ZnO incorporated high phosphate bioactive glasses for guided bone regeneration implants: enhancement of in vitro bioactivity and antibacterial activity

Abstract

Bioactive phosphate glasses incorporated with Zn2+ (predicted to be useful for bone regeneration applications) were synthesized. Characterization of the bioglasses were done using XRD, FTIR, SEM, and EDS techniques, both prior to and after soaking in simulated body fluid (SBF) solution. The bioactive performance of samples was evaluated by incubated in SBF for different days by means of the pH measuring and comparing the results of XRD and SEM studies. The obtained results show the formation of hydroxyapatite (HAP) layer on the surface of as-developed bioactive glasses. The degradation of the samples evaluated by weight loss and pH of the remnant solution measured as functions of ZnO concentration and immersion time revealed the enhanced formation of HAP layer on the sample surface. The results further indicated the rate of degradation can be monitored by tailoring the concentration of ZnO and immersion time. The studies were also extended to in vitro cytocompatibility and cell proliferation measurements on rMSC using CCK-8 for incubation periods of 24 h and 72 h. These studies have revealed the considerable levels of rMSC proliferation and improved viability within the limits of nontoxic levels. The measurements of antibacterial activity of ZnO-doped phosphate bioactive glasses against E. coli and S. aureus, carried out for 24 h and 48 h have confirmed their potential antibacterial activity. Finally, quantitative analysis of these results confirmed an enhanced in vitro biological and antibacterial activity of the samples due to the ZnO doping and subsequent controlled release of Zn2+ ions in the glass matrix.

Keywords

• P2O5 bioactive glass
• Zinc oxide
• HAP layer
• rMSCs
• Cytotoxicity
• Antibacterial activity