School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA, USA.
Lab Chip. 2019 Oct 9;19(20):3427-3437. doi: 10.1039/c9lc00575g.
Isolation and analysis of circulating tumor cells (CTCs) from blood samples present exciting opportunities for basic cancer research and personalized treatment of the disease. While microchip-based negative CTC enrichment offers both sensitive microfluidic cell screening and unbiased selection, conventional microchips are inherently limited by their capacity to deplete a large number of normal blood cells. In this paper, we use 3D printing to create a monolithic device that combines immunoaffinity-based microfluidic cell capture and a commercial membrane filter for negative enrichment of CTCs directly from whole blood. In our device, stacked layers of chemically-functionalized microfluidic channels capture millions of white blood cells (WBCs) in parallel without getting saturated and the leuko-depleted blood is post-filtered with a 3 μm-pore size membrane filter to eliminate anucleated blood cells. This hybrid negative enrichment approach facilitated direct extraction of viable CTCs off the chip on a membrane filter for downstream analysis. Immunofluorescence imaging of enriched cells showed ∼90% tumor cell recovery rate from simulated samples spiked with prostate, breast or ovarian cancer cells. We also demonstrated the feasibility of our approach for processing clinical samples by isolating prostate cancer CTCs directly from a 10 mL whole blood sample.
从血液样本中分离和分析循环肿瘤细胞 (CTC) 为癌症的基础研究和个体化治疗提供了令人兴奋的机会。基于微芯片的负向 CTC 富集方法提供了敏感的微流控细胞筛选和无偏选择，但传统微芯片在耗尽大量正常血细胞的能力方面存在固有局限性。在本文中，我们使用 3D 打印技术创建了一种整体式设备，该设备将基于免疫亲和性的微流控细胞捕获与商用膜过滤器结合，可直接从全血中进行负向 CTC 富集。在我们的设备中，化学功能化的微流道堆叠层可并行捕获数百万个白细胞 (WBC)，而不会饱和，并且去白细胞后的血液再用 3μm 孔径的膜过滤器过滤，以去除无核血细胞。这种混合的负向富集方法便于在膜过滤器上直接从芯片上提取有活力的 CTC 进行下游分析。对富集细胞进行免疫荧光成像显示，从模拟样本中（掺入前列腺癌、乳腺癌或卵巢癌细胞）回收的肿瘤细胞回收率约为 90%。我们还通过直接从 10mL 全血样本中分离前列腺癌 CTC ，证明了我们的方法用于处理临床样本的可行性。
