Our laboratory investigates the environmental, health and safety impacts of nanotechnology in order to support the responsible development of this rapidly growing industry. Our current lack of information on the environmental fate and toxic potential of nanomaterials prohibits us from performing valid risk assessments. Issues of particle behavior, bioavailability and toxicity are central to quantitative risk assessment. Integrative studies in the Harper laboratory are designed to effectively improve our understanding of how and why nanomaterials interact with and sometimes alter living systems.
Comparative Ecotoxicology - Food web studies comprising 4-trophic microcosms of algae, daphnids, crayfish embryos and zebrafish embryos are being used to determine the bioavailability and biomagnification potential of nanoparticles in simulated aquatic ecosystems. Both acute and chronic exposures are being conducted to delineate the short and long-term dynamics and impact of nanoparticle-biological interactions in controlled aquatic environments.
Integrative Studies to Define Drivers of Nanomaterial Toxicity – This work addresses the hypothesis that uptake, effects and mechanism of toxicity are dependent on nanomaterial size, shape, and surface chemistry. The objective is to determine the relative influence that each of these parameters has on toxicity. We are currently determining the limits of data-derived nanomaterial structure-activity relationships (nano-SARs) for environmentally and occupationally relevant nanomaterials. The embryonic zebrafish model is being used to define dose-responses to a series of prioritized nanomaterial formulations. Uptake, biodistribution and time-course relationships are also being determined for the subset of the nanomaterials that elicit toxicity in embryonic zebrafish. The research goal is to identify inherent nanomaterial properties that confer toxicity.
Knowledgebase of Nanomaterial-Biological Interactions - The immediate need to gain comprehensive information on biological-nanomaterial interactions has led us to develop a comparative knowledgebase (i.e. knowledgebase of Nanomaterial-Biological Interactions, NBI, http://nbi.oregonstate.edu). NBI is intended to consolidate and integrate data of nanomaterial effects in experimental animal models (including humans) and evaluate biological effects from a variety of research platforms (i.e. in vivo and in vitro approaches). This effort will provide unbiased informatics approaches to identify the relative importance of characterization parameters on nanomaterial-biological interactions and to determine the capacity of biological assessment platforms to provide us with knowledge on the biological activity and toxic potential of nanomaterials.
Nanotechnology-enabled pesticides - Nanotechnology-based pesticides (NBP) are based on existing active ingredients, and possess internal functional features less than 100 nm that are purposely engineered to have different properties in the environment than the active ingredient. Nanoformulation of pesticides may not increase the toxicity of the active ingredient per se, but are likely to alter their environmental fate and thus exposure to off-target organisms. The overarching goal of the project is to reduce the uncertainty associated with NBP formulations in aquatic environments and communities through studies of NBP toxicity in zebrafish, crustaceans and other aquatic organisms.