A liposome is a man-made vesicle made of a bilayer of lipids. The liposomes can be used to represent vehicles that are used for the administration of nutrients as well as pharmaceutical drugs. They are usually prepared using disrupting biological membranes which may include sonication.

Liposomes are typically made of natural phospholipids. Besides, they may also be made of a combination of lipid chains bearing somewhat a high degree of surfactant features. These lipid chains might contain egg phosphatidylethanolamine. Their model may take the shape of surface ligands which are used for linking the tissues which are unhealthy.

There are different types of these artificial lipid rich vesicles. The main types of liposomes include multilamellar vesicle which is abbreviated as MLV, a small unilamellar vesicle which is shortened as SUV, a large unilamellar vesicle whose abbreviation is LUV, and finally the cochleate vesicle.

These products can easily be confused with micelles and reverse micelles. This might occur because they are nearly similar in structure. Their only difference is that liposomes have a double layer of lipids whereas micelles as well as reverse micelles are made of single layers of lipids.

The membranes of the structures are usually made of phospholipids, which allude to the molecules with head groups as well as tail groups. Their heads are typically attracted to water. Nevertheless, the tail is only made of long chains of hydrocarbons hence are usually resisted by water.

Their hydrophilic heads do make up the outermost layers while their hydrophobic tails make up the inner layers. This is because their heads are attracted to water while their tails are resisted by water. However, in every cell, a layer of heads always faces outside, and gets attracted to the polarized environment. Other layer of heads faces inside cell, and gets attracted to water molecules found within the cell. However, hydrophobic tails of its outer layer face hydrophobic tails of inner layers, thus forming a dual layer structure.

Liposomes were described by the British hematologist called Dr. Alec D Bangham in the year 1961 at the institute of Babraham in Cambridge. It was then published in 1964. They were obviously found to resemble plasmalemma. This was first evidenced by the pictures that were produced by the microscope that Bangham used.

They encapsulate an aqueous solution using a hydrophobic membrane. Chemicals which are insoluble in water easily pass across their membranes whereas the ones soluble in water do not. Nonetheless, dissolved hydrophilic particles are able to go through hydrophilic heads. As a result, it may be utilized in releasing hydrophobic and hydrophilic particles. It releases its constituents by adhering to other organelles with similar bilayer walls for instance cell membranes.

These vesicles are used in both drug and gene delivery application. The drugs and the DNA to be delivered are usually made to contain the pH that is suitable for the functions of the liposome. Its use in the transformation of DNA is called lipofection. Furthermore, it can also be used to deliver dyes to textiles, enzymes and dietary supplements to foods, pesticides to plants and also cosmetics to skin.