Photosensitizers, porphyrin-based

Porphyrin-based photosensitizers for use in photodynamic therapy 98T4151. 

Novel porphyrin-based photosensitizers, bacteriochlorins exhibiting long-wavelength absorptions between 788 and 831 nm, are promising candidates for... 

Sternberg, E.D. and Dolphin, D. (1998) Porphyrin-based Photosensitizers for Use in Photodynamic Therapy, Tetrahedron 54, 4151-4202. 

Sternberg ED, Dolphin D. Porphyrin-based photosensitizers for use in photodynamic therapy. Tetrahedron 1998 54 4151-202. 

DESIGN OF PORPHYRIN-BASED PHOTOSENSITIZERS FOR PHOTODYNAMIC THERAPY... 

Another concern specific to the use of porphyrin-based photosensitizers is the fact that singlet state lifetimes are usually less than 10 ns and photosensitization occurs mostly from the triplet state. This requires the selection of systems that efficiently generate triplet states, which is not the case of paramagnetic metalloporphyrins. 

Guidelines to Design Better Porphyrin-Based Photosensitizers for PDT... 

Another porphyrin-based photosensitizer, benzoporphyrin derivative monoacid A (Verteporphin, Visudyne ), has received approval for treatment of age-related macular degeneration, and a form of pathologic myopia. 

The structures of porphyrin-based photosensitizers currently in clinical trials are shown in Scheme 96. 

Designing Porphyrin-Based Photosensitizers for Photodynamic Therapy... 

At present, Photofrin , a hematoporphyrin derivative, is the only photosensitizer that has been approved worldwide for the treatment of various types of cancer by PDT. It fits some of the criteria for ideal photosensitizers, but it also suffers from several drawbacks. First, it is a complex mixture of various monomeric, dimeric, and oligomeric forms. Second, its long wavelength absorption falls at 630 nm, which lies well below the wavelength necessary for maximum tissue penetration. Finally, it induces prolonged cutaneous phototoxicity, a major adverse effect associated with most of the porphyrin-based photosensitizers. 

Synthetic Strategies in Designing Porphyrin-Based Photosensitizers... 

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