BIOACTIVITY OF FE2O3-CONTAINING CAO-SIO2 GLASSES - IN-VITRO EVALUATION

In order to reveal conditions for obtaining bioactive and ferrimagnetic glass-ceramics useful as thermoseeds for hyperthermia treatment of cancer, the effects of additives on the bioactivity of an Fe2O3-CaO-SiO2 glass were investigated by examining apatite formation on the surfaces of the glasses in a simulated body fluid with ion concentrations nearly equal to those in human blood plasma. A 3Fe2O3, 100CaO . SiO2 (in weight ratio) glass did not form an apatite layer on its surface in the fluid, but glasses of the same compositions with 3Na2O, B2O3 and/or P2O5 added (in weight ratio) formed an apatite layer. This indicates that bioactive and ferrimagnetic glass-ceramics could be obtained from Fe2O3-containing CaO-SiO2 glasses with Na2O, B2O3 and/or P2O5 added. Apatite formation on the surfaces of the glasses with the additives are interpreted in terms of the dissolution of the calcium and silicate ions from the glasses.