Fe3O4/Au nanocomposites: Characterization and cytotoxicity effects in vitro
https://doi.org/10.1016/j.matchemphys.2024.129524
Magnetic nanocomposites containing iron oxide and gold components take great attention last years because of their relative biocompatibility and the ability to combine the magnetic properties of iron and the chemical bonding properties of gold for the possible drug delivery or diagnostics for various diseases. However, such particles have some toxicity to living cells, and the effect depends on many factors, including size, shape, the ratio of components in the composites, and the type of cells affected. And thus, the search for compositions and technologies for producing iron-gold particles with improved properties and reduced cytotoxicity remains relevant. The aim of the study was to synthesize and characterize Fe3O4/Au nanocomposites and evaluate their influence on living cells using the example of cell line HEK293.
Fe3O4 nanoparticles (NPs) were synthesized by co-precipitation of Fe2+/Fe3+ water solution in alkaline conditions and then boiled with HAuCl4 in 0.1 M sodium citrate. The NPs properties were estimated by transmission electron microscopy (TEM), vibration magnetometry and ferromagnetic resonance (FMR).
According to magnetometric measurements, nanoparticles are mainly in a superparamagnetic state. By fitting magnetization curves, the magnetic characteristics of nanoparticles were determined: saturation magnetization (59.3 emu/g) and magnetic anisotropy constant (� = 0.86·105 erg/cm3). The average particle size estimated from magnetic measurements was 8.7 nm. Considering the presence of a magnetically dead layer, this is in good agreement with the TEM results. The temperature dependence of the FMR linewidth was analyzed using two models. As a result, the parameters ��� and �/�� were determined. The models used showed good agreement. The values of the anisotropy constant (� = 1.06·105 erg/cm3) and the average particle size (6.8 nm) are estimated.
The effect of the NPs on the HEK293 cells was studied by MTT-assay, flow cytometry and RT-PCR. The exposure with the NPs lead to a significant decrease of cell metabolic activity in HEK293 cell culture, but this effect was not accompanied by cell death. It was shown that the expression of antioxidant enzymes SOD1 and GPX1 was reduced at the mRNA stage. So the NPs synthesized may affect gene expression and metabolism of HEK293 cells, but this does not have fatal consequences for cell viability.