Elucidating Multiparametric Nanoparticle - Intestinal Membrane Interactions in an In Vitro Model System

纳米技术是一门科学和工程学科，它利用尺寸为几十亿分之一米的材料的尺寸依赖性来增强其光学，电学和化学特性。这一学科的基本组成部分，工程纳米材料，有望在消费品中找到广泛的用途，但它们有可能暴露于动物和人类。由于对纳米材料与生物体的相互作用了解不够，因此需要开发适当的分析方法，以帮助了解工程纳米材料与生物系统的相互作用，并确定潜在的风险。该提案的主要目标是实施一个实验模型，以提高目前对摄入的纳米材料如何与小肠相互作用的认识，并澄清一般纳米材料特性（如尺寸、形状和表面电荷）在这些相互作用中的作用。在这个项目中获得的知识最终将有助于最大限度地减少摄入纳米颗粒可能对健康造成的不利影响。 除了科学使命外，该项目还有明确的教育和外联内容。该项目构成了纳米技术领域至少一篇博士论文的基础。此外，还将举办讲习班和研讨会，向大学和高中学生以及感兴趣的教师介绍提案的主题。课程材料将通过万维网传播，教育公众了解消费品中的纳米技术，并为评估潜在的健康风险提供科学依据。纳米颗粒的超细尺寸与大的表面积与体积比相关，这可能导致与细胞系统的毒性相互作用。尽管人们普遍认为人类肠道细胞和工程纳米材料之间的相互作用取决于多种材料特性，但仍不清楚单个材料特性是否以及如何协同增强其细胞毒性效应。这项建议将在两个调查层次上解决这个重要问题。一个系统的筛选膜损伤和跨膜转运的扩展库的良好表征的金纳米粒子，将有可能相关的纳米粒子的形态，大小和表面电荷对肠膜的不利影响。在第二步中，新的成像方法，如等离子体耦合显微镜，将被应用于监测和成像纳米颗粒-细胞相互作用，细胞内纳米颗粒分布，和纳米颗粒跨膜运输。金纳米颗粒之间的电磁相互作用不仅可以跟踪肠膜中的单个纳米颗粒，还可以监测它们作为位置和时间的函数的更大单位的关联。这种信息内容的增益，当与传统的荧光显微镜相结合，将阐明纳米颗粒和肠膜之间的相互作用的机制，特征纳米颗粒的大小，形状和表面电荷的组合。总的来说，拟议的实验将提供定量基础，为开发精确的计算模型，以评估纳米颗粒对肠膜的影响。该奖项反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。

Nanotechnology is the science and engineering discipline that utilizes the size-dependent properties of materials with dimensions of a few billionths of a meter to enhance their optical, electrical and chemical properties. The elementary building blocks of this discipline, engineered nanomaterials, are poised to find broad use in consumer products, but they have a potential for exposure to animals and humans. Since the interactions of nanomaterials with living organisms are insufficiently understood, there is a need for the development of appropriate assays that help to understand the interactions of engineered nanomaterials with living systems and identify potential risks. The main goals of this proposal are to implement an experimental model that improves the current knowledge of how ingested nanomaterials interact with the small intestine and to clarify what role general nanomaterial properties, such as size, shape and surface charge have in these interactions. The knowledge obtained in this project will eventually help minimize the possible adverse health impacts of ingested nanoparticles. In addition to its scientific mission, the project also has clear education and outreach components. The project forms the basis for at least one PhD thesis in the area of nanotechnology. Furthermore, workshops and seminars will be developed that introduce college and high school students as well as interested teachers to the subject matter of the proposal. The course material will be disseminated through the world-wide-web and educate the public about nanotechnology in consumer products and provide a scientific basis for the evaluation of potential health risks. The ultrafine size of nanoparticles is associated with a large surface-to-volume ratio, which could lead to toxic interactions with cellular systems. Although it is accepted that interactions between human intestinal cells and engineered nanomaterials depend on multiple material properties, it is still not clear if and how individual material properties synergistically enhance their cytotoxic effects. This proposal will address this important question on two levels of investigation. A systematic screening of membrane damage and transmembrane transport for an extended library of well characterized gold nanoparticles, will make it possible to correlate nanoparticle morphology, size and surface charge with adverse effects on the intestinal membrane. In a second step, novel imaging methods, such as plasmon coupling microscopy, will be applied to monitor and image nanoparticle-cell interactions, intracellular nanoparticle distributions, and nanoparticle transmembrane transport. Electromagnetic interactions between the gold nanoparticles make it possible to not only track individual nanoparticles in the intestinal membrane, but also to monitor their association into larger units as function of location and time. This gain in information content, when combined with conventional fluorescence microscopy, will elucidate the mechanisms underlying the interactions between nanoparticles and the intestinal membrane for characteristic nanoparticle size, shape, and surface charge combinations. Overall, the proposed experiments will provide the quantitative foundation for developing accurate computational models for evaluating the effects of nanoparticles on intestinal membranes.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.