Photochemical internalization for delivery of molecules into the cytosol

A method for introducing a molecule into the cytosol of a cell, said method comprising

• contacting said cell with a photosensitising agent,
• irradiating said cell with light of a wavelength effective to activate the photosensitising agent and, at the same time or at a time after the irradiation,
• contacting said cell with an isolated transfer molecule wherein said transfer molecule consists of a protein, peptide, or antibody or fragment thereof,
• wherein said transfer molecule is taken up into endosomes by the cell and wherein as a consequence of said irradiation said transfer molecule is released into the cytosol of said cell, and
• wherein one or both of the photosensitising agent and the transfer molecule is attached to, associated with, or conjugated to, one or more carrier molecules, targeting molecules or vectors.

A method of treating cancer in a patient comprising

• introducing a cytotoxic drug into one or more cells in vitro, in vivo or ex vivo according to a method comprising
• contacting a cancer cell with a photosensitising agent,
• contacting said cancer cell with a cytotoxic drug which comprises a cytotoxic protein, peptide, or fragment thereof, and
• irradiating said cancer cell with light of a wavelength effective to activate the photosensitising agent,
• wherein said cytotoxic drug is taken up into endosomes by the cancer cell and wherein as a consequence of said irradiation said cytotoxic drug is released into the cytosol of said cancer cell, wherein said irradiation is performed prior to cellular uptake of said cytotoxic drug into any intracellular compartment, and where necessary administering said cell to said patient.