Development Of A Drosophila Melanogaster Model System For Nanoparticle Toxicity Assessment

Nanoparticles (NPs) are a growing facet of our industrial, medical and environmental economy. Toxicity research has focused on acute exposures both in vitro and in vivo. Few in vivo studies on chronic lifetime effects of NP exposure are available. Drosophila melanogaster provides a powerful model for investigating human health and nanotoxicity. Counterparts of genes responsible for more than 700 different human genetic diseases, including neurological, immunological, cardiovascular, auditory, visual, developmental and metabolic disorders, are found in Drosophila (Koh et al. 2006; Wolf et al. 2006; Rieter et al. 2001, Sykiotis and Bohmann 2008). The cost effectiveness, experimental flexibility, and short generation time of Drosophila permit rapid assessment of the vast number of NPs being produced, including chronic and reproductive effects, thus providing a first tier assessment. We have developed an in vivo chronic nanotoxicity model using Drosophila melanogaster. The effects of different nanoparticles (silver and titanium) exposure on Drosophila reproduction, development, and survivorship, were assessed based on different sizes, and coatings. We've found that chronic exposure to silver NPs via ingestion has toxic effects on fly viability and reproductive effort. Conversely, titanium oxide has no effect on fly life history, and serves to verify the ability of our model to discriminate among nanoparticle toxicity. We also demonstrate the reversal of NP silver toxicity through diet supplementation with vitamin C. By including vitamin C in NP treated fly food, the flies were protected from the toxic life history effects of nanosilver ingestion. This corroborates previous results that implicate oxidative stress as the primary contributor to silver toxicity and provides a potential antioxidant-based strategy for the development of prophylactics to NP exposure.