Tearing open nitrogen-doped multiwalled carbon nanotubes

Meier, Mark S.; Andrews, Rodney; Jacques, D.A.; Cassity, Kelby; Qian, Dali

doi:10.1039/b809348b

Cited by 14 publications

(18 citation statements)

References 21 publications

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“…These physical similarities may be the basis of the formation of functional biohybrids of carbon nanotubes with α- and β-tubulin during polymerization of the microtubules creating a more rigid mitotic spindle pole and, therefore, a reduction in spindle pole integrity [36]. Additionally, the alteration of MWCNT physicochemical properties could affect the direct interaction of carbon nanotubes with other nuclear structures including the microtubules, centrosomes, and DNA [17, 37, 50, 52, 53, 56].…”

Section: Discussionmentioning

confidence: 99%

Mitsui-7, heat-treated, and nitrogen-doped multi-walled carbon nanotubes elicit genotoxicity in human lung epithelial cells

et al. 2019

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Background The unique physicochemical properties of multi-walled carbon nanotubes (MWCNT) have led to many industrial applications. Due to their low density and small size, MWCNT are easily aerosolized in the workplace making respiratory exposures likely in workers. The International Agency for Research on Cancer designated the pristine Mitsui-7 MWCNT (MWCNT-7) as a Group 2B carcinogen, but there was insufficient data to classify all other MWCNT. Previously, MWCNT exposed to high temperature (MWCNT-HT) or synthesized with nitrogen (MWCNT-ND) have been found to elicit attenuated toxicity; however, their genotoxic and carcinogenic potential are not known. Our aim was to measure the genotoxicity of MWCNT-7 compared to these two physicochemically-altered MWCNTs in human lung epithelial cells (BEAS-2B & SAEC). Results Dose-dependent partitioning of individual nanotubes in the cell nuclei was observed for each MWCNT material and was greatest for MWCNT-7. Exposure to each MWCNT led to significantly increased mitotic aberrations with multi- and monopolar spindle morphologies and fragmented centrosomes. Quantitative analysis of the spindle pole demonstrated significantly increased centrosome fragmentation from 0.024–2.4 μg/mL of each MWCNT. Significant aneuploidy was measured in a dose-response from each MWCNT-7, HT, and ND; the highest dose of 24 μg/mL produced 67, 61, and 55%, respectively. Chromosome analysis demonstrated significantly increased centromere fragmentation and translocations from each MWCNT at each dose. Following 24 h of exposure to MWCNT-7, ND and/or HT in BEAS-2B a significant arrest in the G1/S phase in the cell cycle occurred, whereas the MWCNT-ND also induced a G2 arrest. Primary SAEC exposed for 24 h to each MWCNT elicited a significantly greater arrest in the G1 and G2 phases. However, SAEC arrested in the G1/S phase after 72 h of exposure. Lastly, a significant increase in clonal growth was observed one month after exposure to 0.024 μg/mL MWCNT-HT & ND. Conclusions Although MWCNT-HT & ND cause a lower incidence of genotoxicity, all three MWCNTs cause the same type of mitotic and chromosomal disruptions. Chromosomal fragmentation and translocations have not been observed with other nanomaterials. Because in vitro genotoxicity is correlated with in vivo genotoxic response, these studies in primary human lung cells may predict the genotoxic potency in exposed human populations.

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Section: Discussionmentioning

confidence: 99%

Mitsui-7, heat-treated, and nitrogen-doped multi-walled carbon nanotubes elicit genotoxicity in human lung epithelial cells

et al. 2019

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“…Surface functionalizations and substitution reactions (with nitrogen or boron, as examples) to the carbon lattice may increase nanotube reactivity at sites of curvature and breaks in the lattice (Kuzmany et al, 2004; Meier et al, 2008). The increase in porosity greatly increases the surface area (and therefore, reactive surface) of ND-MWCNT, which could have interesting implications for biocompatibility (Meier et al, 2008). Nitrogen functionalization (or “doping”) of CNT has been shown to significantly increase the brittleness, chemical reactivity, and n-type semiconductor activity of this material (Maldonado et al, 2006).…”

