The Importance of Evaluating the Lot-to-Lot Batch Consistency of Commercial Multi-Walled Carbon Nanotube Products

The biological response of multi-walled carbon nanotubes (MWNTs) is related to their physicochemical properties and a thorough MWNT characterization should accompany an assessment of their biological activity, including their potential toxicity. Beyond characterizing the physicochemical properties of MWNTs from different sources or manufacturers, it is also important to characterize different production lots of the same MWNT product from the same vendor (i.e., lot-to-lot batch consistency). Herein, we present a comprehensive physicochemical characterization of two lots of commercial pristine MWNTs (pMWNTs) and carboxylated MWNTs (cMWNTs) used to study the response of mammalian macrophages to MWNTs. There were many similarities between the physicochemical properties of the two lots of cMWNTs and neither significantly diminished the 24-h proliferation of RAW 264.7 macrophages up to the highest concentration tested (200 μg cMWNTs/mL). Conversely, several physicochemical properties of the two lots of pMWNTs were different; notably, the newer lot of pMWNTs displayed less oxidative stability, a higher defect density, and a smaller amount of surface oxygen species relative to the original lot. Furthermore, a 72-h half maximal inhibitory concentration (IC-50) of ~90 µg pMWNTs/mL was determined for RAW 264.7 cells with the new lot of pMWNTs. These results demonstrate that subtle physicochemical differences can lead to significantly dissimilar cellular responses, and that production-lot consistency must be considered when assessing the toxicity of MWNTs.

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Water-Soluble Taurine-Functionalized Multi-Walled Carbon Nanotubes Induce Less Damage to Mitochondria of RAW 264.7 Cells

Journal of Nanoscience and Nanotechnology ◽

10.1166/jnn.2012.6593 ◽

2012 ◽

Vol 12 (10) ◽

pp. 8008-8016 ◽

Cited By ~ 10

Author(s):

Tian Chen ◽

Jiajie Zang ◽

Haifang Wang ◽

Haiyu Nie ◽

Xiang Wang ◽

...

Keyword(s):

Carbon Nanotubes ◽

Water Soluble ◽

Raw 264.7 Cells ◽

Raw 264.7 ◽

Multi Walled Carbon Nanotubes ◽

Walled Carbon Nanotubes

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A New Method for Dispersing Pristine Carbon Nanotubes Using Regularly Arranged S-Layer Proteins

Nanomaterials ◽

10.3390/nano11051346 ◽

2021 ◽

Vol 11 (5) ◽

pp. 1346

Author(s):

Andreas Breitwieser ◽

Uwe B. Sleytr ◽

Dietmar Pum

Keyword(s):

Carbon Nanotubes ◽

Covalent Modification ◽

Silica Layer ◽

Medical Sciences ◽

Lysinibacillus Sphaericus ◽

Wide Range ◽

Catalytic Sites ◽

Multi Walled Carbon Nanotubes ◽

Pristine Mwnts ◽

Walled Carbon Nanotubes

Homogeneous and stable dispersions of functionalized carbon nanotubes (CNTs) in aqueous solutions are imperative for a wide range of applications, especially in life and medical sciences. Various covalent and non-covalent approaches were published to separate the bundles into individual tubes. In this context, this work demonstrates the non-covalent modification and dispersion of pristine multi-walled carbon nanotubes (MWNTs) using two S-layer proteins, namely, SbpA from Lysinibacillus sphaericus CCM2177 and SbsB from Geobacillus stearothermophilus PV72/p2. Both the S-layer proteins coated the MWNTs completely. Furthermore, it was shown that SbpA can form caps at the ends of MWNTs. Reassembly experiments involving a mixture of both S-layer proteins in the same solution showed that the MWNTs were primarily coated with SbsB, whereas SbpA formed self-assembled layers. The dispersibility of the pristine nanotubes coated with SbpA was determined by zeta potential measurements (−24.4 +/− 0.6 mV, pH = 7). Finally, the SbpA-coated MWNTs were silicified with tetramethoxysilane (TMOS) using a mild biogenic approach. As expected, the thickness of the silica layer could be controlled by the reaction time and was 6.3 +/− 1.25 nm after 5 min and 25.0 +/− 5.9 nm after 15 min. Since S-layer proteins have already demonstrated their capability to bind (bio)molecules in dense packing or to act as catalytic sites in biomineralization processes, the successful coating of pristine MWNTs has great potential in the development of new materials, such as biosensor architectures.

