Roles of lipid polymorphism in intracellular delivery

• Published in: Advanced drug delivery reviews Vol. 47; no. 2; pp. 139 - 148
• Main Authors: Hafez, Ismail M., Cullis, Pieter R.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 25.04.2001
• Subjects: Bilayer destabilization; Glycerophospholipids - chemistry; Glycerophospholipids - metabolism; Hydrogen-Ion Concentration; Inverted hexagonal phase; Lipid Bilayers - chemistry; Lipid Bilayers - metabolism; Lipid Metabolism; Lipid-based delivery systems; Lipids - chemistry; Liposomes; Membrane fusion; Membrane Fusion - physiology; Membrane Lipids - chemistry; Membrane Lipids - metabolism; Micelles; pH-sensitive liposomes; Phosphatidylethanolamines; Membrane fusion; Bilayer destabilization; pH-sensitive liposomes; Lipid-based delivery systems; Inverted hexagonal phase
• ISSN: 0169-409X; 1872-8294
• DOI: 10.1016/S0169-409X(01)00103-X

Lipids, which adopt nonbilayer phases, have fascinated researchers as to the functional roles of these components in biomembranes. In particular, lipids capable of adopting the hexagonal H II phase have received considerable attention because of the observation that such lipids can promote membrane fusion. In the rational design of lipid-based delivery systems, H II phase lipids have been employed to endow systems with fusogenic, membrane-destabilizing properties. We will outline the molecular basis for the polymorphic phase behavior of lipids and highlight some of the uses of nonbilayer lipids in the preparation of lipid-based delivery systems. In addition, a distinction will be drawn between lipid-based systems which rely on the inclusion of nonbilayer lipids for activity, and systems which contain components which actively promote formation of nonbilayer structure within biological membranes.