Novel ceramics for biomedical applications

It was found in a simulated body fluid (SBF) that functional groups such as Si-OH, Ti-OH, Zr-OH, Ta-OH, Nb-OH, COOH and PO4H2 are effective for the apatite nucleation. On the basis of these findings, it was shown that NaOH- and heat-treated titanium, its alloys and tantalum, a H3PO4-treated zirconia ceramics and CaO, SiO2 glass-treated poly(ethylene terephthalate) form the bonelike apatite on their surfaces in SBF. Among them, NaOH- and heat-treated titanium, its alloys and tantalum were confirmed to form the apatite on their surfaces in vivo and bond to living bone through the apatite layer. Y2O3-Al2O3-SiO2 glass microspheres were early shown to be effective for in situ radiotherapy of cancers. Recently, pure Y2O3 and YPO4 polycrystalline microspheres with high chemical durabilities were successfully prepared by high-frequency plasma method. They are expected to be more effective for the radiotherapy. Copyright (2000) The Australian Ceramic Society