Photodynamic therapy on a biofilm monospecie of candida albicans: an in vitro study

Antimicrobial photodynamic therapy (aPDT) is a medical treatment based on the use of a light source at a specific wavelength that activates a photosensitive molecule causing the formation of oxidizing agents that provokes the death of the target cells. The aim of this study was to evaluate the activity of aPDT against biofilms of Candida albicans. Biofilms of C.albicans were subjected to aPDT using a diode GaAlAs (λ:635nm) and a toluidin blue solution (0.1mg/ml) as photosensitizer. Three different protocols (1 minute, fluence 24J/cm2; 2 minutes, fluence 48J/cm2 and 3 minutes, fluence 72J/cm2) were tested. To evaluate the number of Candida cells in biofilm before and after treatment, Bio Timer Assay was used. Candida biofilms treated with aPDT showed significant reductions of the microbial population as compared to the control groups. aPDT showed good antifungal properties in vitro. Clinical trials are needed to test its efficacy in vivo and to propose it as an adjuvant or alternative therapy to conventional medical treatment.