Mapping Surface Charge Distribution of Single-Cell via Charged Nanoparticle

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.