Extracellular silver nanoparticles by Citricoccus alkalitolerans and Brevibacillus brevis using response surface methodology: characterization, antibacterial activity, and biocompatibility assessment on nonwoven fabric for wound dressing applications.

Abstract

Textile substrates incorporating antimicrobial agents offer a significant advantage in managing chronic wound infections, a major clinical challenge exacerbated by the rising prevalence of multidrug-resistant pathogens. This study aimed to fabricate silver nanoparticles (AgNPs) with potent antimicrobial activity specifically targeting drug-resistant wound pathogens using a green synthesis approach with locally isolated bacteria. Production was systematically optimized via response surface methodology, and the resulting AgNPs were characterized using UV-Vis spectroscopy, X-ray diffractometry, and transmission electron microscopy, which confirmed nanoparticle formation with average sizes of approximately 10 nm. Optimal biosynthesis was achieved when the producer bacterium was cultured with 1 mM silver nitrate at pH 7 and incubated at 35 °C for 73 h. The biosynthesized AgNPs were subsequently loaded onto nonwoven fabric, a widely used material in wound dressings due to its breathability, absorbency, and conformability and evaluated for antibacterial activity against Staphylococcus aureus (ATCC 6538) and Escherichia coli (ATCC 8739). The AgNP-coated fabric exhibited promising antibacterial activity against both Gram-positive and Gram-negative pathogens, producing inhibition zones of 29 mm and 27 mm, respectively. These findings demonstrate the potential of bacterially synthesized AgNP-loaded nonwoven fabrics as effective, biocompatible antimicrobial wound dressings for combating multidrug-resistant wound infections in clinical settings.