ABSTRACT
Liposomes have evolved during the last 35 years from a laboratory curiosity to an effective delivery vehicle for several important drugs. This was made possible by overcoming initial problems with reproducible particle size, plasma stability, high encapsulation efficiency, long circulation times, and selective deposition in vivo that were encountered with first-generation carrier systems. It is now clear that the great potential of liposomes as drug delivery vehicles will not be fully realized until more effective targeting and membrane fusion mechanisms have been designed and incorporated in their formulations. This chapter summarizes our recent advances toward these goals and the membrane fusion aspect of this challenge.
