Influence of composition on colloidal stability, thermal properties, and magnetic hyperthermia performance of NixZn0.5-xMg0.5Fe2O4 nanoparticles for biomedical applications

초록

Nickel-doped spinel ferrite nanoparticles (NPs) with the chemical composition NixZn0.5-xMg0.5Fe2O4 (x = 0.1, 0.2, 0.3) were successfully synthesized through a solvothermal reflux approach and labeled as NZMF1, NZMF2, and NZMF3. Structural analysis via X-ray diffraction (XRD) confirmed the formation of single-phase spinel structures with no detectable impurities. The average crystallite size was estimated to be between 11 and 10 nm. The crystalline nature and presence of characteristic metal-oxygen stretching vibrations typical of spinel ferrites were further supported by selected area electron diffraction (SAED) and Fourier-transform infrared (FTIR) spectroscopy. Compositional uniformity was validated using energy-dispersive X-ray spectroscopy (EDS) and elemental mapping, which demonstrated even distribution of Ni, Zn, Mg, Fe, and O throughout the nanoparticle matrices. Thermal stability and phase evolution were assessed by thermogravimetric and differential thermal analysis (TGA/DTA), which showed multiple weight loss steps corresponding to decomposition and crystallization events. Zeta potential measurements revealed negatively charged surfaces for all samples, with NZMF3 displaying the highest magnitude of negative charge, indicating improved colloidal stability with increased Ni substitution. Magnetic measurements indicated that NZMF1 exhibited the highest saturation magnetization (Ms) at 67.21 emu/g, followed by NZMF2 at 65.22 emu/g, and NZMF3 at 49.71 emu/g. The heating ability of the NPs under an alternating magnetic field (AMF) of 18.49 kA/m at 316 kHz was investigated for their potential in magnetic hyperthermia therapy (MHT). NZMF1 showed the most effective heating performance, reaching a specific absorption rate (SAR) of 191.56 W/g at a concentration of 1 mg/mL. Biocompatibility was assessed using MTT and live/dead cell assays on BLO-11 (mouse muscle fibroblast) and CT-26 (murine colorectal carcinoma) cell lines. All samples demonstrated no cytotoxicity, reinforcing their suitability for applications in biomedicine.

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