9 March 2012 Efficacy of the photodynamic antimicrobial therapy (PACT) with the use of methylene blue associated with the λ660nm laser in Leishmania (Leishmania) amazonesis: in vitro study
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Proceedings Volume 8211, Mechanisms for Low-Light Therapy VII; 82110R (2012) https://doi.org/10.1117/12.912210
Event: SPIE BiOS, 2012, San Francisco, California, United States
Abstract
The present studied evaluated the in vitro effects of PDT on Leishmania (Leishmania) amazonensis promastigotes. For this examination L. amazonensis promastigotes, stain Josefa, were used and maintained in Warren media supplement with fetal bovine serum at 26°C for 96 hours. A viability curve was accomplished using different concentrations of methylene blue photosensitizer associated to red laser light in order to obtain the most effective interaction to inhibit the parasite's growth. Two pre-irradiation periods, 5 and 30 minutes, were evaluated and the promastigotes were counted by colorimetry. On fluorescence microscopy the autophagic processes and reactive oxygen species were detected. Promastigotes treated with Photodynamic Therapy (PDT) by concentrations of 5 and 0,315ug/mL, presented cellular proliferation inhibition when compared to the control. In the first condition, the cells had structural alterations such as truncated cells, cells with two flagella, bleb formation and cells body deformation, while none of these modifications could be visualized in the control group. When analyzed through fluorescence microscopy, the promastigotes treated were positives for free radicals immediately after light application and also 1 hour after treatment presenting signs of autophagia. PDT on L. (L.) amazonensis is effective causing alterations that can help elucidate the mechanisms of the parasite's death when treated with methilene
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Gustavo M. Pires-Santos, Gustavo M. Pires-Santos, Aparecida M. C. Marques, Aparecida M. C. Marques, Eliomara S. S. Alves, Eliomara S. S. Alves, Susana C. P. S. Oliveira, Susana C. P. S. Oliveira, Juliana S. C. Monteiro, Juliana S. C. Monteiro, Cristiane B. Rosa, Cristiane B. Rosa, Fabio Colombo, Fabio Colombo, Antônio L. B. Pinheiro, Antônio L. B. Pinheiro, Marcos A. Vannier-Santos, Marcos A. Vannier-Santos, } "Efficacy of the photodynamic antimicrobial therapy (PACT) with the use of methylene blue associated with the λ660nm laser in Leishmania (Leishmania) amazonesis: in vitro study", Proc. SPIE 8211, Mechanisms for Low-Light Therapy VII, 82110R (9 March 2012); doi: 10.1117/12.912210; https://doi.org/10.1117/12.912210
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