Development of mesoporous borosilicate bioactive glass nanoparticles containing Mg2+ and Zn2+ : biocompatibility, bioactivity and antibacterial activity

In this study a microemulsion assisted sol-gel method was used to synthesise mesoporous bioactive glass nanoparticles (MBGNs) in the SiO2-B2O3-CaO-MgO-ZnO system, followed by calcination at 600 degrees C/3 h. The obtained MBGNs showed a typical borosilicate glass structure with similar spherical shape and nanometric dimension. Also, they exhibited high specific surfaces and interconnected networks of slit-shape mesopores. In vitro tests proved that all MBGNs had good bioactivity and biocompatibility. Thus, when MBGNs were immersed in simulated body fluid, a uniform layer of calcium phosphates covered the surface of all samples. However, the presence of ZnO led not only to a lower degree of crystallinity of the newly formed layer, but also to different morphologies of the phosphates. The cytotoxicity assays revealed an increase of the cell viability for the samples containing MgO without inducing intracellular oxidative stress. On the other hand, MBGNs with ZnO had a higher antibacterial activity against Escherichia coli.

Automated summary

In this study, mesoporous bioactive glass nanoparticles (MBGNs) were successfully synthesized using a microemulsion assisted sol-gel method, showing good bioactivity and biocompatibility in vitro. Samples containing MgO increased cell viability, while MBGNs with ZnO exhibited higher antibacterial activity against Escherichia coli.