PI: Poynton, Helen / Unrine, Jason Proposal Number: 1437409/ 1437451
The study of nanoparticle (NP) aging and aging conditions is an important part of NP nanotoxicology research. One essential aspect is to be able to differentiate between possible intrinsic toxicity of NPs from the toxicity of their soluble ions. The investigators propose an interdisciplinary approach that combines isotope tracing with NP aging, RNA sequencing technology, and dynamic modeling to study mechanisms of nanoparticle bioavailability in sediment water. The isotopic tracing will use stable isotope tracer techniques, which will enable the investigators to better identify whether the toxicity is due to the NPs themselves or to dissolved Zn ions. The study of nanoparticle aging and aging conditions is an important aspect in nanotoxicology research, as is the ability to differentiate between the effect of the nanoparticles and their soluble ions, which is critical in understanding the fate and transport of these particles in the environment. The PIs have a record of strong commitment to outreach and education of students and will continue their activities, such as making a permanent exhibition of NP interactions with the environment and the human body at the Kentucky Science Center, in Louisville, KY.
This proposal aims to characterize NP partitioning between the water column and sediments, to describe how particle aging influences these processes, and to understand the consequences of this partitioning for sediment dwelling organisms. Specifically, the PI will investigate ZnO nanoparticles and their interaction with sediments, addressing several key parameters in understanding long term NP effects in the environment. Differentiation between the effect of the nanoparticles and their soluble ions is critical in understanding the fate and transport of these particles in the environment. They lay out several hypotheses to test, e.g., that decreasing NP solubility will result in decreased uptake of Zn++ by _Hyalella Azteca_ , a species of amphipod crustacean and that NP uptake will occur primarily at the sediment surface, while Zn++ ion uptake will occur primarily through water column exposure. The investigators call this approach Environmental Transformation, Exposure from Sediments, and Toxicity (E-TEST). These studies and approach will introduce new techniques in an integrated way for nanoparticle assessment. The experiments are well thought-out and it is likely that excellent information will come from the study. This is an excellent collaboration between two investigators that approach the problem from different perspectives.
