Aquatic Toxicology of Carbon-based Nanoparticles
Stephen J. Klaine, Department of Biological Sciences, Graduate Program in Environmental Toxicology, Clemson University
30 Mar 2007
Advancements in the science of engineered nanoparticles (materials with at least one dimension < 100nm) have created a great deal of promise for their application in a wide variety of fields. Their potential uses in medicine, biology, and materials science have resulted in calls for proposals for research in nanoscience from the National Science Foundation (NSF), the National Institute of Health (NIH), the Environmental Protection Agency (EPA), and the Department of Defense (DoD). A National Research Council report on the National Nanotechnology Initiative gave generally positive reviews on advancements in nanotechnology, however, the report also noted that improvements were needed in determining the safety of these emerging technologies. Carbon-based nanomaterials are especially interesting because they can be functionalized to accommodate many applications. This study examined the interactions between Daphnia magna and a water-soluble, lysophophatidylcholine coated single-walled carbon nanotube. D. magna were able to ingest the nanotubes through normal feeding behavior and utilize the lysophophatidylcholine coating as a food source. D. magna were able to modify the solubility of the nanotube, likely through digestion of the lipid coating. This study provides evidence of biomodification of a carbon-based nanomaterial by an aquatic organism. The modification significantly altered the physical properties of the nanomaterial in freshwater. Acute toxicity was observed only in the highest test concentrations. These are important findings related to determining the behavior and potential toxicity of coated nanomaterials released into the environment.