ABSTRACT
Liposomes, the self-assemblies of lipid molecules, come in various shapes and structures both in vitro and in vivo. It is their shape and structure that determine their function, both in a test tube and inside a living cell. This chapter reviews the wealth of liposomal shapes experimentally observed in vitro to date, in particular, focusing on membranes, i.e., lipid bilayer structures. We survey membrane shape evolution in two ways: shape evolution from the simplest to the most complex shapes in the context of scientific discovery, and shape evolution, when a membrane undergoes shape transitions or shape fluctuations in time. We discuss the underlying physical principles such as molecular shape and solvent-dependent molecular interactions, which dictate the shape of membranes and their shape transitions. A comprehensive overview of current continuum models predicting the shape evolution of membranes is provided, and the theoretical predictions of these models are compared against experimental observations. Furthermore, we discuss the shape evolution of biological membranes in the light of this knowledge.
