Photobleaching of Hypericin Bound to Human Serum Albumin, Cultured Adenocarcinoma Cells and Nude Mice Skin¶
| Autor: | Vladimir Iani, Anatoly B. Uzdensky, Li Wei Ma, Johan Emelian Moan |
|---|---|
| Rok vydání: | 2007 |
| Předmět: |
Singlet oxygen
medicine.medical_treatment Photodynamic therapy Absorption (skin) General Medicine Photochemistry Human serum albumin Photobleaching Biochemistry Fluorescence spectroscopy Hypericin chemistry.chemical_compound chemistry Biophysics medicine Photosensitizer Physical and Theoretical Chemistry medicine.drug |
| Zdroj: | Photochemistry and Photobiology. 76:320-328 |
| ISSN: | 0031-8655 |
| DOI: | 10.1562/0031-8655(2002)0760320pohbth2.0.co2 |
| Popis: | Hypericin is a promising photosensitizer for photodynamic therapy (PDT) characterized by a high yield of singlet oxygen. Photobleaching of hypericin has been studied by means of absorption and fluorescence spectroscopy in different biological systems: in human serum albumin solution, in cultured human adenocarcinoma WiDr cells and in the skin of nude mice. Prolonged exposure to light (up to 95 min, 100 mW/cm2) of wavelength around 596 nm induced fluence-dependent photobleaching of hypericin in all studied systems. The photobleaching was not oxygen dependent, and singlet oxygen probably played no significant role. Emission bands in the spectral regions 420–560 nm and above 600 nm characterize the photoproducts formed. An emission band at 615–635 nm was observed after irradiation of cells incubated with hypericin or of mouse skin in vivo but not in albumin solution. The excitation spectrum of these products resembled that of hypericin. Hypericin appears to be more photostable than most sensitizers ... |
| Databáze: | OpenAIRE |
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