Fullerenol C60 Research Articles

Dual-modal fullerenol probe containing glypican-3 monoclonal antibody for electron paramagnetic resonance/fluorescence imaging

The multi-modal imaging contrast agent has been attracted an increased interest to the tumor detecting and diagnosis in these recent years since the multi-modal imaging technology combines the advantages of several medical imaging modalities. A water-soluble fullerenol probe containing glypican-3 monoclonal antibody (GPC3-mAb) group mAb-GPC3-C60(OH)10-(TMIO)3-(NI)3 was synthesized by the incorporation of 5-formyl-1,1,3,3-tetramethylisoindolin-2-yloxyl (FTMIO), naphthalimide (NI) and GPC3-mAb as a tumor-targeting group into fullerenol C60(OH)11. This nanomaterial was further characterized by FTIR, UV, MS, fluorescence, etc., and then its properties including electron paramagnetic resonance (EPR), particle size, electrophoresis, electrochemical assay, cell cytotoxicity, cell uptake and fluorescent imaging of HeLa tumor cells in vitro were also evaluated. Experiment results indicated that mAb-GPC3-C60(OH)10-(TMIO)3-(NI)3 had similar fluorescent properties as NI and similar electrochemical and redox properties as 5-carboxy-1,1,3,3-tetramethylisoindolin-2-yloxyl (CTMIO). Moreover, mAb-GPC3-C60(OH)10-(TMIO)3-(NI)3 possessed low cell cytotoxicity, good fluorescence and good tumor-targeting property. Meanwhile, mAb-GPC3-C60(OH)10-(TMIO)3-(NI)3 can be taken up highly by HeLa tumor cells, achieve good green fluorescent imaging in tumor cells and highly enhance the contrast of fluorescent images. Therefore, mAb-GPC3-C60(OH)10-(TMIO)3-(NI)3 can disperse homogeneously in aqueous solution and be used as a potential tumor-targeting dual-modal contrast agent for EPR imaging/fluorescence imaging (EPRI/FI).

Antioxidant activity of highly hydroxylated fullerene C60 and its interactions with the analogue of α-tocopherol

Polyhydroxylated fullerenes (fullerenols) are excellent free radical scavengers. Despite the large number of reports on their reactions with reactive oxygen species, there is no report on their ability to trap lipid peroxyl radicals and act as chain-breaking antioxidants. In this work we studied the effect of fullerenol C60(OH)36 on the kinetics of peroxidation of polyunsaturated fatty acid ester (methyl linoleate) dispersed in two model systems that mimic biological systems: Triton X-100 micelles and Large Unilamellar Vesicles, at pH 4, 7 and 10. As a control antioxidant 2,2,5,7,8-pentamethyl-6-hydroxychroman (PMHC, an analog of α-tocopherol) was used. In micellar systems at pH 4.0, C60(OH)36 reacts with peroxyl radicals with kinh= (5.8 ± 0.3) × 103 M−1s−1 (for PMHC kinh = 22 × 103 M−1s−1). Surprisingly, at pH 7 a retardation instead of inhibition was recorded, and at pH 10 no effect on the kinetics of the process was observed. In liposomal systems fullerenol was not active at pH 4.0 but at pH 7.0 kinh = (8.8 ± 2.6) × 103 M−1s−1 for fullerenol was 30% lower than kinh for PMHC. Using two fluorescent probes we confirmed that at pH 7.4 fullerenol/fullerenol anions are incorporated into the phospholipid heads of the bilayer. We also studied the cooperation of C60(OH)36 with PMHC: both compounds seem to contribute their peroxyl radical trapping abilities independently at pH 4 whereas at pH 7 and 10 a hyper-synergy was observed. The antioxidant action of C60(OH)36 and its synergy with PMHC was also confirmed for peroxidation of human erythrocytes at pH 7.4. Assuming the simplified structural model of fullerenol limited to 36 hydroxyls as the only functional groups attached to C60 core we found by density-functional theory a low energy structure with OH groups distributed in the form of two polyhydroxyl regions separating two unsubstituted carbon regions with biphenyl-like structure. Our calculations indicate that abstraction of hydrogen atom from fullerenol by peroxyl or tocopheroxyl radical is endoergic. As the electron transfer from fullerenol polyanion to the radicals is also energetically disfavoured, the most probable mechanism of reaction with radicals is subsequent addition of peroxyl/tocopheroxyl radicals to biphenyl moieties surrounded by OH groups.

