Tethered bilayer lipid membranes are versatile solid-supported model membrane systems. Core to these systems is an anchorlipid that covalently links a lipid bilayer to a support. The molecular structure of these lipids can have a significant impact on the properties of the resulting bilayer. Here, the synthesis of anchorlipids containing ester groups in the tethering part is described. The lipids are used to form bilayer membranes, and the resulting structures are compared with membranes formed using conventional anchorlipids or sparsely tethered membranes. All membranes showed good electrical sealing properties; the disulphide-terminated anchorlipids could be used in a sparsely tethered system without significantly reducing the sealing properties of the lipid bilayers. The sparsely tethered systems also allowed for higher ion transport across the membrane, which is in good correlation with higher hydration of the spacer region as seen by neutron scattering.

The direct interaction of drugs with the cell membrane is often neglected when drug effects are studied. Systematic investigations are hindered by the complexity of the natural membrane and model membrane systems can offer a useful alternative. Here some examples are reviewed of how model membrane architectures including vesicles, Langmuir monolayers and solid supported membranes can be used to investigate the effects of drug molecules on the membrane structure, and how these interactions can translate into effects on embedded membrane proteins.

Damage to cellular membranes from oxidative stress has been implicated in aging related diseases. We report the effects of oxidative damage on the structure and properties of biomimetic phospholipid membrane systems. Two oxidation methods were used, in situ oxidation initiated using Fe(II) and ascorbate, and the incorporation of a synthetic "oxidized" phospholipid, PoxnoPC, into biomimetic membranes. The biomimetic systems employed included multibilayer stacks, tethered bilayers, and phospholipid monolayers studied using a combination of reflectometry, attenuated total reflection infrared spectroscopy, electrochemical impedance spectroscopy, and neutron diffraction. We show that oxidation with Fe(II) and ascorbate caused an increase in the order of the membrane, attributed to cross-linking of the phospholipids, and a change in the electrical permeability of the membrane, but no significant impact on the thickness or completeness of the membrane. Incorporation of PoxnoPC, on the other hand, had a larger impact on the structure of the membrane. Inversion of the aldehyde-terminated truncated sn-2 chain of PoxnoPC into the head group region was observed, along with a slight decrease in the thickness and order of the membrane.

The effect of ionic strength and pH on the structure of hydrated plasma polymerized films of allylamine (ppAAm) and acrylic acid (ppAAc) has been analyzed in situ using quartz crystal microbalance with dissipation techniques, electrochemical impedance spectroscopy, ellipsomtery, and X-ray photoelectron spectroscopy. Both materials showed a salt concentration and pH dependent uptake and release of water and ions. Depending on the type of monomer used, the effects showed reversible or non-reversible behavior. The investigation of the electrochemical properties of the film further revealed a non-homogeneous structure, especially in the case of ppAAc films, with regions of higher and lower cross-linking density. The use of complimentary techniques to characterize the films in situ allowed for a deeper understanding of processes happening inside the plasma polymerized films, which can help to optimize film preparation conditions for selected applications.