Ga Incorporation into Calcium Silicate Sol-Gel Bioactive Glasses: Effect of Ga on Glass Structure and Ion Release Behavior

Abstract

SiO₂-CaO-based sol-gel glasses have been well-known as bioactive materials, whereas there is still a concern about the rapid increase of pH in their surrounding after implantation in the body due to the burst release of calcium ions (Ca2+) from the glasses. We incorporated gallium oxide, which is one of intermediate oxides, into SiO₂-CaO sol-gel glasses and evaluated the effects of gallium (Ga) incorporation on the glass structures and ion release behaviors. The release of Ca2+ from the glasses at the initial stage of immersion in a buffer solution was suppressed by the Ga incorporation with dose dependent manner. Ga was found to be mainly tetrahedral coordination in the glasses. Thus, Ga acted as a network former in the silicate network with forming tetrahedral coordination unit and charge balanced by Ca2+ ions. The viability of fibroblast-like cells was significantly higher for the Ga-incorporated glass than non-incorporated one.

Keywords: sol-gel glass, gallium, bioactive glass, ion release