Mapping Surface Charge Distribution of Single-Cell via Charged Nanoparticle

Leixin Ouyang,Ruiting Xu,Rubia Shaik,Jiang Zhe,Ge Zhang

doi:10.3390/cells10061519

Abstract

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.

Highlights

The significance of measuring and visualizing cell surface charge has gradually been recognized during the past decade
The surface charge density of a group of cells can be from the zeta potential meaThe surface charge density of a group of cells can be from the zeta potential meas surement; our results show that some displayed a charge density differing from the measThe surface charge density of acells group of cells cana be fromdensity the zetadiffering potential urement; our results show that some cells displayed charge from the average values
The results demonstrate that, in addition to the difference in bulk surface charge, human umbilical vein endothelial cells (HUVECs) and Hela cells have distinct surface charge distribution, suggesting the potentials of using cell surface charge distribution as a new criterion for cell type identification malignant cell detection

Summary

Introduction

The significance of measuring and visualizing cell surface charge has gradually been recognized during the past decade. Cell surface charge is determined by the composition and dynamic status of the cell membrane. It may differ among species, cell types, benign cells, or differentiation states [1]. The electrophoretic light scattering method remains the dominant method for measuring zeta potential or bulk surface charge of micro or nanoparticles. This method usually detects the motions of a group of cells; it is challenging to identify zeta potential for single cells [9], not to mention the surface charge distribution on a cell.

Methods

Results

Discussion

Conclusion