Monitoring the Effects of Nanoparticles on Human Health Using an Inexpensive Fathead Minnow Microarray

The use of nanoparticles has increased in manufacturing, industry, and commercial products over the past two decades. As a result, governmental agencies, industry, and academia worldwide have formed advisory groups to evaluate exposure and toxicity issues surrounding the potential adverse effects of nanomaterials on human health. However, assessing the potential effects of nanoparticles on human health is not an easy task, as the properties of nanoparticles depend not only on the size of the particle, but also on the structure, microstructure, and surface properties (coating) (Moore 2006, Yin, et al. 2005, Burleson, et al. 2004). Invariably, industrial products and wastes, including some aerosols, tend to end up in waterways despite safeguards; it is inevitable that nanoscale products and by-products will also enter aquatic environments as nanotechnology industries scale up production (Moore 2006, Borm, et al. 2006). Thus, the uptake of nanoparticles into the aquatic biota is a major concern. Potential routes include direct ingestion or entry across epithelial boundaries such as gills, olfactory organs, or body walls; or through phagocytosis or endocytosis (Moore 2006). These processes are integral to key physiological functions such as cellular immunity and intracellular digestion. Only recently have concerns regarding the release of nanomaterials into the environment and their potential effects on fish and wildlife begun to be addressed through toxicological testing. Concerns about environmental contaminants that adversely affect health, development, and reproduction of exposed wildlife have lead to the development of specific in vitro and in vivo assays to test for these effects. Gene microarrays integrate in vivo exposures with mechanistic outcomes. Using this technology, thousands of genes can be tested at one time with mRNAs isolated from tissues of exposed animals. These tools show potential for providing more precise, quantifiable data than existing assays, and are now affordable. The overall goals of this Phase I grant are to employ microarrays to identify genes that fluctuate in fathead minnows after acute exposure to nanotubes. The data will be analyzed to determine what, if any, pathways are affected in the fathead minnow. This information should enable EcoArray to identify genetic fingerprints and to use the database as a tool for identifying contaminants in unknown situations (class prediction), which may lead to an interpretation of human health issues. The research undertaken in the Phase I study of nanotubes should help validate the expediency and affordability of the high density fathead minnow microarrays for compound screening and use in environmental toxicology.