Fate and Toxicity of metallic nanoparticles in aquatic organisms

大量的金属纳米材料正在被利用，但人们对这些材料对环境的影响知之甚少。初步数据表明，铜和银纳米颗粒对斑马鱼和水蚤有急性毒性。拟进行的研究将探讨金属纳米颗粒在不同营养水平下的生物学命运和毒性。总的假设是，接触金属纳米粒子将导致不同于可溶性形式的金属的生物积累和营养转移。此外，长期接触纳米金属可能产生的毒性在质量和数量上都不同于可溶性金属。为了解决这些假设，提出了3个具体目标：1)确定金属纳米颗粒暴露在水生生物中的金属生物积累和营养转移速率；2)确定长期接触铜、银和钛纳米材料对斑马鱼和水蚤的影响；3)确定颗粒介导的活性氧生成在鳃毒性中的作用。为了实现这些目标，斑马鱼（Danio rerio）将暴露于铜、银、镍或二氧化钛的水溶液或纳米颗粒悬浮液中。将确定每种形式的管尾尾绦虫、小头尾绦虫、斑尾尾绦虫和斑马鱼对金属的吸收和分布。然后，我们将确定从生产者到初级消费者和从初级消费者到次级消费者的营养转移。标准方案将用于检查这些颗粒在斑马鱼成年和早期生命阶段以及水蚤生命周期分析中的长期毒性。这些研究将确定死亡率、胚胎和幼虫存活和繁殖的阈值。他们还将通过检查毒性的组织学、生化和分子标记来确定毒性的靶组织。通过比较这些标记物，可以确定纳米颗粒是否产生与同一金属的可溶性形式不同的毒性。最后，金属纳米颗粒产生反应物质的能力将被检验，氧化应激在鳃毒性中的重要性将被确定。智力优势：提议的研究代表了毒理学家、工程师和水生病理学家的跨学科合作，他们带来了独特的经验、设施和资源组合，以承担纳米技术对环境影响的研究。这些研究将确定金属纳米颗粒是否在营养水平上积累和转移。将确定水生生物长期暴露于铜、银和二氧化钛纳米粒子的影响，并确定其毒性的适当标记。数据将被开发，旨在了解粒子介导的自由基生产是如何参与毒性。这些实验将评估用于纳米颗粒的几种标准水生毒性试验的性能，并确定它们是否适合用于这一目的。更广泛的影响：本研究将为粒子科学和生物学交叉领域的博士后研究人员提供研究培训。该项目的调查人员是SEAGEP计划的参与者，这将为代表性不足的少数民族提供研究机会。此外，研究人员计划与其他国家纳米技术资源合作，如亚利桑那州立大学的社会纳米技术中心和莱斯大学的ICON，向科学界和教育界以及整个社会传播研究成果。研究人员还将与佛罗里达大学的格雷厄姆公共政策中心合作，确保将研究成果转化为政策制定者。

CBET-0834075BarberSubstantial amounts of metallic nanomaterials are being utilized yet there is little knowledge about the effects of these materials in the environment. Preliminary data indicates that copper and silver nanoparticles are acutely toxic in zebrafish and daphnia. The proposed studies will investigate the biological fate and toxicity of metallic nanoparticles in various trophic levels. The overall hypothesis is that exposure to metallic nanoparticles will result in bioaccumulation and trophic transfer different than soluble forms of the metal. Moreover, long-term exposure to nanometallics may produce toxicity that is qualitatively and quantitatively different than soluble metals. To address these hypotheses, 3 specific aims are proposed: 1) To determine metal bioaccumulation and trophic transfer rates in aquatic organisms exposed to metallic nanoparticles; 2) To determine effects of long-term exposure to copper, silver and titania nanomaterials on zebrafish and daphnia; and 3) To determine the role of particle mediated reactive oxygen generation in gill toxicity. To address these aims, zebrafish (Danio rerio) will be exposed to copper, silver, nickel or titanium dioxide as aqueous solutions or nanoparticle suspensions. The uptake and distribution of metal will be determined for each form in T. tubifex, P. subcapitata, D. pulex, and zebrafish. We will then determine trophic transfer from producer to primary consumer and from primary consumer to secondary consumer. Standard protocols will be utilized to examine long-term toxicity of these particles in zebrafish as adults and at early life stages as well as in daphnia life-cycle assays. These studies will identify threshold values for mortality, embryonic and larval survival and reproduction. They will also determine target tissues for toxicity by examining histological, biochemical and molecular markers of toxicity. Comparison of these markers will allow determination of if nanoparticles produce toxicity that differs from soluble forms of the same metal. Finally, the ability of metallic nanoparticles to produce reactive species will be examined the importance of oxidative stress in gill toxicity will be determined. Intellectual Merit: The proposed studies represent an interdisciplinary collaboration of toxicologists, engineers, and aquatic pathologists who bring a unique combination of experience, facilities, and resources to bear on the study of environmental impact of nanotechnology. These studies will determine whether metallic nanoparticles are accumulated and transferred across trophic levels. The effects of long term exposure to copper, silver and titania nanoparticles in aquatic organisms will be identified as well as appropriate markers for their toxicity. Data will be developed that seeks to understand how particle mediated radical production is involved in toxicity. The experiments will evaluate the performance of several standard aquatic toxicity tests for use with nanoparticles and determine their suitability for this purpose. Broader Impacts: This research will provide research training for post-doctoral researchers at the interface of particle science and biology. Investigators on this project are participants in the SEAGEP program and this will be leveraged to provide research opportunities for underrepresented minorities. In addition, the investigators plan to collaborate with other national resources in nanotechnology such as Center for Nanotechnology in Society at Arizona State University and ICON at Rice to disseminate research results to the scientific and educational communities and to society at large. Researchers will also work with the Graham Center for Public Policy at the University of Florida to ensure that research findings are translated to policy makers.