Advancements in Superparamagnetic Iron Oxide Nanoparticles for Magnetic Hyperthermia as a Promising Strategy to Combat Antibacterial Resistance.

Antimicrobial resistance and biofilm-associated infections increasingly undermine the efficacy of conventional antibiotic therapy, creating a need for localized treatments that combine complementary physical and chemical antibacterial mechanisms. Superparamagnetic iron oxide nanoparticles (SPIONs) are particularly attractive because they can be magnetically targeted, surface-functionalized, imaged, and remotely activated using an alternating magnetic field (AMF). This Review critically examines SPION-mediated antibacterial magnetic hyperthermia, encompassing nanoparticle synthesis, control of magnetic properties, bactericidal mechanisms, multimodal therapeutic strategies, biosafety, and clinical translation. Particular emphasis is placed on how particle size, morphology, crystallinity, magnetic anisotropy, surface chemistry, aggregation state, AMF amplitude and frequency, specific absorption rate, and intrinsic loss power collectively determine heating efficiency and antibacterial efficacy. Beyond direct thermal damage, magnetic activation can disrupt bacterial membranes and proteins, destabilize biofilm matrices, enhance antibiotic penetration, interfere with quorum sensing, and promote catalytic reactive oxygen species generation. Emerging therapy platforms further integrate magnetothermal heating with other multimodal antibacterial therapies. Despite these advances, clinical translation remains constrained by heterogeneous nanoparticle accumulation, and standardisation of the magnetothermal parameters. Addressing these challenges through reproducible nanoparticle engineering, standardized AMF reporting, rigorous biosafety assessment, and clinically relevant infection models will be essential for advancing SPION-mediated magnetic hyperthermia toward practical antibacterial applications.