Potentiating toxicological interaction of single‐walled carbon nanotubes with dissolved metals

Abstract

The present study explored the ecotoxicology of single-walled carbon nanotubes (SWCNTs) and their likely interaction with dissolved metals, with a focus on the effect of in vivo exposure in marine mussels. Any nano-scale effects were negated by the tendency of uncoated SWCNTs to agglomerate in water, particularly with high ionic strength as is the case in estuarine and full-strength seawater. However, SWCNTs, in combination with natural organic matter, remained suspended in seawater for long enough to become available to filter-feeding mussels, leading to their concentration on and increased contact with gill epithelia during exposure. For the first time, the authors describe a potentiating toxicological effect, expressed as DNA strand breaks obtained using the comet assay, on divalent metals afforded by negatively charged SWCNT agglomerates in seawater at concentrations as low as 5 µg L⁻¹. This is supported by the observation that SWCNTs alone were only toxic at concentrations ≥100 µg L⁻¹ and that the SWCNT-induced DNA damage was correlated with oxidative stress only in the absence of metals. If these laboratory experiments are confirmed in the natural environment, the present results will have implications for the understanding of the role of carbon nanotubes in environmental metal dynamics, toxicology, and consequently, regulatory requirements.

Antimicrobial Activity of Single-Walled Carbon Nanotubes (Swcnts) Against Marine Bacteria Staphylococcus aureus

“…In conclusion, the above experiments demonstrated a possible antibacterial process of SWCNTs on S. aureus cells: SWCNTs maybe caused cell wall breakage, and then internalized into the bacteria cell. Ag-NPs internalized into S. aureus cells and caused DNA damage [17,[18][19][20][21]. SWNTs can exhibit strong antimicrobial activity.…”

An Integrated Testing Strategy for Ecotoxicity (ITS‐ECO) Assessment in the Marine Environmental Compartment using Mytilus spp.: A Case Study using Pristine and Coated CuO and TiO2 Nanomaterials

“…Hemocytes and gill cells were analyzed for genotoxicity using the comet assay. The single‐cell gel electrophoresis or comet assay was performed according to Singh and Hartl (2012) and Al‐Shaeri et al (2013). A detailed description of the methodology can be found in the Supporting Information.…”

“…The ENMs are often functionalized for improved performance, which will also confer a new identity on the material, potentially leading to distinct environmental fate, behavior, and biological effects compared with the core ENM (Perreault et al, 2014). For that reason, and because of the ability of mussels to sort particulates (Al‐Shaeri et al, 2013), we used CuO and TiO 2 ENMs with a series of functionalizations (carboxyl [COOH], polyethylene glycol [PEG], and ammonia [NH 3 ]) to investigate whether distinct hazards and fate are dictated and/or can be controlled by functionalities.…”

“…Furthermore, mussels exhibit extraordinary pre‐ and postingestive selective and differential particle‐processing capabilities (capture, rejection, ingestion, absorption, and egestion; Riisgård et al, 2011). Particle selection/capture efficiency is influenced by particle diameter, shape, surface charge, surface chemistry (protein coating), and wettability (hydrophobicity) (Al‐Shaeri et al, 2013; Rosa et al, 2017; Wang et al, 2021). Given the potential for surface functionalization to influence the aforementioned properties, we hypothesize that distinct uptake and accumulation profiles could be evidenced in mussels exposed to core and functionalized ENMs.…”

Toxic Effect of Single Walled Carbon Nanotubes Combined with Cadmium to the Crustacean <i>Daphnia magna</i>

“…A large number of studies reported the ability of carbon nanotubes to adsorb heavy metal ions but few investigated the effect of this property on the organisms potentially exposed (Li et al 2004, Li et al 2005, Lu et al 2006). A previous study described a potentiating toxicological effect of SWCNT, suspended with organic matter in seawater, co-exposed with divalent metals at very low concentration (µg/L range) on DNA integrity of the mussel Mytilus edulis (Al-Shaeri et al 2013). In other studies, lead toxicity to a freshwater fish increased in the presence of purified MWCNT (Martinez et al 2013) while, in contrast, SWCNT in sediments significantly reduced bioaccumulation of hydrophobic carbon to the deposit/suspensionfeeding of a polychaete (Ferguson et al 2008).…”