Materials Design for Bioactive Function by Surface Modification with Apatite Nuclei

Abstract

When bioinert materials with fine pores were immersed in simulated body fluid with higher pH in comparison with conventional SBF and subsequently temperature of this SBF was raised, fine particles of calcium phosphate, which we named ‘apatite nuclei’, were precipitated on the surface and in the pores of the substrate. Thus-treated substrate showed high hydroxyapatite formation ability in SBF and will be utilized for bioactive functional materials in orthopedic or dental fields. In our present studies, SUS316L steel, CoCr-based alloy and polyetheretherketone, which cannot bond to living bone spontaneously in living body nevertheless they are attractive artificial bones from a viewpoint of mechanical properties, showed high hydroxyapatite formation ability by applying the above surface modification process. By utilizing hydroxyapatite formation ability of apatite nuclei, in addition, hydroxyapatite capsules could be synthesized.