Effect of small addition of C60 fullerenes on the hydrated properties of nanocomposites based on highly dispersed silica and DNA

Water-soluble pristine C60 fullerenes attenuate isometric muscle force reduction in a rat acute inflammatory pain model

BACKGROUND

Being a scavenger of free radicals, C₆₀ fullerenes can influence on the physiological processes in skeletal muscles, however, the effect of such carbon nanoparticles on muscle contractility under acute muscle inflammation remains unclear. Thus, the aim of the study was to reveal the effect of the C₆₀ fullerene aqueous solution (C₆₀FAS) on the muscle contractile properties under acute inflammatory pain.

METHODS

To induce inflammation a 2.5% formalin solution was injected into the rat triceps surae (TS) muscle. High-frequency electrical stimulation has been used to induce tetanic muscle contraction. A linear motor under servo-control with embedded semi-conductor strain gauge resistors was used to measure the muscle tension.

RESULTS

In response to formalin administration, the strength of TS muscle contractions in untreated animals was recorded at 23% of control values, whereas the muscle tension in the C₆₀FAS-treated rats reached 48%. Thus, the treated muscle could generate 2-fold more muscle strength than the muscle in untreated rats.

CONCLUSIONS

The attenuation of muscle contraction force reduction caused by preliminary injection of C₆₀FAS is presumably associated with a decrease in the concentration of free radicals in the inflamed muscle tissue, which leads to a decrease in the intensity of nociceptive information transmission from the inflamed muscle to the CNS and thereby promotes the improvement of the functional state of the skeletal muscle.

Effect of C60 Fullerene on Recovery of Muscle Soleus in Rats after Atrophy Induced by Achillotenotomy

Biomechanical and biochemical changes in the muscle soleus of rats during imitation of hind limbs unuse were studied in the model of the Achilles tendon rupture (Achillotenotomy). Oral administration of water-soluble C₆₀ fullerene at a dose of 1 mg/kg was used as a therapeutic agent throughout the experiment. Changes in the force of contraction and the integrated power of the muscle, the time to reach the maximum force response, the mechanics of fatigue processes development, in particular, the transition from dentate to smooth tetanus, as well as the levels of pro- and antioxidant balance in the blood of rats on days 15, 30 and 45 after injury were described. The obtained results indicate a promising prospect for C₆₀ fullerene use as a powerful antioxidant for reducing and correcting pathological conditions of the muscular system arising from skeletal muscle atrophy.

The effect of water-soluble pristine C60 fullerene on 6-OHDA-induced Parkinson’s disease in rats

Oxidative stress is thought to be one of the mechanisms that leads to the dysfunction and degeneration of dopaminergic neurons in Parkinson’s disease pathogenesis and presumed to be underway during the prodromal phase. Therefore, therapy, which is effective against pre-motor symptoms, might be effective in preventing or delaying the development and progression of Parkinson’s disease. The aim of our study was to investigate the therapeutic efficiency of pristine C60 fullerene aqueous solution (C60FAS) during Parkinson’s disease in rats. The unilateral dopamine deficiency was induced in male Wistar rats (220–250 g) by stereotaxic microinjection of neurotoxin 6-hydroxydopamine (6-OHDA, 12 μg). C60FAS was injected to rats intraperitoneally daily for 10 days (0.65 mg/kg per day). The percentage of destroyed dopaminergic neurons was determined by the apomorphine test and by IHC staining of tyrosine hydroxylase-positive neurons in substantia nigra. We evaluated the rat body weight, the water and food intake, Open Field behavioural test, the level of biochemical antioxidant system, the activity of peritoneal macrophages. Levels of spontaneous and carbachol-stimulated colon motility were estimated by ballonographic method in vivo. C60FAS showed a positive tendency to increase the number of tyrosine hydroxylase-positive cells in the midbrain, which was associated with more profound improvement in apomorphine-rotation behaviour and slight relief of the anxiety level in Open Field test. Furthermore, C60FAS treatment increased the index of stimulated distal colon motor activity while it did not have a significant effect on water content in feces and total gastrointestinal transit time. C60FAS treatment did not affect water intake behaviour or body weight changes while it induced an increase of glutathione level and decrease activity of glutathione peroxidase in the brain as well as an increase in activity of peritoneal macrophages in 6-OHDA-Parkinson’s disease rats. These findings confirmed the potential therapeutic effectiveness of water-soluble pristine C60 fullerene in Parkinson’s disease pathogenesis, though there is ground for caution because of its systemic mild toxic effect.

