Shi Xin, Tan Wei, Lu Yuwen, Cao Wenfeng, Zhu Guorui
School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300350 China.
Tianjin Tumor Hospital, Tianjin Medical University, Tianjin, 300070 China.
Microsyst Nanoeng. 2021 Oct 15;7:81. doi: 10.1038/s41378-021-00311-9. eCollection 2021.
Particle/cell washing is an essential technique in biological and clinical manipulations. Herein, we propose a novel circular contraction-expansion array (CCEA) microdevice. It can be directly connected to a needle tip without connection tubes. Its small size and centrosymmetric structure are beneficial to low sample consumption, high connection stability, and a wide application range. Computational fluid dynamics (CFD) simulation results show that the CCEA structure can produce a stronger Dean flow and lead to faster particle/cell focusing than the circle structure and CEA structure with the same length. Experimentally, an optimal flow rate ratio of 1:3 and an optimal total flow rate of 120 μL/min were found to ensure a stable fluid distribution. Under these conditions, rapid focusing of 10-20 μm particles with high efficiencies was achieved. Compared with a normal CEA device using tubes, the particle loss rate could be reduced from 64 to 7% when washing 500 μL of a rare sample. Cell suspensions with concentrations from 3 × 10/mL to 1 × 10/mL were tested. The high cell collection efficiency (>85% for three cell lines) and stable waste removal efficiency (>80%) reflected the universality of the CCEA microfluidic device. After the washing, the cell activities of H1299 cells and MCF-7 cells were calculated to be 93.8 and 97.5%, respectively. This needle-tip CCEA microfluidic device showed potential in basic medical research and clinical diagnosis.
颗粒/细胞清洗是生物和临床操作中的一项重要技术。在此，我们提出了一种新型的圆形收缩-扩张阵列（CCEA）微器件。它无需连接管即可直接连接到针尖。其小尺寸和中心对称结构有利于低样品消耗、高连接稳定性和广泛的应用范围。计算流体动力学（CFD）模拟结果表明，与相同长度的圆形结构和CEA结构相比，CCEA结构能产生更强的Dean流并导致更快的颗粒/细胞聚焦。实验发现，最佳流速比为1:3，最佳总流速为120 μL/min，以确保稳定的流体分布。在这些条件下，实现了10 - 20μm颗粒的高效快速聚焦。与使用管子的普通CEA装置相比，在清洗500 μL稀有样品时，颗粒损失率可从64%降至7%。测试了浓度范围为3×10/mL至1×10/mL的细胞悬液。高细胞收集效率（三种细胞系均>85%）和稳定的废物清除效率（>80%）反映了CCEA微流控装置的通用性。清洗后，计算得出H1299细胞和MCF-7细胞的细胞活性分别为93.8%和97.5%。这种针尖CCEA微流控装置在基础医学研究和临床诊断中显示出潜力。
