Microsystem-based technologies are providing new opportunities in the area of in vitro diagnostics due to their ability to provide process automation enabling point-of-care operation. As an example, microsystems used for the isolation and analysis of circulating tumor cells (CTCs) from complex, heterogeneous samples in an automated fashion with improved recoveries and selectivity are providing new opportunities for this important biomarker. Unfortunately, many of the existing microfluidic systems lack the throughput capabilities and/or are too expensive to manufacture to warrant their widespread use in clinical testing scenarios. Here, we describe a disposable, all-polymer, microfluidic system for the high-throughput (HT) isolation of CTCs directly from whole blood inputs. The device employs an array of high aspect ratio (HAR), parallel, sinusoidal microchannels (25 µm × 150 µm; W × D; AR = 6.0) with walls covalently decorated with anti-EpCAM antibodies to provide affinity-based isolation of CTCs. Channel width, which is similar to an average CTC diameter (12-25 µm), plays a critical role in maximizing the probability of cell/wall interactions and allows for achieving high CTC recovery. The extended channel depth allows for increased throughput at the optimized flow velocity (2 mm/s in a microchannel); maximizes cell recovery, and prevents clogging of the microfluidic channels during blood processing. Fluidic addressing of the microchannel array with a minimal device footprint is provided by large cross-sectional area feed and exit channels poised orthogonal to the network of the sinusoidal capillary channels (so-called Z-geometry). Computational modeling was used to confirm uniform addressing of the channels in the isolation bed. Devices with various numbers of parallel microchannels ranging from 50 to 320 have been successfully constructed. Cyclic olefin copolymer (COC) was chosen as the substrate material due to its superior properties during UV-activation of the HAR microchannels surfaces prior to antibody attachment. Operation of the HT-CTC device has been validated by isolation of CTCs directly from blood secured from patients with metastatic prostate cancer. High CTC sample purities (low number of contaminating white blood cells, WBCs) allowed for direct lysis and molecular profiling of isolated CTCs.

中文翻译：

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用于高通量分离循环肿瘤细胞 (CTC) 的高纵横比微通道阵列。


基于微系统的技术由于能够提供流程自动化，从而实现现场护理操作，因此为体外诊断领域提供了新的机遇。例如，用于以自动化方式从复杂的异质样品中分离和分析循环肿瘤细胞 (CTC) 的微系统具有更高的回收率和选择性，为这一重要生物标志物提供了新的机会。不幸的是，许多现有的微流体系统缺乏吞吐量能力和/或制造成本太高，无法保证其在临床测试场景中的广泛使用。在这里，我们描述了一种一次性、全聚合物微流体系统，用于直接从全血输入中高通量 (HT) 分离 CTC。该装置采用一系列高纵横比 (HAR)、平行、正弦形微通道（25 µm × 150 µm；W × D；AR = 6.0），其壁用抗 EpCAM 抗体共价装饰，以提供基于亲和力的 CTC 分离。通道宽度与平均 CTC 直径 (12-25 µm) 相似，在最大化细胞/壁相互作用的可能性方面发挥着关键作用，并可实现高 CTC 回收率。扩展的通道深度可以在优化流速（微通道中为 2 mm/s）下提高吞吐量；最大限度地提高细胞回收率，并防止血液处理过程中微流体通道的堵塞。通过与正弦毛细管通道网络正交的大横截面积进料和出口通道（所谓的 Z 几何形状）提供具有最小设备占用空间的微通道阵列的流体寻址。使用计算模型来确认隔离床上通道的统一寻址。 已成功构建了具有从50到320个不同数量的并行微通道的装置。选择环烯烃共聚物 (COC) 作为基底材料是因为其在抗体附着之前在 HAR 微通道表面的紫外线激活过程中具有优异的性能。 HT-CTC 装置的操作已通过直接从转移性前列腺癌患者的血液中分离 CTC 进行了验证。高 CTC 样品纯度（污染性白细胞、WBC 数量较少）可对分离的 CTC 进行直接裂解和分子分析。