Light action spectra for skin chromophores are simulated. Endogenic porphyrins (Pp IX, Cp III, and Up III) are selected as target chro-mophores. They can produce singlet oxygen (SO) under tissue irradiation, which acts as a natural photosensitizer. The SO is toxic for cancer cells. This process is known to be widely used in photodynamic therapy (PDT). The irradiation at wavelengths ranging from 610 to 630 nm is significantly stimulates the production of endogenous porphyrins SO over the entire thickness of the dermis (2–3 times dermis at a depth z<0.15 mm; 10–12 times dermis z>=0.15 mm) compared with exposure to absolute absorption maxima (at about 501 nm for uroporphyrin (UpIII), 495 nm for coproporphyrin (CpIII) and 505 nm for protoporphyrin (PpIX). The presented results can pro-vide new opportunities for the selection of the irradiation wavelengths under application of traditional PDT methods.
Keywords: soft biological tissue, singlet oxygen, endogenic porphyrins, radiative transfer equation, light action spectra.
N.D. Abramovich – Belarusian State University of Informatics and Radioelectronics, Minsk
S.K. Dick – Belarusian State University of Informatics and Radioelectronics, Minsk