Synthesis and characterization of Zn0.4Co0.6Fe2O4 superparamagnetic nanoparticles as a promising agent against proliferation of colorectal cancer cells

Superparamagnetic nanoparticles are being used in cancer therapy as agents of MRI contrasting, drug delivery, and hyperthermia therapy. Their radiosensitization ability is less explored in comparison with gold and other high - Z nanoparticles. Herein, we report the radiotherapy application of Zn0.4Co0.6Fe2O4 superparamagnetic nanoparticles against HT-29 colorectal cancer cells. The nanoparticles were synthesized by the hydrothermal method and they were characterized using XRD, VSM, FTIR, DLS, FE-SEM, and XPS techniques. The nanoparticles have spherical morphology with a cubic spinel structure. The surface of the nanoparticles contains hydroxyl and carbonyl functional groups. The hydrodynamic mean size of the nanoparticles is 55.2 nm with a moderate zeta potential of 29.11 mV. The nanoparticles are superparamagnetic with a good saturation magnetization value of 73 emu/g. The cationic distribution study showed that the tetrahedral crystal positions are occupied by Co2+ and Fe3+ cations whereas the octahedral positions are occupied by Zn2+, Co2+, and Fe3+ with Fe3+ being the most. The cytotoxicity was investigated by MTT assay. The anticancer and radiosensitization ability of the nanoparticles was assessed by colony forming assay. The IC50 obtained from the cytotoxicity study is 100 mu g/mL. The anticancer study showed 43% proliferation inhibition at 100 mu g/mL. The combination of 2 Gy and nanoparticles resulted in more damage on colorectal cancer cells than 4 Gy alone in the radiosensitization study. The present investigation suggests that Zn0.4Co0.6Fe2O4 superparamagnetic nanoparticles are potential candidates to enhance the efficacy of radiotherapy in the case of colorectal cancer.