Polar Lipids: Phospholipids and Glycolipids

AbstractNature was remarkably inventive in creating the variety of polar lipids that form the matrix of biological membranes. Both phospholipids and glycolipids are polar lipids and are important constituents of natural membranes. Typically found on the outer surface of cellular membranes, glycolipids maintain the stability of the membrane, facilitate cellular regulation, and enable cell‐to‐cell communication. Phospholipids are the major lipid constituent in cell membrane, thus maintaining the structural integrity between the cell and its environment and providing boundaries between compartments within the cell. Phospholipids have many functions in biological systems, including as fuels, as membrane structural elements, as signaling agents, and as surfactants. As main components of the cellular membrane, phospholipids have excellent biocompatibility and amphiphilicity. These unique properties make phospholipids most appropriate to be employed as important pharmaceutical excipients, and they have a very wide range of applications in drug delivery systems. In addition, phospholipids are widely used in food, feed, agriculture, cosmetics, and chemical industries. This article focuses on the basic chemistry, sources, synthesis, physical and analytical chemistry, and applications of phospholipids and glycolipids.