Analysis of Biomechanical Parameters of Muscle Soleus Contraction and Blood Biochemical Parameters in Rat with Chronic Glyphosate Intoxication and Therapeutic Use of C60 Fullerene

The widespread use of glyphosate as a herbicide in agriculture can lead to the presence of its residues and metabolites in food for human consumption and thus pose a threat to human health. It has been found that glyphosate reduces energy metabolism in the brain, its amount increases in white muscle fibers. At the same time, the effect of chronic use of glyphosate on the dynamic properties of skeletal muscles remains practically unexplored. The selected biomechanical parameters (the integrated power of muscle contraction, the time of reaching the muscle contraction force its maximum value and the reduction of the force response by 50% and 25% of the initial values during stimulation) of muscle soleus contraction in rats, as well as blood biochemical parameters (the levels of creatinine, creatine phosphokinase, lactate, lactate dehydrogenase, thiobarbituric acid reactive substances, hydrogen peroxide, reduced glutathione and catalase) were analyzed after chronic glyphosate intoxication (oral administration at a dose of 10 μg/kg of animal weight) for 30 days. Water-soluble C₆₀ fullerene, as a poweful antioxidant, was used as a therapeutic nanoagent throughout the entire period of intoxication with the above herbicide (oral administration at doses of 0.5 or 1 mg/kg). The data obtained show that the introduction of C₆₀ fullerene at a dose of 0.5 mg/kg reduces the degree of pathological changes by 40–45%. Increasing the dose of C₆₀ fullerene to 1 mg/kg increases the therapeutic effect by 55–65%, normalizing the studied biomechanical and biochemical parameters. Thus, C₆₀ fullerenes can be effective nanotherapeutics in the treatment of glyphosate-based herbicide poisoning.     

Water-Soluble,Alanine-Modified Fullerene C60 Promotes the Proliferation and Neuronal Differentiation of Neural Stem Cells

As carbon-based nanomaterials, water-soluble C₆₀ derivatives have potential applications in various fields of biomedicine. In this study, a water-soluble fullerene C₆₀ derivative bearing alanine residues (Ala-C₆₀) was synthesized. The effects of Ala-C₆₀ on neural stem cells (NSCs) as seed cells were explored. Ala-C₆₀ can promote the proliferation of NSCs, induce NSCs to differentiate into neurons, and inhibit the migration of NSCs. Most importantly, the Ala-C₆₀ can significantly increase the cell viability of NSCs treated with hydrogen peroxide (H₂O₂). The glutathioneperoxidase (GSH-Px) and superoxide dismutase (SOD) activities and glutathione (GSH) content increased significantly in NSCs treated even by 20 μM Ala-C₆₀. These findings strongly indicate that Ala-C₆₀ has high potential to be applied as a scaffold with NSCs for regeneration in nerve tissue engineering for diseases related to the nervous system.     

Effects of Pin-up Oxygen on [60]Fullerene for Enhanced Antioxidant Activity

The introduction of pin-up oxygen on C₆₀, such as in the oxidized fullerenes C₆₀O and C₆₀O_n, induced noticeable increase in the antioxidant activity as compared to pristine C₆₀. The water-soluble inclusion complexes of fullerenes C₆₀O and C₆₀O_n reacted with linoleic acid peroxyl radical 1.7 and 2.4 times faster, respectively.

Interaction between the Renin–Angiotensin System and Enteric Neurotransmission Contributes to Colonic Dysmotility in the TNBS-Induced Model of Colitis

Angiotensin II (Ang II) regulates colon contraction, acting not only directly on smooth muscle but also indirectly, interfering with myenteric neuromodulation mediated by the activation of AT₁ /AT₂ receptors. In this article, we aimed to explore which mediators and cells were involved in Ang II-mediated colonic contraction in the TNBS-induced rat model of colitis. The contractile responses to Ang II were evaluated in distinct regions of the colon of control animals or animals with colitis in the absence and presence of different antagonists/inhibitors. Endogenous levels of Ang II in the colon were assessed by ELISA and the number of AT₁/AT₂ receptors by qPCR. Ang II caused AT₁ receptor-mediated colonic contraction that was markedly decreased along the colons of TNBS-induced rats, consistent with reduced AT₁ mRNA expression. However, the effect mediated by Ang II is much more intricate, involving (in addition to smooth muscle cells and nerve terminals) ICC and EGC, which communicate by releasing ACh and NO in a complex mechanism that changes colitis, unveiling new therapeutic targets.     

