Fullerene Solutions Research Articles

Reactive Oxygen Species Scavenging Capacity of Functional Fullerenes in Solution and in Macrophage Cells

Reactive Oxygen Species Scavenging Capacity of Functional Fullerenes in Solution and in Macrophage Cells

Hydrophilization and Functionalization of Fullerene C60 with Maleic Acid Copolymers by Forming a Non-Covalent Complex.

In this study, we report an easy approach for the production of aqueous dispersions of C60 fullerene with good stability. Maleic acid copolymers, poly(styrene-alt-maleic acid) (SM), poly(N-vinyl-2-pyrrolidone-alt-maleic acid) (VM) and poly(ethylene-alt-maleic acid) (EM) were used to stabilize C60 fullerene molecules in an aqueous environment by forming non-covalent complexes. Polymer conjugates were prepared by mixing a solution of fullerene in N-methylpyrrolidone (NMP) with an aqueous solution of the copolymer, followed by exhaustive dialysis against water. The molar ratios of maleic acid residues in the copolymer and C60 were 5/1 for SM and VM and 10/1 for EM. The volume ratio of NMP and water used was 1:1.2-1.6. Water-soluble complexes (composites) dried lyophilically retained solubility in NMP and water but were practically insoluble in non-polar solvents. The optical and physical properties of the preparations were characterized by UV-Vis spectroscopy, FTIR, DLS, TGA and XPS. The average diameter of the composites in water was 120-200 nm, and the ξ-potential ranged from -16 to -20 mV. The bactericidal properties of the obtained nanostructures were studied. Toxic reagents and time-consuming procedures were not used in the preparation of water-soluble C60 nanocomposites stabilized by the proposed copolymers.

Raman, UV-Vis, MS, and IR characterization of molecular-colloidal solution of hydrated fullerenes C60 obtained using vacuum-sublimation cryogenic deposition method. Is the C60 molecule truly highly hydrophobic?

Vacuum-sublimation cryogenic deposition (VS-CD) method is successfully applied to produce fullerene water colloidal solution (FWCS): the melting of the solid phase of the mixture obtained by joint condensation of C60 fullerene and water vapors onto a surface cooled with liquid nitrogen results in formation of a stable colloidal solution. The results of the FWCS characterization by means of Raman, IR, and UV-Vis spectroscopy and their comparison with known literature data on hydrated fullerenes give the authors an opportunity to make conclusion that the FWCS contains C60@{H2O}n complexes of hydrated C60 fullerene. Transmission electron microscopy shows that the VS-CD-produced material contains predominantly small C60 clusters of about 2–5 nm size, while mass spectrometry with laser desorption/ionization has demonstrated the presence of pure fullerene C60 and the absence of any products of its transformation. The performed analysis reveals a close similarity of the stable C60@{H2O}n complexes generated by VS-CD with the previously known highly hydrophilic hydrated fullerene obtained by ultrasonication method.

Colloid Chemistry of Fullerene Solutions: Aggregation and Coagulation

This review article is devoted to the colloidal properties of fullerene solutions. According to generally accepted understandings, all solvents in relations to fullerenes are divided into “good”, “poor”, and “reactive”. We have consistently considered the state of fullerenes in these systems. In “good”, predominantly non-polar aromatic solvents and CS2, non-equilibrium dissolution methods lead to the formation of colloidal aggregates, whereas the utilization of equilibrium methods results in the formation of molecular solutions. The latter, however, have some unusual properties; new results considered in this review confirm previously expressed ideas about colloidal properties of these solutions. In “poor” (polar) solvents, lyophobic colloidal systems appear. Both “bottom-up” and “top-down” methods of preparation are well documented in the literature. However, N-methylpyrrolidine-2-one, DMSO, and DMF dissolve fullerenes quite easily and with less energy consumption. These solvents can be considered a subset of “poor” solvents that have some features of being “reactive” at the expense of basic properties. New data confirm that hydrosols of fullerenes are typical hydrophobic colloids that obey the Schulze–Hardy rule and other regularities in the presence of electrolytes. Organosols in acetonitrile and methanol are much less stable with respect to the effects of electrolytes. This allows us to assume a non-DLVO stabilizing factor in the hydrosols. Accordingly, a new estimate of the Hamaker constant of fullerene–fullerene interaction is proposed. In DMSO and DMF, the coagulation of fullerene sols is hindered due to strong solvation with these basic solvents.

