流体增强介电泳单细胞排列与控制芯片的研究

发布时间：2018-04-15 14:22

本文选题：介电泳 + 流体动力学　；参考：《中北大学》2017年硕士论文

【摘要】：单细胞分辨率下细胞生物化学、物理特性的研究与表征,能够有效揭示个体细胞在结构功能与状态上的差异性,对理解不同细胞新陈代谢、细胞性疾病的病理特征、细胞间的相互作用、细胞与介质环境的相互作用等具有十分重要的意义。作为研究单细胞的重要手段,基于微流控芯片的单细胞排列与控制技术受到了愈来愈多的关注,然而目前大多数的单细胞排列与控制技术不仅成本高昂、而且效率很低,严重影响了单细胞排列与控制技术的推广与应用。本文结合介电泳的非侵入、免标记、易控制与流体动力学的高效率、低成本,通过仿真优化和实验测试,设计制作了三明治式流体增强介电泳单细胞排列与控制芯片,实现了高通量阵列化的单细胞排列与控制,主要内容如下:首先,对介电泳、绝缘介电泳和流体动力学的基本理论做了分析,得出了介电泳力的公式及影响其大小与方向的因素、绝缘微墙对空间非均匀电场分布的影响及微墙对层流的影响;然后建立了等效细胞多层球壳模型,对细胞进行受力分析得到流体增强介电泳捕获与释放细胞的原理;最后对OCI细胞的频响特性进行计算得出了不同电导率、不同介电常数溶液对细胞介电响应的影响,为单细胞排列与控制奠定了理论基础。其次,根据介电泳与流体动力学的基本理论,利用计算机辅助软件AutoCAD、Solidworks建立了三明治式流体增强介电泳单细胞排列与控制芯片的结构并提出了其两种工作模式,之后使用有限元软件COMSOL Multiphysics仿真分析了芯片内部电场和流场的分布,并通过仿真不同尺寸结构对电场和流场的影响,得出了最佳的结构尺寸。再次,根据微流控芯片选材原则,选定了各部分的加工材料与工艺,并根据加工方案,采用光刻法制作了上下层ITO微电极及SU-8微墙阵列,使用旋涂法制作了PDMS流体通道与导管接头,最后使用氧等离子键合技术对芯片进行了封装。最后,搭建了微流控芯片实验测试平台,制作了用于连接芯片与外部信号源的PCB转接板。培养人类急性髓细胞性白血病细胞(OCI-AML3),并用叉指电极优化使OCI细胞发生介电泳行为的频率与幅值后,通过荧光染色和处理OCI细胞,在制作的流体增强介电泳芯片中实现了OCI单细胞的阵列化捕获与选择性释放,且单细胞捕获效率大于95%。
[Abstract]:The study and characterization of the biochemical and physical properties of cells at single cell resolution can effectively reveal the differences in the structure, function and state of individual cells, and can be used to understand the pathological characteristics of different cell metabolism and cellular diseases.The interaction between cells and the interaction between cells and mediators is of great significance.As an important means to study single cell, the single cell arrangement and control technology based on microfluidic chip has been paid more and more attention. However, most of the single cell arrangement and control technology is not only expensive, but also inefficient.It seriously affects the popularization and application of single cell arrangement and control technology.In this paper, a sandwich fluid enhanced medium electrophoresis single cell array and control chip is designed and fabricated by simulation, optimization and experimental test, combining with the non invasive, label free, easy control and hydrodynamic high efficiency and low cost of medium electrophoresis.High throughput arrayed single cell alignment and control are realized. The main contents are as follows: firstly, the basic theories of dielectric electrophoresis, dielectric electrophoresis and hydrodynamics are analyzed.The formula of medium electrophoresis force and the factors influencing its size and direction, the influence of insulating microwall on spatial inhomogeneous electric field distribution and the effect of microwall on laminar flow are obtained, and the equivalent cell multilayer spherical shell model is established.The principle of fluid enhanced dielectric electrophoresis was obtained to capture and release the cells. Finally, the effects of different conductivity and dielectric constant solution on the dielectric response of OCI cells were calculated.It lays a theoretical foundation for the arrangement and control of single cell.Secondly, according to the basic theory of dielectric electrophoresis and fluid dynamics, the structure of sandwich fluid enhanced dielectric electrophoresis single cell arrangement and control chip was established by using computer aided software AutoCAD Solidworks, and two working modes were proposed.The distribution of electric field and flow field in the chip is simulated by using the finite element software COMSOL Multiphysics, and the optimum structure size is obtained by simulating the influence of different size structure on the electric field and flow field.Thirdly, according to the material selection principle of microfluidic chip, the machining materials and technology of each part are selected. According to the processing scheme, the upper and lower layer ITO microelectrode and SU-8 microwall array are fabricated by photolithography.The PDMS fluid channel and conduit joint were fabricated by spin-coating method. Finally, the chip was encapsulated by oxygen plasma bonding technology.Finally, the experimental test platform of microfluidic chip is built, and the PCB switch board is made to connect the chip with the external signal source.Human acute myeloid leukemia cells (OCI-AML3) were cultured, and the frequency and amplitude of dielectric electrophoresis behavior of OCI cells were optimized by cross finger electrode. The OCI cells were stained and treated by fluorescence staining.The single cell array capture and selective release of OCI were realized in the fluid enhanced dielectric electrophoresis chip, and the efficiency of single cell capture was greater than 95%.
【学位授予单位】：中北大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN402

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