was also formed at the interface between the host cancellous bone and nacre. These phenomena resulted in the total integration of the implant.