Synergistic Antimicrobial Mechanisms of Antimicrobial Peptide-Coated Silver Nanoparticles for the Targeted Treatment of Multidrug-Resistant (MDR) Infections

Abstract : The emergence of multidrug-resistant (MDR) pathogens poses a critical challenge to global health, necessitating innovative antimicrobial solutions. This study focuses on the synthesis, characterization, and evaluation of antimicrobial peptides (AMP)-coated silver nanoparticles (AgNPs) as a novel approach to combating MDR infections. AMPs, known for their broad-spectrum activity and unique mechanisms, were isolated from Lacticaseibacillus casei and successfully precipitated using ammonium sulfate precipitation. The AMPs were conjugated with AgNPs to improve their stability, bioavailability, and antimicrobial efficacy. AMP-coated AgNPs were synthesized and characterized using UV‒visible spectrophotometry, confirming the successful formation of nanoparticles. Antimicrobial and antifungal activities were assessed against a broad range of pathogens using the agar well diffusion method. The AMP-coated AgNPs exhibited enhanced activity compared to AMP alone, with significant inhibition zones observed for both bacterial and fungal strains. Synergy studies revealed that the combination of AMP-coated AgNPs with conventional antibiotics improved therapeutic efficacy, even at reduced dosages. Hemolysis assay evaluated the biocompatibility of the nanoparticles, indicating potential cytotoxicity of the silver nanoparticles at higher concentrations. These findings underscore the promise of AMP-coated AgNPs as potent, broad-spectrum antimicrobial agents. However, the cytotoxic effects highlight the need for further research into optimizing biocompatibility. This study paves the way for developing advanced therapeutic strategies targeting MDR pathogens, offering an effective alternative to conventional antibiotics in critical healthcare applications.