Structure of CaO-SrO-TiO2-P2O5 Glasses and their Ion-Releasing Abilities in Tris Buffer Solution
SrO-containing calcium phosphate invert glasses, (60-x)CaO∙xSrO∙30P2O5∙7Na2O∙3TiO2 (mol%, x = 0 ~ 60), which are expected to inhibit bone resorption by osteoclast and enhance bone formation, were prepared and estimated in their ion release behavior in Tris buffer solution. The glasses gradually released ions and the dissolved amounts of ions were the smallest when the glass contained 20 mol% of SrO. Laser Raman spectra showed that the peaks of phosphate groups and TiOy polyhedral groups red-shifted with increasing the SrO content in the glasses. The red-shift is suggested to be due to decrease in bonding strength between cations and phosphate groups or TiOy polyhedral groups in the glasses. In the case of the glasses containing SrO over 20 mol%, no Raman peaks of TiOy polyhedral shifted. TiOy (y = 4 or 6) polyhedral in the glasses can coordinate with cation up to 18 mol% since they contain 3 mol% of TiO2. Sr2+ ions are supposed to preferentially coordinate with TiOy polyhedral, the formation of this structure would induce the decrease in the ion amounts released from the glasses containing 0 ~ 20 mol% of SrO.
T. Chandra, N. Wanderka, W. Reimers , M. Ionescu
S. H. Lee et al., "Structure of CaO-SrO-TiO2-P2O5 Glasses and their Ion-Releasing Abilities in Tris Buffer Solution", Advanced Materials Research, Vols. 89-91, pp. 342-346, 2010