Lipid Nanotubes: Formation, Templating Nanostructures and Drug Nanocarriers

Drawing from nature's amazing ability to form highly ordered structures, designed lipid molecules can organize via noncovalent self-assembly in liquid media to form open-ended, hollow cylindrical structures, which are composed of rolled-up bilayer membrane walls. The generated lipid nanotubes (LNTs) represent a potentially powerful architecture, and are considered among the largest self-organized nonliving structures yet observed. LNTs have a few unique properties well suited for a variety of applications in chemistry, biochemistry, materials science, and medicine. The lipid headgroups can function as templates for the nucleation, growth, and deposition of inorganic substances on the external and internal surfaces of preformed LNTs. The well designed cylindrical form of the LNTs, with tunable dimensions (e.g., inner and outer diameters and lengths as well as wall thickness), biocompatible membrane surfaces, and easy surface modification, makes them an ideal nanocarrier for drug delivery. This review assesses recent progress in the formation of the LNTs and in their application as templates for structured nanomaterials and drug nanocarriers.