Advantages of Magnetic Iron Oxide Nanoparticles for Cancer Photothermal Therapy

Many photothermal agents have been developed for cancer photothermal therapy (PTT). However, biocompatible, low toxic, and biodegradable photothermal agents and high photothermal conversion efficiency are potentially suitable for clinical use. In addition, optical absorption in near-infrared regions, excellent photothermal stability, highly efficient tumor targeting, multifunctions, and low cost are also important factors for selecting a suitable photothermal agent. Superparamagnetic iron oxide nanoparticles have been FDA-approved for clinical diagnosis and therapy. Their optical absorption ranges from UV to NIR-I (~700–1000 nm) or even NIR-II region (~1000–1700 nm). Therefore, some magnetic iron oxide nanoparticles, such as iron oxide clusters, can generate much heat upon NIR-I or NIR-II laser irradiation. Magnetic iron oxide nanoparticles maintain their original shapes and photothermal conversion ability after the treatment of laser-induced heat. They can accumulate in the tumor through passive, active, and magnetic, attractive force-triggered targeting. Furthermore, these nanoparticles possess multifunctions, such as transferring the alternating magnetic field energy into heat, producing mechanical force under a dynamic magnetic field, and magnetic resonance imaging. This chapter discusses the biomedical applications and specific properties of magnetic iron oxide materials as a benefit for magnetic material-mediated PTT. The factors related to the toxicity of the magnetic iron oxide were also discussed.