Optimizing Heat Generation in Magnetic Iron Oxide Nanoparticles for Use in Cancer Hyperthermia

Using magnetic fluid hyperthermia (MFH) for cancer treatment is a viable option to achieve local heat generation in tumors, and avoid severe side effects of conventional cancer treatments like radiation and chemotherapy. However to achieve maximum therapeutic efficiency with a minimal patient exposure to magnetic nanoparticles (MNPs), high heat generation using the least possible concentration of iron oxide MNPs is essential. In this study, it was determined that heat generation in MNPs depends on magnetic field strength and frequency, size of MNPs, and viscosity of the medium surrounding these MNPs. The heat generation in these MNPs was standardized using specific absorption rate (SAR), which was used to find the set of parameters that gave the highest SAR values. It was found that the heating rates and SAR increased with corresponding increase in magnetic field strength (15.1 – 47.7 kA/m) and frequency (123 kHz – 430 kHz) in the range tested. Also, SAR and heating rates increased with increase in MNP size in the range of 8 – 18 nm. Increasing the viscosity of the medium decreased the heating rates and SAR values. After analyzing the SAR values it was concluded that maximum heating rate could be obtained for the 18 nm MNPs at the highest field strength and frequency in media with lower viscosity.