Intermediate-sized unilamellar vesicle

Based on size and lamellarity, liposomes can be categorized into four groups (175, 205) (as indicated in Figure 8.22) (i) multilanellar vesicles (MLVs) (ii) large unilamellar vesicles (LUVs) (iii) small unilamellar vesicles (SUVs) and (iv) intermediate-size unilamellar vesicles (lUVs), which are also called reverse-phase evaporation vesicles (REV). 

Intermediate-sized unilamellarvesicles (lUVs) have diameters of the order of magnitude of 100 nm, and are called large unilamellarvesicles (LUVs) if the size is more than 100 nm and they consist of a single bilayer. For unilamellarvesicles, the phospholipid content is related to the surface area of the vesicles, which is proportional to the square of the radius, while the entrapped volume varies with the cube of the radius. In addition, because of the Lnite thickness of the membrane (ca. 4 nm), as thf vesicles become smaller, their aqueous volume is further reduced since the phospholipids occupy more of the internal space. Consequently, for a given quantity of lipid, large unilamellar liposomes... 

Introduction - Liposomes are vesicles composed of one or more lipid bilayers completely surrounding an internal aqueous space. They are usually composed of phospholipids either in pure form or In combination with other amphipathic molecules such as sterols, long chain bases or acids, or membrane proteins. The structure of liposomes varies from large (0.5->5y) multllamellar vesicles to small ( 300 A) unilamellar vesicles.2,3 More recently, new methods have been reported describing the formation of unilamellar vesicles of intermediate size. >5.6 xhe general properties of liposomes and their interaction with various macromolecules have been described in several reviews. ... 

Figure 2. Left Schematic drawing of a unilamellar bilayer vesicle. Right Sketches of vesicles and liposomes of different size. The following abbreviations are commonly used MLV multilamellar vesicles, LUV large unilamellar vesicles, lUV intermediate unilamellar vesicles, SUV small unilamellar vesicles.

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