Paper
5 March 2015 Evaluation of the efficacy of photodynamic antimicrobial therapy using a phenothiazine compound and LED (red-orange) on the interface: macrophage vs S. aureus
Fernando José Pires Sampaio D.D.S., Susana C. P. S. de Oliveira D.D.S., Juliana S. C. Monteiro, Gustavo M. Pires-Santos, Maria de Fátima M. Gesteira D.D.S., Antônio L. B. Pinheiro D.D.S.
Author Affiliations +
Proceedings Volume 9309, Mechanisms for Low-Light Therapy X; 93090Z (2015) https://doi.org/10.1117/12.2079218
Event: SPIE BiOS, 2015, San Francisco, California, United States
Abstract
Antimicrobial Photodynamic therapy is a technique in which microorganisms are exposed to a photosensitizing drug and then irradiated with low-intensity visible light of the appropriate wavelength. The resulting photochemical reaction generates cytotoxic reactive oxygen species, such as singlet oxygen and free radicals, which are able to exert bactericidal effect. Much is already known about the photodynamic inactivation of microorganisms: both antibiotic-sensitive and - resistant strains can be successfully photo inactivated, and there is the additional advantage that repeated photosensitization of bacterial cells does not induce a selection of resistant strains. Recently, a series of studies have shown that it is possible to kill bacteria with a light source after the microorganisms have been sensitized with low concentration of dye, such as phenothiazines. The aim of this study was to evaluate the phagocytic function of macrophages J774 against S. aureus in the presence and absence of AmPDT with phenothiazine compound (12.5 μg/mL) and red-orange LED. Experimental groups: Control Group (L-F-), Phenothiazine group (L-F+) LED group (L+F-), Photodynamic therapy group (L+F+). The tests presented in this study were carried out in triplicate. This study demonstrated that AmPDT is able to increase about twice the phagocytic ability of macrophages; however, the bactericidal capacity of these cells did not show a substantial improvement, probably because the oxidative burst was less intense.
© (2015) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Fernando José Pires Sampaio D.D.S., Susana C. P. S. de Oliveira D.D.S., Juliana S. C. Monteiro, Gustavo M. Pires-Santos, Maria de Fátima M. Gesteira D.D.S., and Antônio L. B. Pinheiro D.D.S. "Evaluation of the efficacy of photodynamic antimicrobial therapy using a phenothiazine compound and LED (red-orange) on the interface: macrophage vs S. aureus", Proc. SPIE 9309, Mechanisms for Low-Light Therapy X, 93090Z (5 March 2015); https://doi.org/10.1117/12.2079218
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KEYWORDS
Light emitting diodes

Photodynamic therapy

Light-emitting diode therapy

Microorganisms

Bacteria

Oxygen

Light sources

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