基于微流控芯片的外周血循环肿瘤细胞分离技术研究

循环肿瘤细胞（CTC）是一种从原发肿瘤组织脱落并进入外周血液循环的癌细胞，它们可以通过血液循环到达身体的各个部位并形成转移病灶。从外周血中分离 CTC 对于癌症的早期诊断，抗癌药物的研发和控制癌症转移等具有重要意义。然而，每毫升外周血中含有大约五十亿个血细胞，却仅含有大约一百个 CTC，因此从外周血中分离 CTC 非常具有挑战性，过滤和离心等常规分离方法已经难以应对这一挑战。本文开发了一种基于微流控芯片的按尺度分离颗粒的方法，用于从人体外周血中高通量地分离 CTC。该方法利用反向流来增强传统惯性挤压流分离器件（iPFF）的性能，通过优化主通道总流量、鞘流比、反向流通道的开口位置和开口大小等多个参数，研究了反向流增强的惯性挤压流分离器件（RF-iPFF）的分离性能。在相同条件下与传统 iPFF 相比，RF-iPFF具有更高的分离分辨率，可以实现对 6、15 和 20 μm 颗粒的分离（分离分辨率为 5 μm），因此可以实现对 CTC 的更高纯度收集。而且该方法可以在极高的总流速（16 mL/h）和极低的鞘流比（α = 1）下正常工作，因此可以极大提高细胞通量。通过综合优化，细胞通量大约可以提高至原来的10 倍，同时鞘液消耗量大约可以减少 50 %。此外，反向流增强效应具有良好的适用性，不仅可以应用于传统 iPFF 器件分离其他尺寸的颗粒，而且也可以应用于其他基于惯性原理的分离器件，例如用于改进传统惯性螺旋分离器件的出口。最后，本文收集了 RF-iPFF 器件分离后的 CTC 并进行了活性测试，细胞活性下降仅约 5 %，证明该方法不会对细胞活性造成明显损伤。总之，本文为外周血 CTC 的分离提供了一种高通量、高分离分辨率和低活性损伤的方法。

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