Theoretical Soft Matter and Biophysics, Institute of Complex Systems and Institute for Advanced Simulation, Forschungszentrum Jülich, 52425 Jülich, Germany.
Division of Solid State Physics, NanoLund, Lund University, PO Box 118, S-221 00 Lund, Sweden.
Sci Rep. 2016 Oct 6;6:34375. doi: 10.1038/srep34375.
Recent advances in cell sorting aim at the development of novel methods that are sensitive to various mechanical properties of cells. Microfluidic technologies have a great potential for cell sorting; however, the design of many micro-devices is based on theories developed for rigid spherical particles with size as a separation parameter. Clearly, most bioparticles are non-spherical and deformable and therefore exhibit a much more intricate behavior in fluid flow than rigid spheres. Here, we demonstrate the use of cells' mechanical and dynamical properties as biomarkers for separation by employing a combination of mesoscale hydrodynamic simulations and microfluidic experiments. The dynamic behavior of red blood cells (RBCs) within deterministic lateral displacement (DLD) devices is investigated for different device geometries and viscosity contrasts between the intra-cellular fluid and suspending medium. We find that the viscosity contrast and associated cell dynamics clearly determine the RBC trajectory through a DLD device. Simulation results compare well to experiments and provide new insights into the physical mechanisms which govern the sorting of non-spherical and deformable cells in DLD devices. Finally, we discuss the implications of cell dynamics for sorting schemes based on properties other than cell size, such as mechanics and morphology.
最近细胞分选技术的进展旨在开发新型方法，这些方法对细胞的各种机械性能敏感。微流控技术在细胞分选方面具有很大的潜力；然而，许多微设备的设计都是基于针对具有尺寸作为分离参数的刚性球形颗粒开发的理论。显然，大多数生物颗粒是非球形和可变形的，因此在流场中表现出比刚性球体更复杂的行为。在这里，我们通过结合介观流体动力学模拟和微流控实验，展示了利用细胞的机械和动力学特性作为分离标志物的方法。研究了不同器件几何形状和细胞内流体与悬浮介质之间的粘度对比对确定性侧向位移（DLD）器件中红细胞（RBC）的动态行为的影响。我们发现，粘度对比和相关的细胞动力学明显决定了 RBC 通过 DLD 器件的轨迹。模拟结果与实验吻合较好，为控制 DLD 器件中非球形和可变形细胞分选的物理机制提供了新的见解。最后，我们讨论了细胞动力学对基于细胞大小以外的其他特性（如力学和形态）的分选方案的影响。
