Effects Of C60 Research Articles

Effect of black phosphorus modified by fullerene C60 on the self-lubricating properties of PEEK-based composite coatings

Poly-ether-ether-ketone (PEEK) has many excellent properties for being used as self-lubricating coatings. In order to further improve the friction performance, black phosphorus (BP) was used as filler to prepare BP/PEEK composite coating. BP-C60 was formed by modification of BP edge by fullerene C60 to solve the problem of BP oxidation, so that BP still existed in the sintered PEEK coating. Then, the effects of C60 and BP-C60 on the tribological properties of PEEK coating were studied, and the results showed that the wear rate and friction coefficient of BP-C60/C60/PEEK composite coating were significantly reduced. This was attributed to the synergistic effect of BP and C60, which enhanced the stability of BP and reduced coating porosity.

Acute toxicity of C60–Cis-Pt nanocomplex in vivo

Acute toxicity of noncovalent nanocomplex of C60 fullerene with Cisplatin (Cis-Pt) (the ratio of compounds C60:Cis-Pt by weight 1:1) in a dose progression (7.5 + 7.5, 15.0 + 15.0, 22.5 + 22.5, 30.0 + 30.0, 37.5 + 37.5, and 45.0 + 45.0 mg/kg) was investigated in mice of BALB/c line. Mice were injected with C60–Cis-Pt nanocomplex or free Cis-Pt at the same doses single intraperitoneally and observed for 14 days. A comparative study of the toxicity of free Cis-Pt and Cis-Pt at noncovalent complexation with C60 fullerene (C60–Cis-Pt nanocomplex) demonstrated halving the toxicity of C60–Cis-Pt nanocomplex in comparison with free Cis-Pt: LD50 (Cis-Pt) 15.6 ± 1.3 mg/kg vs LD50 (C60–Cis-Pt) 36.1 ± 2.8 mg/kg. The toxic effects of C60–Cis-Pt nanocomplex and free Cis-Pt were detected at doses 22.5 + 22.5 mg/kg and 15.0 mg/kg, respectively, and were accompanied by impaired mice behavior, decreased body weight and animal survival, hematotoxicity, and pathological changes in heart, liver, spleen, and kidneys. It was shown that C60 fullerene complexed with Cis-Pt prevented drug-induced decrease in animal survival, anemia, thrombocytosis, and leukopenia development, as well as inflammatory processes in spleen, heart, kidney, and liver. The obtained results indicate the prospects for using noncovalent nanocomplex C60–Cis-Pt in antitumor therapy at low therapeutic doses of Cis-Pt.

Pristine and Hydroxylated Fullerenes Prevent the Aggregation of Human Islet Amyloid Polypeptide and Display Different Inhibitory Mechanisms.

Protein aggregation, involving the formation of dimers, oligomers, and fibrils, is associated with many human diseases. Type 2 diabetes is one of the common amyloidosis and linked with the aggregation of human islet amyloid polypeptide (hIAPP). A series of nanoparticles are reported to be able to interact with proteins and enhance/inhibit protein aggregation. However, the effects of C60 (a model system of hydrophobic nanoparticle) and C60(OH)8 (a hydroxylated fullerene) on hIAPP aggregation remain unknown. In this study, we investigate the influences of pristine fullerene C60 and hydroxylated C60 on the dimerization of hIAPP using molecular dynamics (MD) simulations. Extensive replica exchange molecular dynamics (REMD) simulations show that isolated hIAPP dimers adopt β-sheet structure containing the amyloid-precursor (β-hairpin). Both C60 and C60(OH)8 notably inhibit the β-sheet formation of hIAPP dimer and induce the formation of collapsed disordered coil-rich conformations. Protein—nanoparticle interaction analyses reveal that the inhibition of hIAPP aggregation by C60 is mainly via hydrophobic and aromatic-stacking interactions, while the prevention of hIAPP aggregation by C60(OH)8 is mostly through collective hydrogen bonding and aromatic-stacking interactions. Conventional MD simulations indicate that both C60 and C60(OH)8 weaken the interactions within hIAPP protofibril and disrupt the β-sheet structure. These results provide mechanistic insights into the possible inhibitory mechanism of C60 and C60(OH)8 toward hIAPP aggregation, and they are of great reference value for the screening of potent amyloid inhibitors.

