Abstract
Some ceramics such as Bioglass®, sintered hydroxyapatite, glass-ceramic A-W have been used as important bone repairing materials because of their bioactivities. They are, however, lower in fracture toughnesses and higher in elastic moduli than the human cortical bone. Recently, tough bioactive materials have been prepared by some chemical surface modification of titanium metal and its alloys. Bioactive materials with low elastic moduli are provided by preparing inorganic-organic hybrids by sol-gel method. Bioactive materials with analogous mechanical properties to those of human cortical bone are expected to be provided by preparing nanoapatite-organic fiber composite by a biomimetic process. Some ceramic microspheres containing Y2O3 are already clinically used for in situ radiotherapy of liver cancer. Those containing Fe3O4 are expected to be useful for hyperthermia of the cancers.