The effect of fullerenol C60 on skeletal muscle after lower limb ischemia reperfusion injury in streptozotocin-induced diabetic rats

Aim: Fullerenol, a water-soluble C60-fullerene, has been demonstrated to scavenge free radicals in vitro and in vivo. The aim of the study was to investigate the effects of fullerenol C60 on lower skeletal muscles in a rat model of ischemia/reperfusion (I/R).Methods: After approval of the ethics committee, 30 Wistar Albino rat were divided into 5 groups with six animals per each as follows: Control (C), diabetes (D), diabetes+fullerenol C60 (DF), diabetes+I/R (group DIR) and diabetes I/R+fullerenol C60 (DIR-F) groups. Streptozotocin was administered to the rats to induce diabetes at a dose of 55 mg/kg. Four weeks after the onset of diabetes, rats were subjected to 2 hours of ischemia and 2 hours of reperfusion. At the end of the reperfusion period, skeletal muscle samples were taken from the lower extremity in all groups for histopathological and immunohistopathological examinations. Results: Myositis and endothelial caspase 3 enzyme activities were high in all groups, particularly DIR. Compared to C, DF and DIR-F groups, inflammation and myositis were significantly higher in the DIR group (P=0.001, P=0.006, P=0.001, respectively, and P=0.001, P=0.022, P=0.001, respectively). Vascular dilatation and congestion were significantly more prominent in all groups compared to the control group (P=0.001 for all).Conclusion: Our results confirm that fullerenol C60 has protective effects against skeletal muscle damage resulting from I/R in diabetic rats. Future studies conducted to evaluate these effects may help illuminate the action mechanism of fullerenol C60 and pathophysiology underlying the tissue damage related to I/R injury.

Heat capacity and standard thermodynamic functions of the fullerenol C60(OH)24

In the present investigation, the heat capacity of fullerenol C60(OH)24 was measured by precision adiabatic and differential scanning calorimetry over the temperature range from T = (6 to 670) K. The keto-enol tautomerism was revealed in the temperature range T = (355–575) K and enthalpy of transition was determined. The standard thermodynamic functions: molar heat capacity Cp°, enthalpy [H°(T) − H°(0)], entropy S°(T), and Gibbs energy [G°(T) − H°(0)] of the fullerenol were determined over the temperature range from T = (6 to 350) K from the obtained experimental results. Also, DFT calculations of the heat capacities were performed. The standard thermodynamic properties of the investigated fullerenol were compared to other fullerene derivatives.

A Multiparametric Study of Internalization of Fullerenol C60(OH)36 Nanoparticles into Peripheral Blood Mononuclear Cells: Cytotoxicity in Oxidative Stress Induced by Ionizing Radiation.

The aim of this study was to investigate the uptake and accumulation of fullerenol C60(OH)36 into peripheral blood mononuclear cells (PBMCs). Some additional studies were also performed: measurement of fullerenol nanoparticle size, zeta potential, and the influence of fullerenol on the ionizing radiation-induced damage to PMBCs. Fullerenol C60(OH)36 demonstrated an ability to accumulate in PBMCs. The accumulation of fullerenol in those cells did not have a significant effect on cell survival, nor on the distribution of phosphatidylserine in the plasma membrane. However, fullerenol-induced depolarization of the mitochondrial membrane proportional to the compound level in the medium was observed. Results also indicated that increased fullerenol level in the medium was associated with its enhanced transport into cells, corresponding to its influence on the mitochondrial membrane. The obtained results clearly showed the ability of C60(OH)36 to enter cells and its effect on PBMC mitochondrial membrane potential. However, we did not observe radioprotective properties of fullerenol under the conditions used in our study.

Surface properties of fullerenol C60(OH)20 solutions

The surface properties of fullerenol C60(OH)20 solutions differ significantly from the properties of solutions of more hydrophilic fullerenols. At concentrations below 1 g/l, dynamic surface elasticity proves to be very high (up to 300 mN/m), while surface tension decreases only slightly. The adsorption layer is very sensitive to mechanical perturbations of the solution surface, and surface elasticity decreases under surface compression. The adsorption layer is macroscopically homogeneous but contains microscopic aggregates. The layer can be easily transferred from the liquid surface onto a solid support.

