The combination of methylene blue and sodium dodecyl sulfate enhances the antimicrobial photodynamic therapy of Candida albicans at lower light parameters.

Autor: Gonçalves JMLA; Programa de Pós-Graduação em Biofotônica Aplicada às Ciências da Saúde, Universidade Nove de Julho - UNINOVE, Rua Vergueiro 235-249, São Paulo 01504-001, Brazil., Monteiro CM; Programa de Pós-Graduação em Biofotônica Aplicada às Ciências da Saúde, Universidade Nove de Julho - UNINOVE, Rua Vergueiro 235-249, São Paulo 01504-001, Brazil., Machado GB; Programa de Pós-Graduação em Biofotônica Aplicada às Ciências da Saúde, Universidade Nove de Julho - UNINOVE, Rua Vergueiro 235-249, São Paulo 01504-001, Brazil., Pavani C; Programa de Pós-Graduação em Biofotônica Aplicada às Ciências da Saúde, Universidade Nove de Julho - UNINOVE, Rua Vergueiro 235-249, São Paulo 01504-001, Brazil. Electronic address: chrispavani@gmail.com.
Jazyk: angličtina
Zdroj: Photodiagnosis and photodynamic therapy [Photodiagnosis Photodyn Ther] 2023 Jun; Vol. 42, pp. 103583. Date of Electronic Publication: 2023 Apr 22.
DOI: 10.1016/j.pdpdt.2023.103583
Abstrakt: Background: The growth of resistant microorganisms has been a challenge for health systems. Antimicrobial Photodynamic Therapy (aPDT) has gained attention due to its effects on resistant strains. Recently, it was shown that the association of methylene blue (MB) and sodium dodecyl sulfate (SDS) are an effective strategy to increase the effect of aPDT; however, it is unknown which are the best light parameters (such as irradiance and radiant exposure, RE), to reach the most effective protocols. This work aimed to evaluate the light parameters, irradiance, and radiant exposure, in aPDT with MB when conveyed in water compared to MB associated with SDS.
Methods: Tests were carried out to quantify the colony-forming units (CFU) of ATCC 10,231 strain of Candida albicans when using MB in different media and with different light parameters: Control (water), SDS (0.25%), MB (20 mg/mL), and the MB/SDS at irradiances of 3.7; 11.2; 18.6, and 26.1 mW/cm 2 and varied irradiation times to reach radiant exposures of 4.4; 17.8; 26.7, and 44 J/cm².
Results: The results showed that aPDT with MB/SDS had a higher antimicrobial effect than MB when conveyed in water. Furthermore, for the highest irradiance studied (26.1 mW/cm 2 ), CFU decreases exponentially with increasing RE from 4.4 up to 44 J/cm 2 . Similarly, at a fixed RE, the higher the irradiance used, the higher the antimicrobial effect was observed, except for the lowest RE studied (4.4 J/cm 2 ).
Conclusions: aPDT with MB/SDS had a greater antimicrobial action at the lower light parameters when compared to MB conveyed in water. The authors suggest the use of RE above 18 J/cm 2 and irradiance above 26 mW/cm 2 since at the mentioned parameters the increase in its value caused a greater antimicrobial effect.
Competing Interests: Declaration of Competing Interest None.
(Copyright © 2023 Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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