Sol-gel derived mesoporous 45S5 bioactive glass containing Mg and Zr ions: Synthesis, characterization, and in vitro biological investigation

Bioactive glass is one interesting type of material for bone repair. In this work, a new powder (MBG2) was synthesized by a sol–gel method, in which 5 mol.% Mg and 5 mol.% Zr were incorporated into the structure, to investigate the combined effects of the simultaneous addition of these ions on the biological properties of 45S5 mesoporous bioactive glass. Then, the outcomes of various characterization techniques and in vitro biological analyses performed on this powder were compared with those of pure powder (MBG1). For instance, the XRF investigation proved that Zr and Mg ions were present in powder MBG2′s composition. Additionally, XRD, SEM, and BET tests of the powders MBG1 and MBG2 indicated their amorphous structure and spherical morphology with specific surface areas of 620 and 710 m2/g and average particle sizes of about 30 and 20 nm, respectively. The development of an apatite layer on the surfaces of disc-shaped samples produced from both powders were immersed in phosphate-buffered saline (PBS) and simulated body fluids (SBF), and the behavior of the samples' degradation were observed for 28 days. Furthermore, it was assessed how the Zr and Mg ions in the composition affected the MG-63 cells' survival, growth, and adhesion through in vitro biocompatibility testing. From the obtained results, it can be concluded that 45S5 mesoporous bioactive glass powder with minimal cytotoxicity was entitled to be a safe biomaterial due to the coexistence of 5 mol.% Mg and 5 mol.% Zr in the composition, which successfully enhanced bioactivity, cell proliferation, and biocompatibility.