Synthesis, characterization and microbiological response of silver doped bioactive glass nanoparticles

Glass nanoparticles containing 1, 3, 5, and 10 wt% of Ag2O (coded; GAg1%, GAg3%, GAg5%, and GAg10%, respectively) were synthesized through a quick alkali mediated sol gel method and were characterized by TEM, XRF, FT-IR, XRD, TGA, and DSC. Thermal analysis showed that all organic and inorganic by-products were completely decomposed before 700 C and, hence, all glass samples were stabilized at this temperature. XRD confirmed the amorphous nature of all glasses after stabilization. TEM micrographs showed that the average particle sizes of all samples were less than 100 nm in diameter and the XRF showed that the compositions of the obtained glasses were almost consistent with the designed ones. The samples GAg1%, GAg3To, GAg5%, and GAg10%, showed average pore diameters of 19.85, 18.22, 13.32, and 19.62 nm and specific surface areas of 73.18, 100.38, 192.6, and 55.7 m(2)/g, respectively. In addition, their porosity% was 76.53, 83.20, 77.97, and 79.61%, respectively. The FT-IR spectra of all glasses showed bands located in the range of 1000-1200, 725-800, and 450-480 cm(-1) that correspond to the Si-O-Si asymmetric stretching vibration, the Si-O-Si symmetric stretching vibration, and the Si-O-Si bending mode, respectively. Finally, all samples had an antibacterial effect against different types of bacteria and the extraction of silver ions from them followed a diffusion-controlled mechanism, which could demonstrate their ability to treat bone infection. (C) 2011 Elsevier Ltd and Techna Group S.r.l. All rights reserved.