Highly Sensitive and Robust Blood Test Platform for Screening and Early Detection of Alzheimer's Disease

由于有效的治疗方法尚未开发，早期发现和监测阿尔茨海默病（AD）和阿尔茨海默病相关痴呆（ADRD）的疾病进展对于AD/ADRD的管理和干预至关重要。FDA最近加速批准了针对淀粉样蛋白-β的新型单克隆抗体药物Aducanumab®，该药物在治疗适当分层的患者时可能更有效，这突出了对AD的早期和生物标志物特异性诊断的迫切临床需求。由于成像设施或用于CSF收集的侵入性腰椎穿刺的可用性和可及性有限，目前AD生物标志物靶向正电子发射断层扫描（PET）成像和基于脑脊液（CSF）样本的蛋白质组学分析的临床实践不是早期检测的理想床旁（POC）解决方案。鉴于非侵入性、成本效益和在一般临床环境中容易获得的优点，基于血液的AD生物标志物检测是更适用于AD/ADRD早期诊断的POC诊断工具。虽然两个平台，即，用于Aβ40/Aβ42检测的PrecivityADTM和用于磷酸化tau 181（p-tau 181）检测的Simoa®最近被FDA授予临床应用突破性设备称号，这两种系统都需要高度专业化的高端仪器进行样本检测，限制了它们的广泛可用性，特别是在资源较少或有限以及健康差异的社区和地区。此外，PrecivityADTM和Simoa®使用抗体包被的磁珠来捕获靶向AD生物标志物。然而，血清蛋白在珠粒表面上的非特异性吸附形成蛋白质冠，其可以阻止抗体捕获生物标志物。在这个SBIR I期项目中，我们的目标是开发一个多路AD生物标志物检测平台，该平台可以集成两种创新技术，即，超磁性氧化铁纳米棒（IONR）和IONR的抗生物污染聚合物涂层，用于在血液样品中多路复用六种AD生物标志物。IONR可提供与PrecivityADTM和Simoa®中使用的磁珠一样强的磁性，还可用作纳米搅拌棒，在交变电磁场下改善样品混合，从而更有效地捕获生物标志物。抗生物污染涂层使IONR上的非特异性血清蛋白吸附最小化，以保持抗体对血液样品中靶向生物标志物的亲和力。第一阶段项目将集中于（1）开发一种原型设备，该设备能够有效地将血液样品与抗生物污染的IONR混合，并多重检测六种AD生物标志物，即，Aβ40、Aβ42、总tau（t-tau）、p-tau 181、淀粉样前体蛋白（APP 669 -711）和神经丝轻蛋白（NfL），以及（2）使用患者样本测试开发的系统并评估其性能，然后将结果与相同患者的临床诊断和成像结果进行比较和关联。如果成功，该设备将在第二阶段的大规模测试中进一步评估，将提供一种强大且具有成本效益的POC检测方法，用于筛查和检测有风险的个体的AD，以及监测患者的进展和治疗反应。

With an effective treatment yet to be developed, early detection and surveillance of disease progression for Alzheimer’s disease (AD) and Alzheimer’s disease related dementias (ADRD) are critical for the management and intervention of AD/ADRD. The recent accelerated approval of the new monoclonal antibody drug targeting amyloid-β, Aducanumab®, by FDA, which is likely more efficacious when treating properly stratified patients, highlighted the urgent clinical need for early and biomarker-specific diagnosis of AD. Current clinical practices with AD biomarker targeted positron emission tomography (PET) imaging and cerebrospinal fluid (CSF) sample based proteomics analysis are not desirable point-of-care (POC) solutions for early detection due to the limited availability and accessibility of imaging facilities or invasive lumbar puncture for CSF collection. Given the advantages of non-invasiveness, cost effectiveness and easy access in general clinical settings, blood-based AD biomarker detections are more applicable POC diagnostic tools for early diagnosis of AD/ADRD. While two platforms, i.e., PrecivityADTM for Aβ40/Aβ42 detection and Simoa® for phospho-tau 181 (p-tau181), were recently granted FDA Breakthrough Device designations for clinical uses, both systems require highly specialized high-end instruments for sample testing, limiting their wide availability, particularly in the communities and regions with low or limited resources and health disparity. Furthermore, PrecivityADTM and Simoa® use antibody-coated magnetic beads to capture targeted AD biomarkers. However, the non-specific adsorption of serum proteins on the surface of beads forms a protein corona that can block the antibody from capturing biomarkers. In this SBIR Phase I project, we aim to develop a multiplexed AD biomarker detection platform that can integrate two innovative technologies, i.e., ultramagnetic iron oxide nanorods (IONRs) and anti-biofouling polymer coating for IONRs, for multiplexing six AD biomarkers in blood samples. The IONRs provide as strong magnetism as the magnetic beads used in PrecivityADTM and Simoa®, and also function as nano-stirring-bars to improve sample mixing, under an alternating electromagnetic field, for more efficient biomarker capturing. The anti-biofouling coating minimizes non-specific serum protein adsorption on IONRs to preserve the antibody affinity for targeted biomarkers in blood samples. The Phase I project will focus on (1) developing a prototype device enabling efficient blood sample mixing with anti-biofouling IONRs and multiplexed detection of six AD biomarkers, i.e., Aβ40, Aβ42, total-tau (t-tau), p-tau181, amyloid precursor protein (APP669-711), and neurofilament light protein (NfL), and (2) testing the developed system and evaluate its performance using the patient samples, followed by comparing and correlating the results with clinical diagnosis and imaging findings of the same patients. If successful, the device, to be further assessed by large-scale tests in Phase II, will provide a robust and cost-effective POC detection for screening and detecting AD in individuals at risk as well as surveilling the progression and treatment response for patients.