Nanoparticle Toxicity in ZebrafishEPA Grant Number: R833339
Title: Nanoparticle Toxicity in Zebrafish
Investigators: Mayer, Gregory D. , Nadeau, Jay L. , Nohe, Anja , Smorodin, V.
Institution: University of Maine , McGill University
EPA Project Officer: Lasat, Mitch
Project Period: October 1, 2006 through September 30, 2009
Project Amount: $398,298
RFA: Exploratory Research: Nanotechnology Research Grants Investigating Environmental and Human Health Effects of Manufactured Nanomaterials: a Joint Research Solicitation-EPA, NSF, NIOSH, NIEHS (2006) RFA Text | Recipients Lists
Research Category: Nanotechnology , Health Effects , Health , Safer Chemicals
The overlying objective of this proposed research is to investigate the toxicity of semiconductor nanostructures using an in vivo developmental system (zebrafish, Danio rerio, embryos). Our approach will monitor, in real time, the effects of particle composition, size, and charge on uptake and accumulation of nanostructures in multiple tissues. Additionally, we will monitor the release of ions from the particles using a transgenic zebrafish model that expresses green fluorescent protein (GFP) in the presence of metal ions. We will correlate these data to altered embryo development after particle exposure and extrapolate the effects to human health. Finally, we will develop a model to predict particle toxicity that will help to evaluate potential health risks of the release of semiconductor nanoparticles into the environment.
To effectively determine how particle composition, size, and charge affect toxicity, we must first begin by refining techniques of synthesis and characterization in order to be able to alter one variable at a time. These well-characterized particles will then be applied to cultured zebrafish, zebrafish embryos or embryonic cells. Uptake, accumulation and ion release in cells and whole embryos will be quantitatively measured in real time by multi-color confocal microscopy that will simultaneously detect the nanoparticles, GFP, and co-transfected fluorescent organelle markers. Additionally, we will investigate the force of adhesion of the range of particles to cell membranes and the embryo using laser tweezers. All obtained data will be used to develop a model for the prediction of cellular uptake and resulting cellular toxicity based upon the physical properties of the particles and the cell membranes which they encounter.
We expect the toxicity of semiconductor nanoparticles to depend upon their size, charge, and composition. However, because of the unique properties that arise from their small size and quantum confinement, the exact dependence of toxicity upon each of these factors is likely to be surprising and to be poorly predictable from the behavior of the bulk materials. It is also expected that the nanoparticles will increase mortality and developmental abnormalities in zebrafish. Calculation of LC50’s, hatch success, uptake routes, and acute and developmental toxicity endpoints will help validate our proposed model. The resulting data are expected to be of value for prediction of risks of nanoparticle release, especially into aqueous environments where the particles would have direct access to developing and adult organisms.