Unveiling the Antibacterial Efficacy and Mechanistic Insights of MnO2 Nanoparticles for Advanced Therapeutic Applications

Pathogenic bacterial infections pose serious health risks, underscoring the need for timely treatments. Manganese dioxide (MnO₂) nanoparticles (NPs) have attracted considerable attention owing to their outstanding chemical stability, favorable biocompatibility, high reactivity, and catalytic ability to decompose hydrogen peroxide, making them promising antibacterial agents. A clear understanding of their antibacterial mechanisms is essential for evaluating their therapeutic potential in clinical settings. In this study, MnO₂ NPs were synthesized by reacting potassium permanganate (KMnO₄) with poly(allylamine hydrochloride) (PAH), ensuring complete conversion to MnO₂ NPs. The resulting NPs were characterized for their physicochemical properties, and their antibacterial activity against <i>E. coli</i> and <i>S. aureus</i> was evaluated using growth curve assays and reactive oxygen species (ROS) quantification. Results indicated the killing efficiency of MnO₂ NPs increased with exposure time and concentration, reflecting high susceptibility of both bacterial strains. Scanning electron microscopy (SEM) analysis revealed that the interaction between MnO₂ NPs and bacterial cells caused significant disruption of cell wall integrity. This study provides a valuable platform for evaluating MnO₂ nanoparticles as antibacterial agents and for exploring their mechanisms in medical applications.