Synthesis, characterization and comparison of antimicrobial activity of PEG/TritonX-100 capped silver nanoparticles on collagen scaffold

Silver nanoparticles have received attention as novel antimicrobial agents. In order to study the effects of silver nanoparticles on both Gram positive and negative bacteria, the nanoparticles were synthesized via chemical reduction method using different concentrations (0.3, 0.6 and 0.9 mM) of poly(ethylene) glycol (PEG) and TritonX-100 (TX). Also, mixed PEG/TX systems with equimolar concentrations capped silver nanoparticles were synthesized and confirmed by UV-vis, fluorescence spectroscopy and particle size analysis. These coated silver nanoparticles were incorporated into collagen, lyophilized to form scaffolds and characterized by SEM, XRD, ATR-FTIR, DSC, TGA and zeta potential. Results on mechanical property of all the scaffolds displayed no significant difference in the percentage elongation at break. However, the maximum percentage of 46.67% was observed with the combinations (0.9 mM PEG + 0.9 mM TX). This implies that the combinations of surfactants increase the elasticity, which is useful for biomedical applications, e.g., heart-valve preparations. Furthermore, the antimicrobial activities of these capped silver nanoparticles homogenized with collagen were tested against both Gram positive and negative bacteria. Minimum inhibitory concentration values obtained for the combination (0.9 mM PEG + 0.9 mM TX) were found to be better than others and thus provide strong antibacterial property to the collagen scaffolds prepared for tissue regeneration applications. (C) 2011 Elsevier B.V. All rights reserved.