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Fullerenol (C60(OH)24) nanoparticles (FNP) have a significant role in biomedical research due to their numerous biological activities, some of which are cytoprotective and antioxidative properties. The aim of this study was to measure distribution of fullerenol nanoparticles and zeta potential in cell medium RPMI 1640 with 10% fetal bovine serum (FBS) and to investigate the influence of FNP on Chinese hamster ovary cells (CHO-K1) survival, as well as to determine the activity of three antioxidative enzymes: superoxide-dismutase, glutathione-reductase and glutathione-S-transferase in mitomycin C-treated cell line. Our investigation implies that FNP, as a strong antioxidant, influence the cellular redox state and enzyme activities and thus may reduce cell proliferation, which confirms that FNP could be exploited for its use as a cytoprotective agent.[Projekat Ministarstva nauke Republike Srbije, br. III45005 i Pokrajinski Sekretarijat za nauku i tehnološki razvoj Vojvodine, grant number 114-451-2056/2011-01]

Eukaryotic cell survives in predominantly reduced conditions. Homeostasis of cellular redox system is an imperative of cell surviving and its normal metabolism. ROS are well recognized for playing a dual role as both deleterious and beneficial species, since they can be either harmful or beneficial to living systems. These species are mutagenic compounds known to lead to DNA damage, favor cell transformation, and contribute to the development of a variety of malignant diseases. All the effects of oxidants are influenced by the cellular antioxidant defenses. This multilayer system consists of low molecular weight components and several antioxidant enzymes. Superoxide dismutases (SODs) are the only enzymes dismuting superoxide radicals. Mitomycin C, a cross-linking agent, demonstrated genotoxicity in all in vitro and in vivo test systems in mammalian cells and animals. Water-soluble fullerenes are well known as cytotoxic agents for many cell lines in vitro. At the other side, fullerenols are good free radical scavengers and antioxidants both in vitro and in vivo. This paper investigates the effects of fullerenol on survival and fullerenol/ /mytomicine (MMC) treatment on superoxide-dismutase (SOD) activity in CHO-K1 cells. Samples were treated 3 and 24 h with fullerenol (C60(OH)24) at concentration range 0.01-0.5 mg/mL and survival was monitored with dye exclusion test (DET). The activity of total SOD was estimated in samples treated with chosen concentrations of fullerenol and MMC (0.5 and 0.1 mg/mL) after 3 and 24 h of cell incubation. Increasing of C60(OH)24 concentration leads to decreasing of percent of surviving cells 3 and 24 h after incubation. The activity of total SOD enhanced with higher concentration of fullerenol, while decreased in the highest concentration at both experimental points. In samples treated with MMC, as well as in samples treated with fullerenol (0.0625 mg/mL) + MMC was noticed boost in total SOD activity in comparison with controls. Treatment with fullerenol decreased SOD activity in rest of samples treated with MMC. Decreased activity of superoxide-dismutase in almost all samples treated with fullerenol and MMC might be contributed to antioxidative properties of fullerenol. Increased enzyme level at concentration of 0.0625 mg/mL may be due to its prooxidative activity.

Polyhydroxy fulleren derivates have significant potential in nanomedical application. Research of polyanion nanoparticle fullerenol C60(OH)24 is of high significance for interpretation of biological mechanisms. This paper investigated the properties of polyanion nanoparticle fullerenol C60(OH)24 as a potential polydentat ligand. Fullerenol C60(OH)24 water solutions were added in solution of [Cu(NH3)4]2+ in order to form a dark brown complex. Absorbance of [Cu(NH3)4]2+ solution was decreasing with increasing concentration of polyanion nanoparticle nanoligand fullerenol. This relation was determined in all investigated concentrations of [Cu(NH3)4]2+. The ratio of Cu2+ complex composer to polyanion polydentat nanoligand fullerenol had an increase from 1.5 to 9, proportional to the increase of the complex composer concentration and decrease of polyanion polydentat nanoligand fullerenol in the alkali medium. The thermogram TGA-DTA of fullerenol and fullerenol and CuSO4 complex, clearly show endothermic effects (which are the result of dehydratation and dehydroxylation) and exothermic effects (as the result of degradation of C60(OH)24 molecules and processes of oxidation in CO, CO2. At the beginning of TGA-DTA fullerenol thermogram, there is a very well defined endothermic peak of water loss at 100°C, followed by mass decrease as a consequence of lost hydroxyl groups, covalent bounded for C60. The influence of the complex composer is manifested in the moving of thermal stability towards lower temperatures. The complex composer is a catalyst of the process of polyanion polydentat nanoligand fullerenol oxidation to CO and CO2. The temperature peak of fullerenol oxidation is at 490°C and in the case of complex oxidation two peaks were detected at 380 and 410°C.

This paper investigates the effects of sodium nitroprusside as NO donor on two cell lines in culture: transformed cells of mice fibroblasts (L929) and malignant cells of human eritroleukemia (K562). Low concentrations of NO have stimulative effect, while high concentrations have inhibitive effects on proliferation of K562 cells in a dose-dependent manner. In our experiments, by using sodium nitroprusside (SNP) as NO donor and two kinds of superoxide dismutase, Cu,Zn-SOD and Mn-SOD, we created conditions to generate several kinds of signal molecules and investigated reaction of transformed (L929) and malignant (K562) cells to dose. Results of experiments are showing that chosen parameters (amount of free thiol groups and glutathione) may be relevant in monitoring the effect of exogenous nitrate oxide and its redox descendants in different, both transformed and malignant cell lines.

DET (dye exclusion test) cell count and cell area by computer analysis of the images were determined in cell lines of human eritroleukemia (K562), which were irradiated with X-rays in one dose of 24 Gy and pretreated with 10 nmol/mL fullerenol (Cgo(OH)24). Cell samples obtained using a citocentrifuge and May-Grünvald Giemsi (MGG) during, were analyzed. The cell colony formation ability was monitored using quantative CFU (colony forming unit) test. Irradiation decreases the number of K562 cells, but fullerenol significantly increases cell number on 24th and 48th hour of the experiment. Cell area is larger, and the number of formed cell colonies after irradiation is significantly smaller compared to pretreated groups during the whole experiment. Pretreatment with fullerenol maintains a smaller cell area, and the number of colony formed units was larger compared to the irradiated cells.

Cell culture K562 samples were treated with fullerenol (C6o(OH)24) at a concentration of 10 nmol/mL and thereafter irradiated with X-rays (24Gy). The activity of gamma-glutamyltransfrease (γ-GT), total superoxide-dismutase (SOD) and glutathion-peroxidase (GSH-Px) was determined 1, 24 and 48 hours after irradiation. Irradiation induces an increase in the activity of all the investigated enzymes. Fullerenol in the applied dose decreased the γ-GT activity 24 and 48 h after irradiation. The total SOD activity is increased in both pretreated groups except in the iradiated group at the 48th hour. Treatment with fullerenol before irradiation increased GSH-Px activity in irradiated groups and decreased it in the control groups.