High rate performance of highly dispersed C60 on activated carbon capacitor

Fullerene-activated carbon composite electrodes were prepared and their charge/discharge characteristics were studied for use in a high power electric double-layer capacitor. The capacitance of the C₆₀-loaded activated carbon fiber (ACF) electrodes became greater than that of the unloaded ACF at charge/discharge current densities above 50 mA/cm². In order to obtain a highly dispersed C₆₀-loaded electrode, an ultrasonic treatment was performed. The size of the C₆₀ agglomerate decreased from 1-2 to 0.1 μm or less, and the capacitance of the C₆₀-loaded ACF electrodes increased with an increase in the ultrasonic treatment time. A higher capacitance of 172 F/g was obtained at 50 mA/cm² on a 1 wt% C₆₀-loaded electrode with ultrasonic treatment, and the C₆₀-loaded ACF electrode also showed a higher cycle performance.     

Synthesis and solid-state studies of self-assembled C60 microtubes

C₆₀ microtubes were fabricated by a modified solution evaporation method, evaporating a solution of C₆₀ in toluene in an atmosphere of m-xylene at room temperature. The C₆₀ microtubes have outer diameters ranging from 2 to 8 μm. IR spectra, TG analysis and X-ray diffraction showed a solvated structure for the as-grown C₆₀ microtubes. Through a gentle heat-treatment in vacuum, pure C₆₀ microtubes with single crystalline fcc structure were obtained after the elimination of solvents. It is suggested that the C₆₀ microtubes form through self-assembly from several individual C₆₀ nanorods.     

Linear or branched structure? Probing molecular architectures of fullerene-styrene copolymers by size exclusion chromatographs with online right-angle laser-light scattering and differential viscometric detectors

The poly(C₆₀-co-styrene)s prepared by radical copolymerizations of C₆₀ and styrene in bulk were characterized by multiple-detector size-exclusion chromatographs consisting of a refractometer, a differential viscometer, and/or a right-angle laser-light scattering photometer. The multidetector systems enabled the determinations of reliable, absolute molecular weights of the copolymers. The plots of intrinsic viscosity vs. molecular weight and radius of gyration vs. molecular weight offered valuable information about the molecular architectures of the copolymers. The slopes of the plots reveal that the structure of the copolymer changes with its C₆₀ content: the copolymer with a low C₆₀ content of 0.58 wt% possesses a linear structure, whereas its conger with a high C₆₀ content of 1.14 wt% possesses a branched structure.     

Characterization Of C60/Bi2TiO4F2 as a Potential Visible Spectrum Photocatalyst for The Depolymerization of Lignin

Effects of a photocatalyst, C₆₀-modified Bi₂TiO₄F₂, on pine kraft lignin under visible light irradiation were investigated, along with those of Bi₂TiO₄F₂ and C₆₀/TiO₂ as references. The influences of pH, C₆₀ mass fraction, and the initial lignin concentration on lignin conversion and yields of mono-phenolic products were investigated. Seven products were determined by GC/MS, including phenol, 2-methoxyphenol, 4-ethyl-2-methoxyphenol, 2-methoxy-4-vinylphenol, vanillin, acetovanillone, and homovanillic acid. The yields of products and lignin conversion were higher by C₆₀/Bi₂TiO₄F₂ than Bi₂TiO₄F₂ and C₆₀/TiO₂. C₆₀/Bi₂TiO₄F₂ and C₆₀/TiO₂ were more stable than Bi₂TiO₄F₂ upon repetitive recycling of catalyst. The effectiveness of C₆₀/Bi₂TiO₄F₂ declines 25%, whereas that of Bi₂TiO₄F₂ declines 56.4% after being recycled five times. FTIR and HRTEM indicated that the deactivation of photocatalysts might be caused by lignin adsorbed on the surface of photocatalysts and the change in the crystal structure.     

