Effect of B/Si molar ratio on the structure and properties of borosilicate bioactive glasses assessed using molecular dynamics simulations

Abstract

Abstract Due to the improvement and innovation of theoretical methods and the increasing enhancement of high performance computing, computer simulations provide a new method and strategy for optimizing complex composition of novel bioactive glass. In this work, molecular dynamics simulations were used to analyze the effect of B/Si molar ratio on the structure of borosilicate bioactive glass (BBG) and to investigate the effect of structural alterations on its ions release and biological effects. Structural descriptor a theoretical structural descriptor that estimates the overall strength of the glass network (F net) was calculated from the simulated data, and the linear relationships of F net with B and Mg releasing rate in deionized water and simulated body fluid were built. In vitro mineralization experiments showed that all three BBGs could generate hydroxyapatite and the release of some network modifier ions such as Mg would be regulated by the B/Si ratio. In vitro cellular experiments revealed that the BBG sample with a composition of 1.25B (6Na2O–8K2O–8MgO–22CaO–22.5B2O3–2P2O5–31.5SiO2) promoted the proliferation and osteogenic differentiation of rat bone marrow mesenchymal stem cells, and significantly enhanced the expression of osteogenesis-related genes such as osteopontin, which might be related to the release of Mg at an early stage.