Mechanical Engineering, Department of ENCS, Washington State University, Vancouver, 98686, WA, USA.
Lab Chip. 2014 Jul 21;14(14):2576-84. doi: 10.1039/c4lc00301b.
Various lab on a chip devices have been developed recently to detect and separate circulating tumour cells (CTCs) for early stage cancer detection. Because CTCs are extremely rare in the blood, next generation CTC microfilters aim at significant improvement in both efficiency and throughput. CTC microfilters based on cell deformability seem to be a promising direction. In the present research, we study a CTC passing event through a micro-filtering channel with various 3D geometries. The pressure signatures for different types of cells passing through different channels are characterized numerically. Specifically, five kinds of cross-sections, circular, square, triangular and two kinds of rectangular channels with aspect ratios of 2 and 5, are studied in this work. The total pressures for cells passing through the channels are calculated and reveal different behaviour from what is predicted by the static surface tension model. Among all five cross-sections studied, the circular cross-section features the highest critical pressure and thus is most suitable for high efficiency CTC separation. The square filtering channel provides the second largest critical pressure, and the triangular cross-section provides the least critical pressure among these three cross-sections. All these three cross-sections are better than the rectangular channels with aspect ratios of 2 and 5. For the rectangular channel, a high aspect ratio channel may lead to cell splitting at high speed, which will result in a periodic pressure signature. Our findings will provide valuable information for the design of next generation CTC microfilters.
最近已经开发出各种微流控芯片设备，用于检测和分离循环肿瘤细胞（CTC）以进行早期癌症检测。由于 CTC 在血液中极其罕见，因此下一代 CTC 微滤器的目标是在效率和通量方面都有显著提高。基于细胞变形性的 CTC 微滤器似乎是一个很有前途的方向。在本研究中，我们研究了具有各种 3D 几何形状的微过滤通道中 CTC 通过事件。通过数值方法对不同类型的细胞通过不同通道的压力特征进行了表征。具体来说，在这项工作中研究了五种横截面，圆形、方形、三角形和两种纵横比为 2 和 5 的矩形通道。计算了细胞通过通道的总压力，并揭示了与静态表面张力模型预测的不同行为。在所研究的五个横截面中，圆形横截面具有最高的临界压力，因此最适合用于高效 CTC 分离。方形过滤通道提供第二大临界压力，而三角形横截面在这三个横截面中提供最小的临界压力。所有这三个横截面都优于纵横比为 2 和 5 的矩形通道。对于矩形通道，高纵横比通道可能会导致细胞在高速下分裂，从而导致周期性压力特征。我们的研究结果将为下一代 CTC 微滤器的设计提供有价值的信息。