Study of the Neuroprotective Properties of Fullerenol C60(OH)30 with a Model of Alzheimer’s Disease

An urgent task of modern medicine is the search for drugs that can stop or slow down the course of neurodegenerative diseases, in particular Alzheimer’s disease. The aim of this work was to determine the effect of fullerenol C60(OH)30 on the pathogenesis of Alzheimer’s disease in the Drosophila melanogaster model. The effect of fullerenol on the life expectancy, the level of geotaxis, learning and memory, and the levels of neurodegeneration and reactive oxygen species in the animal brain was studied. Based on the results, it can be assumed that fullerenol C60(OH)30 is a promising agent for the development of complex therapy for Alzheimer’s disease.

Fullerenol/iron nanocomposite diminishes doxorubicin-induced toxicity

Fullerenol C60(OH)24 with its spherical shape, symmetrical structure, 1 nm size and the ability to form polyionic nanoparticles in water solution, was used to synthesise a novel nanocomposite made of fullerenol nanoparticles (FNP) and iron ions (Fe2+). The FNP/Fe2+ nanocomposite was characterised by DLS and TEM-EDS analyses which have shown that the size distribution of FNP/Fe2+ stayed in the same scope as the size distribution of FNP, ranging from 11 to 60 nm. However, Fe2+ did affect the change of FNP’s zeta potential (− 49.2 mV), shifting it to more positive values (− 30.8 mV). In this study, it was assumed that FNP/Fe2+ could reduce the toxic effects of doxorubicin (Dox). Male Wistar rats were treated i.p. with FNP/Fe2+ nanocomposite 1 h prior to Dox treatment. At the subcellular level, the ultrastructural analysis revealed minor alterations sporadically displayed within the heart and liver tissues. Moreover, at the molecular level, the gene expressions analysis of mRNAs for catalase (heart and liver) and MnSOD (only liver) were significantly downregulated, indicating reduction in oxidative stress. Overall, the pretreatment with FNP/Fe2+ nanocomposite, followed by Dox application, significantly diminished harmful effects of the applied drug on the heart and liver, suggesting the potential protective effect of the nanocomposite on the healthy tissues.

Effect of Fullerenol C60 on Erythrocyte Deformability During Ischaemia-Reperfusion Injury of Lower Extremity in Diabetic Rats

Effect of Fullerenol C60 on Erythrocyte Deformability During Ischaemia-Reperfusion Injury of Lower Extremity in Diabetic Rats

Mechanisms of supramolecular ordering of water-soluble derivatives of fullerenes in aqueous media

Fullerenols C60(OH)X and C70(OH)X (X ∼ 30) have been studied in aqueous solutions at the concentrations 0.05–22wt% by X-ray and neutron scattering and using modeling hydroxyls’ arrangements on carbon cages to explain the molecular assembly defined by hydrophobic and hydrophilic interactions of molecules. In the case of C60 quantum chemical calculations minimizing molecular energy for different configurations of OH-groups on the carbon cages showed their preferred localization at C60 spheroids’ equatorial zone and at the opposite poles. However, less symmetric hydroxyls’ localization on C70 molecules was found since hydroxyls do not create closed chains on them. As a result, the molecules C60(OH)X are associated into primary chain-like aggregates (∼20 units, few nanometers in size) more likely in water than the fullerenols C70(OH)X forming similar groups of lower aggregation degree. For C60(OH)X and C70(OH)X the peculiarities in hydroxyls’ grafting affected a coordination of primary groups integrated into secondary and tertiary structures at the distances R ∼ 5 nm and R ∼ 30 nm at the concentrations C > 5wt% and C > 10wt%, respectively. The discovered mechanism of fullerenols’ assembly in water will facilitate their use in chemistry and biomedicine.

Water-Soluble Fullerenol C60(OH)36 toward Effective Anti-Air Pollution Induced by Urban Particulate Matter in HaCaT Cell.

Particulate matter (PM), a widespread air pollutant, consists of a complex mixture of solid and liquid particles suspended in air. Many diseases have been linked to PM exposure, which induces an imbalance in reactive oxygen species (ROS) generated in cells, and might result in skin diseases (such as aging and atopic dermatitis). New techniques involving nanomedicine and nano-delivery systems are being rapidly developed in the medicinal field. Fullerene, a kind of nanomaterial, acts as a super radical scavenger. Lower water solubility levels limit the bio-applications of fullerene. Hence, to improve the water solubility of fullerene, while retaining its radical scavenger functions, a fullerene derivative, fullerenol C60(OH)36, was synthesized, to examine its biofunctions in PM-exposed human keratinocyte (HaCaT) cells. The PM-induced increase in ROS levels and expression of phosphorylated mitogen-activated protein kinase and Akt could be inhibited via fullerenol pre-treatment. Furthermore, the expression of inflammation-related proteins, cyclooxygenase-2, heme oxygenase-1, and prostaglandin E2 was also suppressed. Fullerenol could preserve the impaired state of skin barrier proteins (filaggrin, involucrin, repetin, and loricrin), which was attributable to PM exposure. These results suggest that fullerenol could act against PM-induced cytotoxicity via ROS scavenging and anti-inflammatory mechanisms, and the maintenance of expression of barrier proteins, and is a potential candidate compound for the treatment of skin diseases.

