Salicylic Acid-Mediated Silver Nanoparticle Green Synthesis: Characterization, Enhanced Antimicrobial, and Antibiofilm Efficacy

Abstract

Objectives: Silver nanoparticles (AgNPs) were synthesized via an easy and rapid biogenic synthesis approach, utilizing the dual capabilities of salicylic acid as both a reducing and capping agent. Methods: The characterization of Salicylic Acid-Mediated Silver Nanoparticle (SA-AgNPs) was conducted using a variety of techniques, including ultraviolet-visible spectroscopy, dynamic light scattering, scanning electron microscopy combined with energy dispersive X-ray spectroscopy, transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, as well as thermogravimetric analysis paired with differential scanning calorimetry. Results: SA-AgNPs demonstrated significant antibacterial properties against both Gram-positive (methicillin-resistant Staphylococcus epidermidis, Staphylococcus aureus, Cutibacterium acnes, methicillin-resistant Staphylococcus aureus) and Gram-negative (Escherichia coli), with minimum inhibitory concentrations (MICs) of 8, 9, 8, 4, and 6 μg/mL, respectively. At a concentration of 32 μg/mL, SA-AgNPs exhibited 99.9% killing efficiency against Escherichia coli (E. coli), Cutibacterium acnes (C. acnes), and methicillin-resistant Staphylococcus aureus (MRSA), within 4, 16, and 12 h, respectively. At the same concentration, SA-AgNPs effectively inhibited 95.61% of MRSA biofilm formation. SA-AgNPs induced the leakage of intracellular macromolecular substances by increasing the membrane permeability, which ultimately caused bacterial apoptosis. Conclusions: Overall, this study presents a fast and environmentally friendly approach for synthesizing SA-AgNPs, with potential applications as nano antibiotics antibacterial coatings for implantable medical devices and wound dressings.