Effects of multiwalled carbon nanotubes and triclocarban on several eukaryotic cell lines: elucidating cytotoxicity, endocrine disruption, and reactive oxygen species generation

Abstract

To date, only a few reports about studies on toxic effects of carbon nanotubes (CNT) are available, and their results are often controversial. Three different cell lines (rainbow trout liver cells (RTL-W1), human adrenocortical carcinoma cells (T47Dluc), and human adrenocarcinoma cells (H295R)) were exposed to multiwalled carbon nanotubes, the antimicrobial agent triclocarban (TCC) as well as the mixture of both substances in a concentration range of 3.13 to 50 mg CNT/L, 31.25 to 500 μg TCC/L, and 3.13 to 50 mg CNT/L + 1% TCC (percentage relative to carbon nanotubes concentration), respectively. Triclocarban is a high-production volume chemical that is widely used as an antimicrobial compound and is known for its toxicity, hydrophobicity, endocrine disruption, bioaccumulation potential, and environmental persistence. Carbon nanotubes are known to interact with hydrophobic organic compounds. Therefore, triclocarban was selected as a model substance to examine mixture toxicity in this study. The influence of multiwalled carbon nanotubes and triclocarban on various toxicological endpoints was specified: neither cytotoxicity nor endocrine disruption could be observed after exposure of the three cell lines to carbon nanotubes, but the nanomaterial caused intracellular generation of reactive oxygen species in all cell types. For TCC on the other hand, cell vitality of 80% could be observed at a concentration of 2.1 mg/L for treated RTL-W1 cells. A decrease of luciferase activity in the ER Calux assay at a triclocarban concentration of 125 μg/L and higher was observed. This effect was less pronounced when multiwalled carbon nanotubes were present in the medium. Taken together, these results demonstrate that multiwalled carbon nanotubes induce the production of reactive oxygen species in RTL-W1, T47Dluc, and H295R cells, reveal no cytotoxicity, and reduce the bioavailability and toxicity of the biocide triclocarban.

Multi-walled carbon nanotubes functionalized with recombinant Dengue virus 3 envelope proteins induce significant and specific immune responses in mice

“…Nonetheless, whether CNTs are inherently cytotoxic at any organic systems has yet to be definitely proven. Simon et al [26] tested levels of MWNT cytotoxicity in different eukaryotic cell lines and concluded that exposition to the compound rendered neither cytotoxicity nor endocrine disruption to any of them. Furthermore, it is widely accepted that functionalization of CNTs reduces their toxicity and also increases biocompatibility [27].…”

“…One hypothesis to explain how the association of MWNT has so dramatically changed the immunogenic potential of the very same protein is that the functionalization of the DENV3E with MWNT may have led to a differential profile of antigenic presentation. Moreover, it has been shown that ƒ-CNTs have immunostimulatory properties and are able to induce the production of cytokines [26, 34]. Thus, the increased neutralizing antibody titers could have been a result of CNT-driven immunomodulation.…”

The ecotoxic potential of a new zero-valent iron nanomaterial, designed for the elimination of halogenated pollutants, and its effect on reductive dechlorinating microbial communities

“…A cell free reactive oxygen species (ROS) detection was conducted according to the procedure by Simon et al (2014) and Rushton et al (2010). This assay quantifies the amount of ROS in the medium whereas other assays measure the ROS within animal cells.…”

<p>Toxicity of Carbon Nanotubes as Anti-Tumor Drug Carriers</p>

“…Following delivery of anticancer drugs to target cells, CNTs are transported by blood to the heart, liver, lungs, kidneys, 100 brain, 101 embryo 102 and other organs ( Figure 2), producing oxidative stress and causing cellular damage. 103,104 Due to their specific surface properties and small size, even purified CNTs can cause toxicity to tissues or organs. For example, after 48 h co-culture of HeLa cells with 100 μg/mL untreated and purified SWCNTs by Tsuji and colleagues, 70% HeLa cells in the untreated group displayed apoptosis relative to 40% HeLa cells in the purified group, supporting the theory that CNTs are inherently toxic irrespective of the purity of the preparation.…”