Excellence in Research: Stimuli-Responsive Exosomes for Quantitative Biosensing

外泌体是一类脂质结合的纳米大小的囊泡（由膜形成并充满液体的小囊泡），由体内大多数细胞产生。由于其包装和释放的性质，这些囊泡可以包含具有其起源细胞特征的分子。这意味着外泌体可以携带各种疾病状态的生物标志物，包括癌症和阿尔茨海默病。然而，目前分离和纯化外泌体的方法既昂贵又无效。开发控制外泌体内容物释放的新方法对于设计更好的诊断测试至关重要。该项目将研究一套新的知识和开发工具，通过应用热量来控制外泌体的行为。参加这项多学科研究的学生将得到指导和培训，通过暑期研究经历、会议和动手实验室经验，为他们在STEM领域的成功职业生涯做好准备。这个历史悠久的黑人大学卓越研究（HBCU-EiR）项目的目标是开发和研究工程热敏脂质体在生物传感和下游诊断应用中的应用潜力。这将解决该领域的一个关键挑战，即在混合样本中对特定的外泌体种群施加选择性控制。更具体地说，能够以可靠和高度控制的方式引导外泌体子集从捕获底物中释放，并释放其囊泡内货物，可以取代繁琐的纯化和分离方案，并拓宽集成生物传感器的技术工具箱。受最近工程刺激反应脂质体成功的启发，研究人员提出了外泌体研究领域的新范式。研究旨在验证外泌体在暴露于外部刺激（例如温度）时可以优化以表现出可控行为（例如释放货物）的假设。最终，该项目旨在定义在两种不同情况下实现差异释放的标准(1)2D捕获底物的释放和(2)外泌体内内容物（或目标分析物）的释放。这将通过以下目标来实现：(1)确定细胞衍生模型外泌体的成分差异是否可用于激发刺激反应行为；(2)通过选择性表面修饰来设计热响应性外泌体，并验证其生物传感应用的潜力。这些结果有望通过引入一种新的机制来选择性地控制外泌体和其他细胞外囊泡的行为，从而推进和改变在许多情况下如何操纵外泌体和其他细胞外囊泡。这项工作的相关性还在于有可能定义和测试其他刺激响应技术的概念验证标准，包括光、酶和声学。这将为推进外泌体结合靶标的量化、监测和检测以及与生物传感社区高度相关的能力开辟途径。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Exosomes are a category of lipid-bound, nanosized vesicles ( small sacs formed by a membrane and filled with liquid) produced by most cells in the body. Due to the nature of their packaging and release, these vesicles can contain molecules that are characteristic of their cells of origin. This means that exosomes can carry biomarkers for various disease states, including cancer and Alzheimer’s disease. However, current methods for isolating and purifying exosomes are costly and often ineffective. Developing new ways to control the release of exosome contents is essential to engineer better diagnostic tests. This project will investigate a new set of knowledge and develop tools to control the behavior of exosomes through the application of heat. Students participating in this multidisciplinary research will be mentored and trained to prepare them for a successful career in STEM through summer research experiences, conferences, and hands-on lab experiences. The goal of this Historically Black Colleges and Universities - Excellence in Research (HBCU-EiR) project is to develop and investigate the potential for engineering thermo-sensitive liposomes for applications in biosensing and downstream diagnostic applications. This will address a critical challenge in the field, which is to exert selective control over specific exosome populations within a mixed sample. More specifically, the ability to direct the release of a subset of exosomes from a capture substrate and to discharge their intra-vesicular cargo in a reliable and highly controlled manner could replace burdensome purification and isolation protocols and broaden the technological toolbox for integrated biosensors. Inspired by recent success in engineering stimuli-responsive liposomes, the investigators propose a new paradigm in the field of exosome research. Studies are designed to test the hypothesis that exosomes can be optimized to exhibit controllable behavior (e.g., release cargo) when exposed to an external stimulus (e.g., temperature). Ultimately, the project aims to define the criteria for achieving differential release in two distinct scenarios (1) from release of a 2D captured substrate and (2) from release of intra-exosomal contents (or target analytes). This will be accomplished via the following objectives: (1) Determine whether compositional differences in cell-derived model exosomes can be used to incite stimuli-responsive behavior; and (2) Engineer thermo-responsive exosomes by selective surface modification and validate their potential for biosensing applications. These outcomes are expected to advance and transform how exosomes and other extracellular vesicles are manipulated in many settings by introducing a new mechanism to control their behavior selectively. The relevance of this work additionally lies in the potential to define and test proof-of-concept criteria for other stimuli-responsive technologies, including light, enzymes, and acoustics. This will open pathways for opportunities to advance the quantification, monitoring, and detection of any targets bound in exosomes and capabilities with high relevance to the biosensing community.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.