Decrease of free radical level in organ perfusate by a novel water-soluble carbon-sixty, hexa(sulfobutyl)fullerenes

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.

Synthesis of highly functionalized C60 fullerene derivatives and their applications in material and life sciences

Highly functionalized fullerenes can be efficiently constructed by various techniques.

Immunomodulation of nanoparticles in nanomedicine applications

Nanoparticles (NPs) have promising applications in medicine. Immune system is an important protective system to defend organisms from non-self matters. NPs interact with the immune system and modulate its function, leading to immunosuppression or immunostimulation. These modulating effects may bring benefits or danger. Compositions, sizes, and surface chemistry, and so forth, affect these immunomodulations. Here we give an overview of the relationship between the physicochemical properties of NPs, which are candidates to be applied in medicine, and their immunomodulation properties.

The applications of buckminsterfullerene C60 and derivatives in orthopaedic research

Abstract Buckminsterfullerene C60 and derivatives have been extensively explored in biomedical research due to their unique structure and unparalleled physicochemical properties. C60 is characterized as a "free radical sponge" with an anti-oxidant efficacy several hundred-fold higher than conventional anti-oxidants. Also, the C60 core has a strong electron-attracting ability and numerous functional compounds with widely different properties can be added to this fullerene cage. This review focused on the applications of C60 and derivatives in orthopaedic research, such as the treatment of cartilage degeneration, bone destruction, intervertebral disc degeneration (IVDD), vertebral bone marrow disorder, radiculopathy, etc., as well as their toxicity in vitro and in vivo. We suggest that C60 and derivatives, especially the C60 cores coupled with functional groups presenting new biological and pharmacological activities, are advantageous in orthopaedic research and will be promising in clinical performance for musculoskeletal disorders treatment; however, the pharmacokinetics and toxicology of these agents as local/systemic administration need to be carefully determined.

Effect of a water soluble derivative of fullerene C60 on the features neural progenitor cells in vitro

We studied the effect of a water soluble derivative of fullerene C60 on the behavior of cultured neural stem/progenitor cells. Addition of 20 nM of metal fullerenolate C60 (NaFL) into the cell culture increased the population of the cells almost twice in comparison with the control and also suppressed the formation of neurospheres. The obtained data allow us to suggest that NaFL has a positive effect on the proliferative activity of neural progenitors. The water-soluble fullerene nanostructures such as NaFL promoting the proliferation of neural stem cells might have numerous beneficent applications in cell biology and biotechnology.

The protective activities of water-soluble C(60) derivatives against nitric oxide-induced cytotoxicity in rat pheochromocytoma cells

In this study, the protective activities of water-soluble C(60) derivatives against nitric oxide (NO) induced cytotoxicity were investigated. To overcome C(60) insolubility in water, we modified C(60) with β-alanine, valine or folacin. The compounds were characterized by FT-IR, (1)H NMR, (13)C NMR, LC-MS, elemental analysis, light scattering and TEM. Investigation of the possible NO-scavenging activities of water-soluble C(60) derivatives demonstrated that they expressed direct scavenging activity toward NO liberated within solution of sodium nitroprusside (SNP). In parallel, following exposure of cells to SNP (1 mM), a marked decrease in mitochondrial membrane potential, cell viability, activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px), as well as increased levels of intracellular NO accumulation and malondialdehyde (MDA) production were observed. Moreover, SNP caused significant elevation in intracellular caspase-3 activity, and induced apoptotic death as determined by flow cytometric assay. However, pretreatment of the cells with water-soluble C(60) derivatives prior to SNP exposure blocked these NO-induced cellular events noticeably. Experiments demonstrated that the aggregation morphology could impact the NO-scavenging abilities and protective effects on apoptosis of water-soluble C(60) derivatives. The results suggest that water-soluble C(60) derivatives have the potential to prevent NO-mediated cell death without evident toxicity.

The activity of superoxide-dismutase in animal cell culture CHO-K1 after treatment with fullerenol and mytomicine C

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.

