Cytotoxicity characteristics of green assisted-synthesized superparamagnetic maghemite (γ-Fe₂O₃) nanoparticles

Magnetic nanoparticles such as Fe₃O₄ and γ-Fe₂O₃ are extensively used in medical application, i.e. drug delivery, MRI, etc. Chemical toxicity and side-effect behaviors always play an important role in such applications. Thus, synthesis of such less-toxic compounds with green technology is privilege. In this study, the extract prepared from mango leaves was used for the preparation of iron oxide nanoparticles (γ-Fe₂O₃) using FeSO₄ as iron source with the green-assisted route. The X-ray diffraction pattern indicated single-phase formation with the average crystallite size of 7 ± 2 nm. HRTEM micrographs indicated a dot-cloud-surrounded like particles ranging from 1 to 12 nm. Fourier Transform Infrared (FT-IR) spectroscopy showed two absorption bands at 457 and 634 cm⁻¹, which are attributed to octahedral and tetrahedral sites of Fe–O band, respectively. A vibrating sample magnetometer (VSM) indicated a saturation magnetization (M_s) value about 53 emu/g with negligible coercivity (H_c), suggesting superparamagnetic behavior of the synthesized nanoparticles. The cytotoxicity was evaluated by exposing the breast cancer cell type (MCF7) to different concentrations of the γ-Fe₂O₃ nanoparticles. MTT assay results revealed that the growth and survival of MCF7 cells directly depend on the concentration of synthesized iron oxide nanoparticles. It was found that up to concentration of 200 µg/mL, cell survival has not yet reached 50%, which indicates the safety of nanoparticles and lack of toxicity.