Liposomes: types and uses
A liposome is a vesicle or small bubble that is made up of the same components as a cell membrane. Liposomes are stores of drugs that have been found to be beneficial in curing cancer and various other diseases.
British Hematologist – Dr Alec D Bangham FRS was the first to discover liposomes at the Babraham Institute in Cambridge in 1961.
Liposome derives its name from the Greek words – ‘Lipos’ (fat) and ‘Soma’ (body). Liposomes can have different sizes of molecules and can therefore represent unilamellar or multilamellar constructions. Nanosomes are liposomes in the low nanometer range. However, nanosomes contain water that liposomes do not.
Phospholipids are the building blocks of cell membranes and these molecules with a head and tail group also make up the liposome. The head group of the phospholipid attracts water, while the long chain hydrocarbon tail repels water. Liposomes include naturally occurring phospholipids that have mixed lipid chains. They can also be composed of DOPE (dioleoylphosphatidylethanolamine) as pure surfactants.
Liposomes are of three types:
MLV or multilamellar vesicles
SUV or Small Unilamillary Vesicles
LUV or Large Unilamillary Vesicles
Liposomes are widely used in drug preparation for their unique properties.
They are also used in various gene delivery applications, such as lipofection, in which DNA is transformed into a host cell.
They find use as carriers when dyeing textiles
· They also act as carriers in plants of pesticides, enzymes and various nutritional supplements and cosmetics.
Liposomes are widely used in nanocosmetology and have several benefits.
· One of the strongest positives of liposomes continues to be the treatment of cancer.
Liposomes and nanoliposomes do not form spontaneously. Liposomes can be synthesized by the process of sonication of phospholipids in water. Reducing shear rates gives way to multilamellar liposomes and a continuous flow of high shear sonication leads to smaller unilamellar liposomes. Processes such as the Mozafari method and extrusion are used for the production of liposomes for human use.