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Antimicrobial Photodynamic Therapy (aPDT) was introduced as a therapy due to resistance that microorganisms have developed to conventional drugs. The study aimed to evaluate the potential of successive applications of aPDT in effecting Candida albicans susceptibility and also whether the presence of fluconazole effected the recovery of the fungi in the culture medium. Planktonic cultures and biofilm were subjected to successive applications of Photodithazine-mediated (25 mg/L) LED-associated aPDT (660 nm, 34 mW/cm 2 ). Plating was performed on Sabouraud Dextrose Agar supplemented or not with fluconazole to recover colony-forming units per milliliter (CFU/mL). Surviving cells were recovered, recultivated, and again exposed to the treatment. The treatments were performed until not enough colonies were available for recultivation and continuation of the protocol. The complete inactivation of the fungus was obtained after three and five applications for planktonic culture and biofilm, respectively. A reduction of 6.3 log 10 was observed after third applications in the planktonic cultures grown on medium without fluconazole, while there was a 7 log 10 reduction of these cultures grown on fluconazole medium. However, a reduction of 6.1 log 10 occurred for biofilms after fifth applications for cultures grown on medium without fluconazole, while a reduction of 6.7 log 10 was observed for cultures grown on medium with the antifungal. Thus, aPDT was potentiated by fluconazole. C. albicans in planktonic and biofilm cultures are susceptible to successive applications of PDZ-mediated aPDT, and tolerance to aPDT is higher in the biofilm., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Objective: This randomized clinical trial assessed antimicrobial Photodynamic Therapy (aPDT) mediated by Photodithazine (PDZ) to treat patients with denture stomatitis (DS)., Methodologies: Patients with DS were randomly assigned to the groups: aPDT (n = 30) and nystatin (NYS, n = 35). aPDT patients received 6 aPDT sessions, three times a week for 15 days, which involved PDZ (200 mg/L) topical application (20 min) on the palate and upper denture, followed by LED illumination (660 nm, 50 J/cm²). NYS patients were instructed to rinse one dropper of this medication for one minute, four times a day, for 15 days. Microbiological collections of dentures and palates were performed and cultured on blood agar and CHROMAgar Candida. Microbial viability was determined, and photographs of the palates were taken for clinical evaluation. Data were analyzed by Repeated Measure Linear Model and Bonferroni (p ≤ 0.05)., Results: aPDT was more effective to reduce the total microbiota than NYS. At the end of the treatments, aPDT reduced 1.98 from the palate and 1.91 log 10 from the denture, while NYS reduced 0.05 and 0.17 log 10 , respectively. Moreover, aPDT was as effective as NYS to reduce Candida. Reductions of 0.68 and 0.77 log 10 were observed in the palate and denture of aPDT group, while reductions of 0.57 and 1.43 log 10 were achieved in the NYS group, respectively. Regarding to oral lesion, 53.3 and 54.2 % of the patients from aPDT and NYS groups had clinical improvement. However, the recurrence of DS was observed in both groups., Conclusion: PDZ-mediated aPDT is a promising treatment for DS., (Copyright © 2020 Elsevier B.V. All rights reserved.)

The present study evaluated whether the oxidative stress caused by antimicrobial photodynamic therapy (aPDT) affects the expression of C. albicans genes related to adhesion and biofilm formation (ALS1 and HPW1) and oxidative stress response (CAP1, CAT1, and SOD1). The aPDT was mediated by two photosensitizing agents (PSs) Photodithazine® (PDZ at 100 and 200 mg/L) or Curcumin (CUR at 40 and 80 μM) and LED (37.5 J/cm 2 or 50 J/cm 2 ). The quantification of the expression was performed by Reverse Transcription-Quantitative Polymerase Chain Reaction (RT-qPCR) using specific primers for the target genes. The data were analyzed by Analysis of Variance (α = 0.05), followed by Tukey's post-test. It was observed reduction in the expression of ALS1, HWP1, CAP1, CAT1, and SOD1 when aPDT was performed using 200 mg/L PDZ and 80 μM CUR associated to LED (37.7 and 50 J/cm 2 , respectively) and using 100 mg/L PDZ and 40 μM CUR with LED of 50 J/cm 2 (versus control). Also, the expression of CAP1 and SOD1 genes was reduced after aPDT using 100 mg/L PDZ and LED of 37.5 J/cm 2 . There was a significant reduction in the expression of genes HWP1, CAP1, and SOD1 after aPDT using 40 μM CUR and 37.5 J/cm 2 (versus the control group). The application of LED only at 37.5 and 50 J/cm 2 promoted down-regulation of ALS1, CAP1, CAT1, and SOD1 genes (versus the control group). Therefore, aPDT mediated by LED -associated PSs PDZ and CUR promoted a reduction in the expression of the five C. albicans genes evaluated., (Copyright © 2020 Elsevier B.V. All rights reserved.)