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Engineering of surface-supported lipid membrane model systems is currently a very active field of research. The present contribution will present a number of recent examples in this area from our group, including both different kinds of supported lipid structures; supported lipid bilayers and vesicles, tethered vesicles, and hole-spanning membranes; as well as different kinds of biomolecular interactions associated with them. The main techniques used to follow these processes are the quartz crystal microbalance with dissipation monitoring (QCM-D), surface plasmon resonance (SPR), fluorescence microscopy, and atomic force microscopy (AFM). Some new findings about of the factors influencing how lipid bilayers or monolayers of intact vesicles are formed on SiO2 surfaces will be presented. We will also describe new results about processes on the adsorbed lipid structures. In particular, the action of lipases (via hydrolysis of phospholipids) on supported lipid bilayers has been monitored by different techniques, as well as the effect of lipases on tethered vesicles (including PEG-ylated vesicles of relevance for drug delivery applications). Two types of lag phases have been observed, both the kinetically determined lag time before the onset of rapid hydrolysis, but also the mass transport controlled removal of the hydrolysed membrane from the surface. Another example that will be covered is the exchange of lipid material between charged supported lipid membranes and vesicles; potentially a method for the in situ modification of supported membranes. |