Abstract: The present invention provides a method for introducing a molecule into the cytosol of a cell in which the cell is contacted with a photosensitising agent, the cell is irradiated with light of a wavelength effective to activate the photosensitising agent and, substantially at the same time or after the irradiation, the cell is contacted with the molecule to be introduced, particularly for use in cancer treatment, gene therapy and vaccination.

Abstract: The present invention provides photosensitizing agents obtained by reducing a single double bond in the porphyrin macrocycle of a sulphonated meso-tetraphenylporphyrin, preferably a disulphonated meso-tetraphenylporphyrin such as TPPS2a. The resulting sulphonated meso-tetraphenyl chlorins include compounds of formula (I) (wherein X is —SO3H; n, p, q and r are each independently 0 or 1; and the sum of n, p, q and r is an integer from 1 to 4, preferably at least 2, e.g. 2 or 4) isomers and isomer mixtures thereof. The compounds of the invention and their pharmaceutically acceptable salts find particular use as photosensitizing agents in the photochemical internalization of molecules and in photodynamic therapy.

Abstract: The present invention provides a method for introducing a molecule into the cytosol of a cell in which the cell is contacted with a photosentistising agent, the cell is irradiated with light of a wavelength effective to activate the photosentisitising agent and, substantially at the same time or after the irradiation, the cell is contacted with the molecule to be introduced, particularly for use in cancer treatment, gene therapy and vaccination.