Preparation and characterization of silver nanocrystals decorated mesoporous bioactive glass via synchrotron X-ray reduction

Silver nanocrystals combined with bioactive glass are promising nanocomposites in the field of biomedical engineering, due to their bioactivity and antimicrobial properties. The aim of this work is to devise a fast protocol that combines synchrotron X-ray reduced silver nanoparticles with spray pyrolyzed mesoporous bioactive glass. By using this method, silver nanocrystals decorated mesoporous bioactive glass powder can be successfully prepared. Two types of mesoporous bioactive glass (MBG) were first prepared via spray pyrolysis method with the addition of either spherical powdered or flaked Pluronic® F-127. Synchrotron X-ray irradiation was then used to reduce Ag nanoparticles onto MBG. The as-prepared MBG and Ag-MBG powders were then examined using transmission electron microscopy, UV-Visible spectroscopy, and X-ray diffraction techniques to reveal their structural and morphological characteristics. The antimicrobial activity of Ag-MBG powder was assessed using an antibacterial assay. The experimental results showed that MBG prepared with spherical powdered F127 (i.e., MBG-S) not only exhibited smaller grain size and narrower size distribution, but also more negative zeta potential than those prepared with flaked F127 (i.e., MBG-F). Ag-MBG-S exhibited a more uniform distribution of silver nanoparticles and a better antibacterial performance against E. coli and S. aureus.