Controlling the Size of C70 Fullerene Whiskers by Evaporation of Solution Droplets

"The formation of one-dimensional nanostructures (nanowhiskers) during the evaporation of a drop of C70 fullerene solution in ortho-xylene on a smooth surface of a glass substrate was studied. The growth mechanisms of fullerene nanostructures were analyzed, as well as their morphological and size characteristics were determined. "

Behavior of C70 Fullerene in a Binary Mixture of Xylene and Tetrahydrofuran

The self-organization properties of C70 fullerene molecules in a xylene/tetrahydrofuran binary mixture were studied for the first time by optical absorption, refractometry, and dynamic light scattering. A correlation has been established between the change in the refractive index of the C70/xylene/tetrahydrofuran solution and the degree of self-organization of C70 molecules in the medium at various concentrations and storage periods of the solution. It is shown that the features of the optical absorption spectrum of C70/xylene/tetrahydrofuran at a fixed low concentration of fullerene are sensitive to its storage time. It was determined that the beginning time of the formation of C70 nanoclusters and their final size depend on the degree of concentration of fullerene and the time spent keeping the solution. The observed nature of the C70 fullerene solution in a binary mixture may help to elucidate its mechanism of self-organization in the future.

Features of C60 fullerene in the toluene-hexane solvent system

he behaviors of self-aggregation of C60 molecules in solution of C60/toluene/hexane were studied by the methods of refractometry, ultraviolet-visible spectroscopy, dynamic light scattering (DLS) and electron microscopy. It has been experimentally shown that with a slight increase in both the concentration of C60 fullerene and the volume fraction of toluene in a C60/toluene/hexane solution, a change in the refractive index of the medium and in the behavior of the optical spectrum is observed. An increase in the content of toluene in the solution manifests both a positive solvatochromic effect and a hyperchromic effect in the intense absorption band at 328.8 nm. At the same time, it was established by DLS that with an increase in the mole fraction of toluene in the C60/toluene/hexane system, the size of nanoclusters synthesized inside the solution decreases. After evaporation of hexane/toluene from fullerene solution droplets transferred to a heated substrate (up to 30°C), filamentary crystalline nanostructures based on C60 fullerene are formed on the substrate surface.

Biochemical parameters of blood and tissue of the gastrocnemius muscle in chronically alcoholized rats under oral administration of C(60) fullerene aqueous solution

Biochemical indices of blood and tissue of the gastrocnemius muscle chronically alcoholized (for 3, 6 and 9 months) rats were studied. С60 fullerene aqueous solution (C60FAS) was administered orally as a pharmacological agent at a dose of 1 mg/kg daily throughout the experiment in a three routes: 1 h before alcohol intake (preventive regimen), together with alcohol (therapeutic regimen I) and 1 h after alcohol intake (therapeutic regimen II). Creatine phosphokinase (CPK), lactate dehydrogenase (LDH), catalase, superoxide dismutase, glutathione peroxidase (GPx) activity and the level of creatinine, lactate, hydrogen peroxide, reduced glutathione were estimated with clinical diagnostic kits. A pronounced upward trend in creatinine and lactate content, CPK and LDH activity with increasing degree of alcoholic myopathy during experiment was detected. Administration of C60FAS was shown to reduce the biochemical indices of muscle injury and to reduce oxidative processes by maintaining the balance between pro-oxidant and antioxidant systems. The maximum positive effect was observed when C60FAS was administered together with alcohol (therapeutic regimen I). The results indicate on C60 fullerene ability to correct the pathological condition of the muscular system arising from alcohol intoxication. Keywords: alcohol intoxication, antioxidant system, C60 fullerene, creatine phosphokinase, gastrocnemius muscle, lactate dehydrogenase

On modeling of the kinetics of aggregation in low-polar C60 solutions

Based on some recent experimental evidence, kinetics of cluster growth in a fullerene C60 low-polar solution are considered within a model based on oxides C60Ox as aggregation initializers. A system of equations for the time-evolution of the cluster-size distribution function is developed. First stage of clusters growth consists in formation of packed small C60 clusters around separate fullerene oxides. For this stage analytical solutions of equations were obtained and compared with numerical results. During the next stages, cluster-cluster aggregation events start to play a role. First numerical results for stage II are obtained and discussed. The results are compared with experimental study of clusters growth in the saturated C60/benzene solution by dynamic light scattering.

The Various Packing Structures of Tb@C82 (I, II) Isomers in Their Cocrystals with Ni(OEP).

