Light-Activated Iron Oxide Nanoparticles in Cancer Treatment: Synergistic Roles in Photothermal and Photodynamic Therapy

Iron oxide nanoparticles have emerged as multifunctional compounds with prominent potential in cancer theranostics, particularly in photothermal therapy (PTT) and photodynamic therapy (PDT). Their unique electronic and crystal structures, such as the dispersion of Fe2+ and Fe3+ ions and d-orbital splitting, contribute to their magnetic and catalytic properties. In PTT, Fe3O4 nanoparticles exhibit moderate near-infrared (NIR) absorption and photothermal conversion efficiency, which can be enhanced through adjustments in particle size, surface modification, and combinations with other components. In PDT, Fe3O4 nanoparticles demonstrate intrinsic peroxidase-like catalytic activity, facilitating Fenton and photo-Fenton reactions that generate reactive oxygen species (ROS), including hydroxyl radicals (•OH), thereby amplifying oxidative stress in cancer cells. These nanoparticles can also function as carriers for photosensitisers (PS), promoting targeted delivery and enhanced ROS generation. Multifunctional nanomaterials that integrate Fe3O4 with other therapeutic agents and targeting ligands have demonstrated synergistic antitumour effects through amplified photothermal, photodynamic, chemodynamic, and chemotherapeutic mechanisms. Despite certain drawbacks, such as relatively low NIR absorption and challenges in optimising delivery and light activation, ongoing improvements in Fe3O4-based nanoplatforms present significant potential for enhancing treatment outcomes and the precision of cancer therapy. This article systematically explores the synergistic role of Fe3O4 nanoparticles in PTT and PDT, encompassing their magnetic and catalytic characteristics. Additionally, it focuses on multifunctional hybrid nanoplatforms that combine Fe3O4 with targeting or imaging agents, highlighting their potential to enhance therapeutic precision.