Electrostatically assembled maghemite nanoparticles-Lactobacillus plantarum: A novel hybrid for enhanced antioxidant, antimicrobial, and antibiofilm efficacy

Excessive antibiotic use contributes to oxidative stress and microbial imbalance, leading to increased growth of pathogens and biofilm formation. To address this, we developed a novel electrostatically assembled hybrid of maghemite nanoparticles and Lactobacillus plantarum (MNPs-LAB) as a multifunctional agent. Structural and surface interactions were confirmed through X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS), while transmission electron microscopy (TEM) and field emission scanning electron microscopy (FESEM) analyses revealed a uniform distribution of MNPs on the LAB surface. The MNPs-LAB hybrid exhibited strong antioxidant activity (71.45 % at 500 µg/mL) and enhanced antimicrobial performance against Listeria monocytogenes. In addition, the hybrid inhibited biofilm formation and effectively eradicated preformed biofilms of Staphylococcus succinus, Listeria monocytogenes, Escherichia coli, and Salmonella thompson. Notably, the low cytotoxicity observed in Caco-2 cells indicated good biocompatibility with intestinal epithelial cells. These results highlight the potential of MNPs-LAB hybrid as a safe and effective therapeutic candidate for combating oxidative stress, microbial infections, and biofilm-associated challenges.