Synthesis of C60 Fullerene-Silica Hybrid Nano Structures

We have recently demonstrated a procedure for the synthesis of silica nanometer and micrometer particles under modest conditions. Here we report the synthesis of C₆₀ fullerene-silica hybrid nanometer sized materials via sol-gel processing at neutral pH and under ambient conditions. The C₆₀ fullerene, when functionalized, was water-soluble and also able to facilitate the formation of silica structures from an aqueous silica precursor. This C₆₀ fullerene had similar functionality to the cationically charged polymers, which have been reported earlier to act as catalysts/templates for silicification. The resulting organic-inorganic hybrid was studied using SEM, EDS and UV/Vis spectroscopy. These hybrid materials may have applications in areas such as optical devices, semiconductors, chemical sensors, catalysis and in the medical field. The results presented in this study may be useful in developing a process for the synthesis of novel organic-inorganic nanometer sized materials and for the biomimetic synthesis of silica.     

Preparation and properties of C60-containing poly(vinyl alcohol)

Poly(vinyl alcohol) (PVA) was reacted with strong base NaH to yield pendant oxy anions, followed with nucleophilic addition to C₆₀. The resulted PVA(C₆₀-Na⁺)_n products were then converted to PVA(C₆₀H)_n by stirring with a strong acid cation exchanger of H⁺-form. Extraction of the C₆₀-containing PVAs by toluene, which is a good solvent for C₆₀, exhibits no color transfer to the toluene phase. The C₆₀-containing PVAs were identified by the characteristic IR and UV-Vis absorptions of C₆₀. The electrochemical behaviors in solution or in film state were investigated by cyclic voltammetric methods. The cyclic voltammogram of 4a shows a reduction peak at −2.30 V which should be due to the bonded C₆₀ chromophores. In the film state, obtained by coating C₆₀-containing PVA solution on graphite electrode, PVA(C₆₀-Na⁺)_n is much easily reduced and oxidized than PVA(C₆₀H)_n. Furthermore, the difference in this reduction and oxidation feasibility is enhanced with increasing C₆₀ content. However, coating with PVA(C₆₀H)_n or PVA(C₆₀-Na⁺)_n reduces the redox ability of the graphite electrode.     

Grafting of poly(ethylene oxide) onto C60 fullerene using macroazo initiators

In order to improve the solubility of C₆₀ fullerene in conventional solvents, grafting of hydrophilic poly(ethylene oxide) (PEO) by utilizing the radical-trapping nature of C₆₀ fullerene was investigated. Macroazo initiators containing a poly(ethylene oxide) unit, known as Azo-PEO, were prepared at various molecular weights by the reaction of 4,4′-azobis(4-cyanopentanoyl chloride) with poly(ethylene glycol) methyl ether. PEO radicals formed by thermal decomposition of Azo-PEO were successfully trapped by C₆₀ fullerene to give PEO-grafted C₆₀ fullerene. Their structures were confirmed by FT-IR spectroscopy, size exclusion chromatography, UV-vis spectroscopy, and differential scanning calorimetry. When Azo-PEO with low-molecular weight was reacted with C₆₀ fullerene, a bis-adduct, C₆₀-(PEO)₂, and a tetrakis-adduct, C₆₀-(PEO)₄, were formed. In contrast, in reactions with Azo-PEO of higher molecular weight, only the bis-adduct was formed, and no formation of the tetrakis-adduct was observed. The structure of bis-adduct was found to be 1,4-type. The solubility of C₆₀ fullerene in water, THF, methanol, and other conventional organic solvents was remarkably improved by grafting of PEO. In addition, the thermal stability of PEO was dramatically increased by grafting onto C₆₀ fullerene.     

The Effect of Fullerenol C60(OH)36 on the Antioxidant Defense System in Erythrocytes

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.     

Synthesis of Buckminsterfullerene C60 functionalised core cross-linked star polymers

Buckminsterfullerene C₆₀ core functionalised core cross-linked star (CCS) polymers have been prepared for the first time, using atom transfer radical polymerisation and the arms-first approach. A simple and efficient method is presented which allows the construction of star polymers consisting of a large number of arms and multiple units of C₆₀ per core, far in excess of that obtained previously. The C₆₀ CCS polymers were characterised by gel permeation chromatography (GPC), UV-vis spectroscopy and cyclic voltammetry (CV). GPC revealed that the C₆₀ CCS polymers possess weight average molecular weights (M_w) ranging from 172-411 kDa and up to 30 arms per macromolecule. The average number of molecules of C₆₀ per CCS polymer core was found to be dependent on the C₆₀/PMMA ratio employed and was determined by UV-vis spectroscopy to range up to 6.2. CV revealed that, like pristine C₆₀, the C₆₀ CCS polymers possessed three reversible one electron reductions. However, the reduction potentials were positively shifted, implying that the electron affinity of these macromolecules is higher than pristine C₆₀.     

