Functionalization of Colloids with Robust Inorganic-Based Lipid Coatings

Abstract

Core−shell colloids, particles covered with polyelectrolyte (PE) multilayer films and lipid bilayer membranes, were prepared through self-assembly processes. The PE multilayer films were fabricated by the layer-by-layer (LbL) assembly of poly(diallyldimethylammonium chloride) (PDDA) and poly(sodium 4-styrenesulfonate) (PSS) onto colloidal particles. The inorganic-based synthetic lipid, N-[N-(3-triethoxysilyl)propylsuccinamoyl]dihexadecylamine (Si-lipid), was employed for membrane formation and was deposited onto the PE-coated particles through electrostatic interaction. The naturally occurring lipid, dimyristoylphosphatidic acid, sodium salt (DMPA), was also used for comparison. Multilayer film buildup on the particles was monitored stepwise by microelectrophoresis, and formation of the lipid bilayers was confirmed by fluorescence microscopy as well as scanning and transmission electron microscopy. The morphological stability of the Si-lipid and DMPA membranes to the surfactant Triton X-100 and ethanol wa...