Effect of different pre-irradiation time on Candida albicans in photodynamic therapy using erythrosine combined with potassium iodide

Few studies have investigated how pre-irradiation times in photodynamic therapy (PDT) impact antifungal activity. This study compared fungal reduction after PDT using various pre-irradiation times. 100 or 200 μM Erythrosine and 100 mM KI were applied to mature Candida albicans (ATCC10231) for 1, 3, or 5 minutes. Subsequently, Light-emitting diodes (520-530 nm, 20 J/cm², 250 mW/cm² were applied to the biofilms. The negative and positive controls were phosphate-buffer saline and 1:100, 000 units nystatin, respectively. The fungal quantity was immediately measured using the drop plate method. Subsequently, singlet oxygen was measured using a DMA probe (excitation/emission: 375/436 nm). The Kruskal-Wallis+Dunn test (p<0.05) was used for statistical analyses. 200 μM erythrosine+100 mM KI at all pre-irradiation times decreased the fungal count by 7.59 (0.33) log­ 10 CFU/ml/biofilm weight. The singlet oxygen peak at 1 minute 66.36% (3.18). A 1-minute pre-irradiation time in 100 μM erythrosine+100 mM KI inhibits Candida albicans biofilms.