Characterization of the Potential Toxicity of Metal Nanoparticles in Marine Ecosystems Using OystersEPA Grant Number: R833337
Title: Characterization of the Potential Toxicity of Metal Nanoparticles in Marine Ecosystems Using Oysters
Investigators: Ringwood, Amy Huffman , Carroll, David Loren
Institution: University of North Carolina at Charlotte , Wake Forest University
EPA Project Officer: Carleton, James N
Project Period: April 5, 2007 through April 4, 2010
Project Amount: $399,843
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: Health Effects , Nanotechnology , Health , Safer Chemicals
This research plan is designed to address a number of important issues regarding metal nanoparticle toxicity in marine organisms, e.g. morphological changes of metal nanoparticles in seawater, adverse effects on fundamental cellular responses related to lysosomal integrity, mitochondrial function, effects on antioxidants and oxidative damage, relative sensitivity of different life history stages, and cellular and tissue accumulation patterns.
(1) Characterize the effects of salinity and UV radiation on metal nanoparticle morphology, aggregation, and agglomeration using spectral fluorescence analysis and high resolution microscopy techniques; (2) Conduct cellular toxicity studies with isolated hepatopancreas cells to characterize the toxicity of various metal nanoparticle preparations, based on cell viability, lysosomal integrity, mitochondrial function,and lipid peroxidation damage; (3) Conduct bioaccumulation and toxicity studies with embryos and larvae to compare the responses of different life history stages and isolated cell preparations; (4) Expose young adult oysters to nanomaterials to characterize the bioaccumulation and toxicity of various nanoparticle preparations; (5) Characterize intracellular localization and morphology of nanoparticles using fluorescent confocal microscopy and electron microscopy techniques. These results of these studies will be used to evaluate the following overall hypotheses: H1: Metal nanoparticle morphology and size are important determinants of toxicity. H2: Embryonic and larval stages are more sensitive than adult forms. H3: Oxidative damage is a common mechanism of cellular toxicity.
A variety of toxicity assays will be conducted with oysters to characterize the toxicity and bioaccumulation of metal nanoparticles. Different sizes and morphologies (spheres, rods, crystals) as well as metal concentrations will be evaluated to identify important determinants of toxicity. Confocal and high resolution microscopy will be used to characterize the cellular localization of the particles as well as their structure in cells. These microscopic techniques and spectral analyses will be used to determine how their structure may be affected by common environmental variables (e.g. salinity and UV radiation); and the potential for exacerbation of toxicity in the presence of UV radiation will be examined.
Important concepts regarding changes in particle morphology in seawater, the significance of morphology to toxicity, and relative sensitivities of different life history stages will be elucidated. An important goal of this work is to generate a significant database using a battery of tools to assess the potential toxicity and impacts of metal nanoparticles on marine ecosystems that are essential for identifying risks. While the primary focus of these studies is on aquatic organisms and environmental issues, these studies will also provide valuable information regarding fundamental cellular responses relevant to humans as well as wildlife.