Design of biomedical materials for treatment of cancer and bone diseases

Ceramic microspheres containing yttrium and/or phosphorus are useful for intra-arterial radiotherapy. Indeed, radioactive yttrium oxide (Y ₂0₃) microspheres with high chemical durability can remarkably suppress growth of VX2 tumor. Hollow Y203 microspheres and yttrium phosphate (YP0₄) microspheres have been also developed. Magnetic microspheres are believed to be useful for intra-arterial hyperthermia of cancer. It is confirmed that silica (Si0₂) microspheres containing magnetite (Fe₃0₄) and maghemite (y-Fe₂0 ₃) nanoparticles can generate heat under alternating magnetic field. On the other hand, development of metallic biomaterials with osteoconductivity as well as antibacterial property is desired so that incidence of infection after surgery is decreased. Titanium (Ti) metal with anion-doped titania (Ti0₂) surface might be a novel metallic biomaterials with ex vivo antibacterial property and in vivo osteoconductivity. Further, we recently proposed that specific adsorption of proteins on hydroxyapatite (HAp) might play an important role in the expression of osteoconductivity in vivo. The fundamental reach on relationship between specific protein adoption and osteoconductivity is believed to be useful for development of bone-repairing biomaterials with extremely high osteoconductivity. Development of novel biomedical materials for treatment of cancer and bone diseases is strongly desired to contribute to better health and welfare of patients with cancer and/or bone diseases.