Cytotoxic Impact of Catalytic Activity and Heating Efficiency of Manganese Ferrite Nanoparticles With Different Particle Sizes for Magnetic Fluid Hyperthermia

ABSTRACT Magnetic nanoparticles have garnered significant attention in cancer treatment for their dual ability to generate localized heat under an alternating magnetic field and catalyze heterogeneous Fenton‐based reactions on their surface. These reactions produce free radicals in mildly acidic and reducing environments, such as the tumor microenvironment, leading to oxidative stress in cancer cells. The synergistic combination of magnetic hyperthermia and catalytic activity enhances oxidative stress induction, underscoring the importance of understanding the cytotoxic effects of this approach. In this study, we performed in vitro toxicity assays on the HepG2 cell line to evaluate cytotoxicity and lipid peroxidation induced by hyperthermia using manganese ferrite nanoparticles with mean sizes of 12 and 28 nm. Magnetic hyperthermia efficiency, quantified by Specific Loss Power (SLP), and catalytic activity, assessed through free radical generation using electron paramagnetic resonance (EPR) and substrate oxidation rates via UV–visible spectroscopy, were characterized prior to the biological experiments. Our results showed that the 28 nm nanoparticles achieved a temperature increase of approximately 11.5°C, compared to 3.6°C for the 12 nm particles. Correspondingly, higher cell death was observed for the 28 nm nanoparticles following magnetic fluid hyperthermia treatment. However, lipid peroxidation was more pronounced with the 12 nm nanoparticles, attributed to their larger surface‐to‐volume ratio enhancing catalytic performance. In conclusion, nanoparticle size critically influences both magnetic and catalytic properties, and optimizing these parameters is essential for maximizing therapeutic efficacy in magnetic fluid hyperthermia.