Gallium-containing phosphosilicate glasses: functionalization and vitro bioactivity

A gallium containing glass 45.7SiO2•24.1Na2O•26.6CaO•2.6P2O51.0Ga2O3, referred to as Ga1.0, and a parent Ga-free glass 46.2 SiO2•24.3Na2O•26.9CaO•2.6P2O5, corresponding to Bioglass® 45S5, (H glass) were functionalized with Tetraethoxysilane (TEOS) and (3-Aminopropyl)triethoxysilane (APTS) in order to improve the ability of the glasses to bond biomolecuels. Functionalization with TEOS and APTS promoted increment in OH groups and formation of NH2 groups on the glass surface, respectively. The presence of OH or NH2 groups was investigated by means of IR spectroscopy and elemental analysis. Functionalized glasses were investigated by an in-vitro study in simulated body fluid (SBF) for defining the effect of functionalization on their bioactivity as compared to plain glasses. The results showed that the functionalization was obtained and bioactivity was maintained: the surfaces of both functionalized glasses were covered by a layer of apatite by 30 days of immersion in SBF. In addition, CaCO3 was also identified on the surface of APTS functionalized glasses. No gallium release was detected during the immersion in SBF.