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Multi-Walled Carbon Nanotubes as Electrocatalyst Supports for H2O2 Reduction Reaction

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.860-863.831 ◽

2013 ◽

Vol 860-863 ◽

pp. 831-834

Author(s):

Dan Zheng ◽

Ting Fang Yang ◽

Zhang Fei Guo

Keyword(s):

Cyclic Voltammetry Curve ◽

Chemical Reduction ◽

Reduction Reaction ◽

Carbon Substrate ◽

Acid Media ◽

Multi Walled Carbon Nanotube ◽

Multi Walled Carbon Nanotubes ◽

Current Densities ◽

Reaction Activation Energy ◽

Walled Carbon Nanotubes

This work studies the use of Multi-walled carbon nanotube (MWCNT) as catalyst supports for H2O2 electro-reduction in acid media. Using impregnation-chemical reduction method, we prepared Pt-Ag/CNTs, Pt-Co/CNTs, Pt-Ag/C and Pt-Co/C nanocatalysts. Four catalysts were analyzed by XRD and TEM. Their electrochemical performance was studied via cyclic voltammetry curve. The results show that: the nanoparticles have a better dispersion on CNTs substrate than on XC-72 carbon substrate. Comparing with Pt-Ag and Pt-Co on XC-72 carbon substrate, the H2O2 reduction reaction activation energy of catalysts on CNTs substrate is bigger, and the peak current densities of catalysts on CNTs substrate are larger than that on XC-72 carbon.

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Highly sensitive compression sensors using three-dimensional printed polydimethylsiloxane/carbon nanotube nanocomposites

Journal of Intelligent Material Systems and Structures ◽

10.1177/1045389x19835953 ◽

2019 ◽

Vol 30 (8) ◽

pp. 1216-1224 ◽

Cited By ~ 11

Author(s):

Mohammad Charara ◽

Mohammad Abshirini ◽

Mrinal C Saha ◽

M Cengiz Altan ◽

Yingtao Liu

Keyword(s):

Carbon Nanotubes ◽

Electron Microscope ◽

Carbon Nanotube ◽

Scanning Electron Microscope ◽

Three Dimensional ◽

Multi Walled Carbon Nanotube ◽

Highly Sensitive ◽

Multi Walled Carbon Nanotubes ◽

Walled Carbon Nanotubes ◽

Scanning Electron

This article presents three-dimensional printed and highly sensitive polydimethylsiloxane/multi-walled carbon nanotube sensors for compressive strain and pressure measurements. An electrically conductive polydimethylsiloxane/multi-walled carbon nanotube nanocomposite is developed to three-dimensional print compression sensors in a freestanding and layer-by-layer manner. The dispersion of multi-walled carbon nanotubes in polydimethylsiloxane allows the uncured nanocomposite to stand freely without any support throughout the printing process. The cross section of the compression sensors is examined under scanning electron microscope to identify the microstructure of nanocomposites, revealing good dispersion of multi-walled carbon nanotubes within the polydimethylsiloxane matrix. The sensor’s sensitivity was characterized under cyclic compression loading at various max strains, showing an especially high sensitivity at lower strains. The sensing capability of the three-dimensional printed nanocomposites shows minimum variation at various applied strain rates, indicating its versatile potential in a wide range of applications. Cyclic tests under compressive loading for over 8 h demonstrate that the long-term sensing performance is consistent. Finally, in situ micromechanical compressive tests under scanning electron microscope validated the sensor’s piezoresistive mechanism, showing the rearrangement, reorientation, and bending of the multi-walled carbon nanotubes under compressive loads, were the main reasons that lead to the piezoresistive sensing capabilities in the three-dimensional printed nanocomposites.

