Polyhydroxylated Fullerene Derivatives Research Articles

Polyhydroxylated fullerene nanoparticles attenuate brain infarction and oxidative stress in rat model of ischemic stroke.

Oxidative stress is the common underlying mechanism of damage in ischemic stroke. Therefore, we aimed to evaluate the possible protective effects of polyhydroxylated fullerene derivatives on brain infarction and oxidative/nitrosative stress in a rat model of ischemic stroke. The experiment was performed by four groups of rats (each; n=12); Sham, Control ischemia, and ischemic treatment groups (Pretreatment and Posttreatment). Brain ischemia was induced by 90 min middle cerebral artery occlusion (MCAO) followed by 24 hours reperfusion. Rats received fullerene nanoparticles at dose of 1 mg/kg 30 min before MCAO and immediately after beginning of reperfusion. Infarct volume, contents of malondialdehyde (MDA), glutathione (GSH) and nitrate as well as superoxide dismutase (SOD) activity were assessed 24 hours after termination of MCAO. Brain infarct volume was 310 ± 21 mm3 in control group. Administration of fullerene nanoparticles before and after MCAO significantly decreased the infarct volume by 53 % (145 ± 45 mm3) and 81 % (59 ± 13 mm3), respectively. Ischemia also enhanced MDA and nitrate contents of ischemic hemispheres by 45 % and 25 % , respectively. Fullerene nanoparticles considerably reduced the MDA and nitrate contents of ischemic hemispheres before MCAO by 58 % and 17 % , respectively, and after MCAO by 38 % and 21 % , respectively. Induction of MCAO significantly decreased GSH content (19 % ) and SOD activity (52 % ) of ischemic hemispheres, whereas fullerene nanoparticles increased the GSH content and SOD activity of ischemic hemispheres by 19 % and 52 % before MCAO, respectively, and 21 % and 55 % after MCAO, respectively. Our findings indicate that fullerene nanoparticles, as a potent scavenger of free radicals, protect the brain cells against ischemia/reperfusion injury and inhibit brain oxidative/nitrosative damage.

Fullerenols: Physicochemical properties and applications

Abstract Fullerenols may find the widest application in science and technology. This causes particular interest in developing available and simple methods for the synthesis of water-soluble polyhydroxylated fullerene derivatives on an industrial scale as well as investigating the physicochemical and biological properties and principles of their application. This study systematizes the current literature data on the synthesis, physicochemical properties, and application of polyhydroxylated fullerenes (fullerenols), a class of water-soluble fullerene derivatives. The experimental and theoretical data presented in this study provide a comprehensive overview of these substances and can be valuable to specialists in the fields of nanotechnology, nanomaterials, and nanobiomedicine.

Review of Synthesis and Antioxidant Potential of Fullerenol Nanoparticles

This review describes the chemical synthesis of polar polyhydroxylated fullerene C60 derivatives, fullerenols C60(OH)n, 2 ≤ n ≤ 44, C60HzOx(OH)y, and polyanion fullerenols C60(OH)15(ONa)9, ranging from the very first synthetic methods up to some contemporary approaches to synthesis and separation. It also provides some basic information about physical characteristics of fullerenols. With the increasing number of hydroxyl groups, water solubility of fullerenols increases as well. Fullerenols both in water and biological media build nanoparticles of different dimensions and stability. In different chemical and biological model systems a large number of various polyhydroxylated fullerene derivatives were tested and they showed both their antioxidative and prooxidative characteristics. Several mechanisms have been proposed for the antioxidant activity of fullerenol. In addition, this paper also provides insight into patents referring to the antioxidant properties of fullerenol.

Application of polyhydroxylated fullerene derivatives in hemoglobin biosensors with enhanced antioxidant capacity

Hemoglobin (Hb) biosensors based on polyhydroxylated fullerene derivatives were constructed through layer-by-layer assembly. Not only could fullerene derivatives provide a favorable microenvironment to realize the direct electrochemistry and electrocatalysis of Hb, but they could reduce the oxidant damage for Hb caused by the attack of H2O2 as well. Moreover, the antioxidant effect was closely related with fullerene species.

