Gauging surface charge distribution of live cell membrane by ionic current change using scanning ion conductance microscopy
Gauging surface charge distribution of live cell membrane by ionic current change using scanning ion conductance microscopy
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DOI：
10.1039/d1nr05230f
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发表时间：
2021-11-08
期刊：
影响因子：
6.7
通讯作者：
Gu, Ning
中科院分区：
文献类型：
--
作者：
Chen, Feng;He, Jin;Gu, Ning
细胞膜表面电荷和电位的分布在细胞活动中起着不可或缺的作用。然而，由于缺乏有效的方法，直到最近，在生理条件下探测活细胞的表面电荷仍然是一个艰巨的挑战。扫描离子电导显微镜（SICM）是一种新兴的成像技术，用于成像活细胞膜在其天然状态。在这里，我们介绍了一个简单的基于SICM的成像技术，有效地映射的表面电荷对比度分布的软基板，包括细胞膜，通过利用较高的表面电荷灵敏度的离子电流时，纳米移液管尖端接近基板具有相对较高的电流变化。这种技术进行了评估，带电模型基板上的聚二甲基硅氧烷，离子电流变化的表面电荷的灵敏度支持有限元方法模拟。用这种方法，我们可以区分细胞膜和支持胶原基质之间的表面电荷差异。我们还观察了1%二甲基亚砜（DMSO）处理后，由微小的膜损伤引起的表面电荷变化。这种新的SICM技术提供了机会，研究界面和细胞膜过程的高空间分辨率。
The distribution of surface charge and potential of cell membrane plays an indispensable role in cellular activities. However, probing surface charge of live cells under physiological conditions, until recently, remains an arduous challenge owing to the lack of effective methods. Scanning ion conductance microscopy (SICM) is an emerging imaging technique for imaging a live cell membrane in its native state. Here, we introduce a simple SICM based imaging technique to effectively map the surface charge contrast distribution of soft substrates including cell membranes by utilizing the higher surface charge sensitivity of the ionic current when the nanopipette tip is close to the substrate with a relatively high current change. This technique was assessed on charged model substrates made of polydimethylsiloxane, and the surface charge sensitivity of ionic current change was supported by finite element method simulations. With this method, we can distinguish the surface charge difference between the cell membrane and the supporting collagen matrix. We also observed the surface charge change induced by the small membrane damage after 1% dimethyl sulfoxide (DMSO) treatment. This new SICM technique provides opportunities to study interfacial and cell membrane processes with high spatial resolution.