As engineered nanomaterials (ENM) become more common in consumer products, it is crucial to rapidly assess toxicity of unique ENM. Previous studies rarely focused on standardizing nanotoxicity testing, leading to inconsistent and irreproducible results. This study characterized a variety of ENM of different size, shape, core type, and surface charge using a standardized characterization method. Eight ENM were characterized in collaboration with the National Institute for Health Research (NIHR) Consortium, which consists of a number of laboratories using different models. The NIHR Consortium was founded to evaluate the toxicity of ENM generated by Harvard University. Following characterization, ENM were evaluated for developmental toxicity using the high throughput zebrafish model to examine behavioral and morphological abnormalities. An embryonic photomotor response (EPR) assay evaluated early behavioral effects at 24 hours post fertilization (hpf). Examination of larval zebrafish behavior occurred after 120hpf using larval photomotor response (LPR) and morphological screening of 22 endpoints. From these screenings, it was found that silver on silica nanocomposites exhibited elevated early life stage toxicity. In order to evaluate low level exposure effects of a silver on silica 4% w/w nanocomposite, fish were exposed to a low concentration (0.107ppm) and raised to adulthood. A zebrafish Visual Imaging System (zVIS) measured adult fear, social, and startle behavior. Adult fish that were exposed silver on silica 4% w/w nanocomposite as embryos exhibited a heightened fearful response to a predator as adults. These exposed adults exhibited antisocial behavior, and initial elevated startle response to the tap assay.
Keywords: nanomaterials, silver on silica nanocomposites, toxicity, zebrafish, behavior