Natu Rucha, Martinez-Duarte Rodrigo
Multiscale Manufacturing Laboratory, Department of Mechanical Engineering, Clemson University, Clemson, SC 29634, USA.
Micromachines (Basel). 2016 Nov 30;7(12):217. doi: 10.3390/mi7120217.
Neural stem cells are of special interest due to their potential in neurogenesis to treat spinal cord injuries and other nervous disorders. Flow cytometry, a common technique used for cell sorting, is limited due to the lack of antigens and labels that are specific enough to stem cells of interest. Dielectrophoresis (DEP) is a label-free separation technique that has been recently demonstrated for the enrichment of neural stem/progenitor cells. Here we use numerical simulation to investigate the use of streaming DEP for the continuous sorting of neural stem/progenitor cells. Streaming DEP refers to the focusing of cells into streams by equilibrating the dielectrophoresis and drag forces acting on them. The width of the stream should be maximized to increase throughput while the separation between streams must be widened to increase efficiency during retrieval. The aim is to understand how device geometry and experimental variables affect the throughput and efficiency of continuous sorting of SC27 stem cells, a neurogenic progenitor, from SC23 cells, an astrogenic progenitor. We define efficiency as the ratio between the number of SC27 cells over total number of cells retrieved in the streams, and throughput as the number of SC27 cells retrieved in the streams compared to their total number introduced to the device. The use of cylindrical electrodes as tall as the channel yields streams featuring >98% of SC27 cells and width up to 80 µm when using a flow rate of 10 µL/min and sample cell concentration up to 10⁵ cells/mL.
神经干细胞因其在神经发生方面具有治疗脊髓损伤和其他神经疾病的潜力而备受关注。流式细胞术是一种常用的细胞分选技术，但由于缺乏足够特异性的抗原和标记物来区分目标干细胞，其应用受到限制。介电电泳（DEP）是一种无标记的分离技术，最近已被证明可用于富集神经干细胞/祖细胞。在此，我们使用数值模拟来研究流动式DEP用于神经干细胞/祖细胞连续分选的情况。流动式DEP是指通过平衡作用于细胞的介电电泳力和拖曳力，将细胞聚焦成流。流的宽度应最大化以提高通量，而流之间的间距必须加宽以提高回收效率。目的是了解设备几何形状和实验变量如何影响从星形胶质祖细胞SC23中连续分选神经源性祖细胞SC27干细胞的通量和效率。我们将效率定义为SC27细胞数量与流中回收的细胞总数之比，将通量定义为流中回收的SC27细胞数量与其引入设备的总数之比。当流速为10 μL/min且样品细胞浓度高达10⁵个细胞/mL时，使用与通道一样高的圆柱形电极可产生含有>98%的SC27细胞且宽度达80 µm的流。
