Studying Lyotropic Crystalline Phases Using High-Resolution MAS NMR Spectroscopy

Abstract

There is a large area, both in basic science and in applied research, in which lamellar liquid-crystalline phases play in important role. Dispersions of lipids and water, forming such phases, serve as models for biological membranes or because of there unique physico-chemical properties, they have been used as drug delivery systems. In this chapter the reader will be introduced in NMR methods for studying such systems. The chapter focuses on an experimental approach that is based on techniques that were developed for investigations of liquid-crystalline phases in combination with MAS. These techniques unsheathe properties that are related to the dynamic, liquid character of liquid-crystalline phases. Their general applicability and their limits are discussed. Their use is demonstrated with some examples covering biophysical studies as well as practical applications. The major focus is on problems that are related to molecules interacting with the lipid–water interfaces. The methods discussed reach from two-dimensional NOE spectroscopy for structure determination, up to the latest development, the combination of MAS with pulsed field gradient NMR spectroscopy to study diffusion properties.