Figure 6: Schematic illustration of PCI. [38] A. No PCI: Drugs taken up through endocytosis are transported to lysosomes where they are degraded before they have exerted their action. B. PCI: PSs are co-administered with drugs and accumulate in endosomes and lysosomes. Light exposure causes rupture of the endo/lysosomal membrane and releases the drugs into the cytosol where the drugs can interact with their targets. Reprinted with permission from the [34]. Copyright © 2011 Wiley- Liss, Inc.