Soot-containing terbium (Tb)-embedded fullerenes were prepared by evaporation of Tb4O7-doped graphite rods in an electric arc discharge chamber. After 1,2,4-trichlorobenzene extraction of the soot and rotary evaporation of the extract, a solid product was obtained and then dissolved into toluene by ultrasonication. Through a three-stage high-pressure liquid chromatographic (HPLC) process, Tb@C82 (I, II) isomers were isolated from the toluene solution of fullerenes and metallofullerenes. With the success of the growth of cocrystals of Tb@C82 (I, II) with Ni(OEP), the molecular structures of Tb@C82 (I) and Tb@C82 (II) were confirmed to be Tb@C2v(9)-C82 and Tb@Cs(6)-C82, respectively, based on crystallographic data from X-ray single-crystal diffraction. Moreover, it was found that Tb@C82 (I, II) isomers demonstrated different packing behaviors in their cocrystals with Ni(OEP). Tb@C2v(9)-C82 forms a 1:1 cocrystal with Ni(OEP), in which Tb@C2v(9)-C82 is aligned diagonally between the Ni(OEP) bilayers to form zigzag chains. In sharp contrast, Tb@Cs(6)-C82 forms a 2:2 cocrystal with Ni(OEP), in which Tb@Cs(6)-C82 forms a centrosymmetric dimer that is aligned linearly with Ni(OEP) pairs to form one-dimensional structures in the a-c lattice plane. In addition, the distance of a Ni atom in Ni(OEP) to the Cs(6)-C82 cage is much shorter than that to the C2v(9)-C82 one, indicative of a stronger π-π interaction between Ni(OEP) and the C82 carbon cage in the cocrystal of Tb@CS(6)-C82 and Ni(OEP). Density functional theory calculations reveal that the regionally selective dimerization of Tb@CS(6)-C82 is the result of a dominant unpaired spin existing on a particular C atom of the CS(6)-C82 cage.

Quasi-liquid composites based on poly(ethylene terephthalate) films with fullerene and dichlorobenzene

Quasi-liquid composites based on poly(ethylene terephthalate) (PET) films with 9 wt% solution of the C60 (70%) and C70 (∼30%) fullerenes mixture in dichlorobenzene (DCB) have been obtained. It has been shown that PET swelling in the fullerene solution in DCB is accompanied by penetration of fullerene into the polymer structure, and PET films are deformed by the mechanism of intercrystallite crazing. As has been revealed by UV spectroscopy, fullerene incorporated into composite remains monomeric as in solution.

Adjuvant effect of dispersed fullerene C60 on the immune response to constructs harboring amino acid and nucleotide sequences of hepatitis C virus nonstructural NS5B protein

A vaccine against hepatitis C has not yet been developed. Recombinant proteins and plasmids encoding hepatitis C virus (HCV) proteins, the components of candidate vaccines, induce a weak immune response and require the use of adjuvants. The aim of the work was to study the adjuvant action of an aqueous solution of fullerene C60 during immunization of mice with HCV recombinant protein NS5B (rNS5B) that is an RNA-dependent RNA polymerase, or with NS5B-encoding pcNS5B plasmid. An aqueous solution of dispersed fullerene (dnC60) was obtained by ultrafiltration. C57BL/6 mice were immunized with rNS5B subcutaneously, pcNS5B intramuscularly mixed with different doses of dnC60 three times, then the humoral and cellular response to HCV was evaluated. Mice immunization with rNS5B in a mixture with dnC60 at doses of 250 g/mouse significantly induced humoral response: a dose-dependent increase in IgG1 antibody titers was 720 times higher than in the absence of fullerene. There was no increase in the cellular response to rNS5B when administered with dnC60. The humoral response to DNA immunization was weak in mice of all groups receiving pcNS5B. The cellular response was suppressed when the plasmid was injected in a mixture with dnC60. Dispersed fullerene dnC60 is a promising adjuvant for increasing the immunostimulating activity of weakly immunogenic proteins including surface and other HCV proteins, important for a protective response. Further research is needed to enhance the ability of dnC60 to boost the cellular immune response to the components of the candidate vaccine.

Complexation study of a 1,3-phenylene-bridged cyclic hexa-naphthalene with fullerenes C60 and C70 in solution and 1D-alignment of fullerenes in the crystals.

To investigate the host ability of a simple macrocycle, 1,3-phenylene-bridged naphthalene hexamer N6, we evaluated the complexation of N6 with fullerenes in toluene and in the crystals. The complexes in the solid-state demonstrate the one-dimensional alignment of fullerenes. The single-crystals of the C60@N6 composite have semiconductive properties revealed by photoconductivity measurements.

C60 Fullerene Clusters Stabilize the Biologically Inactive Form of Topotecan.

