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 the case of the cell wall, the heads and tails form a two-layered circle around the cell. The heads face out into the body, while the tails connect with each other, allowing the heads of the other side to face into the cell. The same holds true of the walls of liposomes.
The inside of a liposome can be packed with medication, vaccines, DNA, and a variety of other substances. When liposomes are introduced into the body, they can mesh with various cells, delivering their payload. One advantage to using liposomes is that they can be used to shield delicate cells from harsh drugs, and they are believed to be nontoxic, so the delivery method for the drugs should not cause a reaction.
In the lab, liposomes have been used to transfer DNA into target cells. This allows researchers to use liposomes rather than viral or bacterial vectors to make genetic modifications, which carries some distinct advantages. The lab experiments also suggest that liposomes could be used to deliver gene therapy to patients, with the cells bringing in replacement DNA for damaged material, up to entire chromosomes.
In addition to being used in science and medicine, the liposome also shows up in cosmetics. These structures are especially effective for moisturizers, increasing the strength and efficacy of such products considerably. Like many developments which started in the scientific community, they are also used as an advertising point in ingredient lists, as some cosmetics consumers prefer products which are associated with science and medicine.