Distinct Binding Dynamics, Sites and Interactions of Fullerene and Fullerenols with Amyloid-β Peptides Revealed by Molecular Dynamics Simulations.

The pathology Alzheimer’s disease (AD) is associated with the self-assembly of amyloid-β (Aβ) peptides into β-sheet enriched fibrillar aggregates. A promising treatment strategy is focused on the inhibition of amyloid fibrillization of Aβ peptide. Fullerene C60 is proved to effectively inhibit Aβ fibrillation while the poor water-solubility restricts its use as a biomedicine agent. In this work, we examined the interaction of fullerene C60 and water-soluble fullerenol C60(OH)6/C60(OH)12 (C60 carrying 6/12 hydroxyl groups) with preformed Aβ40/42 protofibrils by multiple molecular dynamics simulations. We found that when binding to the Aβ42 protofibril, C60, C60(OH)6 and C60(OH)12 exhibit distinct binding dynamics, binding sites and peptide interaction. The increased number of hydroxyl groups C60 carries leads to slower binding dynamics and weaker binding strength. Binding free energy analysis demonstrates that the C60/C60(OH)6 molecule primarily binds to the C-terminal residues 31–41, whereas C60(OH)12 favors to bind to N-terminal residues 4–14. The hydrophobic interaction plays a critical role in the interplay between Aβ and all the three nanoparticles, and the π-stacking interaction gets weakened as C60 carries more hydroxyls. In addition, the C60(OH)6 molecule has high affinity to form hydrogen bonds with protein backbones. The binding behaviors of C60/C60(OH)6/C60(OH)12 to the Aβ40 protofibril resemble with those to Aβ42. Our work provides a detailed picture of fullerene/fullerenols binding to Aβ protofibril, and is helpful to understand the underlying inhibitory mechanism.

A novel Pebax-C60(OH)24/PAN thin film composite membrane for carbon dioxide capture

Fullerenol C60(OH)24 derived from the surface hydroxylation of fullerene was incorporated into the Pebax matrix for the first time to fabricate Pebax-C60(OH)24/PAN thin film composite membranes (TFCMs) via dip coating method. To fully understand the behavior of Pebax-based TFCMs, the corresponding dense membranes were prepared and characterized by Fourier transform infrared spectroscopy (FTIR) with attenuated total reflection (ATR) mode, X-ray diffraction (XRD), scanning electron microscopy (SEM) and gas permeation tests (CO2, N2, CH4, H2) to survey the effect of C60(OH)24 on Pebax matrix. The interaction between C60(OH)24 and Pebax improved their compatibility as confirmed by FTIR and SEM. The presence of C60(OH)24 disrupted the Pebax chain packing, resulting in a decrease of crystallinity and an increase of permeability. The CO2 permeance of Pebax-C60(OH)24 (1 wt%)/PAN TFCMs was 338 GPU at 35 °C and 0.5 MPa, and the selectivity of CO2/N2 was 41. The gas performance of the TFCMs was further improved as pressure increasing. Pebax-C60(OH)24/PAN TFCMs were a promising candidate for CO2 capture.

Performance enhancement of perovskite solar cells through interfacial engineering: Water-soluble fullerenol C60(OH)16 as interfacial modification layer

Abstract TiO2 is widely used in conventional n-i-p type perovskite solar cells (Pero-SCs) as electron transporting layer (ETL). However, its drawbacks such as photocatalytic properties, low electron mobility, and a process of high temperature sintering, hindered the further improvement of device performance. In this work, a vacuum-deposited fullerene C60 was utilized as ETL, and a easily accessible fullerene derivative, C60(OH)16 fullerenol, was employed between ITO electrode and C60 ETL to modify ITO for the first time. After introducing the C60(OH)16 fullerenol layer, the Pero-SC obtained the favorable energy level alignment between ITO cathode and perovskite layer, and the device based on C60(OH)16/C60 ETL achieved a champion PCE of 16.70%, which showed a 15.41% enhancement compared to the Pero-SC with pristine C60 ETL (14.47%). The mechanisms of performance improvement were systemically discussed with respect to the optimized energy level, efficient charge transport and reduced interfacial resistance. This work exhibited that fullerenol C60(OH)16 is a promising interfacial modification material for the n-i-p type Pero-SCs.

