Affiliations: Clinica Universitaria de Dermatologia, Hospital de Santa Maria, Lisbon, Portugal | INSERM ERI 12, Laboratoire de Biochimie, CHU Amiens, Amiens, France | INSERM U 697, Institut de Recherche sur la Peau, Hôpital Saint Louis et Muséum National d'Histoire Naturelle, Paris, France
Note: [] Corresponding author: René Santus. INSERM U697, Institut de Recherche sur la Peau, Pavillon Bazin, 1 rue Claude Vellefaux, 75475 Paris cedex 10, France. Tel.: +33 01 40793726; E-mail: santus@mnhn.fr.
Abstract: Photodynamic therapy (PDT) by porphyrins and related tetrapyrrole derivatives is an emerging new treatment modality of tumors of lung, eosophagus and skin and of age-related macular degeneration. Phase III clinical trials for other applications such as re-stenosis after angioplasty are also underway. Under systemic conditions, the transport of porphyrin photosensitizers by serum low density lipoproteins and their specific delivery to tumor cells and vasculature is a determinant of treatment effectiveness. However, this effectiveness can be improved by increasing the selectivity of the photosensitizer uptake by tumors and by using photosensitizers absorbing light in the 660–800 nm range where tissues have the highest transmittance. Another treatment showing great promise is the PDT of skin cancers after topical application of the protoporphyrin IX precursor delta-aminolevulinic acid (or its ester forms). In all the cases, the photosensitizers should be rapidly excreted to avoid a long lasting skin photosensitivity.
