Photodynamic Inactivation of Candida albicans Sensitized by Porphyrins.

ÁLVAREZ M G, FUNES M, OTERO L A, DURANTINI E N.

Mendoza

Congreso; “XXVI Reunión Científica Anual de la Sociedad de Biología de Cuyo. I Reunión Científica Anual se la Dirección de Investigación, Ciencia y Técnica dependiente del Ministerio de Salud Gobierno de Mendoza; 2008

XXVI Reunión Científica Anual de la Sociedad de Biología de Cuyo. I Reunión Científica Anual se la Dirección de Investigación, Ciencia y Técnica dependiente del Ministerio de Salud Gobierno de Mendoza

Antimicrobial resistance is a growing problem that complicates the treatment of nosocomial and community-acquired infections. In the last years, resistance of C. albicans is increasing against traditional antifungal. The search for new therapeutic approaches is stimulated by the fact that standard antifungal treatments are prolonged and expensive. Photodynamic inactivation (PDI) represents an interesting alternative that involves the pre-treatment with a sensitizer, which it accumulates in microbial cells. The exposure to visible light leads to the generation of singlet oxygen (1O2), which produces photodamage and destruction of cells. In this work was studied the PDI of C. albicans sensitized by a tetracationic porphyrin (P) and its metal complex with Pd (II). The cultures were treated with different concentration of sensitizer (1-10 mM) for 30 min at 37 C in dark. Under these conditions, these porphyrins were innocuous in dark. The binding of porphyrin (P) to cells was determined by fluorescence, giving a value of 0.23±0.05 nmol/106 cells. After irradiation, the cell viability was depending of the concentration used and light fluency. When the cultures are irradiated for 30 min with visible light (90 mW/cm2), over 99% of the cells are inactivated. The studies indicate that these porphyrins are interesting sensitizers to inactivate C. albicans in cellular suspensions by PDI.