What are Liposomes?
Liposomes are microscopic vesicles developed in a laboratory environment. Each liposome has an outer wall comprised of lipids similar and sometimes identical to those which compose the cell wall, allowing liposomes to interact directly with cells. There are a number of applications for liposomes, ranging from targeted delivery of medications to specific areas of the body to genetics research in the laboratory. The liposome was first developed by a British researcher, Alec Bangham, in 1961. According to legend, he was experimenting with new laboratory equipment, and he made a noted observation about the structure of the cell wall and developed liposomes at the same time. Numerous other researchers have worked with these structures since, developing new information about them along with potential uses. Natural cell membranes, as Bangham learned, are made from a double layer of phospholipids. Each phospholipid has a head which is drawn to water and a tail which is repelled by it, and in t
Liposomes are small, spherical vesicles which consist of amphiphilic lipids, enclosing an aqueous core. The lipids are predominantly phospholipids which form bilayers similar to those found in biomembranes (see figure 1). In most cases the major component is phosphatidyl choline. Depending on the processing conditions and the chemical composition, liposomes are formed with one or several concentric bilayers.
Liposomes were discovered in 1961 by Alec D. Bangham who was studying phospholipids and blood clotting, and since then they became very versatile tools in biology, biochemistry and medicine. Liposomes are nano size artificial vesicles of spherical shape that can be produced from natural phospholipids and cholesterol. Bangham discovered that phospholipids combined with water immediately forms a bi-layered sphere because one end of each molecule is water soluble, while the opposite end is water insoluble (see Figure bellow). Liposomes are broadly classified by their structure Multilamellar liposomes: Spherically concentric multilamellar (many bilayers) structures Unilamellar liposomes: Spherical concentric unilamellar (one bilayer) structures The properties of liposomes in addition to the general properties of surfactants those make them useful for different applications are Structural stability on dilution Varying permeability of the bilayer to different molecules. Ability to entrap bot
