Silver Nanoparticles as Potential Antibacterial and Antibiofilm Agents: Insights from Experimental and Computational Approaches

Abstract

Background: In the present study we prepared silver nanoparticles (AgNPs) by the chemical reduction method which is considered more preferable than other previously reported methods. The prepared AgNPs were further evaluated for their antibacterial properties and their mode of action was putatively elucidated by molecular dynamics (MD) simulations. Results: The structure and uniformity of the prepared AgNPs was confirmed by different characterization techniques including XRD, SEM, FT-IR, UV-vis spectroscopy, zeta potential, and DLS. Testing these AgNPs for their antibacterial and antibiofilm activities revealed very good potential against E. coli and K. pneumoniae (MIC = 37.5 and 18.75 μg/mL, respectively), P. aurigenosa and C. albicans (Percent of biofilm inhibition = 43% and 50%, respectively). Further comprehensive MD simulations revealed that the desorbed Ag atoms can bind with and probably inhibit the bacterial GSH reductase resulting in fatal increased oxidative stress inside the bacterial cell. Conclusions: AgNPS produced by chemical methods are easy to prepare nanomaterial that exert considerable antibacterial effects via the inhibition of the bacterial GSH reductase. To the best of our knowledge, this is the first comprehensive MD simulation work that uncover the mechanism of the bacterial GSH reductase inhibition by Ag atoms. Accordingly, we believe that the results presented herein will pave the way for additional research into metal-protein interactions, which will aid in the development of new metal-based treatments.