- 1. A spherical particle of lipid substance suspended in an aqueous medium within a tissue. 2. Any small, roughly spherical artificial vesicle consisting of a lipid bilayer enclosing some of the suspending medium. [lipo- + G. soma, body]
* * *li·po·some 'lip-ə-.sōm, 'lī-pə- n1) one of the fatty droplets in the cytoplasm of a cell2) an artificial vesicle that is composed of one or more concentric phospholipid bilayers and is used esp. to deliver microscopic substances (as DNA or drugs) to body cellsli·po·so·mal .lip-ə-'sō-məl, .lī-pə- adj
* * *n.a microscopic spherical membrane-enclosed vesicle or sac (20-30 nm in diameter) made artificially in the laboratory by the addition of an aqueous solution to a phospholipid gel. The membrane resembles a cell membrane and the whole vesicle is similar to a cell organelle. Liposomes can be incorporated into living cells and may be used to transport relatively toxic drugs into cancer cells, where they can exert their maximum effects. The cancerous organ is at a higher temperature than normal body temperature, so that when the liposome passes through its blood vessels the membrane melts and the drug (e.g. doxorubicin) is released. Liposomes are also undergoing clinical trials as vehicles in gene therapy for cystic fibrosis.
* * *lipo·some (lipґo-sōm) [lipo- + -some] a spherical particle in an aqueous medium, formed by a lipid bilayer enclosing an aqueous compartment.
Medical dictionary. 2011.