Comparison of in vitro physico-chemical and antibacterial properties of 68S and 58S bioactive glasses synthesized by sol-gel method

The major aim of this study was to evaluate the effect of CaO content on in vitro hydroxyapatite formation, MC3T3cells cytotoxicity and proliferation as well as antibacterial efficiency of sol-gel derived SiO2–CaO–P2O5 ternary system. For this purpose, first two grades of bioactive glass (BG); BG-58s (mol%: 60%SiO2–36%CaO–4%P2O5) and BG-68s (mol%: 70%SiO2–26%CaO–4%P2O5)) with the fixed P2O5 content were synthesized by sol-gel method. Second, the effect of CaO content in their composition on in vitro bioactivity was investigated by soaking the BG-58s and BG-68s powders in simulated body fluid (SBF) for time periods up to 14 days. The evolution of the SBF composition was monitored by inductively coupled plasma atomic emission spectrometry (ICP-AES) analyses. Additionally, Fourier transform infrared (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM) were performed to characterize formed hydroxyapatite on BG's surface. On the other hand, Live/dead staining, 3-(4,5dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and alkaline phosphatase (ALP) activity assays were conducted respectively, as qualitatively and quantitatively assess for cell viability, proliferation and differentiations of MC3T3cells in presence of 58s and 68s BGs. Eventually, BG-58s with enhanced MC3T3 cells proliferation and ALP activity, acceptable bioactivity and significant high antibacterial effect against MRSA bacteria is suggested as a suitable candidate in comparison to BG-68S in order to further functionalizing for delivery of therapeutic ions and growth factors in bone tissue engineering.