Rosseti Isabela Bueno, Chagas Luciene Reginato, Costa Maricilia Silva
Instituto de Pesquisa e Desenvolvimento (IP&D), Universidade do Vale do Paraíba (UNIVAP), Av. Shishima Hifumi, 2911, 12244-000, São José dos Campos, São Paulo, Brazil.
Lasers Med Sci. 2014 May;29(3):1059-64. doi: 10.1007/s10103-013-1473-4. Epub 2013 Nov 1.
The opportunistic fungal Candida albicans is able to produce both superficial and systemic infections in immunocompromised patients. Photodynamic antimicrobial chemotherapy (PACT) is a process that combines visible light and a photosensitizer, producing reactive oxygen species (ROS) that can kill the treated cells and has been presented as a potential antimicrobial therapy. In this work, we study the effects of PACT, using toluidine blue (TB) as a photosensitizer drug, on ROS production and cell damage and the ability of C. albicans to form biofilm. A significant decrease was observed in the cell growth after PACT in a TB concentration-dependent manner. This effect was dependent on the incubation time after PACT. In addition, an increase in both the ROS production and cell permeability, after PACT, in a TB concentration-dependent manner was observed. PACT, using 0.1 mg/ml TB was able to reduce biofilm formation in 30, 50, and 62%, in cells submitted to incubation times of 1, 2, and 3 h, respectively. These results suggested that PACT, using TB, is able to decrease both growth and biofilm formation by C. albicans, possibly by a mechanism evolving both ROS production and the increase in the cell permeability.
机会性真菌白色念珠菌能够在免疫功能低下的患者中引起浅表和全身感染。光动力抗菌化学疗法（PACT）是一种将可见光和光敏剂相结合的过程，可产生活性氧（ROS），从而杀死被处理的细胞，并且已被视为一种潜在的抗菌疗法。在这项研究中，我们使用甲苯胺蓝（TB）作为光敏剂药物，研究了PACT对ROS产生、细胞损伤以及白色念珠菌形成生物膜能力的影响。PACT处理后，细胞生长以TB浓度依赖性方式显著下降。这种效应取决于PACT后的孵育时间。此外，PACT后，ROS产生和细胞通透性均以TB浓度依赖性方式增加。使用0.1 mg/ml TB的PACT能够分别在孵育1、2和3小时的细胞中，使生物膜形成减少30%、50%和62%。这些结果表明，使用TB的PACT能够降低白色念珠菌的生长和生物膜形成，可能是通过一种涉及ROS产生和细胞通透性增加的机制。
