Evaluation of dual application of photodynamic therapy-PDT in Candida albicans

This study aimed to evaluate, in vitro, the efficacy of photodynamic therapy - PDT using dimethyl methylene blue zinc chloride double salt (DMMB) and red LED light on planktonic cultures of Candida albicans. The tests were performed using the ATCC 90,028 strain grown at 37 degrees C for 24 h, according to a growth curve of C. albicans. The colonies were resuspended in sterile saline adjusted to a concentration of 2 x 10(8) cells / mL, with three experimental protocols being tested (Protocol 1, 2 and 3) with a fixed concentration of 750 eta g/mL obtained through the IC50, and energy density 20 J/cm(2). Protocol 1 was carried out using conventional PDT, Protocol 2 was applied double PDT in a single session, and Protocol 3 was applied double PDT in two sessions with a 24 h interval. The results showed logarithmic reductions of 3 (4.252575 +/- 0.068526) and 4 logs (2.669533 +/- 0.058592) of total fungal load in protocols 3 and 2 respectively in comparison to the Control (6.633547 +/- 0.065384). Our results indicated that double application in a single session of PDT was the most effective approach for inhibiting the proliferation of Candida albicans (99.991% inhibition).

Automated summary

This study aimed to evaluate the efficacy of photodynamic therapy (PDT) using dimethyl methylene blue zinc chloride double salt (DMMB) and red LED light on Candida albicans. The results showed that applying double PDT in a single session was the most effective approach for inhibiting the proliferation of Candida albicans.