OBJECTIVES: The purpose of this study was to evaluate the clinical plaque disclosing agent erythrosine as a photosensitizer in the photodynamic killing of the oral bacterium Streptococcus mutans grown as a biofilm. METHODS: S. mutans biofilms of 200 microm thickness were grown in a constant-depth film fermenter. In addition to determining localization of the photosensitizer within biofilms using confocal laser scanning microscopy (CLSM), we compared the bacterial killing efficacy of erythrosine with that of two well-characterized photosensitizers, methylene blue (MB) and photofrin. Incubations were carried out with each photosensitizer (22 microM), and irradiation was for 15 min using a 400 W white light source. RESULTS: The CLSM results showed that erythrosine is taken up into S. mutans biofilms, where it is associated with the biomass of the biofilm rather than the fluid-filled channels and voids. Comparison of the cell killing efficacy of erythrosine in S. mutans biofilms of different ages showed that erythrosine was 1-2 log(10) more effective at killing biofilm bacteria than photofrin and 0.5-1 log(10) more effective than MB. The results were statistically significant (P < 0.01). Photodynamic therapy (PDT) with all three photosensitizers was increasingly effective as biofilm age increased, suggesting that temporal changes in biofilm architecture and composition affect susceptibility to PDT. CONCLUSIONS: PDT using erythrosine as photosensitizer shows excellent potential as a treatment for oral plaque biofilms.
OBJECTIVES: The purpose of this study was to evaluate the clinical plaque disclosing agent erythrosine as a photosensitizer in the photodynamic killing of the oral bacterium Streptococcus mutans grown as a biofilm. METHODS:S. mutans biofilms of 200 microm thickness were grown in a constant-depth film fermenter. In addition to determining localization of the photosensitizer within biofilms using confocal laser scanning microscopy (CLSM), we compared the bacterial killing efficacy of erythrosine with that of two well-characterized photosensitizers, methylene blue (MB) and photofrin. Incubations were carried out with each photosensitizer (22 microM), and irradiation was for 15 min using a 400 W white light source. RESULTS: The CLSM results showed that erythrosine is taken up into S. mutans biofilms, where it is associated with the biomass of the biofilm rather than the fluid-filled channels and voids. Comparison of the cell killing efficacy of erythrosine in S. mutans biofilms of different ages showed that erythrosine was 1-2 log(10) more effective at killing biofilm bacteria than photofrin and 0.5-1 log(10) more effective than MB. The results were statistically significant (P < 0.01). Photodynamic therapy (PDT) with all three photosensitizers was increasingly effective as biofilm age increased, suggesting that temporal changes in biofilm architecture and composition affect susceptibility to PDT. CONCLUSIONS: PDT using erythrosine as photosensitizer shows excellent potential as a treatment for oral plaque biofilms.
Authors: Carlos de Paula Eduardo; Patricia Moreira de Freitas; Marcella Esteves-Oliveira; Ana Cecília Corrêa Aranha; Karen Müller Ramalho; Alyne Simões; Marina Stella Bello-Silva; Jan Tunér Journal: Lasers Med Sci Date: 2010-07-17 Impact factor: 3.161
Authors: Paula Gabriela Faciola Pessôa de Oliveira; Adriana Maria Mariano Silveira E Souza; Arthur Belém Novaes; Mário Taba; Michel Reis Messora; Daniela Bazan Palioto; Márcio Fernando Moraes Grisi; Antônio Cláudio Tedesco; Sérgio Luis Scombatti de Souza Journal: Lasers Med Sci Date: 2016-06-28 Impact factor: 3.161
Authors: C R Fontana; A D Abernethy; S Som; K Ruggiero; S Doucette; R C Marcantonio; C I Boussios; R Kent; J M Goodson; A C R Tanner; N S Soukos Journal: J Periodontal Res Date: 2009-07-08 Impact factor: 4.419