Deposition of C60, C70 and C84 fullerene molecules, in benzene via a change of the fluid state, from a gas–liquid two phase region to the critical point

We dissolve C₆₀, C₇₀ or C₈₄ molecules in benzene and change the fluid state from a gas–liquid two-phase region (25.0 °C) to the critical point (289.0 °C) and from the critical point to the original state (25.0 °C) along the gas–liquid coexistence curve. We find that particle-like and whisker-like nano/micro clusters, which are composed of C₆₀ molecules, deposit on the surface of a silicon substrate placed vertically in C₆₀/benzene solution during the temperature change, whereas no appreciable clusters are detected on the silicon substrate in either C₇₀/benzene or C₈₄/benzene solutions. The clusters, in which fcc lattice structures are formed by C₆₀ molecules, remain stable in the solution. The present result suggests that C₆₀ molecules can be separated and extracted from a mixture of C₆₀, C₇₀ and C₈₄ molecules dissolved in benzene.     

Fullerenes synthesis in combustion

The early suggestion in fullerenes research that fullerenes might be produced in flames was soon supported by the observation of polyhedral carbon ions in flames and in 1991 was confirmed by the recovery and identification of fullerenes C₆₀ and C₇₀ from benzene/oxygen flames. Recent research has determined the effects of pressure, carbon/oxygen ratio, temperature and the type and concentration of diluent gas, on the yields of C₆₀ and C₇₀ in subatmospheric pressure premixed laminar flames of benzene and oxygen. Similar flames but with acetylene as fuel have also been found to produce fullerenes, but in smaller yields than with benzene fuel. The largest observed yields of C₆₀ + C₇₀ from benzene/oxygen flames are substantial, being 20% of the soot produced and 0.5% of the carbon fed. The largest rate of production of C₆₀ + C₇₀ was observed at a pressure of 69 Torr, a C/O ratio of 0.989 and a dilution of 25% helium. Several striking differences between fullerenes formation in flames as compared to the widely used graphite vaporization method include, in the case of flames, an ability to vary the C₇₀/C₆₀ ratio from 0.26 to 8.8 (cf., 0.02 to 0.18 for graphite vaporization) by adjustment of flame conditions and production of several isomers each of fullerenes C ₆₀, C₇₀, C₆₀O and C₇₀O. Many of the apparent isomers are thermally metastable, one C₆₀ converting to the most stable form with a half-life of 1h at 111°C. The structures of the apparent C₆₀ and C₇₀ isomers necessarily must include abutting five-membered rings, previously assumed to be disallowed because of their high strain energy. The chemistry of fullerenes formation in flames is in some ways similar to that of soot formation, but important differences are seen and assumed to reflect the effects of the curved, strained structures of fullerenes and their precursors.     

Electrochemistry of the films of a novel class C60 covalently linked PPV derivative: Electrochemical quartz crystal microbalance study in acetonitrile solutions of tetra‐n‐butylammonium cations

The electrochemical behaviors of a novel class C₆₀ covalently linked PPV derivatives (i.e., PPV‐1‐C₆₀ and PPV‐2‐C₆₀) in thin solid films as well as in solutions are reported. The first cathodic peak potentials of PPV‐1‐C₆₀ and PPV‐2‐C₆₀ have positive shifts by 30 and 50 mV, respectively, compared to pristine C₆₀ in formal cyclic voltammetry (CV). Simultaneous CV and piezoelectric microgravimetry of the drop‐coated thin solid films of PPV‐1‐C₆₀ and PPV‐2‐C₆₀ in acetonitrile solutions of TBA⁺ counteractions are strongly influenced by the structure of the polymer‐C₆₀, including the length of the chain macromolecule and the steric hindrance effect. In addition, the atomic force microscopy (AFM) images of PPV‐1‐C₆₀ and PPV‐2‐C₆₀ films deposited on Au/quartz electrode both exhibit even distribution. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 2737–2741, 2002     

