Liposomes have attracted much attention since they were first discovered. These artificially created, microscopic spheres have many properties that make them extremely useful. One of these is their bio-compatibility. They act in exactly the same way as the cellular membranes of the body. This means they can be used as a unique delivery system for nutrients, drugs and other agents to specific areas in an organism. There are a numbers of ways in which liposome manufacturing is achieved, all of which have advantages and disadvantages.
Phospholipids like lecithin is used as raw material. The phospholipid molecules have heads that love water. They also have two tails that are essential fatty acid chains repelled by water. When the phospholipids are put in a solution that is water-based, the heads end up side by side with the tails trailing behind. The fact that the tails repel water means that another layer lines up with the tails facing the tails of the first layer. This natural alignment results in two rows of tightly fitting molecules. These layers form membranes around and inside all cells.
Liposomes are used to deliver toxic drugs to target cancer cells. They are used for delivering nutrients deficient in the body or cosmetic nutrients to the skin. Many other medical applications are possible too such as in the field of genetics. Preparation methods depend on various factors such as the characteristics of the material to be carried, the consistency offered from batch to batch and scale of production.
The tiny size of liposomes means they are quickly assimilated into the bloodstream for delivery throughout the body. The payload is biologically inert until it is delivered to needy cells. They are all basically the same but the differences between them occur in the way they are released, how long this takes as well as where and why this occurs.
Liposomes are usually synthesized by mixing and dissolving phospholipids in organic solvent. A clear lipid film is formed by removing the solvent. Hydration of this film eventually leads to formation of large vesicles which have several layers, much like the structure of an onion. Each bilayer is separated from the other by water. A form of energy is required to reduce their size. Sonication, agitation by sound waves, is one method used and extrusion is another.
Liposomes are actually fairly simple to make, not requiring complex materials, equipment or methods. Each method and technique offers certain benefits and has some failings. Sonication can cause structural changes to what is entrapped. Liquid hydration methods do not produce a high payload.
Some of the problems that have to be faced are structural instability, inconsistency in size and expensive production costs. Liposomal delivery systems are still in the experimental stage. The precise ways in which they act within the body are being carefully studied as well as ways in which they can be made to target diseased tissue or a specific organ.
Although conventional methods of manufacture are effective, research continues apace to make them more so. Much research is being conducted into ways in which liposomes can be created that have a strong chemical affinity for the cells of a particular organ or kind of tissue. They also need to have the ability to deliver payloads to the cells as efficiently as possible.
Phospholipids like lecithin is used as raw material. The phospholipid molecules have heads that love water. They also have two tails that are essential fatty acid chains repelled by water. When the phospholipids are put in a solution that is water-based, the heads end up side by side with the tails trailing behind. The fact that the tails repel water means that another layer lines up with the tails facing the tails of the first layer. This natural alignment results in two rows of tightly fitting molecules. These layers form membranes around and inside all cells.
Liposomes are used to deliver toxic drugs to target cancer cells. They are used for delivering nutrients deficient in the body or cosmetic nutrients to the skin. Many other medical applications are possible too such as in the field of genetics. Preparation methods depend on various factors such as the characteristics of the material to be carried, the consistency offered from batch to batch and scale of production.
The tiny size of liposomes means they are quickly assimilated into the bloodstream for delivery throughout the body. The payload is biologically inert until it is delivered to needy cells. They are all basically the same but the differences between them occur in the way they are released, how long this takes as well as where and why this occurs.
Liposomes are usually synthesized by mixing and dissolving phospholipids in organic solvent. A clear lipid film is formed by removing the solvent. Hydration of this film eventually leads to formation of large vesicles which have several layers, much like the structure of an onion. Each bilayer is separated from the other by water. A form of energy is required to reduce their size. Sonication, agitation by sound waves, is one method used and extrusion is another.
Liposomes are actually fairly simple to make, not requiring complex materials, equipment or methods. Each method and technique offers certain benefits and has some failings. Sonication can cause structural changes to what is entrapped. Liquid hydration methods do not produce a high payload.
Some of the problems that have to be faced are structural instability, inconsistency in size and expensive production costs. Liposomal delivery systems are still in the experimental stage. The precise ways in which they act within the body are being carefully studied as well as ways in which they can be made to target diseased tissue or a specific organ.
Although conventional methods of manufacture are effective, research continues apace to make them more so. Much research is being conducted into ways in which liposomes can be created that have a strong chemical affinity for the cells of a particular organ or kind of tissue. They also need to have the ability to deliver payloads to the cells as efficiently as possible.
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