In this paper, we focused on a microfluidic sorting method based on bionic splenic sinus microstructures to capture circulating tumor cells (CTCs). A dynamic multiphase fluidic model was developed to explore the effects of different flows and the parameters of the spleen-specific structure of the interendothelial slit (IES) on the cell membrane strain, as represented by the interface area between two phases. The results indicated that parameters of the IES and flow velocity strongly influence cell membrane strain. The biomimetic IES structure has more advantages than do circular pores because the slit structure has a lower flow resistance compared to the circle structure. A microfluidic device based on a biomimetic IES with ultrathin (500 nm thick) silicon nitride filters was designed and fabricated for high-throughput enrichment of high-viability CTCs. The silicon nitride filters had areas as large as 36 mm² (6 × 6 mm) and included nearly 18,000 slit units, which was conducive to obtaining a high-throughput device. Moreover, the effects of different parameters, such as velocity, slit width, dilution ratio and solution volume, on the cell capture efficiency and cell viability were explored. The results show that the microfluidic device based on a biomimetic IES has a high potential for preserving viable cells. This study quantitatively explored the effects of different parameters on cell viability during the CTC physical filtration process. Additionally, this study will be helpful for designing high-throughput CTC enrichment devices that capture high-viability cells.

在本文中，我们专注于一种基于仿生脾窦微结构的微流体分选方法来捕获循环肿瘤细胞 (CTC)。开发了一种动态多相流体模型，以探索不同流量的影响以及内皮间裂隙 (IES) 的脾脏特异性结构参数对细胞膜应变的影响，如两相之间的界面面积所示。结果表明，IES和流速的参数强烈影响细胞膜应变。仿生IES结构比圆形孔结构更具优势，因为狭缝结构与圆形结构相比具有更低的流动阻力。基于具有超薄（500 nm 厚）氮化硅过滤器的仿生 IES 的微流体装置被设计和制造，用于高活性 CTC 的高通量富集。氮化硅过滤器的面积高达 36 mm² (6 × 6 mm)，包括近 18,000 个狭缝单元，有利于获得高通量设备。此外，还探讨了不同参数（如速度、狭缝宽度、稀释比和溶液体积）对细胞捕获效率和细胞活力的影响。结果表明，基于仿生 IES 的微流体装置在保存活细胞方面具有很高的潜力。本研究定量探讨了 CTC 物理过滤过程中不同参数对细胞活力的影响。此外，这项研究将有助于设计捕获高活力细胞的高通量 CTC 富集装置。