Formation and Diffusivity Characterization of Supported Lipid Bilayers with Complex Lipid Compositions

摘要

The moving edge of a hydrodynamically manipulatednsupported lipid bilayer (SLB) can be used to catalyze SLB formation ofnadsorbed lipid vesicles that do not undergo spontaneous SLB formationnupon adsorption on SiO2. By removing the lipid reservoir of an initiallynformed SLB, we show how a hydrodynamically moved SLB patchncomposed of POPC can be used to form isolated SLBs withncompositions that to at least 95% represent that of the adsorbed lipidnvesicles. The concept is used to investigate the diffusivity of lissamine rhodamine B 1,2-dihexadecanoyl-sn-glycero-3-nphosphoethanolamine (rhodamine−DHPE) in SLBs made from complex lipid compositions, revealing a decrease in diffusivity byna factor of 2 when the cholesterol content was increased from 0% to 50%. We also demonstrate how the concept can be used toninduce stationary domains in SLBs containing 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC), 1,2-dioleoyl-sn-glycero-3-nphosphoethanolamine (DOPE), and cholesterol (39:21:40 mol %, respectively). Because the method serves as a means to formnSLBs with lipid compositions that hamper SLB formation via spontaneous rupture of adsorbed lipid vesicles, it opens up thenpossibility for new biophysical investigations of SLBs with more nativelike compositions.