#1508931<br/>Lead, Jamie<br/><br/>Nanoparticles may be an important environmental contaminant because their use leads to discharge into the environment and many of them have been shown to be toxic. In order to be toxic, nanoparticles must enter an organism such as a bacterium or a fish. This "bioavailability" is governed by the uptake from the environment, loss from the organism and other processes. However, it is not known if these processes occur directly with the particle or if the particle dissolves to give ions and the ions are taken into an organism. This project will develop new nanoparticles which can distinguish directly between ion and nanoparticle bioavailability processes; once developed the nanoparticles will be used on environmental organisms such as shellfish to answer the question: is nanoparticle bioavailability controlled by particle or ion uptake? The outcome will be a better understanding of nano-bioavailability as a precursor to nanotoxicity.<br/><br/>This proposal will help to understand the mechanisms of bioavailability and bioaccumulation, as a precursor to toxicity; in particular, experimental and modelling studies will allow definitive answers to be generated on the question: is nanoparticle bioavailability controlled by particle specific uptake (and loss) or by ion uptake after dissolution. In addition, a set of tools will be produced, which will be disseminated to the research community, which will enable these questions of fundamental biological processes and hazard levels to be answered more broadly for a range or organisms and conditions. The proposed research will develop a library of novel particles, which are three layer core-shell materials, isotopically labelled with different stable isotopes in the core and outer shell, separated by an insoluble central layer. The tightly constrained and fully characterized nanoparticles will then be used as probes to perform scoping studies on model organisms to answer fundamental questions related particle or ion bioaccumulation. The relative importance of the ion and particle in biouptake and elimination mechanisms, in food and aquatic exposures and the importance of solution chemistry will also be investigated.<br/><br/>The developed nanoparticle (patent pending) and the study of toxicity feed directly into the development of a safe and sustainable industry, which will be of general societal benefit. Two doctoral students will be trained in interdisciplinary areas involving synthetic chemistry, metrology and toxicology. The students will be given experience in both academic and government laboratories. The outputs of the project will be incorporated into teaching performed at the Center for Environmental Nanoscience and Risk (CENR) and the students will help in this as a training exercise. The CENR employs a postdoctoral fellow to specifically aid in outreach and we will pursue specific dissemination measures to reach the public and the student body and inform them of the projects scientific and technological advances.