Effects of fullerene C60 in blue mussels: Role of mTOR in autophagy related cellular/tissue alterations.

The effects of C60 on mTOR (mechanistic Target of Rapamycin) activity in mussel digestive gland were investigated. mTOR is a kinase that senses physiological and environmental signals to control eukaryotic cell growth. mTOR is present in two complexes: the phosphorylated mTORC1 regulates cell growth by activating anabolic processes, and by inhibiting catabolic processes (i.e. autophagy); mTORC2 also modulates actin cytoskeleton organization. Mussels were exposed to C60 (0.01, 0.1 and 1mg/L) for 72h. Immunocytochemical analysis using a specific antibody revealed the cellular distribution of C60 in mussel digestive gland, already at the lowest concentration. In exposed mussels, the dephosphorylation of mTORC1 and mTORC2 may explain the C60 effects, i.e. the reduction of lysosomal membrane stability, the enhancement of LC3B protein, and the increase of lysosomal/cytoplasmic volume ratio; as well the cytoskeletal alterations. No oxidative stress was observed. Multivariate analysis was used to facilitate the interpretation of the biomarker data. Finally, a low density oligo-microarray was used to understand the cellular responses to fullerene. Transcriptomics identified a number of differentially expressed genes (DEGs) showing a maximum in animals exposed to 0.1mg/L C60. The most affected processes are associated with energy metabolism, lysosomal activity and cytoskeleton organization. In this study, we report the first data on the subcellular distribution of C60 in mussel's cells; and on the involvement of mTOR inhibition in the alterations due to nanoparticle accumulation. Overall, mTOR deregulation, by affecting protein synthesis, energy metabolism and autophagy, may reduce the capacity of the organisms to effectively grow and reproduce.

Metallothionein and Superoxide Dismutase-Antioxidative Protein Status in Fullerene-Doxorubicin Delivery to MCF-7 Human Breast Cancer Cells.

Doxorubicin (DOX) is one of the most frequently used anticancer drugs in breast cancer treatment. However, clinical applications of DOX are restricted, largely due to the fact that its action disturbs the pro/antioxidant balance in both cancerous and non-cancerous cells. The aim of this study was to investigate the influence of fullerene (C60) in cell treatment by DOX on the proliferation of human breast cancer cells (MCF-7), concentration of metallothionein (MT) and superoxide dismutase (SOD), and SOD activity in these cells. The use of C60 in complexes with DOX causes a change in the level of cell proliferation of about 5% more than when caused by DOX alone (from 60–65% to 70%). The use of C60 as a DOX nanotransporter reduced the MT level increase induced by DOX. C60 alone caused an increase of SOD1 concentration. On the other hand, it led to a decrease of SOD activity. C60 in complex with DOX caused a decrease of the DOX-induced SOD activity level. Exposure of MCF-7 cells to DOX-C60 complexes results in a decrease in viable cells and may become a new therapeutic approach to breast cancer. The effects of C60 in complexes with DOX on MCF-7 cells included a decreased enzymatic (SOD activity) and nonenzymatic (MT) antioxidant status, thus indicating their prooxidant role in MCF-7 cells.

Effects of C60 on the Glass Transition Temperature of Carbazole-based Photorefractive Polyphosphazenes

The bi-functional carbazole-based photorefractive polyphosphazenes with different content of C60-doped were fabricated. The glass transition temperature (Tg) of these polymer composite materials was determined using a differential scanning calorimetric (DSC) method. According to the DSC measurement results with different heating rates, the variation of Tg and the active energy of glass transition (Eg) were analyzed in detail. The analysis results indicate that the transition region shifts to higher temperatures with increasing heating rate, and C60 content (below 1.0wt%) can influence the Tg of photorefractive polyphosphazenes. The Tg first increases and then decreases with the C60 content (below 1.0wt%). The probable causes of the influence of C60 on Tg was proposed.

