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.
J Photochem Photobiol B
; 200: 111646, 2019 Nov.
Article
en En
| MEDLINE
| ID: mdl-31655457
ABSTRACT
Antimicrobial 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 (λ400-2000â¯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®, 40â¯mW, á´â¯=â¯15.8â¯cm2) using different energy densities. Based on the IC50, 150 and 300â¯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) of the bacterial inoculum were used and the DMMB was added using the two previously determined concentrations. After 5â¯min of preincubation the dilutions of the inoculum were illuminated by the polarized light source. Subsequently, 100⯵L of each dilution, in triplicate, were inoculated into Petri dishes containing TSA medium and incubated in a bacteriological oven at 37⯰C for 24-h and quantification of UFCs was done. The results showed significant exponential reduction (pâ¯<â¯.0001) of 99.93% (150â¯ng/mLâ¯+â¯LP 10â¯J/cm2) and 99.97% (300â¯ng/mLâ¯+â¯LP 5â¯J/cm2) the CFU counts in comparison to non-illuminated control. The results of this study allow to conclude that aPDT carried out with 1,9-Dimethyl-Methylene Blue Zinc Chloride Double Salt-DMMB and a PL souce was efficacious on the reduction (99.97%), in vitro, of the bacterial counts of S. aureus.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Staphylococcus aureus
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Cloruros
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Fármacos Fotosensibilizantes
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Compuestos de Zinc
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Azul de Metileno
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Antiinfecciosos
Idioma:
En
Revista:
J Photochem Photobiol B
Asunto de la revista:
BIOLOGIA
Año:
2019
Tipo del documento:
Article
País de afiliación:
Brasil