The surface modification of magnetite nanoparticles (Fe₃O₄ NPs) is a promising approach to obtaining biocompatible and multifunctional nanoplatforms with numerous applications in biomedicine, for example, to fight cancer. However, little is known about the effects of Fe₃O₄ NP-associated reductive stress against cancer cells, especially against chemotherapy-induced drug-resistant senescent cancer cells. In the present study, Fe₃O₄ NPs in situ coated by dextran (Fe₃O₄@Dex) and glucosamine-based amorphous carbon coating (Fe₃O₄@aC) with potent reductive activity were characterized and tested against drug-induced senescent breast cancer cells (Hs 578T, BT-20, MDA-MB-468, and MDA-MB-175-VII cells). Fe₃O₄@aC caused a decrease in reactive oxygen species (ROS) production and an increase in the levels of antioxidant proteins FOXO3a, SOD1, and GPX4 that was accompanied by elevated levels of cell cycle inhibitors (p21, p27, and p57), proinflammatory (NFκB, IL-6, and IL-8) and autophagic (BECN1, LC3B) markers, nucleolar stress, and subsequent apoptotic cell death in etoposide-stimulated senescent breast cancer cells. Fe₃O₄@aC also promoted reductive stress-mediated cytotoxicity in nonsenescent breast cancer cells. We postulate that Fe₃O₄ NPs, in addition to their well-established hyperthermia and oxidative stress-mediated anticancer effects, can also be considered, if modified using amorphous carbon coating with reductive activity, as stimulators of reductive stress and cytotoxic effects in both senescent and nonsenescent breast cancer cells with different gene mutation statuses.

A series of thioacetyl-functionalized fullerene-C₆₀ derivatives were synthesized using the Prato reaction of fullerene-C₆₀ with six different 4-(S-acetylthioalkyl)benzaldehydes. The structures of the synthesized compounds were characterized by FT-IR, ¹H NMR and ESI-MS techniques. The LUMO–HOMO band gaps, derived from DFT B3LYP/6-31G* calculations, for the azomethine ylides corresponding to each 4-(S-acetylthioalkyl)benzaldehyde and fullerene-C₆₀ were correlated with the efficiency of the Prato reaction. The compounds were deposited onto gold electrodes via self-assembly following an in situ deprotection procedure which transformed the thioacetyl-functionalized compounds into their thiolated derivatives. The redox properties of the C₆₀ derivatives in solution were characterized using Voltammetry. The LUMO–HOMO band gaps obtained from the electrochemical data were compared with the density functional theory (DFT) values for the optimized structures. The thioacetyl-functionalized C₆₀ derivatives were employed for the catalytic reduction of halogenated hydrocarbons. Following deprotection, they were also employed for the modification of gold substrates. The solvent dependent barrier properties of the thiolated fullerene films were investigated using Cyclic Voltammetry (CV) and Electrochemical Impedance Spectroscopy (EIS). The topography of the C₆₀ derivative modified electrode was investigated using X-ray Photoelectron Spectroscopy (XPS) and Atomic Force Microscopy (AFM), which confirmed stable modification of the Au support with a three dimensional (3D) film of worm-like fullerene aggregates.

The purpose of this study was to make an initial assessment of new PEG (polyethylene glycol)-functionalized C₆₀ fullerene derivative for potential bone tissue engineering applications. Thus, Fourier Transform Infrared spectroscopy analysis, thermogravimetric analysis, and cyclic voltammetry measurement were performed. Moreover, cell culture experiments in vitro were carried out using normal human osteoblasts. Cell viability and proliferation were evaluated using colorimetric 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) test as well as by fluorescent staining. It was demonstrated that resultant derivative possessed good solubility in water, high temperature stability, and retained favorable electron accepting properties of C₆₀ fullerene core. Most important, new fullerene derivatives at low concentrations did not exhibit cytotoxic effect and supported osteoblast proliferation compared to control. Thanks to all mentioned properties of new PEG-functionalized C₆₀ fullerene derivative, it seems that it could be used as a component of polymer-based bone scaffolds in order to enhance their biological properties.

Background: Fullerenols (water-soluble derivatives of fullerenes), such as C₆₀(OH)₃₆, are biocompatible molecules with a high ability to scavenge reactive oxygen species (ROS), but the mechanism of their antioxidant action and cooperation with endogenous redox machinery remains unrecognized. Fullerenols rapidly distribute through blood cells; therefore, we investigated the effect of C₆₀(OH)₃₆ on the antioxidant defense system in erythrocytes during their prolonged incubation. Methods: Human erythrocytes were treated with fullerenol at concentrations of 50–150 µg/mL, incubated for 3 and 48 h at 37 °C, and then hemolyzed. The level of oxidative stress was determined by examining the level of thiol groups, the activity of antioxidant enzymes (catalase, glutathione peroxidase, glutathione reductase, and glutathione transferase), and by measuring erythrocyte microviscosity. Results: The level of thiol groups in stored erythrocytes decreased; however, in the presence of higher concentrations of C₆₀(OH)₃₆ (100 and 150 µg/mL), the level of -SH groups increased compared to the control. Extending the incubation to 48 h caused a decrease in antioxidant enzyme activity, but the addition of fullerenol, especially at higher concentrations (100–150 µg/mL), increased its activity. We observed that C₆₀(OH)₃₆ had no effect on the microviscosity of the interior of the erythrocytes. Conclusions: In conclusion, our results indicated that water-soluble C₆₀(OH)₃₆ has antioxidant potential and efficiently supports the enzymatic antioxidant system within the cell. These effects are probably related to the direct interaction of C₆₀(OH)₃₆ with the enzyme that causes its structural changes.