Section: Discussionmentioning

confidence: 99%

Effects of nitrogen-doped multi-walled carbon nanotubes compared to pristine multi-walled carbon nanotubes on human small airway epithelial cells

Mihalchik¹,

Ding²,

Porter³

et al. 2015

Toxicology

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Nitrogen-doped multi-walled carbon nanotubes (ND-MWCNTs) are modified multi-walled carbon nanotubes (MWCNTs) with enhanced electrical properties that are used in a variety of applications, including fuel cells and sensors; however, the mode of toxic action of ND-MWCNT has yet to be fully elucidated. In the present study, we compared the interaction of ND-MWCNT or pristine MWCNT-7 with human small airway epithelial cells (SAEC) and evaluated their subsequent bioactive effects. Transmission electron microscopy, X-ray photoelectron spectroscopy, Raman spectroscopy, and X-ray diffraction suggested the presence of N-containing defects in the lattice of the nanotube. The ND-MWCNTs were determined to be 93.3% carbon, 3.8% oxygen, and 2.9% nitrogen. A dose–response cell proliferation assay showed that low doses of ND-MWCNT (1.2 mg/ml) or MWCNT-7 (0.1 mg/ml) increased cellular proliferation, while the highest dose of 120 mg/ml of either material decreased proliferation. ND-MWCNT and MWCNT-7 appeared to interact with SAEC at 6 h and were internalized by 24 h. ROS were elevated at 6 and 24 h in ND-MWCNT exposed cells, but only at 6 h in MWCNT-7 exposed cells. Significant alterations to the cell cycle were observed in SAEC exposed to either 1.2 mg/ml of ND-MWCNT or MWCNT-7 in a time and material-dependent manner, possibly suggesting potential damage or alterations to cell cycle machinery. Our results indicate that ND-MWCNT induce effects in SAEC over a time and dose-related manner which differ from MWCNT-7. Therefore, the physicochemical characteristics of the materials appear to alter their biological effects.

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“…Two main synthetic routes are utilized for the production of nitrogen-doped carbon materials (Nishihara and Kyotani, 2012;Zheng et al, 2012). One method employed for the in situ inclusion of nitrogen into the carbon matrix is the use of a nitrogen containing precursor during pyrolysis (Meier et al, 2008;Sharifi et al, 2012;Shin et al, 2012). This method is predominantly used in the fabrication of highly ordered structures such as nitrogen-doped carbon nanotubes and nanofibers.…”

Section: Nitrogen-doped Carbons (N-carbon) In Sulfur Cathodementioning

confidence: 99%

Nitrogen-doped carbons in Li–S batteries: materials design and electrochemical mechanism

Sun

2014

Front. Energy Res.

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Li-S batteries have been considered as next generation Li batteries because of their hightheoretical energy density. Over the past few years, researchers have made significant efforts in breaking through critical bottlenecks, which impede the commercialization of Li-S batteries. Beginning with a basic introduction to Li-S systems and their associated mechanism, this review will highlight the application of one specific carbon family, nitrogen-doped carbon materials in sulfur-based cathodes. These materials will include nitrogen-doped porous carbon, carbon nanotubes, nanofibers, and graphene. The article will conclude with a summary of recent research efforts in this field as well as the future prospects for the use of nitrogen-doped carbon materials in Li-S batteries.

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Tearing open nitrogen-doped multiwalled carbon nanotubes

Abstract: Reductive alkylation of N-MWNTs with Li/NH 3 results in fracturing of the nanotubes, ripping channels that breach the central core and generating significant new pore volume.

Cited by 14 publications

References 21 publications

Mitsui-7, heat-treated, and nitrogen-doped multi-walled carbon nanotubes elicit genotoxicity in human lung epithelial cells

Mitsui-7, heat-treated, and nitrogen-doped multi-walled carbon nanotubes elicit genotoxicity in human lung epithelial cells

Effects of nitrogen-doped multi-walled carbon nanotubes compared to pristine multi-walled carbon nanotubes on human small airway epithelial cells

Nitrogen-doped carbons in Li–S batteries: materials design and electrochemical mechanism

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