The History And Function Of The Liposome

A liposome is an artificially-created bubble (vesicle) that is situated within a cell. These vessels can be used as artificial cells in research and experimentation. They also can be designed to deliver and distribute medications. These microscopic orbs were discovered in 1961 by British hematologist, Dr. Alec D. Bangham.

Drugs with liposomal delivery systems have been approved for the treatment of many conditions. Among them are protozoal and fungal infections, influenza, Hepatitis A, age-related macular degeneration, HIV-related Kaposi's sarcoma, as well as metastatic ovarian and breast cancer. It is also effective as a post-surgical alalgesic, and as part of a menopausal therapy program.

A wide range of liposome formulations may be developed by highly specialized laboratories. Among them is the plain variety, which contains no drugs. Known as the artificial cell model, it is frequently utilized in studies of membrane proteins. There are two types available: the unilamellar (single bi-layer), and the multi-lamellar (multiple layers, like onions).

These artificial cell-like structures may also be magnetized. The ability to be identified and manipulated by magnetic forces can be very valuable. For example, they can be directed toward specific area of interests, such as to the location of tumors. The magnetic liposome has many applications in the pharmaceutical realm, as well as in government and academic research labs.

Fluorescent models are also available. They give scientists the ability to monitor cellular activity, membrane permeability and transportation through gap junctions. Also, cell-to-liposome and cell-to-cell fusion can be analyzed. The groups of fluorescent lipids include glycerol and sphingosine-based fatty acids, as well as glycerol-based head groups.

Freeze-dried systems enhance storage stability. They prevent the hydrolysis of phospholipids and help delay degradation. However, in order to prevent damage, lyoprotectants must be used. The most effective are disaccharides, such as trehalose, lactose, and sucrose. If freeze-drying is conducted without the protection of lyoprotectants, aggregation and fusion will occur, as well as the extensive leakage of water-soluble compounds upon hydration.

Liposomes have historically been used for targeted drug delivery. However, a small number of dietary companies are pioneering a new trend which would use these micro-vessels to deliver specific nutritional supplements to the body. Since oral nutrients are widely known to have low absorption rates, scientists are particularly encouraged by the possibility of a more effective and complete delivery system. The phospholipid compound has the ability to create a natural bond with nearly each cell in the human body. This relationship allows the entrapped dietary supplements to be effectively transmitted to the body.