Robinson M, Marks H, Hinsdale T, Maitland K, Coté G
Department of Biomedical Engineering, Texas A&M University , College Station, Texas 77843, USA.
Biomicrofluidics. 2017 Mar 24;11(2):024109. doi: 10.1063/1.4979198. eCollection 2017 Mar.
Blood, saliva, mucus, sweat, sputum, and other biological fluids are often hindered in their ability to be used in point-of-care (POC) diagnostics because their assays require some form of off-site sample pre-preparation to effectively separate biomarkers from larger components such as cells. The rapid isolation, identification, and quantification of proteins and other small molecules circulating in the blood plasma from larger interfering molecules are therefore particularly important factors for optical blood diagnostic tests, in particular, when using optical approaches that incur spectroscopic interference from hemoglobin-rich red blood cells (RBCs). In this work, a sequential spiral polydimethylsiloxane (PDMS) microfluidic device for rapid (∼1 min) on-chip blood cell separation is presented. The chip utilizes Dean-force induced migration via two 5-loop Archimedean spirals in series. The chip was characterized in its ability to filter solutions containing fluorescent beads and silver nanoparticles and further using blood solutions doped with a fluorescent protein. Through these experiments, both cellular and small molecule behaviors in the chip were assessed. The results exhibit an average RBC separation efficiency of ∼99% at a rate of 5.2 × 10 cells per second while retaining 95% of plasma components. This chip is uniquely suited for integration within a larger point-of-care diagnostic system for the testing of blood plasma, and the use of multiple filtering spirals allows for the tuning of filtering steps, making this device and the underlying technique applicable for a wide range of separation applications.
血液、唾液、黏液、汗液、痰液及其他生物流体在即时检测（POC）诊断中的应用常常受到阻碍，因为其检测需要某种形式的现场外样本预处理，以便有效地从诸如细胞等较大成分中分离生物标志物。因此，对于光学血液诊断测试而言，尤其是在使用会受到富含血红蛋白的红细胞（RBC）光谱干扰的光学方法时，从较大的干扰分子中快速分离、鉴定和定量循环于血浆中的蛋白质及其他小分子尤为重要。在这项工作中，展示了一种用于快速（约1分钟）片上血细胞分离的连续螺旋聚二甲基硅氧烷（PDMS）微流控装置。该芯片利用通过两个串联的5圈阿基米德螺旋产生的迪恩力诱导迁移。对该芯片进行了表征，评估其过滤含有荧光珠和银纳米颗粒的溶液的能力，以及进一步使用掺杂有荧光蛋白的血液溶液的能力。通过这些实验，评估了芯片中的细胞和小分子行为。结果显示，在每秒5.2×10个细胞的流速下，红细胞平均分离效率约为99%，同时保留95%的血浆成分。该芯片特别适合集成到用于检测血浆的更大的即时诊断系统中，并且使用多个过滤螺旋可实现过滤步骤的调整，使得该装置及底层技术适用于广泛的分离应用。
