Virosomes: evolution of the liposome as a targeted drug delivery system.

The drug delivery system (DDS) is attractive as a therapeutic method. Liposomes are of particular interest as a DDS because they can reduce drug toxicity, and offer promise as gene carriers. An evolution has occurred in the construction of liposomes in the effort to develop efficient vectors for in vivo use. To avoid uptake by the reticuloendothelial system (RES); Lipid components have been optimized. To enhance tissue targeting, liposome surface has been modified with antibodies or ligands recognized by specific cell types. To enhance the efficiency of gene delivery by the introduction of molecules directly into cells, virosomes have been developed by combining liposomes with fusiogenic viral envelope proteins. Liposomes are now being used in the treatment of intractable human diseases such as cancer and monogenic disorders. In the future, many medical procedures will be performed using liposomes.