A Diagnostic Platform for Extracellular Vesicle-Derived Biomarkers - Towards Early Detection of Alzheimer's Disease

细胞外囊泡衍生生物标志物的诊断平台： 阿尔茨海默病的早期诊断 项目摘要。 阿尔茨海默病（AD）给我们的社会带来了越来越大的负担，预计病例将达到1270万 到2050年虽然研究支持早期检测的生物标志物，但大多数阿尔茨海默病患者都是在 在出现临床症状后。在这个阶段，老年斑的进展和 神经系统缠结对有效的干预提出了重大挑战。此外，建立 生物标志物如淀粉样蛋白β-42/淀粉样蛋白β-40和磷酸化tau目前仅限于 这使得他们几乎不可能进行常规筛查。因此， 迫切需要一种新的、非侵入性的方法来快速筛查临床前阿尔茨海默病， 早期干预的应用，如物理，药物和认知疗法。最近 工作已经证明了循环细胞外囊泡作为生物标志物的有希望的来源的潜力 监测和诊断各种疾病，包括AD。然而，可用的技术可以准确地 检测AD相关的细胞外囊泡及其成分目前还没有在临床实践中。 此外，血液中的浓度存在于低皮科至飞摩尔的范围内，限制了常规药物的使用。 通过ELISA和Western blot检测。本提案旨在满足这些关键需求，并侧重于 开发一个新的平台来检测神经元衍生的细胞外囊泡（NDEV）中的tau蛋白。我们假设 NDEV-tau的超灵敏检测（< 5 pg/mL）可以通过优化我们的表面增强 拉曼光谱（Sers）纳米标签技术使用合理的实验设计方法。如果我们的 假设是正确的，我们希望这项工作作为基础，发展一个即时保健设备 可用于症状前AD的常规筛查。为了实现这一目标，我们将重点关注 （1）合成对NDEV-tau具有高亲和性的“Sers纳米标签”，并鉴定NDEV-tau蛋白。 （2）使用Sers平台评估NDEV-tau敏感性和特异性 加入了人血清最终，我们希望建立检测限和所需的样品体积 用于精确的tau检测。通过设计用于NDEV-tau的超灵敏检测的SERS活性基底， 然后，我们可以建立在这个平台上，以增强几种AD相关生物标志物的多路复用， 复杂的生物样本我们的长期目标是发展基于SERS的生物分析， 在临床和研究环境中改进AD分子检测的当前标准。

A Diagnostic Platform for Extracellular Vesicle-Derived Biomarkers: Towards Early Detection of Alzheimer’s Disease PROJECT SUMMARY. Alzheimer’s disease (AD) poses a growing burden on our society, with cases expected to reach 12.7 million by 2050. While research supports biomarkers for early detection, most Alzheimer’s patients are diagnosed after exhibiting clinical symptoms. At this stage, the advanced progression of senile plaques and neurofibrillary tangles pose significant challenges to effective interventions. Moreover, established biomarkers, such as amyloid beta-42/amyloid beta-40 and phosphorylated tau, are currently limited to analysis in cerebrospinal fluid, making their potential for routine screening nearly impossible. Thus, there is a critical need for novel, non-invasive approaches to rapidly screen for preclinical Alzheimer’s to facilitate the application of early interventions, such as physical, pharmaceutical, and cognitive therapies. Recent work has demonstrated the potential of circulating extracellular vesicles as a promising source of biomarkers to monitor and diagnose various diseases, including AD. However, accessible technologies to accurately detect AD-associated extracellular vesicles and their constituents are not currently in clinical practice. Moreover, concentrations in blood are present in the low pico- to femtomolar range, limiting conventional detection by ELISA and Western blot. This proposal aims to address these critical needs and focuses on developing a new platform to detect tau in neuron-derived extracellular vesicles (NDEVs). We hypothesize that ultrasensitive detection (< 5 pg/mL) of NDEV-tau can be achieved by optimizing our surface-enhanced Raman spectroscopy (SERS) nanotag technology using a rational design-of-experiment approach. If our hypothesis is correct, we expect this work to serve as the foundation for developing a point-of-care device that can be used for routine screening of pre-symptomatic AD. With this goal in mind, we will focus on the following specific aims: (1) Synthesize ‘SERS nanotags’ with a high affinity for NDEV-tau and identify the characteristics for effective binding; (2) Assess NDEV-tau sensitivity and specificity using the SERS platform in spiked human serum. Ultimately, we expect to establish the limit of detection and sample volumes needed for accurate tau detection. By engineering SERS-active substrates for ultrasensitive detection of NDEV-tau, we can then build upon this platform to enhance the multiplexing of several AD-associated biomarkers in complex biological samples. Our long-term goal is to develop SERS-based bioanalysis to drastically improve current standards in molecular detection for AD in both clinical and research settings.