Synthesis and in vitro investigation of cationic 5,15-diphenyl porphyrin-monoclonal antibody conjugates as targeted photodynamic sensitisers.

The synthesis of three cationic 5,15-diphenyl porphyrins, bearing an isothiocyanate group for conjugation to proteins is described. The potential of these compounds as targeted photosensitisers for use in photodynamic therapy (PDT) is demonstrated by their efficient conjugation to monoclonal antibodies and the ability of the bioconjugates to bind and photodynamically inactivate cancer cells that express the corresponding antigen.