The polyhydroxylated fullerene derivative C 60(OH) 24 protects mice from ionizing-radiation-induced immune and mitochondrial dysfunction

Although the protective effect of the polyhydroxylated fullerene derivative C 60(OH) n against ionizing radiation is an area of much interest, the mechanisms relating to how polyhydroxylated fullerene derivatives improve mitochondrial dysfunction remain unknown. In order to find new and effective radioprotective agents, we synthesized a new polyhydroxylated fullerene molecule with 24 hydroxyl groups of known positions on C 60 and studied its protective effects in mice subjected to irradiation. Mice were pretreated with C 60(OH) 24 for 2 weeks (daily, 40 mg/kg i. p.), then subjected to a lethal dose of whole body γ-irradiation (from a 60Co source). Survival was observed for 30 days after irradiation. Immune and mitochondrial dysfunction and oxidative damage were analyzed in mice with the same C 60(OH) 24 pretreatment and irradiation except that the animals were euthanized at day 5 after the irradiation. It was found that 2-week C 60(OH) 24 pretreatment effectively reduced whole body irradiation-induced mortality without apparent toxicity. C 60(OH) 24 pretreatment also showed significant protective effects against ionizing-radiation-induced decreases in immune and mitochondrial function and antioxidant defense in the liver and spleen. These results suggest that the polyhydroxylated fullerene derivative C 60(OH) 24 protects against ionizing-radiation-induced mortality, possibly by enhancing immune function, decreasing oxidative damage and improving mitochondrial function.

Fullerene derivatives protect against oxidative stress in RAW 264.7 cells and ischemia-reperfused lungs.

Fullerene derivatives have often been used as effective scavengers for reactive oxygen species (ROS). This study was designed to test whether polyhydroxylated fullerene derivatives [C(60)(OH)(7+/-2)] protect against oxidative stress in cultured RAW 264.7 cells and ischemia-reperfused (IR) lungs. In RAW 264.7 cells, sodium nitroprusside (SNP, 1 mM) and H(2)O(2) (400 microM) caused a marked (90%) decrease in cell viability, and this decrease was dose dependently reversed by pretreatment with C(60)(OH)(7+/-2) (10-50 microM). The increase in ROS production induced by SNP and H(2)O(2) was significantly suppressed by C(60)(OH)(7+/-2). Also, the decrease in mitochondrial membrane potential induced by SNP and H(2)O(2) was significantly reversed by C(60)(OH)(7+/-2). However, high concentration of C(60)(OH)(7+/-2) (1 and 1.5 mM) lead to cell death (apoptosis or necrosis). In the isolated rat lung, the increases in pulmonary artery pressure and capillary filtration pressure induced by SNP during IR were reversed significantly by C(60)(OH)(7+/-2) (10 mg/kg). These results indicate that polyhydroxylated fullerene derivatives C(60)(OH)(7+/-2) at low concentrations protect against oxidative stress in RAW 264.7 cells and IR lungs.

Efficient one-flask synthesis of water-soluble [60]fullerenols

C 60 molecule exhibited high reactivity towards the addition reaction of nitrogen dioxide radicals (·NO 2), which were generated by reaction of sodium nitrite with conc. HNO 3. This chemical functionalization of C 60 resulted in polynitro fullerenes, C 60(NO 2) n. Hydrolysis of polynitro fullerenes in aqueous NaOH gave the corresponding polyhydroxylated fullerene derivatives (fullerenols) in moderate overall yields. Results from mass spectra (FAB, negative ion) of fullerenols indicated their structure as C 60 derivatives with at least 16 hydroxy groups.

Free radical scavenging activity of water-soluble fullerenols

Water-soluble polyhydroxylated fullerene derivatives (fullerenols) show excellent efficiency in eliminating superoxide radicals (O2–˙), generated by xanthine and xanthine oxidase, thus revealing the potential use of these compounds as novel potent free radical scavengers in biological systems.

Efficient Synthesis of Polyhydroxylated Fullerene Derivatives via Hydrolysis of Polycyclosulfated Precursors

Cyclosulfated fullerene derivatives were hydrolyzed in the presence of water or in aqueous NaOH solution giving polyhydroxylated fullerenes. Both sulfated precursors and hydroxylated products were characterized. 7 figs.

Medical Applications of Water-Soluble Polyhydroxylated Fullerene Derivatives

ABSTRACTThe promising positive results in reducing superoxide free radicals (O2-.), generated by invitro xanthine and xanthine oxidase, have been demonstrated in the evaluation of potential uses of novel water-soluble [60] fullerenols as free radical scavengers. Observation reveals the inherent application of fullerenols in a wide range of medical and clinical areas as preventive alternatives for a long-term medical treatment.

Synthesis of Fullerols as Polyhydroxylated Fullerene Derivatives

ABSTRACTwe outline three methods for the preparation of fullerols as polyhydroxylated fullerene derivatives through the reaction of fullerenes with electrophilic reagents. The synthetic methodology includes a sequence of reactions using an aqueous acid chemistry, the epoxidation reaction, or the interesting nitronium chemistry as an key approach for the conversion of fullerenes to fullerols. The structure of fullerols was characterized and proposed to consist of at least 13 hydroxy functional moieties incorporating both hydroxy and hemi-ketal as parts of the structural components.