Effect of magnesium content on bioactivity of near invert phosphate‐based glasses

摘要

Abstract A series of phosphate glasses 40P 2 O 5 ‐(40?x)CaO‐ xMgO ‐(20?y)Na 2 O‐ yTiO 2 (where 0 ≤ x ≤ 24 and y = 0 or 1) with varying MgO contents were investigated for their in vitro calcium phosphate (CaP) formation. Thermal analysis of these glass compositions was conducted and a significant decrease in glass transition temperature from 448°C to 430°C was seen with reducing MgO content from 24 to 8 mol%. Degradation studies were performed in phosphate buffered saline ( PBS ) at 37°C, where the 8 mol% MgO glass showed the highest mass loss of around 3.4% after 28 days of immersion. Cation release studies were conducted via ion chromatography, using ultrapure water at 37°C as the degradation medium. The highest release of Ca 2+ and Na + ions was observed with the 8 mol% MgO glass. In vitro CaP formation studies were conducted using glass discs immersed in simulated body fluid ( SBF ) at 37°C for up to 28 days. The amorphous phase and chemical composition of deposited CaP layers on the glass discs were confirmed via X‐ray diffraction ( XRD ) and energy‐dispersive X‐ray spectroscopy ( EDX ) analysis, respectively. CaP layers with Ca/P ratio 0.8‐1.1 were found to be deposited on the lower MgO content (8 to 2 mol%) glass surface after 28 days of SBF study.