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Self-assembly fabrication of a graphene/multi-walled carbon nanotube hybrid material for suppressing potential heat radiation and toxic effluent

RSC Advances ◽

10.1039/c5ra19227g ◽

2015 ◽

Vol 5 (125) ◽

pp. 103365-103372 ◽

Cited By ~ 1

Author(s):

Lei Liu ◽

Dong Wang ◽

Yuan Hu

Keyword(s):

Carbon Nanotubes ◽

Aqueous Solution ◽

Graphene Oxide ◽

Carbon Nanotube ◽

Hybrid Material ◽

Self Assembly ◽

Heat Radiation ◽

Multi Walled Carbon Nanotube ◽

Multi Walled Carbon Nanotubes ◽

Walled Carbon Nanotubes

Negative graphene oxide was combined with positive chitosan-modified multi-walled carbon nanotubes in aqueous solution and then thermally reduced to fabricate a multi-walled carbon nanotube/graphene (MWCNT/G) hybrid material.

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Physicochemical Properties of Bis-GMA/TEGDMA Dental Resin Reinforced with Silanized Multi-Walled Carbon Nanotubes

Silicon ◽

10.1007/s12633-018-9930-0 ◽

2018 ◽

Vol 11 (3) ◽

pp. 1345-1353 ◽

Cited By ~ 1

Author(s):

Weizhen Zeng ◽

Fang Liu ◽

Jingwei He

Keyword(s):

Carbon Nanotubes ◽

Physicochemical Properties ◽

Dental Resin ◽

Multi Walled Carbon Nanotubes ◽

Walled Carbon Nanotubes

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Comparative carcinogenicity study of a thick, straight-type and a thin, tangled-type multi-walled carbon nanotube administered by intra-tracheal instillation in the rat

Particle and Fibre Toxicology ◽

10.1186/s12989-020-00382-y ◽

2020 ◽

Vol 17 (1) ◽

Cited By ~ 1

Author(s):

Dina Mourad Saleh ◽

William T. Alexander ◽

Takamasa Numano ◽

Omnia Hosny Mohamed Ahmed ◽

Sivagami Gunasekaran ◽

...

Keyword(s):

Peritoneal Cavity ◽

Initial Study ◽

Pleural Mesothelioma ◽

Rat Lung ◽

Carcinogenicity Study ◽

Carcinogenic Potential ◽

Multi Walled Carbon Nanotube ◽

Multi Walled Carbon Nanotubes ◽

Walled Carbon Nanotubes ◽

Observation Period

Abstract Background Multi-walled carbon nanotubes can be divided into two general subtypes: tangled and straight. MWCNT-N (60 nm in diameter) and MWCNT-7 (80–90 nm in diameter) are straight-type MWCNTs, and similarly to asbestos, both are carcinogenic to the lung and pleura when administered to rats via the airway. Injection of straight-type MWCNTs into the peritoneal cavity also induces the development of mesothelioma, however, injection of tangled-type MWCNTs into the peritoneal cavity does not induce carcinogenesis. To investigate these effects in the lung we conducted a 2-year comparative study of the potential carcinogenicities of a straight-type MWCNT, MWCNT-A (approximately 150 nm in diameter), and a tangled-type MWCNT, MWCNT-B (7.4 nm in diameter) after administration into the rat lung. Crocidolite asbestos was used as the reference material, and rats administered vehicle were used as the controls. Test materials were administered by intra-Tracheal Intra-Pulmonary Spraying (TIPS) once a week over a 7 week period (8 administrations from day 1 to day 50), followed by a 2-year observation period without further treatment. Rats were administered total doses of 0.5 or 1.0 mg MWCNT-A and MWCNT-B or 1.0 mg asbestos. Results There was no difference in survival between any of the groups. The rats administered MWCNT-A or asbestos did not have a significant increase in bronchiolo-alveolar hyperplasia or tumors in the lung. However, the rats administered MWCNT-B did have significantly elevated incidences of bronchiolo-alveolar hyperplasia and tumors in the lung: the incidence of bronchiolo-alveolar hyperplasia was 0/20, 6/20, and 9/20 in the vehicle, 0.5 mg MWCNT-B, and 1.0 mg MWCNT-B groups, respectively, and the incidence of adenoma and adenocarcinoma combined was 1/19, 5/20, and 7/20 in the vehicle, 0.5 mg MWCNT-B, and 1.0 mg MWCNT-B groups, respectively. Malignant pleural mesothelioma was not induced in any of the groups. Conclusions The results of this initial study indicate that tangled-type MWCNT-B is carcinogenic to the rat lung when administered via the airway, and that straight-type MWCNT-A did not have higher carcinogenic potential in the rat lung than tangled-type MWCNT-B.

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