Water solubility, antioxidant activity and cytochrome C binding of four families of exohedral adducts of C60 and C70

Over the past decade, surface-modified, water soluble fullerenes have been shown by many different investigators to exhibit strong antioxidant activity against reactive oxygen species (ROS) in vitro and to protect cells and tissues from oxidative injury and cell death in vivo. Nevertheless, progress in developing fullerenes as bona fide drug candidates has been hampered by three development issues: 1) lack of methods for scalable synthesis; 2) inability to produce highly purified, single-species regioisomers compatible with pharmaceutical applications; and 3) inadequate understanding of structure-function relationships with respect to various surface modifications (e.g., anionic versus cationic versus charge-neutral polarity). To address these challenges, we have designed and synthesized more than a dozen novel water soluble fullerenes that can be purified as single isomers and which we believe can be manufactured to scale at reasonable cost. These compounds differ in addition pattern, lipophilicity and number and type of charge and were examined for their water solubility, antioxidant activity against superoxide anions and binding of cytochrome C. Our results indicate that dendritic water soluble fullerene[60] monoadducts exhibit the highest degree of antioxidant activity against superoxide anions in vitro as compared with trismalonate-derived anionic fullerenes as well as cationic fullerenes of similar overall structure. Among the higher adducts, anionic derivatives have a higher antioxidant activity than comparable cationic compounds. To achieve sufficient water solubility without the aid of a surfactant or co-solvent at least three charges on the addends are required. Significantly, anionic in contrast to cationic fullerene adducts bind with high affinity to cytochrome C.

The influence of fullerenol on antioxidative enzyme activity in irradiated human erythroleukemic cell line (K562)

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 (?-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 ?-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.

Effects of Fullerenol C60(OH)24 on Cytotoxicity Induced by Antitumor Drugs on Human Breast Carcinoma Cell Lines

The aims of this paper were to investigate cell growth activity of fullerenol C60(OH)24, its modulating effect on antitumor drug-induced cytotoxicity, and genotoxic influence of fullerenol at nanomolar concentrations. Human breast cancer cell lines, MCF-7 and MDA-MB-231, were treated with fullerenol at concentrations from 0.9 to 3.9 µg/ml alone or simultaneously with antitumor drugs (doxorubicin, cisplatin, taxol, and tiazofurin; IC50 concentrations) for 2 hours. Growth inhibition was evaluated by colorimetric SRB assay after recovery period of 24, 48, and 96 hours. The genotoxic examination was performed using sister chromatid exchange test and micronucleus assay, at fullerenol concentration ranging from 1 to 5 µg/ml. The fullerenol alone mildly inhibits the growth of both cell lines. Simultaneous administration of fullerenol and antitumor drugs strongly suppressed antitumor drug-induced cytotoxicity. The rate of cytotoxicity inhibition depended on fullerenol concentration, type of antitumor drug and cell line. Protection against doxorubicin and cisplatin was more pronounced than against taxol and tiazofurin. Fullerenol was not found to be genotoxic to investigated cell lines.

Modulating activity of fullerol C60(OH)22 on doxorubicin-induced cytotoxicity

Paper presents the effects of the newly synthesized fullerol C60(OH)22 on the growth of tumor cells in vitro and its modulating activity on doxorubicin (DOX)-induced cytotoxicity in human breast cancer cell lines. Cell growth inhibition was evaluated by tetrazolium colorimetric WST1 assay. Electron spin resonance (ESR) "trapping" method was used to investigate OH-radical scavenger activity of fullerol during Fenton's reaction. At a range of nanomolar concentrations fullerol induced cell growth inhibition, which was cell line, dose and time dependent. Fullerol also strongly suppressed DOX-induced cytotoxicity at all concentrations regardless the time of fullerol addition. Proanthocyanidins added as single agent to MCF-7 cell culture for 48 h induced low growth inhibition but in combination with DOX strongly decreased DOX cytotoxicity. Fullerol was found to be a potent hydroxyl radical scavenger: the relative intensity of ESR signals of DMPO-hydroxyl radical (DMPO-OH) spin adduct decreased by 88% in the presence of 0.5 microg/ml of fullerol. The obtained results suggest that antiproliferative effect of the fullerol and its protective effect on DOX-induced cytotoxicity might be mediated through hydroxyl-radical scavenger activity of C60(OH)22.

