Preparation of Bifunctional Orthosilicophosphate MgO-CaO-ZnO-P₂O₅-SiO₂ Glasses: In Vitro Evaluation of Antibacterial Activity and Osteoblast Gene Expression Behavior.

Abstract

Phosphate and phosphate invert glasses contain various elements, with a wide range of compositions. Recently, our group reported orthosilicophosphate glasses (SPGs) and the glass network structure composed of orthophosphates and orthosilicates crosslinked by cations. ZnO is an intermediate oxide that improves the chemical durability of glass. Additionally, Zn²⁺ ions exhibit antibacterial activity and stimulate bone formation. In this work, ZnO-containing SPGs are prepared for biomedical applications. The glasses are mainly composed of PO₄, SiO₄, MgO₄, and ZnO₄ orthotetrahedral structures. The ZnO-containing SPGs exhibit excellent antibacterial activity, with bacterial counts > 5 orders of magnitude lower than that of the control. Meanwhile, ZnO-containing SPGs have mild inhibitory effects on cell proliferation by Zn²⁺ ions; however, they exhibit significant upregulation of osteogenic markers compared with the control owing to the release of inorganic ions from the glasses. The ZnO-containing SPGs prepared in this work exhibit bifunctional properties suitable for biomedical applications. They serve as bioadaptive materials capable of controlling gene expression by releasing therapeutic ions.