Nonlinear electrokinetics at polarizable soft interfaces: implications for cell membrane characterization and nanopore transport

可极化的软界面，如生物细胞膜，在外部施加的场的存在下，由于它们与环境的复杂相互作用而经历显著的变形。这些相互作用对于开发微流体和芯片实验室设备以及其他生物医学和生物分析系统（如扫描离子电导显微镜（SICM）和膜片钳）至关重要。这种相互作用对于基于电穿孔的药物递送技术也是至关重要的，因为将生物分子精确递送到靶细胞中的能力强烈依赖于理解细胞膜和所施加的场之间的相互作用。然而，在外加场的情况下解开细胞膜的物理学是具有挑战性的。该项目将开发一个系统平台，该平台将能够检查与施加电压的可极化软界面相关的多种物理效应。该研究小组将进行数学，计算和实验研究，以揭示非线性电动和流体动力学的可极化软界面的相互作用。还将研究这些相互作用对界面处纳米孔的影响，以将目标生物分子精确递送到单细胞中。该项目将提供细胞生物学和免疫学方面的新知识，以及对与神经退行性疾病和心脏病相关的初始分子事件的新见解。该项目将涉及本科生和研究生，团队将开展广泛的推广活动，旨在激发所有学术水平的学生对科学和工程的兴趣。该项目将数学和计算方法与创新的实验平台相结合，以确定含有纳米孔的可极化软膜上的非线性电动效应。它将集成感应电荷电渗（ICEO）的非线性电动现象和电流体动力学的界面和流体动力学来表征膜性能和非线性电动力学之间的关系。在膜尺度上，ICEO在确定膜表面的形貌形状中的作用将被定量分析，然后将获得细胞膜的弯曲刚度或刚度。在孔尺度上，ICEO对跨膜上的纳米孔的流体动力学流动的影响将被解决，并且将获得流体动力学力和膜变形之间的关系。同时，将在两种规模下对各种单细胞进行使用创新纳米毛细管系统的微流体实验，以验证基础模型和假设。有了定量模型和创新的实验系统，通过创建表面特性（如电荷和刚度）的地图，将有可能为SICM成像过程添加新的层，更重要的是提供有关这些特性影响细胞膜上流动的方式的细节。 该项目由颗粒和多相过程计划和刺激竞争研究的既定计划（EPSCoR）共同资助。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Polarizable soft interfaces such as biological cell membranes undergo significant deformations in the presence of an externally applied field due to their complex interactions with their environment. These interactions are crucial for the development of microfluidic and lab-on-chip devices, as well as other biomedical and bioanalytical systems, such as scanning ion conductance microscopy (SICM) and patch-clamping. Such interactions are also critical for electroporation-based drug delivery technologies, because the ability to precisely deliver biomolecules into target cells depends strongly on understanding the interactions between a cell membrane and applied field. However, unraveling the physics of a cell membrane in the presence of an applied field is challenging. This project will develop a systematic platform that will enable the examination of multiple physical effects relevant to polarizable soft interfaces with applied voltages. The research team will conduct mathematical, computational, and experimental studies to uncover nonlinear electrokinetic and hydrodynamic interactions of the polarizable soft interface. The effects of these interactions on nanopores at the interface will also be investigated for the precise delivery of target biomolecules into single cells. The project will provide new knowledge in cell biology and and immunology, as well as new insights into the initial molecular events associated with neurodegenerative and heart disease. The project will involve undergraduate and graduate students, and the team will conduct extensive outreach activities aimed at stimulating interest in science and engineering among students at all academic levels .This project combines mathematical and computational approaches with an innovative experimental platform to determine the nonlinear electrokinetic effects on a polarizable soft membrane containing nanopores. It will integrate induced-charge electro-osmosis (ICEO) for the nonlinear electrokinetic phenomenon and electro-hydrodynamics for interfacial and fluid dynamics to characterize the relationship between membrane properties and nonlinear electrokinetics. At the membrane scale, the role of ICEO in determining the topographical shape of the membrane surface will be analyzed quantitatively, and the bending rigidity or stiffness of the cell membrane will then be obtained. At the pore scale, the effects of ICEO on hydrodynamic flows across nanopores on the membrane will be addressed, and the relationship between a hydrodynamic force and membrane deformation will be obtained. In parallel, microfluidic experiments using an innovative nanocapillary system will be performed at both scales for various single cells to validate the underlying models and assumptions. Armed with a quantitative model and innovative experimental system, it will be possible to add new layers to a SICM imaging process by creating a map of surface properties such as its charge and rigidity, and more importantly provide details on the way in which these properties influence the flow on the cell membrane. This project is jointly funded by the Particulate and Multiphase Processes Program and the Established Program to Stimulate Competitive Research (EPSCoR).This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.