Does engineering of nanoshapes have antibacterial synergy with magnetic signal exposure?

Abstract

The widespread use of antibiotics in diverse areas led many bacterial strains to become highly resistant. Thus, considerable concerns were recently raised to overcome and/or to find other alternatives to the use of antibiotics. In this context, combining antibacterial effects of exposure to pulsed magnetic signals and supplying of silver nanoparticles recently indicated a significant bactericidal impact. The interplay between silver nanoshapes (spheres, rods and prisms) and exposure to pulsed magnetic signals (0·32 mT, 20 Hz–30 min) was studied to explore whether engineering of silver nanoshapes has a synergistic antibacterial effect against Klebsiella pneumoniae. In this regard, the bacterial growth rates, kinetics and enzymatic changes (protein leakage and lactate dehydrogenase levels) were investigated. The results confirmed that silver nanoprisms with a higher specific-area-to-volume ratio and appreciable analogy of charge distribution exhibit the highest synergistic inhibition effect with pulsed magnetic signals by 35% at 10 parts per million concentration. Moreover, the coupling of magnetic signals with nanoprisms showed significant cellular injuries and loss of membrane integrity as a consequence of the elevation of lactate dehydrogenase and protein leakage levels by more than fivefold and 15-fold, respectively. These new findings substantiate the antibacterial synergism of silver nanoparticles with pulsed magnetic signals in a shape-dependent manner.