Molecular dynamics analysis of a buckyball-antibody complex

This is a multinanosecond molecular dynamics study of a bio-nano complex formed by a carbon nanoparticle, a buckyball C(60), and a biological molecule, an antibody, with high binding affinity and specificity. In the simulation, the ball is completely desolvated by the binding site of the antibody by means of a nearly perfect shape complementarity and extensive side-chain interactions, with the exception that about 17% of the surface is persistently exposed to solvent and could be used for functional derivatization. The interactions are predominantly hydrophobic, but significant polar interactions occur as well. There exists a rich body of various pi-stacking interactions. Aromatic side chains are involved in both double and triple stackings with the ball. Some ionic side chains, such as the guanidinium group of arginine, also form pi-stackings with the ball. The results suggest that pi-stackings are very efficient and common modes of biological recognition of pi-electron-rich carbon nanoparticles. Most importantly, the results demonstrate that, in general, an ordinary protein binding site, such as that of an antibody, can readily bind to a carbon nanoparticle with high affinity and specificity through recognition modes that are common in protein-ligand recognition.

In vitro action of carboxyfullerene

Fullerene compounds have avid reactivity with free radicals and are regarded as 'radical sponges'. The trimalonic acid derivative of fullerene is one of the water-soluble compounds that has been synthesized and found to be an effective antioxidant both in vivo and in vitro. Carboxyfullerene has been shown to be effective in the treatment of both Gram-positive and -negative infections, although its mode of action is poorly understood. We determined the MIC and minimal bactericidal concentration of carboxyfullerene for 20 isolates, including Staphylococcus spp., Streptococcus spp., Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa, Salmonella typhi and Klebsiella pneumoniae. We further investigated the action of carboxyfullerene using transmission electron microscopy (TEM), anticarboxyfullerene antibody binding assay and a membrane perturbation assay. All Gram-positive species were inhibited by < or = 50 mg/L of carboxyfullerene, whereas Gram-negative species were not inhibited, even at 500 mg/L carboxyfullerene. Bactericidal activity was demonstrated only for Gram-positive species, particularly for Streptococcus pyogenes A-20, which was killed rapidly. Intercalation of carboxyfullerene into the cell wall of staphylococci and streptococci was demonstrated by TEM and anti-carboxyfullerene binding assay. Damage to the cell membrane in Gram-positive, but not Gram-negative, bacteria was confirmed by the membrane perturbation assay. These findings indicate that the action of carboxyfullerene on Gram-positive bacteria is achieved by insertion into the cell wall and destruction of membrane integrity.

Systemic administration of a water-soluble hexasulfonated C(60) (FC(4)S) reduces cerebral ischemia-induced infarct volume in gerbils

Buckminsterfullerence and its derivatives have recently been shown to exhibit considerable in vivo biological activities. A water-soluble hexasulfonated C(60) (FC(4)S) has been shown to protect against oxidative stress. Neuroprotective effects of FC(4)S were investigated in the present study. Focal cerebral ischemia was produced by a permanent occlusion of the right middle cerebral artery in gerbils. Infarct volumes were determined by 2,3,5-triphenyltetrazolium chloride transcardiac perfusion 24 h after cerebral ischemia. Chronic pretreatment of FC(4)S (0.5 and 5.0 mg/kg/day, intraperitoneally for 2 weeks) significantly reduced the infarct volume (by 42% and 68%, respectively) when compared to that of the control group. Results revealed that chronic pretreatment of FC(4)S may protect the brain against focal cerebral ischemia.

X-ray crystal structure of an anti-Buckminsterfullerene antibody fab fragment: biomolecular recognition of C(60)

We have prepared a monoclonal Buckminsterfullerene specific antibody and report the sequences of its light and heavy chains. We also show, by x-ray crystallographic analysis of the Fab fragment and by model building, that the fullerene binding site is formed by the interface of the antibody light and heavy chains. Shape-complementary clustering of hydrophobic amino acids, several of which participate in putative stacking interactions with fullerene, form the binding site. Moreover, an induced fit mechanism appears to participate in the fullerene binding process. Affinity of the antibody-fullerene complex is 22 nM as measured by competitive binding. These findings should be applicable not only to the use of antibodies to assay and direct potential fullerene-based drug design but could also lead to new methodologies for the production of fullerene derivatives and nanotubes as well.