Environmental Implications of Engineered Nanomaterials on the Important Environmental Model Daphnia

0933720了解工程纳米材料对环境、健康和安全的影响对新兴纳米技术领域的发展至关重要。工程纳米材料正被提议用于从医学到环境清理的各种应用，这最终将导致它们直接或作为废物释放到环境中。随着许多污染物进入水环境，评估纳米颗粒释放对环境的影响，包括它们对水生态系统内物种的潜在影响，将变得越来越重要。许多监管组织正在努力确定如何评估与纳米材料相关的潜在环境影响，因为它们表现出与较大的同类材料不同的特性。到目前为止，研究的重点是细胞毒性，而不是整个生物体的研究，并且在任何一项研究中都包括有限类型的纳米材料，这导致很难建立关于纳米材料的性质如何影响与关键生物体相互作用的理论。PI的实验室发现，纳米材料的组成和表面化学对水生甲壳类动物的反应有影响。需要解决的问题包括：a)表面化学相似的纳米材料对水生生物是否有类似的影响，或者纳米材料核心的组成是否更重要？B)不同的纳米材料如何与水生生物的生理相互作用？在本实验中，将以水蚤为模型水生生物，从分子和生理反应方面对各种纳米材料对种群水平反应的影响进行实验研究。一般毒性实验、生理和行为分析将被用来确定接触几种不同化学成分的纳米材料的影响。暴露对分子生理学的影响将使用关键基因的定量聚合酶链式反应以及用于全球基因表达分析的微阵列进行。白纹伊蚊是生态学和毒理学的模式水生物种，现在是研究环境变化对基因组影响的公认模式物种。利用这种物种，纳米粒子实验的结果可以与已经为其他化合物开发的基因组和毒理学信息进行比较，并将利用该物种的可用资源。该项目的目标是以大型蚤为模式物种，确定纳米材料对水生生物有毒的特性。最终目标将是确定开发纳米材料以降低对水生无脊椎动物的毒性的方法。具体地说，他们将1)确定纳米颗粒化学结构和表面化学变化对水蚤一般毒性的影响，2)确定对生殖、生理和行为的潜在亚致死性影响，3)通过表征每次暴露的特定基因表达模式，确定纳米材料对水蚤的分子效应。这些分子数据将提供纳米材料改变水生无脊椎动物生理的机制。这里提出的项目将采取一种集中的方法来研究一类纳米材料(基于富勒烯碳结构的纳米材料)的结构和表面化学变化如何影响粒子与水生生态、毒理学和基因组模式物种Daphnia Pulex的相互作用。采用这种方法将有助于深入了解结构和表面化学如何在纳米材料-有机体相互作用中发挥作用，并将提供假说，用于测试具有不同核心结构的其他类型的粒子。最终的产品不仅是毒理学数据，而且是评估其他纳米材料的工具。此外，该项目将提供一种手段，以跨学科的方式培训学生，这是理解纳米技术对环境的影响所必需的。

0933720 KlaperAn understanding of the environmental, health, and safety implications of engineered nanomaterials is fundamental to the progression of the emerging field of nanotechnology. Engineered nanomaterials are being proposed for use for applications ranging from medicine to environmental cleanup, which will ultimately lead to their release into the environment, either directly or as waste. As many pollutants reach the aquatic environment it will become increasingly important to assess the environmental implications of nanoparticle release, including their potential impact on species within aquatic ecosystems. Many regulatory organizations are struggling to identify how to assess potential environmental impacts associated with nanomaterials as they exhibit properties that are distinct from their larger counterparts. Studies to date have focused on cellular toxicity rather than whole organism studies, and have included limited types of nanomaterials in any one study leading to difficulties in creating theories about how nanomaterial properties influence the interaction with key organisms. The PI's lab has found that nanomaterial composition and surface chemistry has an influence on the responses of the aquatic crustaceans in the genus Daphnia. Questions that need to be addressed include: A) Do nanomaterials with similar surface chemistry have similar impacts on aquatic organisms or is the composition of the core of the nanomaterial more important? B) How do different nanomaterials interact with the physiology of aquatic organisms? In this experiment, Daphnia pulex will be used as a model aquatic organism to conduct experiments on the impacts of various nanomaterials from molecular and physiological responses to population level responses. General toxicity experiments, physiological and behavioral assays will be used to determine the impact of exposure to several nanomaterials of differing chemical composition. Impacts of exposure on molecular physiology will be conducted using quantitative PCR of key genes as well as microarrays for global gene expression analysis. D. pulex is a model aquatic species for ecology and toxicology and is now a recognized model species for studies of the impact of environment changes on the genome. Using this species, results from nanoparticle experiments can be compared to genomic and toxicology information that has already been developed for other compounds and will take advantage of the resources available for this species.The objectives of this project are to determine the characteristics of nanomaterials that make them toxic to aquatic organisms, using Daphnia pulex as a model species. The ultimate goal will be to identify the ways in which nanomaterials may be developed to be less toxic to aquatic invertebrates. Specifically they will 1) determine the impact of changes in nanoparticle chemical structure and surface chemistry on the general toxicity to Daphnia pulex, 2) determine the potential sublethal impacts on reproduction, physiology, and behavior, and 3) determine the molecular effects of nanomaterials on Daphnia pulex by characterizing gene expression patterns specific to each exposure. This molecular data will provide an indication of the mechanism by which nanomaterials alter the physiology of aquatic invertebrates.The project proposed here will take a focused approach to examine how alterations in structure and surface chemistry of one class of nanomaterials (those based on fullerene carbon structures) will affect the interaction of a particle with the aquatic ecological, toxicological and genomic model species, Daphnia pulex. Taking this approach will provide insight into how structure and surface chemistry play a role in nanomaterial-organism interactions and will provide hypotheses with which to test with other types of particles with different core structures. The ultimate product will be not only toxicological data but a tool with which to evaluate other nanomaterials. In addition the project will provide a means to train students in an interdisciplinary manner that is requisite for understanding the environmental implications of nanotechnology.