Interaction between anaesthetics and model biomembrane systems

Supported layers of vesicles of dimyristoyl and dipalmitoyl phosphatidylcholine containing cholesterol are adequate models for eukaryotic plasma membranes. In this work it was investigated the adsorption of unilamellar vesicles on the surface of oxidized gold, using a QCM-D, AFM and LSCFM. The results of all techniques indicate that a dense layer of intact liposomes irreversibly adsorbs on the gold surface. It was also investigated the interaction of some examples of local and general anaesthetics with these membrane models, using a QCM-D. Lidocaine, tetracaine, ropivacaine and levobupivacaine were chosen as local anaesthetics examples, and propofol as general anaesthetic. Simultaneously, the interaction of the anaesthetics with the same liposomes in suspension was studied, using DSC. The results showed that all the studied anaesthetics interacted with the used models, causing changes such as raised fluidity and depressed phase transition temperature.