Efficient singlet oxygen photosensitization upon two-photon excitation of porphyrins

Summary from only given. Use of porphyrin photosensitizers in photodynamic therapy (PDT) is gaining acceptance worldwide as an alternative treatment of tumors' and age-related macular degeneration. It has been proposed that by utilizing two-photon absorption (TPA), in which case illumination is carried out at near-IR wavelengths, the PDT may be delivered deeper into the tissue. However, tetrapyrrolic photosensitizers studied so far display disappointingly small TPA cross-sections. We introduce new porphyrin photosensitizers with greatly enhanced TPA cross-section in near-IR range of wavelengths.