Liposomal drug delivery system

Abstract

Lipid-based self-assembling vesicles were first described in 1961 and reported in 1964 by Dr. Alec D. Bangham (Bangham and Horne in J Mol Biol 8:660–668, 1964) at the Babraham Institute in Cambridge, UK, in which he wrote: “It is probable that at equilibrium each and every lipid bilayer forms an unbroken membrane-there being no exposed hydrocarbon/water interface-from which it follows that every aqueous compartment would be discrete and isolated from its neighbor, including a complete separation of the outermost compartment of the whole structure from the continuous phase in which it is suspended”. It is thermodynamically possible for each lipid bilayer to form a discrete membrane, separating the vesicle from the continuous aqueous phase in which it is suspended. These “unbroken membranes” were called as “liquid crystal” or “smectic mesophase”, “Bangasomes” after the name of Dr. Bangham, and finally “liposomes”. The word “liposome” derives from two Greek words of “lipo-meaning fat” and “soma-meaning body”. In the earlier days, these artificial vesicles (or liposomes) were used for the study of cell physiology such as ion (or drug) permeability, membrane fusion, membrane-bound enzyme properties or as a membrane model. More recently, much attention was brought to the uses of liposomes in medical fields as drug delivery systems and the first article of this kind was published in 1971 in FEBS Letters by Dr. George Gregoriadis and his co-workers, where amyloglucosidase and albumin were entrapped into liposome for the purpose of enzyme replacement therapy (Gregoriadis et al. in FEBS Lett 14(2):95–99, 1971). Since then, tremendous amounts of papers were published on the uses of liposomes as a drug delivery system (DDS). So, this mini-review is mainly focused on the use of liposome as DDS.