Fullerenol C60(OH)36 at relatively high concentrations impairs hippocampal theta oscillations (in vivo and in vitro) and triggers epilepsy (in vitro) – A dose response study

Since the first identification of fullerenes (C60) and their synthesis in 1985, those compounds have been extensively studied in the biomedical field. In particular, their water-soluble derivatives, fullerenols (C60(OH)n, n = 2–48), have recently been the subject of numerous investigations concerning their antioxidant and prooxidant properties in biological systems. A small fraction of that research has focused on the possible use of C60 and C60(OH)n in neuroscience and the therapy of pathologies such as dementia, amyloid-β (Aβ) formation, and Parkinson's disease. However, only a few studies have focused on their direct effects on neuronal network viability and excitability, especially with the use of electrophysiological and electrochemical approaches. Therefore, we addressed the issue of the direct effect of hydroxylated fullerene nanoparticles C60(OH)36 on local field potentials at the hippocampal formation (HPC) level. With the use of in vitro hippocampal formation slices as a stable model of inducing theta oscillations, and an in vivo model of an anesthetized rat, herein we provide the first convergent electropharmacological evidence that C60(OH)36 at relatively high concentrations (60 μM and 80 μM in vitro; 0.2 μg/μl in vivo) is capable of attenuating the amplitude, power, and frequency of theta oscillations in the HPC neuronal network. At the same time, lower concentrations did not induce any apparent changes. Theta band oscillations constitute a key physiological phenotypic property, which served here as a sensitive assay enabling the study of neural network excitability. Moreover, we report that C60(OH)36 at the concentrations of 60 μM and 80 μM is capable of producing epilepsy in the HPC in vitro, which suggests that C60(OH)n, when applied at higher doses, may have a deleterious effect on the functioning of neuronal networks.

Fullerenol C60(OH)36 protects human erythrocyte membrane against high-energy electrons

Fullerenols (polyhydroxylated fullerene C60) are nanomaterial with potentially broad applicability in biomedical sciences with high antioxidant ability, thus, we investigated the radioprotecting potential of fullerenol C60(OH)36 on human erythrocytes irradiated by high-energy electrons of 6 MeV. The results demonstrate that C60(OH)36 at concentration of 150 μg/mL protects the erythrocytes against the radiation-induced hemolysis (comparing to non-protected cells, we observed 30% and 39% protection for 0.65 and 1.3 kGy irradiation doses, respectively). The protecting effect was confirmed by 32% decreased release of potassium cations comparing to the cells irradiated without C60(OH)36. Measurements of the amount of lactate dehydrogenase (LDH) released from the irradiated erythrocytes showed that the size of the pores formed by irradiation was not sufficient to release LDH across the erythrocyte membranes. We also report a significant decrease of the affinity of acetylcholinesterase (AChE) for the substrate in the presence of fullerenol, indicating the relatively strong adsorption of C60(OH)36 to components of plasma membrane. Changes in membrane fluidity detected by fluorescence spectroscopy and conformational changes in membrane proteins detected by spin labeling suggest the dose-dependent formation of disulfide groups as an effect of oxidation and this process was inhibited by C60(OH)36. We suppose that scavenging the ROS as well as adsorption of fullerenol to membrane proteins and steric protection of -SH groups against oxidation are responsible for the observed effects.

Fabrication and characterization of polyamide-fullerenol thin film nanocomposite hollow fiber membranes with enhanced antifouling performance

Fullerenol C60(OH)22–24 was incorporated into the polyamide (PA) selective layer to develop novel thin film nanocomposite (TFN) hollow fiber membranes for low molecular weight cut-off ultrafiltration. TFN membranes were fabricated via interfacial polymerization technique by alternately pumping fullerenol dispersion in triethylenetetramine (TETA) aqueous solution and isophthaloyl chloride solution in hexane through polysulfone hollow fiber membranes. Developed TFN PA/fullerenol membranes were investigated by FTIR, Raman spectroscopy, SEM, TEM, AFM, contact angle measurements and evaluated by determining the permeability, rejection and antifouling performance. Introduction of fullerenol to the PA skin layer was revealed to yield in the decrease of pure water flux and slight increase of lysozyme rejection which is attributed to the increase of the thickness of PA layer. Water contact angle of the skin layer was found to decrease sharply from 34° to 21° when the concentration of fullerenol increased up to 0.5wt% in the TETA aqueous solution. Antifouling properties of the PA/fullerenol membranes were found to be superior to initial membrane. Fouling recovery ratio increased from 54% for the pristine membrane to 93% for the membrane with 0.5wt% of fullerenol in the TETA aqueous solution. Irreversible fouling ratio was found to decrease from 38% to 6%, respectively. A correlation between surface properties and fouling behavior of TFN membranes upon increase of fullerenol concentration was established.

