A novel technique of antimicrobial photodynamic therapy – aPDT using 1,9-dimethyl-methylene blue zinc chloride double salt-DMMB and polarized light on Staphylococcus aureus

Publication date: Available online 13 October 2019Source: Journal of Photochemistry and Photobiology B: BiologyAuthor(s): Darcy de A. Santos, Pedro Jorge L. Crugeira, Iago P.F. Nunes, Paulo Fernando de Almeida, Antônio Luiz B. PinheiroAbstractAntimicrobial Photodynamic Therapy (aPDT) is an alternative to conventional treatments of local infections such as the use of antibiotics, which may lead to the development of resistance. aPDT besides requiring the use of a photosensitiser also needs a light source do be carried out. In the search for efficient and low-cost procedure the use of multispectral polarized light (λ400–2000 nm) emerges as a possibility for the execution of aPDT. The use of a highly effective photosensitizer is also of great importance. 1,9-Dimethyl-Methylene Blue Zinc Chloride Double Salt – DMMB is a potent phenothiazine derivative that presents high photodynamic action due to its high lipophilicity as well as a greater quantum yield of Singlet oxygen and phototoxicity when compared to other Photosensitizers. The aim of this study was to assess, In Vitro, the efficacy of aPDT on Staphylococcus aureus (ATCC 25923) using different concentrations of DMMB associated to a Polarized light source (Bioptron®, 40 mW, ᴓ = 15.8 cm2) using different energy densities. Based on the IC50, 150 and 300 ng/mL of DMMB concentrations were chosen for this study. Twelve experimental groups were used: (Control, PLs, PSs and aPDTs). Serial dilutions (up to 10−8...
Source: Journal of Photochemistry and Photobiology B: Biology - Category: Speech-Language Pathology Source Type: research