Water-soluble C60-(OH)24 fullerene hydroxide as a therapeutic agent against the degeneration of articular cartilage in osteoarthritis

Purpose: During the development of osteoarthritis (OA), mechanical stress on articular cartilage downregulates the stable cellular activities of chondrocytes and induce the production of catabolic factors, such as proinflammatory cytokines and chemokines. In addition, it is well known that chondrocytes produce excess amounts of reactive oxygen species (ROS; superoxide, nitric oxide, hydrogen peroxide and peroxynitrite) in response to mechanical stress. Recent reports have demonstrated that mechanical stress to articular cartilage stimulates excess production of ROS from chondrocytes, consequently resulting in the depolymerization of hyaluronic acid and chondrocyte death. It has been suggested that the generation of ROS and the depletion of cellular antioxidants may be involved in the pathogenesis of OA. C60 fullerene is a molecule composed completely of carbon in a unique spherical structure that has a high reactivity with oxygen free radicals and can potentially act as a free radical scavenger. It has been reported that the antioxidant level of C60 is several hundred-fold higher than that of other antioxidants. Recently, C60 fullerene has shown to inhibit neuronal apoptosis by scavenging oxygen reactive species and protects human skin keratinocytes from ROS-induced cell death after UV stress, suggesting that C60 is a useful agent to protect against the oxygen free radical-induced pathological features in a variety of diseases. Use of C60 could lead to the development of novel therapeutic strategies in the prevention of both chondrocyte aging and cartilage degeneration. To prevent the degeneration of articular cartilage in OA, we have newly developed on water-soluble C60(OH)24 fullerene hydroxide, a strong free radical scavenger, as an anti-oxidative agent. In this study, we examined the therapeutic effects of water-soluble C60(OH)24 on chondrocyte activity and energy metabolism, which were monitored by the production of cartilage component (proteoglycan), matrix degrading enzyme MMP-3, and the uptake of glucose in the cells, respectively. Methods: In the presence or absence of C60(OH)24 (1.0 nM, 10.0 nM, 100.0 nM), human OA chondrocytes were incubated with IL-1β (1.0, 10.0 ng/ml). After the 24-hour incubation period, chondrocyte activities (production of proteoglycan and MMP-3, glucose metabolism) were analyzed. Our previous study revealed that expression of DNA repair enzyme, apurinic/apyrimidinic endonuclease (Apex) 2, in chondrocytes was associated with the degeneration of articular cartilages and was induced by OA-relating catabolic factors. Thus, we also studied effects of C60(OH)24 on the expression of Apex 2 in osteoarthritic chondrocytes. Results: IL-1β significantly inhibited the production of proteoglycan and the glucose uptake in chondrocytes, and accelerated the secretion of MMP-3 from chondrocytes. Even in the presence of IL-1β (1.0 ng/ml, but not 10.0 ng/ml), C60(OH)24 inhibited the IL-1β-induced production of MMP-3, the IL-1β-induced down-regulation of proteoglycan production and glucose metabolism in OA chondrocytes. C60(OH)24 fullerene hydroxide also reduced the OA-relating catabolic factor-induced up-regulation of DNA repair enzyme, Apex 2, in OA chondrocytes. Conclusions: Our data indicated that nM order of water-soluble C60(OH)24 fullerene hydroxide may have a potential to protect against the catabolic factor-induced down-regulation of chondrocyte activities in OA. Our findings provide a novel pathogenic mechanism linking oxidant-mediated degenerative process of articular cartilage in OA.Figure 2. Effect of C60(OH)24 on proteoglycan production in chondrocytesView Large Image Figure ViewerDownload Hi-res image Download (PPT)Figure 3. Effect of C60(OH)24 on glucose uptake into chondrocytesView Large Image Figure ViewerDownload Hi-res image Download (PPT)

