Functionalized Magnetite Nanoparticles: Characterization, Bioeffects, and Role of Reactive Oxygen Species in Unicellular and Enzymatic Systems

Abstract

The current study evaluates the role of reactive oxygen species (ROS) in bioeffects of magnetite nanoparticles (MNPs), such as bare (Fe3O4), humic acids (Fe3O4-HA), and 3-aminopropyltriethoxysilane (Fe3O4-APTES) modified MNPs. Mössbauer spectroscopy was used to identify the local surrounding for Fe atom/ions and the depth of modification for MNPs. It was found that the Fe3O4-HA MNPs contain the smallest, whereas the Fe3O4-APTES MNPs contain the largest amount of Fe2+ ions. Bioluminescent cellular and enzymatic assays were applied to monitor the toxicity and anti-(pro-)oxidant activity of MNPs. The contents of ROS were determined by a chemiluminescence luminol assay evaluating the correlations with toxicity/anti-(pro-)oxidant coefficients. Toxic effects of modified MNPs were found at higher concentrations (>10−2 g/L); they were related to ROS storage in bacterial suspensions. MNPs stimulated ROS production by the bacteria in a wide concentration range (10−15–1 g/L). Under the conditions of model oxidative stress and higher concentrations of MNPs (>10−4 g/L), the bacterial bioassay revealed prooxidant activity of all three MNP types, with corresponding decay of ROS content. Bioluminescence enzymatic assay did not show any sensitivity to MNPs, with negligible change in ROS content. The results clearly indicate that cell-membrane processes are responsible for the bioeffects and bacterial ROS generation, confirming the ferroptosis phenomenon based on iron-initiated cell-membrane lipid peroxidation.

Fenton reaction-driven pro-oxidant synergy of ascorbic acid and iron oxide nanoparticles in MIL-88B(Fe)

“…The nonstoichiometry parameter δ 38 of magnetite Fe 3− δ O 4 was calculated following the procedure described in ref. 39 and 40. All isomer shift values are reported relative to α-Fe measured at 296 K.…”

The Waelz Slag from Electric Arc Furnace Dust Processing: Characterization and Magnetic Separation Studies

“…Evidently, the WS1 sample contains a more oxidized form of non-stoichiometric Fe 3−δ O 4 , whereas the WS2 sample contains predominantly reduced iron atoms in octahedral positions, which is confirmed by a high value of the isomeric shift of the second sextet. Based on the data obtained at 78 K and the application of the method described in [45], we determined that the WS1 sample contains Fe 2 . 667 O 4 , i.e., pure maghemite γ-Fe 2 O 3 , and the WS2 sample contains Fe 2 .…”

Synthesis, Characterization, and In Vitro Cytotoxicity Evaluation of Doxorubicin-Loaded Magnetite Nanoparticles on Triple-Negative Breast Cancer Cell Lines

“…In addition, magnetic nanoparticles have another remarkable property—internal enzymatic activity [ 34 , 35 ]. For example, iron oxide magnetic nanoparticles have demonstrated an ability to produce reactive oxygen species (ROS) [ 36 , 37 ] and can also initiate a new iron-dependent form of programmed cell death—ferroptosis [ 37 , 38 ]. The discussion of this phenomenon is presented in a recent review [ 38 ], where the generation of ROS by doxorubicin-loaded iron oxide nanoparticles and their effect on bacteria and cancer cells is discussed.…”

“…For example, iron oxide magnetic nanoparticles have demonstrated an ability to produce reactive oxygen species (ROS) [ 36 , 37 ] and can also initiate a new iron-dependent form of programmed cell death—ferroptosis [ 37 , 38 ]. The discussion of this phenomenon is presented in a recent review [ 38 ], where the generation of ROS by doxorubicin-loaded iron oxide nanoparticles and their effect on bacteria and cancer cells is discussed. IONPs with doxorubicin were shown to induce oxidative stress and, owing to their superparamagnetic characteristic, can be prospective for magnetic-field-mediated anticancer therapy [ 39 , 40 ].…”