There is a range of experimental proofs that biologically relevant compounds change their activity in the presence of C60 fullerene clusters in aqueous solution, which most frequently act as a nanoplatform for drug delivery. Inspired by this evidence, we made an effort to investigate the interaction of fullerene clusters with the antibiotic topotecan (TPT). This study proceeded in three steps, namely, UV/vis titration to confirm complexation and in vitro assays on proliferating and nonproliferating cells to elucidate the role of C60 fullerene in the putative change in TPT activity. Surprisingly, although the nonproliferating cell assay is consistent with the titration data and confirms complex formation, it contradicted the results of the proliferating cell assay. The latter showed that the mixture of TPT and fullerene affects the cells in the same way as pure TPT, as if there were no fullerenes in solution at all, whereas the action of TPT was expected to be enhanced. We explained this contradiction by the specific stabilization of the biologically inactive carboxylate form of the antibiotic adsorbed in the alkaline shell of large fullerene clusters, which leads to neutralization of the drug delivery function and almost zero net biological effect of the antibiotic in vitro. The practical outcome of the work is that fullerene clusters can be used for the selective delivery of pH-sensitive drug forms.

The state of gluconeogenic liver function of white rats under the influence of a nanocomposite aqueous solution of fullerene С60

Biocompatible nanoparticles attract the attention of researchers as a means of correcting a wide range of diseases. The carbonbased nanostructure, fullerene C60, is one of the most promising compounds. However, the use of compounds based on fullerene nanoparticles remains limited. Therefore, the development of domestic innovative medicinal compounds based on fullerenecontaining nanoparticles is one of the priority areas of veterinary medicine. The research was carried out in the laboratory of the Department of "Morphology, Pathology of Animals and Biology" of the Saratov State Agrarian University named after N.I. Vavilov. The first group served as a control. An aqueous solution of fullerene C60 was administered at a dose of 1 ml per (DV 5 mg / kg) 1 kg of body weight (group 2 animals). A compound based on an aqueous solution of fullerene C60 was also introduced, including an aqueous solution of fullerene C60, Lcarnosine and succinic acid in the following ratio of components, wt. / mg: an aqueous solution of fullerene C60 stabilized with pluronic F-127– - 5 ml (5 mg by DV), Lcarnosine -50 mg, succinic acid - 50 mg per 1 kg of body weight (group 3). The studied compounds were administered intramuscularly, once. Glycerin loading was carried out 24 hours after the introduction of the studied compounds. It was found that aqueous solutions of fullerene C60 have a distinct effect on carbohydrate metabolism in the body of white rats. The initial blood glucose level in animals of all groups turned out to be approximately at the same level, but the highest rate of gluconeogenesis was found in animals of group 2. As for the gluconeogenic function of the liver, in animals after the introduction of aqueous solutions of fullerene C60, the increase in newly formed glucose and the rate of gluconeogenesis significantly exceeded the control values. The results obtained indicate a failure in glucose metabolism after the introduction of aqueous solutions of fullerenes.

The kinetics of dissolution and cluster formation of fullerene in polar and low polar solutions

Fullerene and fullerene like nanostructures play a main role in various research areas. Theamount of investigations of fullerene C60 and C70 has grown up considerably due to their several unique properties [1-2, 6]. In this report we present theoretical models for cluster growth, the modeling of small angle neutron scattering curves, and the results of structural analysis (SANS) for polar solutions of these macromolecules. Investigation of kinetics of dissolution and complex formation are studied for C60/Benzene, C60/Toluene and C60/Nmethyl-2-pyrrolidone (NMP) solutions of various concentrations by UV-Vis spectrometry. We model the kinetics of simultaneously occurring processes in the solution via a system of basic kinetic equations and obtain the corresponding parameters dependence on preparation conditions. The investigation of structural properties of fullerene solution in CS2 was performed at the YuMO instrument of the IBR-2 reactor. The results are compared tomolecular dynamics simulations, and other research works

Study of stabilization of self-assembly processes in fullerene C60 solution

The dynamics of changes in the values of the refractive index of solutions of C60 in xylene at various concentrations has been studied by the refractometric method. It was found that the deviation from the linear form of the dependence of the refractive index on the C60 concentration occurs at a C60 concentration of 1.8 mg/ml. The deviation is associated with the largest number of molecular interactions between C60−C60 and the formation of large nanoclusters on their basis in solution. It was found by the dynamic light scattering (DLS) that the final size of C60 nanoclusters in solution depends on the initial concentration of the solute. A higher initial concentration of C60 leads to the synthesis of nanoclusters with a larger diameter. Using the method of optical spectroscopy, the processes of self-organization of fullerene C60 molecules in a xylene solution in time are studied. The character of stability of synthesized fullerene nanoclusters in solution is discussed. The results obtained are of particular importance for numerous applications of nanotechnology for understanding self-assembly processes and the development of new nanomaterials.

