School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA, 30332, USA.
Interdisciplinary Program in BioEngineering and George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA, 30332, USA.
Small. 2017 Jul;13(27). doi: 10.1002/smll.201700789. Epub 2017 May 26.
All cells have a resting membrane potential resulting from an ion gradient across the plasma membrane. The resting membrane potential of cells is tightly coupled to regeneration and differentiation. The ability to control this parameter provides the opportunity for both biomedical advances and the probing of fundamental bioelectric pathways. The use of poly(3,4-ethylenedioxythiophene): polystyrene sulfonate (PEDOT:PSS) conducting polymer microwires to depolarize cells is tested using E. coli cells loaded with a fluorescent dye that is pumped out of the cells in response to depolarization; a more positive membrane potential. Fluorescence imaging of the cells in response to a conducting-polymer-microwire applied voltage confirms depolarization and shows that the rate of depolarization is a function of the applied voltage and frequency. Microwire activity does not damage the cells, demonstrated with a propidium iodide assay of membrane integrity. The conducting polymer microwires do not penetrate the cell, or even come into contact with the cell; they only need to generate a minimum electric field, controlled by the placement of the wires. It is expected that these microwires will provide a new, noninvasive, cellular-scale tool for the control of resting membrane potential with high spatial precision.
所有细胞都具有由于质膜两侧离子梯度而产生的静息膜电位。细胞的静息膜电位与再生和分化密切相关。控制这一参数的能力为生物医学的进步和对基本生物电通路的探究提供了机会。使用聚(3,4-乙二氧基噻吩)：聚苯乙烯磺酸盐(PEDOT：PSS)导电聚合物微丝使细胞去极化，方法是使用加载有荧光染料的大肠杆菌细胞，该荧光染料在去极化时被泵出细胞，即膜电位变得更正；细胞对导电聚合物微丝施加电压的荧光成像证实了去极化，并表明去极化的速率是施加电压和频率的函数。微丝活性不会损坏细胞，这可以通过质膜完整性的碘化丙啶测定来证明。导电聚合物微丝不会穿透细胞，甚至不会与细胞接触；它们只需要产生一个由导线位置控制的最小电场。预计这些微丝将提供一种新的、非侵入性的、细胞尺度的工具，用于以高精度的空间控制静息膜电位。
