ABSTRACT
Because of the importance of haematoporphyrin (Chapter 6) the porphyrins have a special position amongst the sensitisers considered for PDT applications. It will emerge that the hydroporphyrins, and especially the chlorins (Chapter 9) appear at present to be the most promising second generation compounds. Nevertheless some porphyrins with extended chromophoric systems (eg meso-2\kyny\ porphyrins, sec tion 8.4.2) and endogenously produced protoporphyrin (section 8.5) deserve special attention.
