| Abstract [eng] |
The development of multidrug resistance and its spreading among the pathogens, increased the demand for alternative treatment methods of bacterial infections. One of the most promising techniques is photodynamic antibacterial chemotherapy. The main idea of it lays in combining three initially harmless components (the oxygen, photosensitizer and appropriate light) has fatal consequences to bacteria. The study was designed to investigate spectroscopic features of a new tetra-cationic meso-substituted photosensitizer tetrakis(N-ethylpyridinium-4-yl)porphyrin tetratosylate (TN-Et-PyP), its interaction with different cellular components and to analyse the photodynamic action of the porphyrin on the integrity and selected functions of E. coli KMY1 cell membranes. It was shown that tetracationic TN-Et-PyP symmetry changes strongly depend on the polarity of the solvent. The dye forms complexes with nucleic acids and lipopolysaccharides in buffer solution, the interaction being of electrostatic nature. The interaction with surface structures of E. coli may facilitate the targeting of bacterial envelope. The study presents evidences for outer membrane permeabilization, inactivation of periplasmic marker enzyme alkaline phosphatase and impairment of the inner membrane functions expressed in drop in respiration efficiency and decrease of membrane voltage upon irradiation with blue light. The inner components of the cells are consequently damaged as has been shown with decreased cytoplasmic marker enzyme β – galactosidase activity. The cell death is prompted by blow of the big vesicular structure formed in one of the cell poles and full of inner cellular material, which is consequently leaking into the media. |
