liposome


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liposome

(lī`pəsōm', lĭp`ə–), microscopic, fluid-filled pouch whose walls are made of layers of phospholipidsphospholipid
, lipid that in its simplest form is composed of glycerol bonded to two fatty acids and a phosphate group. The resulting compound called phosphatidic acid contains a region (the fatty acid component) that is fat-soluble along with a region (the charged phosphate
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 identical to the phospholipids that make up cell membranes. Liposomes are used to deliver certain vaccines, enzymes, or drugs (e.g., insulin and some cancer drugs) to the body. When used in the delivery of certain cancer drugs, liposomes help to shield healthy cells from the drugs' toxicity and prevent their concentration in vulnerable tissues (e.g., the kidneys, and liver), lessening or eliminating the common side effects of nausea, fatigue, and hair loss. Liposomes are especially effective in treating diseases that affect the phagocytes of the immune system because they tend to accumulate in the phagocytes, which recognize them as foreign invaders. They have also been used experimentally to carry normal genes into a cell in order to replace defective, disease-causing genes (see gene therapygene therapy,
the use of genes and the techniques of genetic engineering in the treatment of a genetic disorder or chronic disease. There are many techniques of gene therapy, all of them still in experimental stages.
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). Liposomes are sometimes used in cosmetics because of their moisturizing qualities.

Liposomes were first produced in England in 1961 by Alec D. Bangham, who was studying phospholipids and blood clotting. It was found that phospholipids combined with water immediately formed a sphere because one end of each molecule is water soluble, while the opposite end is water insoluble. Water-soluble medications added to the water were trapped inside the aggregation of the hydrophobic ends; fat-soluble medications were incorporated into the phospholipid layer.

In some cases liposomes attach to cellular membranes and appear to fuse with them, releasing their contents into the cell. Sometimes they are taken up by the cell, and their phospholipids are incorporated into the cell membrane while the drug trapped inside is released. In the case of phagocytic cells, the liposomes are taken up, the phospholipid walls are acted upon by organelles called lysosomes, and the medication is released. Liposomal delivery systems are still largely experimental; the precise mechanisms of their action in the body are under study, as are ways in which to target them to specific diseased tissues.

liposome

[′lip·ə‚sōm]
(cell and molecular biology)
One of the fatty droplets occurring in the cytoplasm, particularly of an egg.
References in periodicals archive ?
The report provides brief overview of Taiwan Liposome Company, Ltd.
While the sites of action of liposome-cell interactions are largely determined by size, knowing the zeta potential of a liposome preparation can help predict the fate of the liposomes in vivo.
Review of current pipeline of Taiwan Liposome Company, Ltd.
Doxorubicin hydrochloride liposome injection is administered intravenously by a health care professional.
According to the beauty industry liposomes are capable of transporting active ingredients deep into the skin and release the active ingredients so that they can alter the skin's structure by rejuvenating and smoothing the skin.
The injection is the generic equivalent to Janssen Research and Development's Doxil Liposome Injection, two mg/ml.
Currently, liposomes are being used as excipient for preparing better tolerated preclinical and clinical formulations of several lipophilic, poorly water-soluble drugs such as amphotericin B [57], porphyrins, minoxidil, some peptides and anthracyclines, furthermore, in some cases hydrophilic drugs, such as anticancer agent doxorubicin [58] or acyclovir can be encapsulated in the liposome interior at concentrations several fold above their aqueous solubility.
Merck Serono remains highly committed to the development of BLP25 liposome vaccine and the well-being of the patients.
You may know that liposomes are tiny bubbles--vesicles--made out of the same material as a cell membrane.
Liposome Herbasec has the advantage of being manufactured from plant-derived, non-GMO raw materials derived from renewable resources and is water-dispersible, solvent- and preservative-free and BDIH conforming.
The present data suggested that lipid vesicle-trapped herbal antioxidant quercetin and CDP-Choline may not only be effective in combating the cerebral ischemic reperfusion oxidative damage but also to prevent cerebral edema development both in young and old animals) The mechanism how quercetin and CDP-Choline in mannosylated liposome exerts a complete protection against ischemia-reperfusion mediated cerebral oxidative damage in young and aged rats is not fully clear) Although expression of the mannose mannosylated liposomes were successfully incorporated into mouse brain)
An anionic liposome was used recently for the encapsulation of condensed plasmid DNA.