Axon Guidance by Critical Cues - Engineering Nerve Growth In Vitro and Observing From Afar

通过关键线索进行轴突引导 - 体外工程神经生长和远距离观察

• 批准号: 1134166
• 负责人: Diane Hoffman-Kim
• 金额: $ 30万
• 依托单位: Brown University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-09-01 至 2015-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1134166&HistoricalAwards=false
• 关键词: Axon; Guidance; Critical; Cues; Engineering

1134166Hoffman-KimIntellectual Merit: Nerves fail to reconnect properly after injury and current medical practice is unable to successfully control the process of nerve regeneration. The proposed research seeks to attend to this problem by quantifying how guidance cues, both individually and in combination, promote axon growth. This knowledge is central to understanding nerve development and promoting nerve regeneration. The working hypothesis is that directed axon growth requires multiple cues, which must be well-defined and coordinated at the level of the local cellular environment. To test this hypothesis will necessitate the fabrication of new platforms upon which to study neuronal growth. These platforms will (1) deliver combinations of cues in a controllable and quantifiable manner; and (2) provide a means by which to test their hierarchical and cooperative interactions, specifically at the level of cellular traction forces. With interdisciplinary expertise in nerve development, regeneration, biomaterials, and microfabrication, the group has designed a set of such platforms, and has shown with preliminary data that they have the capability to deliver biochemical and topographical guidance cues to neurons. These platforms make possible innovative experiments that will test how combinations of cell-topographical and biochemical guidance cues promote neurite growth, and how neurites exert traction forces during growth. The objective is to correlate directed axon growth to specific quantities and ratios of cues, thus transforming the understanding of how the precise connections of the nervous system form as well as strategies to rewire these connections after injury.Investigations will determine which cellular topographical features encode critical guidance information to a navigating neuron, and subsequently, how topographical and biochemical guidance cues interact to influence neurite growth, testing on both cooperative and competitive platforms. Further, neuronal traction forces will be determined during nerve guidance by multiple cues. Neurite growth will be characterized on patterned materials with custom designed image analysis approaches, and time-lapse microscopy with phase contrast and laser scanning confocal optics. Conditions will be determined by which contact with topographical features limits the set of angles over which growing neurites can orient. The overarching goal is to develop methods by which axons can be guided following injury to the nervous system. The proposed multidisciplinary experiments quantify how growing axons respond to specific topographical and biochemical stimuli, and as such they will provide critical information with which to develop new conduits, scaffolds, and general biomaterial-based strategies to regenerate nerve tissue.Broader Impacts: This project will have multiple Broader Impacts. It will provide to the larger engineering and scientific communities, in particular the Biomedical Engineering, Neurobiology and Cell Biology communities, a set of versatile, tailorable platforms with which to test a wide variety of types of information of relevance to multiple cell and tissue types, including mechanical, topographical and biochemical cues. It will also generate new frameworks with which to conceptualize cell behaviors in the local cellular environment, where the environment can be deconstructed and reassembled to advance understanding. Through this project, the numbers of female undergraduate and graduate students involved in Biomedical Engineering research will be increased as the PI has a strong record of training female biomedical engineers. Further, this project includes an Outreach Program to enhance the exposure of middle school students in the Providence Public Schools to biomedical engineering research. There is an urgent need to improve middle school science performance, and this infusion of technology, engineering, and inquiry-based learning provides an ideal strategy to address this challenge. Video conferencing will allow large numbers of middle school students to interact in real time with experiments in otherwise inaccessible environments, following a series of curriculum-integrated classroom modules by trained graduate students as well as teacher-laboratory visits. This intensive program will augment the middle school science curriculum, train biomedical engineering students to explain science and engineering concepts to audiences with diverse backgrounds, provide teachers with internship opportunities, and inspire middle school students, at critical points in their education, to consider science and engineering careers.

1134166Hoffman-KimIntellectual Merit：神经损伤后不能正常连接，目前的医学实践无法成功控制神经再生过程。拟议的研究试图通过量化单个和组合的引导线索如何促进轴突生长来解决这个问题。这些知识对于理解神经发育和促进神经再生至关重要。工作假设是，定向轴突生长需要多种线索，这些线索必须在局部细胞环境水平上被明确定义和协调。为了验证这一假设，需要制造新的平台来研究神经元的生长。这些平台将(1)以可控和可量化的方式提供线索组合；(2)提供一种方法来测试它们的等级和合作相互作用，特别是在细胞牵引力的水平上。利用神经发育、再生、生物材料和微加工等跨学科的专业知识，该小组设计了一套这样的平台，并通过初步数据表明，它们有能力向神经元传递生化和地形引导线索。这些平台使创新实验成为可能，这些实验将测试细胞地形和生化引导线索的组合如何促进神经突生长，以及神经突在生长过程中如何施加牵引力。目标是将定向轴突的生长与特定数量和比例的线索联系起来，从而改变对神经系统的精确连接是如何形成的理解，以及在受伤后重新连接这些连接的策略。研究将确定哪些细胞地形特征对导航神经元的关键引导信息进行编码，随后，地形和生化引导线索如何相互作用以影响神经突生长，在合作和竞争平台上进行测试。此外，神经元牵引力将在神经引导过程中由多种线索决定。神经突的生长将通过定制设计的图像分析方法，以及采用相衬和激光扫描共聚焦光学的延时显微镜在图案材料上进行表征。条件将取决于与地形特征的接触限制了生长神经突可以定向的角度集。总体目标是发展神经系统损伤后轴突的引导方法。拟议的多学科实验量化了生长的轴突对特定地形和生化刺激的反应，因此，它们将为开发新的导管、支架和基于生物材料的一般神经组织再生策略提供关键信息。更广泛的影响：本项目将产生多重更广泛的影响。它将为更大的工程和科学社区，特别是生物医学工程、神经生物学和细胞生物学社区，提供一套通用的、可定制的平台，用于测试与多种细胞和组织类型相关的各种类型的信息，包括机械、地形和生化线索。它还将产生新的框架，用它来概念化局部细胞环境中的细胞行为，在那里环境可以被解构和重组，以促进理解。通过这个项目，参与生物医学工程研究的女性本科生和研究生的人数将会增加，因为PI在培养女性生物医学工程师方面有着良好的记录。此外，该项目还包括一个外展计划，以提高普罗维登斯公立学校中学生对生物医学工程研究的接触。我们迫切需要提高中学的科学成绩，而这种技术、工程和探究式学习的融合为解决这一挑战提供了理想的策略。视频会议将允许大量中学生在其他难以进入的环境中与实验进行实时互动，随后由训练有素的研究生进行一系列课程整合的课堂模块以及教师实验室访问。这个密集的课程将增加中学科学课程，训练生物医学工程专业的学生向不同背景的观众解释科学和工程概念，为教师提供实习机会，并激励处于教育关键阶段的中学生考虑科学和工程职业。