THE USE OF NANO AND BIOTECHNOLOGICAL RAW MATERIALS IN THE CREATION OF DRUGS FOR AGRICULTURE

The article is devoted to the consideration of the possibility of using fullerene-containing water as part of humic growth-stimulating preparations for agriculture with the addition of yeast production waste. More recently, the problems of the economy and the environment were perceived as opposite. Currently, there is a need for a mutually dependent and mutually beneficial combination of economic and environmental interests, which was the basis for this study. The analysis of the wastewater of the yeast-producing enterprise shows the presence of a large number of chemical and organic substances that pose a certain danger to the environment, but are useful after processing waste for use in agriculture. The largest number of substances is found in waste, after the stage of production of pure culture. The experiment shows that the use of structured water in combination with biologically active waste from the production of bread yeast obtained on the basis of the Saccharomyces cerevisiae strain increases the yield of grain crops. Based on the established fact of a wide and universal spectrum of biological activity of the water-carbon structure of hydrated fullerenes, according to patent and scientific and technical literature, they have not been widely tested as plant growth regulators. We will investigate the interaction of substances with water structured with fullerenes, the effect of surfactants on the formation and stability of emulsified humates with film-forming agents, the adhesive properties of the components, the effect of concentrated yeast fermentation liquid separated after the stage of growing a pure culture of baking yeast, the effect of both a fullerene-like structure – shungite of natural origin and hydrated fullerenes – highly stable finely dispersed aqueous solutions of native fullerenes (have the properties of lyophobic molecular colloidal systems) on grain yield, protection of vegetative plants. The result of the work will be the substantiation of the principles of the methodology for the application of nanostructured substances for use in biotechnologies of multifunctional highly effective drugs for agriculture with biologically active additives.

ИЗМЕНЕНИЕ БЕЛКОВО-АЗОТИСТОГО ОБМЕНА У ЛАБОРАТОРНЫХ ЖИВОТНЫХ ПОД ДЕЙСТВИЕМ ВОДНОГО РАСТВОРА ФУЛЛЕРЕНА С60

The active use of fullerene C60 in veterinary medicine has a positive effect on the functions of hepatocytes, promotes the restoration of metabolic processes in the gastrointestinal tract, improving metabolic and redox processes in the body, reducing inflammatory and fibrosing processes in the liver. The aim of the work was to change the protein-nitrogen metabolism in laboratory animals under the action of an aqueous solution of fullerene C60. For the research, 3 groups of white rats were formed. It was found that after the introduction of the studied compounds, we observed changes in the parameters of protein-nitrogen metabolism, which were expressed in an increase in the level of total protein, urea, ammonia and urea in the blood serum of white rats. However, there was a decrease in the concentration of glutamine. The change in the content of albumins in the blood serum by 8.6-10.1 % and globulins by 6-6.5 % was also found. The results obtained indicate a positive effect of C60 fullerene solutions on the animal body.

Mechanical activation of fullerene containing soot during extraction of higher and endohedral metallofullerenes

For extraction of higher fullerenes and endohedral metallofullerenes (EMF) with yttrium from fullerene-containing carbon soot (soot) obtained by combined spraying of graphite and yttrium oxide powders in an arc plasma, we developed a device (Extractor*) that provides mechanical activation effects on agents combined with filtration. It has been shown that the soot recovery percentage of a mixture of higher fullerenes and EMF with different solvents (carbon disulfide, o-xylene, pyridine) and the EMF mass fraction in the mixture is significantly higher than in the extraction with a Soxhlet apparatus traditionally used for these purposes. The time spent on the extraction process is reduced significantly. Due to a known reaction with titanium chloride (TiCl4) and removal of a solution of empty fullerenes, subsequent bonding of EMF with yttrium into an insoluble complex directly in the extractor allows the product to be significantly enriched with EMF. In general, we were able to significantly reduce both the duration of extraction of the fullerenes mixture and EMF and the production of EMF separately. Highlights A mechanical extractor (Extractor*) developed by us, which allows processing a larger amount of carbon black and, accordingly, extracting more fullerenes per unit of time, has been applied. The percentage of extraction from the soot of a mixture of higher fullerenes and EMF with various solvents was significantly higher than with extraction using the Soxhlet apparatus. It has been shown that mechanical extractor using makes it possible to increase the coefficient of mass transfer from the surface of the particles to the extracting agents. The Extractor* was first used for the non-HPLC separation of endohedral metallofullerenes with TiCl4. The use of the new device made it possible to isolate a product significantly enriched in endohedral metallofullerenes.