Water-Soluble Pristine C60 Fullerene Inhibits Liver Alterations Associated with Hepatocellular Carcinoma in Rat

Excessive production of reactive oxygen species is the main cause of hepatocellular carcinoma (HCC) initiation and progression. Water-soluble pristine C₆₀ fullerene is a powerful and non-toxic antioxidant, therefore, its effect under rat HCC model and its possible mechanisms were aimed to be discovered. Studies on HepG2 cells (human HCC) demonstrated C₆₀ fullerene ability to inhibit cell growth (IC₅₀ = 108.2 μmol), to induce apoptosis, to downregulate glucose-6-phosphate dehydrogenase, to upregulate vimentin and p53 expression and to alter HepG2 redox state. If applied to animals experienced HCC in dose of 0.25 mg/kg per day starting at liver cirrhosis stage, C₆₀ fullerene improved post-treatment survival similar to reference 5-fluorouracil (31 and 30 compared to 17 weeks) and inhibited metastasis unlike the latter. Furthermore, C₆₀ fullerene substantially attenuated liver injury and fibrosis, decreased liver enzymes, and normalized bilirubin and redox markers (elevated by 1.7–7.7 times under HCC). Thus, C₆₀ fullerene ability to inhibit HepG2 cell growth and HCC development and metastasis and to improve animal survival was concluded. C₆₀ fullerene cytostatic action might be realized through apoptosis induction and glucose-6-phosphate dehydrogenase downregulation in addition to its antioxidant activity.

Water-Soluble Pristine C60 Fullerenes Inhibit Liver Fibrotic Alteration and Prevent Liver Cirrhosis in Rats

Liver cirrhosis is an outcome of a wide range of liver chronic diseases. It is attributed to oxidative stress; therefore, antioxidant usage could be a promising treatment of that. So, exploring the impact of effective free radical scavenger pristine C₆₀ fullerenes on liver fibrosis and cirrhosis and their ability to interact with main growth factor receptors involved in liver fibrogenesis was aimed to be discovered. We used N-diethylnitrosamine/carbon tetrachloride-induced simulations of rat liver fibrosis (10 weeks) and cirrhosis (15 weeks). Pristine C₆₀ fullerene aqueous colloid solution (C₆₀FAS) was injected daily at a dose of 0.25 mg/kg throughout the experiment. Liver morphology and functional and redox states were assessed. C₆₀ fullerenes' ability to interact with epidermal, vasoendothelial, platelet-derived, and fibroblast growth factor receptors (EGFR, VEGFR, PDGFR, and FGFR, respectively) was estimated by computational modeling. We observed that C₆₀FAS reduced the severity of fibrosis in fibrotic rats (0.75 vs. 3.0 points according to Ishak score), attenuated the hepatocyte injury, normalized elevated blood serum alkaline phosphatase (ALP) and lactate dehydrogenase (LDH), and mitigated oxidative stress manifestation in liver tissue restoring its redox balance. When applied to cirrhotic animals, C₆₀FAS reduced connective tissue deposition as well (2.4 vs. 5.4 points according to Ishak score), diminished ALP and LDH (by 16% and 61%), and normalized conjugated and nonconjugated bilirubin, restoring the liver function. Altered liver lipid and protein peroxides and glutathione peroxidase activity were also leveled. Within a computer simulation, it was shown that C₆₀ fullerenes can block hinge prohibiting ATP binding for EGFR and FGFR and thus blocking associated signal pathways. This ability in addition to their antioxidant properties may contribute to C₆₀ fullerene's antifibrotic action. Thus, C₆₀FAS may have a substantial therapeutic potential as an inhibitor of liver fibrosis and cirrhosis.

C60 fullerene aggregation in aqueous solution

In the present work we develop a novel approach for quantification of the energetics of C60 fullerene aggregation in aqueous media in terms of equilibrium aggregation constant KF. In particular, it is shown that the experimental determination of the magnitude of KF is possible only within the framework of the 'up-scaled aggregation model', considering the C60 fullerene water solution as a solution of fullerene clusters. Using dynamic light scattering (DLS) data we report the value, K(F) = 56,000 M(-1), which is in good agreement with existing theoretical estimates and the results of energetic analyses. It is suggested that the proposed 'up-scaled model' may be used in any instances of non-specific aggregation resulting in formation of large spherical particles. The measurement of the translational diffusion coefficient and the dimensions of the light scattering particles using a DLS approach with respect to C60 fullerene aggregates is found to contain significant systematic errors originating from the interaction effect that is well-known for micellar solutions. As a result, corrections to the equations associated with DLS data are proposed.

Complexation of C60 fullerene with aromatic drugs

The contributions of various physical factors to the energetics of complexation of aromatic drug molecules with C(60) fullerene are investigated in terms of the calculated magnitudes of equilibrium complexation constants and the components of the net Gibbs free energy. Models of complexation are developed taking into account the polydisperse nature of fullerene solutions in terms of the continuous or discrete (fractal) aggregation of C(60) molecules. Analysis of the energetics has shown that stabilization of the ligand-fullerene complexes in aqueous solution is mainly determined by intermolecular van der Waals interactions and, to lesser extent, by hydrophobic interactions. The results provide a physicochemical basis for a potentially new biotechnological application of fullerenes as modulators of biological activity of aromatic drugs.

Using water-soluble C60 fullerenes in anticancer therapy

Growth experiments of transplanted malignant tumors in the presence of water-soluble C₆₀ fullerenes were performed on groups of mice. It was found that C₆₀ fullerenes efficiently inhibit the growth of transplanted malignant tumors. This behavior can be explained through their high antioxidant activity and the blocking of the specific cell receptors (for example, endothelial growth factor). The findings demonstrate the possibility of using C₆₀ fullerenes in anticancer therapy.