Exposure of sticklebacks (Gasterosteus aculeatus) to cadmium sulfide nanoparticles: Biological effects and the importance of experimental design

Abstract

Effects of nanoparticles on aquatic organisms have been little studied to date and toxicological data are urgently needed for development of regulatory frameworks for these substances. Here, we report the findings of a study exposing sticklebacks to cadmium sulfide (CdS) as bulk material and quantum dots. Fish were exposed for 21 d in a flow through test system to 5, 50 or 500 microg l(-1) CdS nanoparticles (nCdS) coated in thiol terminated methyl polyethylene glycol (MPEG), bulk CdS or MPEG at 500 microg l(-1) (nominal concentrations). With the exception of the highest nCdS exposure, measured concentrations were approximately one order of magnitude below nominal. A single fish from each group (excluding MPEG) was examined using energy dispersive X-ray analysis (EDX) to localise cadmium, however, cadmium could not be detected in whole body sections. Elevated levels of oxidized glutathione were measured in the gills of fish exposed to 50 and 500 microg l(-1) nCdS. Induction of vitellogenin synthesis was not detected in any of the treatment groups. The number of males engaged in nest-building behaviour following exposure to 500 microg l(-1) nCdS was reduced and livers of 4/6 fish in the same treatment displayed hepatocellular nuclear pleomorphism. The results are discussed emphasising the fundamental importance of experimental design and the need to understand the behaviour of nanoparticles in the aqueous phase.

Cytotoxic effects and cellular oxidative mechanisms of metallic nanoparticles on renal tubular cells: impact of particle solubility

“…49 Release of Cd 2+ has been described to initiate lipid peroxidation and disrupt membrane composition, 50 and Li et al 19 have previously suspected intracellular ROS production, GSH depletion, and release of Cd 2+ ions as the main toxic mechanisms in CHL cells exposed to CdS NPs. Other studies using Cd NPs or QDs have also found similar results: ROS production, decrease in the GSH/GSSG ratio, 19,51 and cell viability, 52,53 associated with Cd 2+ release. Our results were also consistent with the effects of Zn 2+ described in the literature, i.e.…”

Tissue specific responses to cadmium-based quantum dots in the marine mussel Mytilus galloprovincialis

“…ROS generation and oxidative damages induced by Cd-based QDs were already reported at various trophic levels in the aquatic environment, e.g., in algae Chlamydomonas reinhardtii and Thalassiosira pseudonana (Domingos et al, 2011;Zhang et al, 2013), cnidarians Hydra vulgaris (Ambrosone et al, 2012), ragworms Hediste diversicolor (Buffet et al, 2014b), bivalve molluscs E. complanata, M. galloprovincialis and S. plana (Gagné et al, 2008a;Rocha et al, 2014;2015a;Buffet et al, 2015) and fishes Oncorhynchus mykiss and Gasterosteus aculeatus (Gagné et al, 2008b;Sanders et al, 2008), indicating that the MoA of Cd-based QDs is mainly mediated by ROS production and oxidative stress.…”

Innovations in nanotechnology for water treatment

“… 85 The livers of sticklebacks ( Gasterosteus aculeatus ) exposed to CdS quantum dots exhibited hepatocellular nuclear pleomorphism. 86 …”