Magnetic hyperthermia of AFe2O4 (A = Fe, Mn, Co) nanoparticles prepared by Co-precipitation method

With 10 million deaths in 2020 cancer remains one of the most challenging diseases in contemporary medicine. Chemotherapy, surgery, and radiation therapy are commonly used to treat tumors. These treatments harm healthy tissues and succeed rarely in advance stages of cancer. Recent studies indicate that magnetic hyperthermia, which involves targeted delivery of magnetic nanoparticles to tumor cells followed by localized remote heating of cancer tissues could revolutionize clinical practice in the treatment of cancer, either as standalone intervention or adjunct to radiotherapy and chemotherapy. Water dispersible magnetic nanoparticles (MNPs) of ferrites (AFe2O4; A = Fe, Mn, Co) are the promising candidates for magnetic hyperthermia due to their high chemical stability, biocompatibility, moderate magnetization and high specific absorption rates (SAR). In this article, we have evaluated magnetic hyperthermia efficiency of water based magnetic fluids of AFe2O4. AFe2O4 NPs were synthesized by chemical co-precipitation method. Nanoparticles were coated with a bilayer of oleic acid and dispersed in water. Structural and magnetic properties of MNPs were investigated by X-Ray diffraction (XRD) and vibrating sample magnetometer (VSM). XRD study revealed that AFe2O4 NPs exhibits cubic inverse spinel structure. Fe3O4 (Ms = 48 emu/g, Mr = 2.60 emu/g, Hc = 49 Oe), MnFe2O4 (Ms = 40 emu/g, Mr = 2.60 emu/g, Hc = 35 Oe) and CoFe2O4 (44 emu/g, Mr = 10.10 emu/g, Hc =440 Oe) NPs exhibits soft ferromagnetic behaviour. Magnetic hyperthermia measurements were performed as a function of magnetic field strength (2–10 mT), field frequency (162–935.6 kHz) for 10 minutes. MNPs exhibits highest SAR values for 10 mT field strength at 935.6 kHz. Amongst the tested MNPs, Fe3O4 possess the highest SAR value (27.35 W/g), followed by MnFe2O4 (1.91 W/g) and CoFe2O4 (0.94 W/g). Considering this, it is concluded that amongst the inverse spinel ferrites AFe2O4, Fe3O4 NPs and most suitable for magnetic hyperthermia applications.