Liposomes, vesicles with one or more lipid bilayers entrapping an inner aqueous core, are widely used as drug delivery systems. When liposomes are smaller than 100 nanometers (nano liposomes) they have a unique capability of selectively accumulating in tumors and inflamed tissues. This phenomenon, known as the enhanced permeability and retention (EPR) effect, is related to the relatively high leakiness of blood vessels in these diseased tissues. In this book, we present a novel approach for triggering drug release from liposomes at the target site, by use of a remote trigger - low...