Biosurfactant assisted synthesis and characterization of silver nanoparticles: In vitro investigation of their anti-oxidant, anti-inflammatory, anti-infective and wound healing potential

Silver nanoparticles (AgNPs) hadshowen immense potential for managing inflammatory responses, oxidative stress, and severe microbial infections leading to chronic wounds by reducing environmental impact and resistance. Plant -mediated synthesis offers eco-friendly solutions, especially in degrading harmful textile dyes, benefiting ecosystems. Still, frequent aggregation and destabilization are the major limitations of metallic nanoparticles. Mannosylerythritol (MST), a lipid derived from microorganisms stabilises metallic nanoparticles. AgNPs were prepared by a chemical reduction method, characterized for optical, surface properties, and elemental analysis, and evaluated for ionic silver release, antioxidant effect, inhibition of ROS generation and NF-kB upregulation, anti -infective and wound closure potentials. The AgNPs comprised of 0.04% w/v AgNO 3 , 0.3% w/v sodium borohydride and 0.5% w/v MST exhibited nanosized (50 -80 nm) orbicular particles with high purity and stability. EDX analysis portrayed the presence of 92.82% Ag by weight. Unlike acidified AgNPs, plane AgNPS showed consistent Ag + release for 24 h, owing to which this group showed tremendous utility in scavenging DPPH-induced free radicals (20 -fold lesser IC 50 value) with a slight decrease in RAW 264.7 cell viability when tested by MTT assay. The MIC of AgNPs against C. albicans, S. aureus and P. aeruginosa was 10, 10 and 5 ppm, respectively. The microbial GI of AgNPs was found to be 62.44 ppm against C. albicans, 110.69 against S. aureus and 91.58 against P. aeruginosa. Flowcytometry showed a reduction in ROS generation, and NF- kappa beta upregulation justifies the safer use of AgNPs against oxidative stress and inflammatory conditions. The in vitro scratch test in RAW 264.7 cells justifies the rapid wound closure claim. Controlling a wide range of pathogens while mitigating oxidative stress and inflammation is the optimal strategy for expediting wound healing. Consequently, these AgNPs hold significant promise as innovative wound dressing materials for the future.