Supported lipid bilayer formation by the giant vesicle fusion induced by vesicle–surface electrostatic attractive interaction

Abstract

The effect of the electrostatic attractive force between giant unilamellar vesicles (GUVs) and the SiO 2 surface on the formation of a Ca 2+-free supported lipid bilayer (SLB) was investigated by atomic force microscopy and fluorescence microscopy. When negatively charged GUVs were incubated for 1 h without Ca 2+, the surface coverage of lipid bilayer was <1% on the SiO 2 surface. In contrast, a high coverage was obtained without addition of Ca 2+ on the positively charged surface modified by aminopropyldimethylethoxysilane, and the coverage of SLBs decreased with increasing KCl concentrations. The thickness of the water layer under SLB was reduced by modification of APS.