Size distribution effects of cadmium tellurium quantum dots (CdS/CdTe) immunotoxicity on aquatic organisms

• Published in: Environmental science--processes & impacts 2013-01, Vol.15 (3), p.596-67
• Main Authors: Bruneau, A, Fortier, M, Gagne, F, Gagnon, C, Turcotte, P, Tayabali, A, Davis, T. L, Auffret, M, Fournier, M
• Format: Article
• Language: English
• Subjects: Animals; Bivalvia - drug effects; Bivalvia - physiology; Cadmium Compounds - chemistry; Cadmium Compounds - immunology; Cadmium Compounds - toxicity; Cell Survival - drug effects; Elliptio; Elliptio complanata; Hemocytes - cytology; Hemocytes - drug effects; Macrophages - cytology; Macrophages - drug effects; Mytilus; Oncorhynchus; Oncorhynchus mykiss; Oncorhynchus mykiss - physiology; Particle Size; Phagocytosis - drug effects; Quantum Dots; Sulfides - chemistry; Sulfides - immunology; Sulfides - toxicity; Tellurium - chemistry; Tellurium - immunology; Tellurium - toxicity
• ISSN: 2050-7887; 2050-7895
• DOI: 10.1039/c2em30896g

The increasing use of products derived from nanotechnology has raised concern about their potential toxicity to aquatic life. This study sought to examine the comparative immunotoxicity of capped cadmium sulphide/cadmium telluride (CdS/CdTe) quantum dots (QDs) and possible impact of particle/aggregate size on two bivalves ( Mytilus edulis and Elliptio complanata ) and a fish ( Oncorhynchus mykiss ). The QDs were dispersed in sterile water and fractionated using a series of micro/ultrafiltration membranes of decreasing pore size: 450 nm, 100 nm, 50 nm, 25 nm, 100 kDa (6.8 nm), 30 kDa (4.6 nm), 10 kDa (3.2 nm) and 1 kDa (1.5 nm). The total concentrations of cadmium and tellurium were determined for the filtered material and for that retained on the filters (retentate). The immunotoxicity was determined by measuring cell viability and phagocytosis. Results revealed that nanoparticles retained on the ultrafilters had a higher Cd/Te ratio compared to the permeate fraction (ratio of 5 and 2 respectively) which could indicate that the CdS core was not associated with the permeable fraction of Cd. Our results demonstrate that the toxicity of CdS/CdTe QDs was concentration and size dependent. Large CdS/CdTe QD aggregates (25 nm < size < 100 nm) reduced phagocytosis more than did smaller nanoparticles (