The formation of supported lipid bilayers on silica nanoparticles revealed by cryoelectron microscopy

The controlled fabrication of biocompatible devices made of lipid bilayers deposited onto flat solid supports presents interest as models of cell membranes as well as for their biotechnological applications. We report here on the formation of supported lipid bilayers on silica nanoparticles (nanoSLBs). The successive steps of the adsorption of lipid vesicles on nanoparticles and the formation of nanoSLBs are revealed in detail by cryotransmission electron microscopy (cryo-EM). The formation of nanoSLBs was achieved for liposomes with positive, neutral, and low net negative charge, while liposomes with a high net negative charge adsorbed to silica nanoparticles but did not rupture. The nanoSLBs were found to follow faithfully the surface contours of the particles, information yet unavailable for SLB formation on planar solid substrates.