Novel inorganic materials for biomedical applications

The essential requirement for artificial material to bond to living bone is the formation of bonelike apatite layer on its surface in the living body. Some functional groups such as Si-OH and Ti-OH are effective for the apatite nucleation in the living body. On the basis of these findings, bioactive Ti metals and its alloys with high fracture toughnesses were developed by NaOH and heat treatments. Nanoapatite-polymer fiber composites were developed by modification of polymer surfaces with CaO-SiO2 or TiO2 gel and soaking in simulated body fluid (SBF). Some ceramic microsphere also can play an important role in in situ treatment of deep-seated cancers. For example, Y2O3 polycrystalline microspheres 20 to 30 mum in diameter were developed for in situ radiotherapy of liver cancer. Magnetite (Fe3O4) polycrystalline microspheres were developed for in situ hyperthermia of cancers.