Engineered Mn–Zn-doped ferrite nanomaterials: exploring magnetothermal effects for cancer treatment

Abstract

The present work investigates the potential of Mn–Zn-doped ferrite (FMZ) nanoparticles for magnetic hyperthermia, focusing on the optimization of their magnetic characteristics to enhance their heat generation efficiency. The co-precipitation route was used to design FMZ (Mn_xZn_1−xFe₂O₄) nanomaterials with x = 0, 0.25, 0.50, 0.75, and 1.0. Redshifts in their inverse spinel diffraction patterns confirmed the doping. Functional group analysis further verified the interactions of Zn and Mn within the ferrite lattice, while X-ray photoelectron spectroscopy (XPS) revealed their occupancy. The single-domain nature of the FMZ nanoparticles showed a spherical particle, with size varying linearly from 13.6 ± 2 to 15.7 ± 3 nm with an increase in the Mn content. Magnetic characterization revealed the linear relation of magnetization and Mn content with the superparamagnetic nature of the synthesized FMZ samples. The FMZ0.75 sample showed the highest magnetic saturation (M_S) value of 38.90 emu g⁻¹ among the FMZ samples. The specific absorption rate (SAR) values for the FMZ0.75 sample at 1, 3, and 5 mg mL⁻¹ were 173.24, 107.12, and 105.42 W g⁻¹, respectively. Notably, FMZ0.75 at 3 mg mL⁻¹ reached hyperthermia temperature within 5 minutes. Furthermore, a peak function elucidated the interrelationship among particle size, M_S, and SAR values, identifying an optimum particle size of 14.7 nm and an Mn fraction of 0.7. Cytocompatibility assays confirmed the suitability of FMZ samples against HEK-293 cells for the tested concentrations of up to 5 mg mL⁻¹. Simulated hyperthermia studies revealed a significant reduction (35%) in the viability of the A549 cancer cell line, underlining the selective efficacy of FMZ nanomaterials. Considering the observed effective cytocompatibility and SAR values, FMZ samples can be effectively used for hyperthermia and related adjuvant therapy, such as chemotherapy for drug delivery applications.