Self-assembly, stability and the electrical characteristics of cell membranes

Living cells are enveloped in an ultra thin ( ~ 6 nm) membrane which consists basically of a bi-molecular film of lipid molecules in which are embedded functional proteins that perform a variety of functions, including energy transduction, signalling, transport of ions (and other molecules) etc., and also acts as a diffusion barrier between the cell interior (cytoplasm) and the external medium. A simple statistical mechanical analysis of the self-assembly of the membrane from its components provides useful insights into the molecular organisation of the membrane and its electrical properties. The stability of the structure is also closely connected to its electrical properties and this has provided not only a useful tool for fundamental research but has spawned also applications, some of which have had a major impact in biomedical research and are now being exploited commercially. An overview is given of the rapid progress made in our understanding of the physics of both the molecular organisation and function of cell membranes and some of the fascinating and socially and commercially important applications that have flowed from this.