Radiosensitization Induced by Magnetic Hyperthermia of PEGylated Nickel Ferrite Nanoparticles on Breast Cancer Cells

Magnetic hyperthermia can complement traditional cancer treatments by exploiting the greater heat sensitivity of tumor cells. This approach allows for localized action, increasing its therapeutic effectiveness. In this study, MCF-7 breast cancer cell radiosensitization, induced by the magnetic hyperthermia of PEGylated nickel ferrite magnetic nanoparticles (PEG-NiF MNPs), was evaluated by exposing the cells in the presence of MNPs to an alternating magnetic field followed by ⁶⁰Co gamma irradiation. Superparamagnetic PEG-NiF MNPs (25.6 ± 0.5 nm) synthesized via the hydrothermal method exhibited a hydrodynamic size below 150 nm, a saturation magnetization of 53 emu·g^-1, biocompatibility of up to 100 µg·mL^-1, selectivity for breast cancer cells, and an up-to-fivefold increase in therapeutic efficacy of radiation. When combined with magnetic hyperthermia, this increase reached up-to-sevenfold. These results indicate that PEG-NiF MNPs are suitable thermal radiosensitization agents for breast cancer cells.