ABSTRACT

This chapter examines what is known about polymeric vesicles and highlights future drug delivery applications. The commercial liposome-encapsulated doxorubicin formulation is the only polymeric vesicle formulation licensed for clinical use. Polymeric vesicles appear to be largely unilamellar, and unilamellarity is favored when the molecular weight of the amphiphile increases. The production of polymeric vesicles and the resultant reduction in cytotoxicity enables poly (L-lysine) derivatives to be used as an in vivo gene carrier because the unmodified polymer is too toxic for use as an in vivo gene-transfer system. However, polymeric systems have been fabricated with responsive capability, and it is possible that in the future these may be fine-tuned to produce truly intelligent and dynamic drug delivery systems. Vesicles that release their contents in the presence of an enzyme may be formed by loading polymeric vesicles with an enzyme-activated prodrug.