C60 reduces the bioavailability of mercury in aqueous solutions

The effects of C60 on mercury bioavailability and sorption were investigated at different C60 dosages, reaction times, and pH ranges using the merR::luxCDABE bioluminescent bioreporter Escherichia coli ARL1. The results demonstrated that the bioavailability of mercury (Hg2+) decreased with increasing C60 dosage. Approximately 30% of aqueous mercury became biologically unavailable 2h after interaction with C60 at a mass ratio of C60 to mercury as low as 0.01. However, this reduction in bioavailability plateaued at a mass ratio of C60 to mercury of 10 with a further increase in C60 concentrations resulting in only a 20% additional decrease in bioavailability. If this reduction in bioluminescence output is attributable to mercury sorption on C60, then each one log-order increase in C60 concentration resulted in a 0.86 log-order decrease in the mercury partitioning coefficient (Kd). This relationship implies the presence of high mercury-affinitive sites on C60. The length of reaction time was found to play a more important role than C60 dosage in reducing Hg2+ bioavailability, suggesting an overall slow kinetics of the C60–Hg interactions. In addition, lowering the pH from 7.2 to 5.8 decreased mercury bioavailability due likely to the increase in mercury’s association with C60. These results suggest that C60 may be useful in capturing soluble mercury and thus reducing mercury biotoxicity.

The Effects of C60(C(COOH)2)2-FITC on Proliferation and Differentiation of Human Mesenchymal Stem Cells In Vitro

As manufactured nanoparticles, fullerene nanoparticles were used as the model to research the manufactured nanoparticles entering into cells and hence have been rapidly developed for biomedical uses. Human mesenchymal stem cells (hMSCs) have become the most widely used seeding cells in tissue engineering because they are readily obtained without ethical problems and are multipotent with regard to adipogenic, chondrogenic, and osteogenic lineages. Because of their favorable biological and cellular activities, C60 carboxyl derivatives are among the most widely studied C60 derivatives. FITC labeled C60(C(COOH)2)2 nanoparticles were charactered by FTIR, ESI-MS, XPS and DLS. The effects of C60(C(COOH)2)2-FITC on proliferation and differentiation of human mesenchymal stem cells (hMSCs) in vitro were observed. The fullerene nanoparticles are quickly internalized by the cells and they had low toxicity to proliferation of hMSCs. The C60(C(COOH)2)2 nanoparticles could promote cell proliferation, enhance osteoclast differentiation of hMSCs.

Quantitative determination of fullerene (C60) in soils by high performance liquid chromatography and accelerated solvent extraction technique

Environmental context.Due to the increasing adoption of nanotechnology, synthetic nanoparticles such as fullerenes (nC60), are likely to emerge as contaminants in aquatic and terrestrial environments. Currently, our understanding of the fate and effects of C60 in the terrestrial environment is poor and is primarily hampered by the lack of reliable quantitative analytical methods. In this paper, we describe a method for effective extraction and sensitive detection of C60 residues in soils which will facilitate environmental fate studies on nC60. Abstract.Fullerenes (e.g. C60) are emerging as environmental contaminants due to their wide range of applications, such as in optics, electronics, cosmetics and biomedicine. Residue analysis is a crucial step in understanding the fate and effects of C60 in the terrestrial environments. However, there is a lack of reliable quantitative analytical methods for extraction and analysis of C60 in soils or sediments. We developed a method for determination of C60 in soils using accelerated solvent extraction (ASE) followed by HPLC-UV detection. Separation of C60 from soil matrix interferences was achieved by gradient elution using methanol–toluene mobile phase. Mean recoveries obtained from extraction efficiency tests using six contrasting soils spiked (wet and dry tests with freeze drying of wet and aged soils before ASE) at varying concentrations of C60 ranged from 84 to 107%. The current method provides adequate sensitivity (limit of quantitation = 20 μg kg–1), and can be used for quantitative determination of C60 in soils and sediments (especially for environmental fate studies) without needing expensive HPLC-mass spectrometry.

