Fig. 1.

Endosomal escape of hydrophilic drug by combined MHT and PCI 1. An amphiphilic photosensitizer is given before administration of the drug. The photosensitizer binds to the plasma membrane and is 2. taken into the cell together with the drug by endocytosis. The photosensitizer and the drug co-localize in the endosomes. Since the photosensitizer is partly hydrophilic and partly hydrophobic it will remain in the membrane of the endosome, while the hydrophilic drug will localize in the lumen. 3. Combined thermal and light exposure leads to induced rupture of the endosome with subsequent release of the sequestered drug into the cytosol or nucleus resulting in cell death.