Characterization of Functionally Gradient Hydroxyapatite / Recombinant Bone Morphogenetic Protein Composites with Excellent Bio-Absorption and Osteoinduction Properties

抄録

Functionally gradient hydroxyapatite (fg-HAp) was prepared using cattle bone-originated apatite by a partial or complete dissolution-precipitation method to obtain the biomimetic materials, which showed fast in vivo-absorption and bone-remodelling. The fg-HAp ceramics with active surfaces for bio-absorption property exhibited 100~600μm pore sizes, 60~80% porosities, and small amounts of metal ions derived from living body. From surface layer to inner parts in the ceramics, the crystallinity of hydroxyapatite was better and the grain size increased from 20 nm to 1μm. Recombinant human bone morphogenetic protein (rhBMP-2) was added to the fg-HAp ceramics to accelerate osteoinduction property. The fg-HAp/rhBMP-2 composites were implanted to the subcutaneous tissue of rats. After 2 weeks, active bone formation occurred and newly formed bone revealed a structure of trabecular bone with numerous osteocytes. Accordingly, the composites were found to be one of biomimetic apatite materials, which gave faster bio-absorption and osteoinduction.