摘要
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 120μL/min were found to ensure a stable fluid distribution.Under these conditions,rapid focusing of 10-20μm 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 500μL of a rare sample.Cell suspensions with concentrations from 3×10^(5)/mL to 1×10^(3)/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.
基金
the National Natural Science Foundation of China(22078236).