Enhancement of nano titanium dioxide coatings by fullerene and polyhydroxy fullerene in the photocatalytic degradation of the herbicide mesotrione

The surface modification of commercial TiO2 Hombikat (TiO2) using nanoparticles of fullerene C60 with tetrahydrofuran (THF-nC60), as well as fullerenol C60(OH)24 nanoparticles (FNP) was investigated in this study. Characterization of THF-nC60, FNP, TiO2, TiO2/THF-nC60, and TiO2/FNP was studied by using DES, ELS, TEM, SEM, DRS and BET measurements and their photoactivity has been examined on the mesotrione degradation under simulated sunlight. It was found that FNP in self-assembled nanocomposite TiO2/FNP increased negatively charge, as well as catalytic surface of TiO2. In addition, TiO2/FNP exhibits a shift of band gap energy to lower values compared to TiO2 and TiO2/THF-nC60. BET surface area has not showed significant differences among catalysts. Furthermore, it was found that the highest photoactivity was obtained for TiO2/FNP system. Besides, influence of different concentrations of electron acceptors (H2O2 and KBrO3), as well as scavengers on the kinetics of mesotrione removal in aqueous solution with/without TiO2 and FNP under simulated sunlight was investigated. Namely, addition of mentioned electron acceptors has resulted in higher mesotrione degradation efficiency compared to O2 alone. Besides, in the first period substrate degradation probably takes place via hydroxyl radicals and after 60 min of irradiation the reaction mechanism proceeds mainly via holes. The most efficient system for mesotrione degradation and mineralization were TiO2/7 mM KBrO3 and TiO2/7 mM KBrO3/40 μl FNP, respectively.

Effect of number of hydroxyl groups of fullerenol C 60 (OH) n on its interaction with cell membrane

Fullerenol C60(OH)n, where multiple hydroxyl groups are chemically bound to surface of a fullerene C60, is a highly potential nanomaterial for biomedical and pharmaceutical applications. To realize such biomedical and pharmaceutical applications, the C60(OH)n is required to be transported on the cell surface and/or to be transported into the cell interior. However, molecular mechanism underlying the interaction of C60(OH)n with the cell membrane is still far from being understood. This study presents an atomistic molecular dynamics (MD) simulation study on the interaction of C60(OH)n with the cell membrane. Here we focused on effect of number of the hydroxyl groups of C60(OH)n on its adhesion on, penetration into, and permeation across the cell membrane. The MD simulation results suggested that number of the hydroxyl groups of C60(OH)n can be a critical factor to control the interaction with a cell membrane; i.e., C60(OH)n with less number of hydroxyl groups (n ≦ 2) can penetrate into hydrophobic core of a lipid bilayer, while C60(OH)n with higher number of hydroxyl groups (n ≧ 8) can adhere onto surface of a cell membrane. Our simulation results also revealed that C60(OH)n with intermediate number of hydroxyl groups (n = 6) can permeate across whole lipid bilayer and reach to inside of the cell.

Facile synthesis of isomerically pure fullerenols C60(OH)5Br and 1,4-C60(OH)2 from chlorofullerene C60Cl6

The chlorofullerene C60Cl6 was demonstrated as a versatile precursor for the synthesis of two isomerically pure fullerenols via tetrabutylammonium bromide promoted reactions with water. Performing the synthesis in wet chlorobenzene produced 1,4-C60(OH)2 as the only isolable product along with substantial amounts of non-functionalized C60. However, the addition of DMSO as a co-solvent altered the reaction pathway, leading to the formation of C60(OH)5Br as the main product. Both isolated compounds were novel and their molecular compositions and structures were confirmed by mass spectrometry and NMR spectroscopy. The fullerenol C60(OH)5Br, which was formed in a moderate yield, represents the first isomerically pure polyhydroxylated fullerene available on a large scale.