Abstract：
In recent years, the cargo profiles of extracellular vesicles (EVs), which were inherited from their parent cells, have emerged as a reliable biomarker for liquid biopsy (LB) in disease diagnosis, prognosis, and treatment monitoring. EVs secreted by different cells exhibit distinct characteristics, particularly in terms of disease diagnosis and prediction. However, currently available techniques for the quantitative analysis of EV cargoes, including enzyme-linked immunosorbent assay (ELISA), cannot specifically identify the cellular origin of EVs, thus seriously affecting the accuracy of EV-based liquid biopsy. In light of this, we here developed ultrabright fluorescent nanosphere (FNs)-based test strips which have the unique capability to specifically assess the levels of PD-L1-positive EVs (PD-L1+ EVs) derived from both tumor cells and immune cells in bodily fluids. The levels of PD-L1+ EV subpopulations in human saliva were quantified using the ultrabright fluorescent nanosphere-based test strips with more convenience and higher efficiency (detection time <30 min). Results demonstrated that the fluorescence intensity of the test line exhibited a good linear relationship respectively with the PD-L1 levels of tumor cell- (R2 = 0.993) and immune cell-derived EVs (R2 = 0.982) in human saliva. By assessing the levels of PD-L1+ EV subpopulations, our test strips hold immense potential for advancing the application of PD-L1+ EV subpopulation-based predictions in tumor diagnosis and prognosis evaluation. In summary, by integrating the benefits of FNs and lateral flow chromatography, we here provide a strategy to accurately measure the cargo levels of EVs originating from diverse cell sources in bodily fluids.
摘要：
近年来,细胞外囊泡（EV）的货物谱，它们是从它们的亲本细胞遗传而来的，已成为疾病诊断中液体活检（LB）的可靠生物标志物，预后,和治疗监测。不同细胞分泌的电动汽车表现出不同的特征，特别是在疾病诊断和预测方面。然而,目前可用的电动汽车货物定量分析技术，包括酶联免疫吸附测定（ELISA），无法明确识别电动汽车的细胞起源，从而严重影响基于EV的液体活检的准确性。鉴于此,我们在这里开发了基于超亮荧光纳米球(FNs)的测试条,该测试条具有独特的能力来特异性评估体液中源自肿瘤细胞和免疫细胞的PD-L1阳性EV(PD-L1+EV)的水平.使用基于超亮荧光纳米球的测试条以更方便和更高的效率(检测时间<30分钟)定量人唾液中的PD-L1+EV亚群的水平。结果表明，测试线的荧光强度分别与人唾液中肿瘤细胞（R2=0.993）和免疫细胞衍生的EV（R2=0.982）的PD-L1水平呈良好的线性关系。通过评估PD-L1+EV亚群的水平，我们的试纸条在推进PD-L1+EV亚群预测在肿瘤诊断和预后评估中的应用方面具有巨大潜力.总之,通过整合FN和侧流色谱的好处，我们在这里提供了一种策略，以准确测量源自体液中多种细胞来源的EV的货物水平。
