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特性来增强它们的光学、电学和化学性质。这一学科的基本组成部分--工程纳米材料--有望在消费产品中得到广泛应用，但它们有可能接触到动物和人类。由于对纳米材料与活体的相互作用了解不足，因此有必要开发适当的分析方法，以帮助理解工程纳米材料与活体系统的相互作用，并识别潜在的风险。这项建议的主要目标是实施一个实验模型，改善目前关于摄入的纳米材料如何与小肠相互作用的知识，并澄清一般纳米材料的性质，如尺寸、形状和表面电荷在这些相互作用中起什么作用。在该项目中获得的知识最终将有助于将摄入的纳米颗粒可能对健康造成的不利影响降至最低。除了其科学使命外，该项目还包括明确的教育和宣传部分。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，向大学生和高中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，教育公众有关消费产品中的纳米技术，并为评估潜在的健康风险提供科学依据。纳米粒子的超细尺寸与较大的表面积与体积比有关，这可能会导致与细胞系统的有毒相互作用。虽然人们已经接受了人类肠道细胞与工程纳米材料之间的相互作用取决于多种材料性质，但目前仍不清楚单独的材料性质是否以及如何协同增强其细胞毒作用。这项提案将在两个调查层面上解决这一重要问题。对具有良好特性的金纳米颗粒的扩展文库进行膜损伤和跨膜转运的系统筛选，将使纳米颗粒的形态、大小和表面电荷与对肠膜的不良影响相关。在第二步，新的成像方法，如等离子耦合显微镜，将被应用于监测和成像纳米颗粒-细胞相互作用，纳米颗粒在细胞内的分布，以及纳米颗粒的跨膜运输。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，还可以监测它们随着位置和时间的变化而进入更大单位的情况。这种信息含量的增加，当与传统的荧光显微镜相结合时，将阐明纳米颗粒与肠膜之间的相互作用机制，从而获得具有特征的纳米颗粒大小、形状和表面电荷组合。总体而言，拟议的实验将为开发准确的计算模型来评估纳米粒子对肠道膜的影响提供量化基础。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

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.