Anti-pseudomonal and anti-endotoxic effects of surfactin-stabilized biogenic silver nanocubes ameliorated wound repair in streptozotocin-induced diabetic mice

Abstract

Pseudomonas aeruginosa and its lipopolysaccharides play a key role in the pathogenesis of diabetic foot infection, for which, currently no effective therapeutic agents are available. Hence, newer forms of therapeutic agents are required for treating Pseudomonas aeruginosa infection. In this present study, nanocrystalline silver nanoparticles (AgNPs) were synthesized using culture filtrate of Brevibacillus brevis KN8(2) followed by an investigation of its in vivo anti-pseudomonal and anti-endotoxic properties. Biosynthesized AgNPs was predominantly cubical in shape with an average particle size of 15.40 nm as observed through field emission scanning electron microscopy (FESEM) and X-ray diffraction analysis. The LC-ESI-MS/MS analysis indicates the presence of surfactin in culture filtrate of B. brevis KN8(2). The MIC of surfactin-stabilized AgNPs against P. aeruginosa was 10 μg ml−1 and its wound repair activity was observed in P. aeruginosa-infected wounds of diabetic mice by measuring wound area closure, bacterial counts, mRNA expressions, and histopathology. Further, surfactin-stabilized AgNPs suppressed the transcription of LPS-triggered expression of the TNF-α in wounds that LPS-assisted extension of wound repair in diabetes mellitus conditions was circumvented quite well. Results gathered in this study established that surfactin-stabilized AgNPs could effectively offer to the novel treatment of Gram-negative bacilli infection in diabetic wounds.