Sensitivity of detection by biological AFM for gold-labeled liposomes at human coronary artery endothelial cell (HCAEC) membranes

Biological processes such as endocytosis/exocytosis, interactions between cells and the dynamic reorganization of the cytosqueleton are between the topics extensively studied using the Atomic Force Microscopy (AFM) technique. The topographical structure of the cell membrane itself is complex, rich in natural corrugations and ridges. These surface characteristics obscure the identification of extracellular structures when using AFM for membrane imaging. We have endeavored the utilization of 90nm nano-gold particles to label functionalized liposomes and monitor their endocytosis process on HCAEC. We successfully established a suitable and systematic method to study the internalization mechanism, binding sites, and distribution of gold labeled liposomes as a novel delivery system on endothelial cells. Our findings also demonstrated the usefulness of the AFM technique, combined with fluorescent microscopy, to investigate liposome detection within the membrane surface of endothelial cells and elucidate their binding mechanism.