Mapping Cd²⁺-induced membrane permeability changes of single live cells by means of scanning electrochemical microscopy.
Mapping Cd²⁺-induced membrane permeability changes of single live cells by means of scanning electrochemical microscopy.
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DOI：
10.1016/j.aca.2015.12.027
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发表时间：
2016-02
影响因子：
6.2
通讯作者：
F. Filice;Michelle S. M. Li;J. D. Henderson;Z. Ding
中科院分区：
文献类型：
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作者：
F. Filice;Michelle S. M. Li;J. D. Henderson;Z. Ding
扫描电化学显微镜（SECM）是一种功能强大的非侵入性分析方法，可用于研究活细胞膜渗透性。深度扫描SECM成像允许生成活细胞相对于x-z或y-z平面中的电极位置的2D电流图。取决于分辨率，一个深度扫描图像可以包含数百个探头接近曲线（PAC）。通过简单地从2D图像中提取垂直横截面来获得个体PAC。将这些实验PAC叠加到在特定几何条件下模拟的理论生成的PAC上。使用COMSOL Multiphysics中的3D模型进行模拟，以确定细胞表面不同位置的细胞膜渗透系数。在文献中常见的是，使用2D轴对称几何形状生成理论PAC。这节省了计算时间和内存利用率。然而，由于模型的对称性限制，只有电池上方的一个实验PAC可以与模拟PAC数据相匹配。本文中的完整3D模型是为活细胞的SECM系统开发的，允许整个细胞上的所有实验PAC都可用。镉诱导的单个人膀胱（T24）细胞的膜通透性的变化进行了研究，在几个位置以上的细胞，从中心轴位移。研究中的实验T24细胞与不同浓度的Cd 2+孵育。实验观察到，50和100 μM Cd 2+导致膜渗透性降低，无论Cd 2+浓度如何，细胞所有位置的膜渗透性均一致。Cd ~（2+）对细胞有不利影响，细胞体积缩小，膜透性降低。通过所提出的方法实现了Cd 2+胁迫下细胞膜渗透性分析的映射技术。
Scanning Electrochemical Microscopy (SECM) is a powerful, non-invasive, analytical methodology that can be used to investigate live cell membrane permeability. Depth scan SECM imaging allowed for the generation of 2D current maps of live cells relative to electrode position in the x-z or y-z plane. Depending on resolution, one depth scan image can contain hundreds of probe approach curves (PACs). Individual PACs were obtained by simply extracting vertical cross-sections from the 2D image. These experimental PACs were overlaid onto theoretically generated PACs simulated at specific geometry conditions. Simulations were carried out using 3D models in COMSOL Multiphysics to determine the cell membrane permeability coefficients at different locations on the surface of the cells. Common in literature, theoretical PACs are generated using a 2D axially symmetric geometry. This saves on both compute time and memory utilization. However, due to symmetry limitations of the model, only one experimental PAC right above the cell can be matched with simulated PAC data. Full 3D models in this article were developed for the SECM system of live cells, allowing all experimental PACs over the entire cell to become usable. Cd2+-induced membrane permeability changes of single human bladder (T24) cells were investigated at several positions above the cell, displaced from the central axis. The experimental T24 cells under study were incubated with Cd2+in varying concentrations. It is experimentally observed that 50 and 100 μM Cd2+caused a decrease in membrane permeability, which was uniform across all locations over the cell regardless of Cd2+concentration. The Cd2+was found to have detrimental effects on the cell, with cells shrinking in size and volume, and the membrane permeability decreasing. A mapping technique for the analysis of the cell membrane permeability under the Cd2+stress is realized by the methodology presented.