Water-soluble fullerene (C60) inhibits the osteoclast differentiation and bone destruction in arthritis

Recently, it has been demonstrated that oxygen free radicals have an important role as a signaling messenger in the receptor activator NFkappaB (RANK) signal pathway required for osteoclast differentiation. The aim of this study was to examine the potential of a strong free-radical scavenger, water-soluble fullerene (C60), as a protective agent against the RANK-induced osteoclastogenesis and osteoclastic bone destruction in arthritis, both in vitro and in vivo. The effects of C60 on the RANK-induced osteoclastogenesis and osteoclastic bone resorption were examined in vitro. Adjuvant-induced arthritic rats were used as an animal model of arthritis. Rats were divided into two subgroups: control and treatment with C60 at 1.0 microM. The left ankle joint was injected intra-articularly with water-soluble C60 (20 microl) in the C60-treated group, while, as a control, the left ankle joint in the control rats received phosphate-buffered saline (20 microl) once weekly for eight weeks. Ankle joint tissues were prepared for histologic analysis. C60 significantly inhibited the responses of osteoclast precursor cells to RANK ligand, including osteoclast differentiation and osteoclastic bone resorption in vitro. In adjuvant-induced arthritic rats, intra-articular treatment with C60 in vivo reduced the number of osteoclasts and alleviated bone resorption and destruction in the joints, while control ankle joints showed progression of joint destruction with time. These findings indicate that C60 downregulates the RANK-induced osteoclast differentiation and is a potential therapeutic agent for inhibition of osteoclastic bone destruction in arthritis.

Effects of Bphen Layer as Hole Blocking Material on the Performance of Vertical Type Light Emitting Transistor Using C60 and MEH-PPV

Vertical type organic light emitting transistors (OLETs) using C60 as a n-type active material and MEH-PPV as an emitting polymer were fabricated. C60 shows n-type semiconductor property and relatively high electron mobility. Furthermore, MEH-PPV has high quantum efficiency for light emitting diode. We have investigated structural effects of C60 and Bphen blocking layer on the performance of light emitting diode consisting of ITO/PEDOT-PSS (50 nm)/MEH-PPV (80 nm)/Bphen (3 nm)/C60 (30 nm)/Al (100 nm). Vertical type OLET has layered structure of metal(source)/C60/metal(gate)/C60/Bphen/MEH-PPV/PEDOT-PSS/ITO glass. The thickness of source and gate electrode was 100 nm and 10 nm, respectively. Source and gate electrodes were deposited with several kinds of materials. The characteristics of the fabricated OLETs were studied from the measurements of current-voltage and on-off ratio.

Effects of C60, a Fullerene, on the Activities of Glutathione S-Transferase and Glutathione-Related Enzymes in Rodent and Human Livers

The effects of C60, a fullerene, on the activities of glutathione 5-transferase (GST), glutathione peroxidase (GSH-Px) and glutathione reductase (GR) in rodent and human livers were investigated. the GST activity in rat liver towards frans-4-phenyl-3-buten-2-one and that in mouse liver towards ethacrynic acid were inhibited by C60- the GST activity towards 1,2-dichloro-4-nitrobenzene, isomerase activity of GST towards androst-5-ene-3,17-dione, GSH-Px activity and GR activity were not affected by C60 a kinetic study using purified mouse GST-π with ethacrynic acid (25-100 μM) as the substrate revealed that C60 was a non-competitive inhibitor of the enzyme with a Ki = 48.8 ± 0.25 μM and a Ki = 47.9 ±0.18 μM. However, C60 did not inhibit the activity of purified mouse GST-π towards l-chloro-2,4-dinitrobenzene. Thus, the inhibition by C60 appears to be substrate-specific. In human liver, C60 inhibited the GST activity towards ethacrynic acid, and moderately inhibited GSH-Px and GR activities.

Effects of C60 on conducting polymer with small band gap

Abstract The C60/poly(isothianaphthene) (PITN) heterojunction device was fabricated and its electrical characteristics and photoirradiation effects were investigated. This device has current-rectifying function. Upon photoirradiation, both forward and backward currents were enhanced, and photovoltaic effects was also appeared. These results were discussed in terms of charge transfer between C60 and PITN in the ground state and photoexcited state.