Inactivation of Candida albicans Biofilm by Radachlorin-Mediated Photodynamic Therapy

원광보건대학교 임상병리과The purpose of this study was to evaluate the in-vitro efficacy of PDT using red light emitting diode (LED) with Radachlorin for biofilm inhibition of clinical Candida albicans isolates.The suspensions containing C. albicans at 9×10 8 CFU/mL were prepared on yeast nitrogen base containing 5% glucose.The biofilm formation was grown for 3 h after seeding suspensions each 100 ul on a 96-well plate and then supernatant was discarded.Each well was treated with 0.39 g/mL from 50 g/mL concentrations of Radachlorin on adherent biofilm.After a 30-minute incubation, light was irradiated for 30, 60, or 90 minutes using the following light source of wavelength 630 nm LED, at energy densities of 14, 29, and 43 J/cm 2 .Afterwards, all supernatant was removed and dried.Adherent cells were stained with safranin O and dried.The cell viability was measured using a microplate reader at 490 nm.Also, a fluorescent signal on C. albicans was observed by saturation of a photosensitizer.In conclusion, a significant inhibition of 72.5% was observed to C. albicans on biofilm at the Radachlorin dose of 50 g/mL with 630 nm LED.The Photosensitizer (Radachlorin) was adequate at 30 minuttes for C. albicans.Overall, the results showed that inhibition of biofilm formation was Radachlorine dose-dependent.The results suggest that PDT, using Radachlorin with 630 nm LED, is able to decrease biofilm formation of C. albicans.