Liposomes, Polymeric-Surface Recognition

Thus far, it could be shown that stable liposomes can be prepared by polymerization of lipids. These vesicle systems, however, are still far away from being a real biomembrane model. As of now, they do not show any typical biological behavior such as surface recognition, enzymatic activities, variable lipid distribution, and the ability to undergo fusion. 

The specific surface recognition of polymerized liposomes has been demonstrated by a simple model reaction A dispersion of polymerized liposomes of glycolipid 38 was mixed with the lectin Concanavalin A, which caused a rapid agglutination and precipitation of the liposomes. This effect was not observed for polymerized liposomes without sugar headgroups. 

Generally, the amphiphilic core/shell stmcture of polymeric micelles is formed from block polymers. Polyethylene glycol (PEG) and polyethylene oxide (PEO) are often used as the hydrophilic blocks. They have been shotvn to prevent recognition by the reticuloendothelial system and increase circulation time in vivo. As in the case of liposomes and niosomes, the grafting of specific ligand molecules on the surface of the polymeric micelles allows... 

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