Enhancing the magnetic properties of superparamagnetic iron oxide nanoparticles using hydrothermal treatment for magnetic hyperthermia application

Superparamagnetic iron oxide nanoparticles (SPIONs) are the most commonly used inorganic nanoparticles for magnetic hyperthermia in cancer treatment. In this technique, the temperature of the tumor is increased by applying an external alternating magnetic field, which induces heat release from magnetic nanoparticles located at the tumor site. In this study, SPIONs were produced using the chemical co-precipitation technique combined with hydrothermal treatment to reduce their size dispersibility and increase their crystallinity, which are directly related to their magnetic properties. The size of the SPIONs increased from 9 nm to 20 nm after hydrothermal treatment at 160 degrees C for 24 h. These NPs exhibit a cubic/rectangular shape with a structure composed of both magnetite and maghemite. Their superparamagnetic behavior was confirmed, and the magnetic saturation increased from 58 to 73 emu g-1 at RT and from 67 to 81 emu g-1 at 10 K. Magnetic hyperthermia measurements showed an increase in SAR values from 83 to about 160-200 W g-1, depending on the hydrothermal treatment conditions. Additionally, the exposure of normal and melanoma cells to SPIONs in the presence of an alternating magnetic field leads to a significant reduction in cell viability, with a more pronounced effect in melanoma cells. These results demonstrate the high potential of this synthesis technique for producing SPIONs for cancer treatment via magnetic hyperthermia.