MECHANOCHEMICAL ENERGY TRANSDUCTION IN MUSCLE CONTRACTION

An alternative mechanochemical model of muscle contraction is proposed. The model combines interaction among four elements: chemical kinetics of the actomyosin ATPase pathway, C a ²⁺ binding kinetics, mechanical coupling during P _i release, and working stroke motion to constitute simultaneous relations among mechanical and chemical variables. The model is derived from a different basis than the classical Huxley model. Force developed from strongly attached crossbridges is related to chemical component concentrations, chemical equilibrium and rate constants for the ATPase activity, and velocity of contraction. The chemical dynamics of the ATPase activity is also related to the velocity of contraction. A model for P _i release during force generation and a model for chemical-mechanical coupling transition during a working stroke are also proposed and are the important keys of the mechanochemical linkage in energy transduction and muscle dynamics. The steady force-velocity relation is predicted by only one dimensionless parameter, and it provides an excellent fit to the Hill force-velocity equation. The model is able to simultaneously predict the peak in the ATPase activity as a function of velocity of contraction and supports the argument of multiple cycles of crossbridge attachment per one ATP molecule hydrolysis. Also the relation between the amount of C a ²⁺ and the force development can be predicted from this model.     

C60 Fullerene Reduces 3-Nitropropionic Acid-Induced Oxidative Stress Disorders and Mitochondrial Dysfunction in Rats by Modulation of p53, Bcl-2 and Nrf2 Targeted Proteins

C₆₀ fullerene as a potent free radical scavenger and antioxidant could be a beneficial means for neurodegenerative disease prevention or cure. The aim of the study was to define the effects of C₆₀ administration on mitochondrial dysfunction and oxidative stress disorders in a 3-nitropropionic acid (3-NPA)-induced rat model of Huntington’s disease. Animals received 3-NPA (30 mg/kg i.p.) once a day for 3 consecutive days. C₆₀ was applied at a dose of 0.5 mg/kg of body weight, i.p. daily over 5 days before (C₆₀ pre-treatment) and after 3-NPA exposure (C₆₀ post-treatment). Oxidative stress biomarkers, the activity of respiratory chain enzymes, the level of antioxidant defense, and pro- and antiapoptotic markers were analyzed in the brain and skeletal muscle mitochondria. The nuclear and cytosol Nrf2 protein expression, protein level of MnSOD, γ-glutamate-cysteine ligase (γ-GCLC), and glutathione-S-transferase (GSTP) as Nrf2 targets were evaluated. Our results indicated that C₆₀ can prevent 3-NPA-induced mitochondrial dysfunction through the restoring of mitochondrial complexes’ enzyme activity, ROS scavenging, modulating of pro/antioxidant balance and GSH/GSSG ratio, as well as inhibition of mitochondria-dependent apoptosis through the limitation of p53 mitochondrial translocation and increase in Bcl-2 protein expression. C₆₀ improved mitochondrial protection by strengthening the endogenous glutathione system via glutathione biosynthesis by up-regulating Nrf2 nuclear accumulation as well as GCLC and GSTP protein level.     

Cross-sectional structural analysis of C60 nanowhiskers by transmission electron microscopy

Cross-sectional observations of C₆₀ nanowhiskers (C₆₀NWs) were successfully conducted using the focused ion beam (FIB) method. The C₆₀NWs were observed to possess the core-shell structures with porous cores and dense surface thin layers. The size and number of pores decreased from the center to the surface, showing that the densification of C₆₀NWs proceeds from the surface to the center upon drying. A cross-sectional high-resolution transmission electron microscopy (HRTEM) image of a C₆₀NW showed a disordered structure comprising the domains with sizes on the order of 10 nm. The most frequently observed cross-sections were hexagons, reflecting the solvated hexagonal crystal structures of as-grown C₆₀NWs. From the observation of various cross-sectional shapes of C₆₀NWs with different diameters and crystallographic surface analysis, it is suggested that C₆₀NWs grow longer above a critical diameter D_c with the development of low-energy crystal surfaces.