Enhanced Hyperthermic Response of Dextrose-Coated Mn_0.5Zn_0.5Fe₂O₄ Nanorings Containing Magnetic Fluid and Its Cytotoxicity and Uptake in HeLa Cells

The present work explores the application of a temperature-sensitive magnetic fluid designed for magnetic fluid hyperthermia (MFH). The nanorings composed of Mn_0.5Zn_0.5Fe₂O₄ are an alternative to the traditional superparamagnetic magnetite nanoparticles, since they present superior heating response as compared to even their nanoparticles synthesized using different methods. In addition, the present work demonstrates that the synthesized nanoring has a 155.3 W/g_mag heating response for the smallest concentration of 1 mg/mL at a frequency of 332 kHz and a field of 10 kA/m. Thereby, we demonstrate an efficient magnetic hyperthermia strategy in which small but well-stable nanorings can promote an efficient hyperthermic response. The cytotoxicity of the nanorings is observed very low in HeLa cells, while its efficient cellular internalization makes it a promising candidate for the MFH. Upon exposure to MFH treatment on HeLa cells containing these A55-Ring, 55% cells died in a single session of hyperthermia treatment. These findings suggest a promising potential of utilizing Mn_0.5Zn_0.5Fe₂O₄ ferrite nanorings for advancing the MFH study.