Electrochemiluminescence imaging of cellular adhesion in vascular endothelial cells during tube formation on hydrogel scaffolds

Abstract

This study describes a method for electrochemiluminescence (ECL) imaging of cellular adhesion in vascular endothelial cells during tube formation on hydrogel scaffolds. Human umbilical vein endothelial cells were cultured on a Matrigel-coated indium tin oxide (ITO) electrode to facilitate tubule growth. Once these tubes were formed, the culture medium was changed to an ECL solution containing [Ru(bpy)3]2+ and tripropylamine and then subjected to 1.2 V vs Ag/AgCl (sat. KCl) to produce ECL signals at the ITO electrode. This allowed for ECL imaging of cellular adhesion because these ECL signals were blocked in areas typified by strong cell–cell and cell–substrate adhesion. The imaging showed that there were two types of cellular adhesion during tube formation. To the best of our knowledge, this is the first report on ECL imaging for adhesion between cells and between cells and substrates during tube formation on hydrogel scaffolds. We believe that this ECL imaging technique will be useful for the evaluation of organs-on-a-chip and for drug screening targeting cell–cell and cell–substrate interactions in the future.