Synthesis, Characterization, and Antimicrobial Efficacy of Fidaxomicin-Loaded Copper Nanoparticles Against Multidrug-Resistant Clostridium difficile

Abstract

This study investigates the potential of fidaxomicin-loaded copper nanoparticles (CuNPs) as a synergistic treatment strategy for multidrug-resistant Clostridium difficile (C. difficile) infections. Copper nanoparticles, known for their antimicrobial properties, were synthesized using a chemical reduction method, and their size, surface charge, morphology, and encapsulation efficiency were characterized using dynamic light scattering (DLS), zeta potential (ZP) analysis, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The encapsulation of fidaxomicin was confirmed, and the drug release profile was evaluated using in vitro assays, which demonstrated a controlled and sustained release of the drug over 48 hours. Fourier-transform infrared spectroscopy (FTIR) analysis confirmed the successful loading of fidaxomicin onto the CuNPs. Antimicrobial activity was assessed through minimum inhibitory concentration (MIC) and time-kill assays, revealing a synergistic effect of fidaxomicin-loaded CuNPs, which significantly enhanced the bactericidal activity against multidrug-resistant C. difficile. The formulation showed minimal cytotoxicity, with a cell viability of over 85% in mammalian cells. These results suggest that fidaxomicin-loaded copper nanoparticles provide an effective and promising approach to combat C. difficile infections, overcoming existing challenges of drug resistance and improving therapeutic outcomes.