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

<b>Objectives:</b> 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. <b>Methods:</b> 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. <b>Results:</b> SA-AgNPs demonstrated significant antibacterial properties against both Gram-positive (methicillin-resistant <i>Staphylococcus epidermidis</i>, <i>Staphylococcus aureus</i>, <i>Cutibacterium acnes</i>, methicillin-resistant <i>Staphylococcus aureus</i>) and Gram-negative (<i>Escherichia coli</i>), 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 <i>Escherichia coli</i> (<i>E. coli</i>), <i>Cutibacterium acnes</i> (<i>C. acnes</i>), and methicillin-resistant <i>Staphylococcus aureus</i> (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. <b>Conclusions:</b> 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.