Queensland Micro and Nanotechnology Centre, Griffith University, Brisbane QLD 4111, Australia.
School of Environment and Science, Nathan Campus, Griffith University, 170 Kessels Road, Brisbane, QLD 4111, Australia.
Anal Chem. 2020 Sep 1;92(17):11558-11564. doi: 10.1021/acs.analchem.0c00273. Epub 2020 Jul 9.
Floating cancer cells can survive the programmed death anoikis process after detaching from the extracellular matrix for the anchorage-dependent cells. Purification of viable floating cancer cells is essential for many biomedical studies, such as drug screening and cancer model development. However, the floating cancer cells are mixed with dead cells and debris in the medium supernatant. In this paper, we developed an inertial microfluidic device with sinusoidal microchannels to continuously remove dead cells and debris from viable cells. First, we characterized the differential inertial focusing properties of polystyrene beads in the devices. Then, we investigated the effects of flow rate on inertial focusing of floating MDA-MB-231 cells. At an optimal flow condition, purification of viable cells was performed and the purity of live cells was increased significantly from 19.9% to 76.6%, with a recovery rate of 69.7%. After separation, we studied and compared the floating and adherent MDA-MB-231 cells in terms of cell proliferation, protrusive cellular structure, and the expression of cyclooxygenase (Cox-2) which is related to epithelial-mesenchymal transition (EMT) changes. Meanwhile, drug screening of both floating and adherent cancer cells was conducted using a chemotherapeutic drug, doxorubicin (Dox). The results revealed that the floating cancer cells possess 30-fold acquired chemoresistance as compared to the adherent cancer cells. Furthermore, a three-dimensional (3D) double-cellular coculture model of human mammary fibroblasts (HMF) spheroid and cancer cells using the floating liquid marble technique was developed.
悬浮癌细胞在脱离细胞外基质后可以逃脱程序性细胞死亡（anoikis）过程，而锚定依赖性细胞则会发生程序性细胞死亡。从依赖于附着的细胞中分离出存活的悬浮癌细胞对于许多生物医学研究（如药物筛选和癌症模型开发）至关重要。然而，悬浮癌细胞与培养基上清液中的死细胞和碎片混合在一起。在本文中，我们开发了一种具有正弦微通道的惯性微流控装置，可连续从活细胞中去除死细胞和碎片。首先，我们对设备中聚苯乙烯珠的差异惯性聚焦特性进行了表征。然后，我们研究了流速对悬浮 MDA-MB-231 细胞惯性聚焦的影响。在最佳的流动条件下，对活细胞进行了纯化，活细胞的纯度从 19.9%显著提高到 76.6%，回收率为 69.7%。分离后，我们从细胞增殖、突起细胞结构以及与上皮-间充质转化（EMT）变化相关的环氧化酶（Cox-2）的表达等方面对悬浮和贴壁 MDA-MB-231 细胞进行了研究和比较。同时，使用化疗药物阿霉素（Dox）对悬浮和贴壁癌细胞进行了药物筛选。结果表明，与贴壁癌细胞相比，悬浮癌细胞具有 30 倍的获得性化疗耐药性。此外，我们还使用悬浮液滴 marble 技术开发了一种人乳腺成纤维细胞（HMF）球体和癌细胞的三维（3D）双细胞共培养模型。
