Smartphone-imaged microfluidic biochip for measuring CD64 expression from whole blood
Smartphone-imaged microfluidic biochip for measuring CD64 expression from whole blood
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DOI：
10.1039/c9an00532c
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发表时间：
2019-07-07
期刊：
影响因子：
4.2
通讯作者：
Bashir, Rashid
中科院分区：
文献类型：
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作者：
Ghonge, Tanmay;Koydemir, Hatice Ceylan;Bashir, Rashid
败血症是一种危及生命的综合征，每年导致全球数百万人死亡，对医疗保健系统来说是一种道德和经济负担。尽管目前还没有单一的生物标志物，甚至是多种生物标志物的联合应用来诊断脓毒症，但多项研究表明中性粒细胞表面CD64的表达对脓毒症的诊断具有很高的特异性。分析感染后2-6小时前炎症阶段升高的nCD64对脓毒症的早期诊断有重要意义。因此，一种快速、自动化的设备在护理点(POC)定期测量nCD64的表达可能会导致及时的医疗干预和降低死亡率。目前公认的检测nCD64表达的技术，如流式细胞术，需要人工制备样品和较长的孵育时间。然而，对于POC应用，该技术应该能够测量nCD64的表达，而几乎不需要样品制备。在本文中，我们展示了一种智能手机成像的微流控生物芯片，可以在50分钟内检测nCD64的表达。在我们的检测中，首先将未经处理的全血注入捕捉室，沿着交错的柱子阵列免疫捕获nCD64，这些柱子以前是用抗CD64的抗体功能化的。然后，使用基于智能手机的显微镜拍摄捕获通道的图像。该图像用于测量作为通道中长度的函数的捕获细胞的累积百分比(伽马)。在图像分析过程中，为了提取每次与柱子(Epsilon)碰撞捕获中性粒细胞的概率，将统计模型与伽马拟合。拟合结果与流式细胞仪检测的nCD64表达有很强的相关性(R-2=0.82)。最后，通过分析8名患者(分析了37份血液样本)在入院期间的nCD64，证明了该设备对脓毒症的适用性。使用智能手机成像的微流控生物芯片获得的分析结果与流式细胞仪进行了比较。相关系数R2=0.82(斜率=0.99)，表明两种方法具有良好的线性相关性。在ICU中部署这项技术可以显著提高世界各地的患者护理水平。
Sepsis, a life-threatening syndrome that contributes to millions of deaths annually worldwide, represents a moral and economic burden to the healthcare system. Although no single, or even a combination of biomarkers has been validated for the diagnosis of sepsis, multiple studies have shown the high specificity of CD64 expression on neutrophils (nCD64) to sepsis. The analysis of elevated nCD64 in the first 2-6 hours after infection during the pro-inflammatory stage could significantly contribute to early sepsis diagnosis. Therefore, a rapid and automated device to periodically measure nCD64 expression at the point-of-care (POC) could lead to timely medical intervention and reduced mortality rates. Current accepted technologies for measuring nCD64 expression, such as flow cytometry, require manual sample preparation and long incubation times. For POC applications, however, the technology should be able to measure nCD64 expression with little to no sample preparation. In this paper, we demonstrate a smartphone-imaged microfluidic biochip for detecting nCD64 expression in under 50 min. In our assay, first unprocessed whole blood is injected into a capture chamber to immunologically capture nCD64 along a staggered array of pillars, which were previously functionalized with an antibody against CD64. Then, an image of the capture channel is taken using a smartphone-based microscope. This image is used to measure the cumulative fraction of captured cells (gamma) as a function of length in the channel. During the image analysis, a statistical model is fitted to gamma in order to extract the probability of capture of neutrophils per collision with a pillar (epsilon). The fitting shows a strong correlation with nCD64 expression measured using flow cytometry (R-2 = 0.82). Finally, the applicability of the device to sepsis was demonstrated by analyzing nCD64 from 8 patients (37 blood samples analyzed) along the time they were admitted to the hospital. Results from this analysis, obtained using the smartphone-imaged microfluidic biochip were compared with flow cytometry. Again, a correlation coefficient R-2 = 0.82 (slope = 0.99) was obtained demonstrating a good linear correlation between the two techniques. Deployment of this technology in ICU could significantly enhance patient care worldwide.