Investigating the influence of Na^sup +^ and Sr^sup 2+^ on the structure and solubility of SiO2-TiO2-CaO-Na^sub 2^O/SrO bioactive glass

• Published in: Journal of materials science. Materials in medicine Vol. 26; no. 2; p. 1
• Main Authors: Li, Y, Placek, L M, Coughlan, A, Laffir, F R, Pradhan, D, Mellott, N P, Wren, A W
• Format: Journal Article
• Language: English
• Published: London Springer Nature B.V 01.02.2015
• Subjects: Biological activity; Biomedical materials; Crystallization; Hydroxyapatite; Ions; Materials science; Mineral solubility
• ISSN: 0957-4530; 1573-4838
• DOI: 10.1007/s10856-015-5415-5

This study was conducted to determine the influence that network modifiers, sodium (Na^sup +^) and strontium (Sr^sup 2+^), have on the solubility of a SiO2-TiO2-CaO-Na^sub 2^O/SrO bioactive glass. Glass characterization determined each composition had a similar structure, i.e. bridging to non-bridging oxygen ratio determined by X-ray photoelectron spectroscopy. Magic angle spinning nuclear magnetic resonance (MAS-NMR) confirmed structural similarities as each glass presented spectral shifts between -84 and -85 ppm. Differential thermal analysis and hardness testing revealed higher glass transition temperatures (T^sub g^ 591-760 °C) and hardness values (2.4-6.1 GPa) for the Sr^sup 2+^ containing glasses. Additionally the Sr^sup 2+^ (~250 mg/L) containing glasses displayed much lower ion release rates than the Na^sup +^ (~1,200 mg/L) containing glass analogues. With the reduction in ion release there was an associated reduction in solution pH. Cytotoxicity and cell adhesion studies were conducted using MC3T3 Osteoblasts. Each glass did not significantly reduce cell numbers and osteoblasts were found to adhere to each glass surface.