While the industrial biotechnology sector is rushing full steam ahead to develop and commercialize new nanotechnology products, scientists working in areas of human and ecological toxicity are scrambling to keep up. Nanoparticle toxicity is a prominent topic at this year's SETAC NA conference, with several dedicated platform and poster sessions. The society is primarily concerned with environmental toxicology, rather than human, but the number of papers, and the variety of different types of nanoparticles and target organisms being investigated, is reassuring. I'm glad to see the potential dangers of nanoparticle toxicity are being taken seriously by industry and regulators alike. Here are some of the presentations I came across:
- Kovacs, T. et al. Ensuring the Environmental Compatibility of Manufactured Nanocrystalline Cellulose (NCC). NCC is being developed for the pulp and paper industry. Four aquatic species were tested to determine possible adverse effects of an accidental release. Both acute and subacute endpoints were measured and conclusions were that NCC is of low risk to the aquatic environment.
- Ahamed, M. et al. Silver Nanoparticles-Induced Heat Shock Protein 70, Oxidative Stress and Apoptosis in Drosophila melanogaster. Silver nanoparticles (Ag NP) are already in commercial use in many different forms. There were a number of presentations on their uptake, accumulation and toxicity. This paper reported the induction of a number of enzymes involved in apoptosis, DNA repair, reactive oxygen species scavenging and a number of other response mechanisms to cellular stressors. In another presentation (Shoults-Wilson, W. et al. The Influence of Particle Size, Concentration and Surface Functionalization on Bioavailability of Ag Nanoparticles in the Earthworm Eisenia fetida), earthworms were found to avoid soil containing Ag NP. Bioaccumulation of Ag NP was observed, and exposure resulted in a dose-dependant reduction in reproduction.
- Roh, J.Y. et al. Toxicological Investigation of Multi-Well Carbon Nanotubes in Caenorhabditis elegans Using Genomics and Proteomics Approach. The soil nematode was exposed to multi-well carbon nanotubes (MW-CNT) and toxicity investigated using endpoints such as mortality, growth and reproduction, in addition to whole genome microarray and proteomics methods. Although mortality was not significantly affected, reproductive potential was reduced after exposure to the MW-CNT. A number of genes were differentially expressed including those for heat-shock proteins, suggesting the organisms were under stress. Work from the same research team also reported for Ag NP, for which toxicity was measured using this organism and an ecotoxicogenomic approach (Park, YJ and Choi, J. A Toxicity Assay Using Stress Responsive Caenorhabditis elegans Mutant Strains).
- Kim, J. et al. Ultraviolet B Light Enhances Toxicity of CdSe/ZnSe Quantum Dots in Daphnia magna. The results of this study suggest that phototoxicity is mediated by both release of Cd from the quantum dot (QD), and production of reactive oxygen species on the QD surface.