Topical application of zinc oxide nanoparticles reduce bacterial skin infection in mice and exhibit antibacterial activity by inducing oxidative stress response and cell membrane disintegration in macrophages.

Nanomedicine : nanotechnology, biology, and medicine

PubMedID: 24607937

Pati R, Mehta RK, Mohanty S, Padhi A, Sengupta M, Vaseeharan B, Goswami C, Sonawane A. Topical application of zinc oxide nanoparticles reduce bacterial skin infection in mice and exhibit antibacterial activity by inducing oxidative stress response and cell membrane disintegration in macrophages. Nanomedicine. 2014;.
Here we studied immunological and antibacterial mechanisms of zinc oxide nanoparticles (ZnO-NPs) against human pathogens. ZnO-NPs showed more activity against Staphylococcus aureus and least against Mycobacterium bovis-BCG. However, BCG killing was significantly increased in synergy with antituberculous-drug rifampicin. Antibacterial mechanistic studies showed that ZnO-NPs disrupt bacterial cell membrane integrity, reduce cell surface hydrophobicity and down-regulate the transcription of oxidative stress-resistance genes in bacteria. ZnO-NP treatment also augmented the intracellular bacterial killing by inducing reactive oxygen species production and co-localization with M. smegmatis-GFP in macrophages. Moreover, ZnO-NPs disrupted biofilm formation and inhibited hemolysis by hemolysin toxin producing S. aureus. Intradermal administration of ZnO-NPs significantly reduced the skin infection, bacterial load and inflammation in mice, and also improved infected skin architecture. We envision that this study offers novel insights into antimicrobial actions of ZnO-NPs and also demonstrates ZnO-NPs as a novel class of topical anti-infective agent for the treatment of skin infections.