Department of Mechanical Engineering, University of Akron, Akron, OH 44325, USA.
Department of Biomedical Engineering, University of Akron, Akron, OH 44325, USA.
Cells. 2021 Jun 16;10(6):1519. doi: 10.3390/cells10061519.
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.
许多细胞的生物功能可以通过其表面电荷特性来调节。绘制单个细胞表面的表面电荷密度对于深入了解细胞行为至关重要。本文展示了一种通过静电细胞-纳米颗粒（NP）相互作用来绘制细胞表面电荷图的方法。荧光纳米颗粒（NPs）被用作标记物来研究单个细胞的表面电荷分布。带相反电荷的纳米颗粒静电键合到细胞表面；在一系列垂直距离处对细胞表面上的荧光分布进行成像和分析。通过建立荧光强度与纳米颗粒数量之间的关系，从荧光分布中定量细胞表面的电荷分布。测试了两种类型的细胞，人脐静脉内皮细胞（HUVECs）和 HeLa 细胞。从一组单细胞的测量表面电荷密度中，获得了两种类型细胞的平均 zeta 电位，这与标准电泳光散射测量非常吻合。这种方法可用于快速绘制单个颗粒或细胞的表面电荷图，并可推进许多生物医学领域中细胞表面电荷特性的应用。
