MONITORING OF INTRACELLULAR VISCOSITY OF CANCER CELLS UNDER PHOTODYNAMIC TREATMENT WITH A PORPHYRAZINE PHOTOSENSITIZER
The possibility of monitoring of cancer cells response to photodynamic treatment by the use of porphyrazine photosensitizer as a viscosity sensor is shown. The research was done with tetrapyrrole dye - tetra(4- benzyloxyphenyl)tetracyanoporphyrazine. The dye was shown to demonstrate effective absorption and fluorescence in biological transparent window. In addition, the dye has a molecular rotor properties showing high sensitivity of fluorescence parameters to media viscosity changes. Pre-nuclear region and nuclear membrane or its environment are shown to be the primary space of intracellular accumulation of the dye. The high photodynamic activity of the porphyrazine was detected in relation to epidermoid carcinoma cells of human skin. The significant increase of fluorescence life-time of the dye inside the cells was registered after the photodynamic therapy. It may be concerned as an evidence of the local intracellular viscosity increase and a verification of irreversible degenerative processes onset, leading to the death of cancer cells.