scholarly journals Direct measurement of surface charge distribution in phase separating supported lipid bilayers

Nanoscale ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 4538-4544 ◽  
Author(s):  
Thomas Fuhs ◽  
Lasse Hyldgaard Klausen ◽  
Steffan Møller Sønderskov ◽  
Xiaojun Han ◽  
Mingdong Dong

The local surface charge density of the cell membrane influences regulation and localization of membrane proteins.

Cells ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1519
Author(s):  
Leixin Ouyang ◽  
Rubia Shaik ◽  
Ruiting Xu ◽  
Ge Zhang ◽  
Jiang Zhe

Many bio-functions of cells can be regulated by their surface charge characteristics. Mapping surface charge density in a single cell’s surface is vital to advance the understanding of cell behaviors. This article demonstrates a method of cell surface charge mapping via electrostatic cell–nanoparticle (NP) interactions. Fluorescent nanoparticles (NPs) were used as the marker to investigate single cells’ surface charge distribution. The nanoparticles with opposite charges were electrostatically bonded to the cell surface; a stack of fluorescence distribution on a cell’s surface at a series of vertical distances was imaged and analyzed. By establishing a relationship between fluorescent light intensity and number of nanoparticles, cells’ surface charge distribution was quantified from the fluorescence distribution. Two types of cells, human umbilical vein endothelial cells (HUVECs) and HeLa cells, were tested. From the measured surface charge density of a group of single cells, the average zeta potentials of the two types of cells were obtained, which are in good agreement with the standard electrophoretic light scattering measurement. This method can be used for rapid surface charge mapping of single particles or cells, and can advance cell-surface-charge characterization applications in many biomedical fields.


2021 ◽  
Author(s):  
Leixin Ouyang ◽  
Rubia Shaik ◽  
Ruiting Xu ◽  
Ge Zhang ◽  
Jiang Zhe

Abstract Background: Many bio-functions of cells can be regulated by their surface charge characteristics. Mapping surface charge density in a single cell’s surface is vital to advance the understanding of cell behaviors. Results: This article demonstrates a method of cell surface charge mapping via electrostatic cell–nanoparticle interactions. Nanoparticles with fluorescence were used as the marker to investigate single cells’ surface charge distribution. The nanoparticles with opposite charges were electrostatically bonded to the cell surface; a stack of fluorescence distribution on a cell’s surface at a series of vertical distances was imaged and analyzed. By establishing a relationship between fluorescence light intensity and surface charge density, cells’ surface charge distribution was quantified from the fluorescence distribution. Two types of cells, HUVECs and Hela cells, were tested. From the measured surface charge density of a group of single cells, the average zeta potential of the two types of cells was obtained, which is in good agreement with the standard electrophoretic light scattering measurement. Conclusions: This method can be used for rapid surface charge mapping of single particles or cells and can advance cell-surface-charge characterization applications in many biomedical fields.


Nanoscale ◽  
2021 ◽  
Author(s):  
Feng Chen ◽  
Jin He ◽  
Prakash Manandhar ◽  
Yizi Yang ◽  
Peidang Liu ◽  
...  

The distribution of surface charge and potential of cell membrane plays an indispensable role in cellular activities. However, probing surface charge of live cells in physiological conditions, until recently, remains...


1982 ◽  
Vol 60 (1) ◽  
pp. 42-48 ◽  
Author(s):  
G. Roy ◽  
Y. Okada ◽  
R. Laprade

The adsorption of Br-X537A and its effect on the surface potential of monoolein lipid bilayers was measured using the nonactin conductance as a probe to determine the surface charge density. Because of the pH dependence of this adsorption, it was concluded that not only the negatively charged molecules X− could induce a surface charge but also a dimer HX2− made from X− and the neutral molecule HX. Also an important bilayer conductance was induced by Br-X537A. From the Br-X537A concentration dependence of this conductance, the effect of pH, and the induced surface potential, it was found that two charged complexes are transported across the bilayer depending on pH. At pH ≥ 7 the conducting molecule is X− and at pH ≤ 5 the complex is H2X3−. A quantitive model is obtained to calculate both the induced surface potential and the conductance.


Author(s):  
Andrey B. Yakovlev ◽  
Valeriya S. Federyaeva

AbstractAn analytical solution is presented for the electric field response generated by a nonconducting ellipsoid (prolate spheroid) in a homogeneous conducting fluid subject to an external primary electric field, including surface charge distribution. Such a solution might be useful for different purposes, including cell modeling subject to an external quasistatic electromagnetic stimulus. The solution utilizes the well-known analogy between the electrostatics of dielectrics and DC conduction. The solution obtained includes an expression for the volumetric fields and an expression for the induced surface charge density at the membrane.


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