Effectiveness in total reduction of Candida albicans promoted by PDT with hypocrellin B: lanthanum

Abstract

In this work we described the potentiality of the Hypocrellin B (HB) modified with the presence of lanthanum (La3+) ions, in eliminate Candida albicans in suspension. The results showed that the presence of lanthanum ions promotes a red shift of the HB absorption band and an enhancement in singlet oxygen quantum yield in 32%. Also in this work we obtained that the best molar ration between HB and La concentrations was 1:2. No photobleaching was observed in our experimental conditions. Antimicrobial activity was studied exciting C. albicans suspension with a 460 nm LED and a 660 nm laser both with 330 mW/cm2 irradiance. Best irradiation time, PS concentration and ROS production profile were determined showing that using 460 nm LED with 10 μM of PS, only 30 s of irradiation time was sufficient to reduce 100 % C. albicans colonies.