A heat-generating bioactive glass-ceramic for hyperthermia.
Glass plates of the chemical composition: CaO (29.0), SiO 2 (31.0), Fe 2O 3 (40.0), B 2O 3 (3.0), P 2O 5 (3.0) in weight ratio were heated to 1050  degrees C at a rate of 5  degrees C/min and then cooled to laboratory temperature.  The resulting glass-ceramic containing magnetite and wollastonite crystals showed high-saturation magnetization.  The bonding ability of this new glass-ceramic to bone tissue was evaluated using rabbit tibiae, and compared with glass of the same composition.  This glass-ceramic formed a Ca, P-rich layer on its surface and bonded tightly with bone within 8 weeks of implantation. However, the glass did not form this Ca, P-rich layer, nor had it bonded with bone at 25 weeks.  The bone-heating ability of this glass-ceramic was investigated by applying a max. 300-Oe, 100-kHz magnetic field.  The granules of the glass-ceramic filled in the rabbit tibiae heated the whole surrounding bone to more than 42  degrees C and maintained this temperature for 30 min.  Bioactive ceramics reinforce the mechanical strength of bone tissue.  Furthermore, this heat-generating bioactive glass-ceramic can be used for hyperthermic treatment of bone tumors.
Department of Orthopaedic Surgery, Kyoto University, Japan.
K
K
Ohura
M
M
Ikenaga
T
T
Nakamura
T
T
Yamamuro
Y
Y
Ebisawa
T
T
Kokubo
Y
Y
Kotoura
M
M
Oka
D000818:Animals; D001672:Biocompatible Materials; D001843:Bone Cements / Q000737:chemistry / Q000627:therapeutic use; D001859:Bone Neoplasms / Q000628:therapy*; D002516:Ceramics / Q000737:chemistry; D005544:Forecasting; D005898:Glass; D006979:Hyperthermia, Induced / Q000379:methods*; D007501:Iron; D008280:Magnetics; D008422:Materials Testing; D010087:Oxides; D011817:Rabbits