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Item Effects of antimicrobial photodynamic therapy with photodithazine® on methicillin-resistant Staphylococcus aureus (MRSA): Studies in biofilms and experimental model with Galleria mellonella(Elsevier) Souza, Beatriz Müller Nunes; Miñán, Alejandro Guillermo; Brambilla, Isabelle Ribeiro; Pinto, Juliana Guerra; Garcia, Maíra Terra; Junqueira, Juliana Campos; Ferreira-Strixino, JulianaStaphylococcus aureus infections are a severe health problem due to the high mortality rate. Conventional treatment of these infections is via the administration of antibiotics. However, its indiscriminate use can select resistant microorganisms. Thus, it is necessary to develop alternatives for antibiotic therapy. Antimicrobial Photodynamic Therapy (aPDT), a therapeutic method that associates a photosensitizer (PS), a light source with adequate wavelength to the PS, interacts with molecular oxygen generating reactive oxygen species responsible for cell inactivation, is a viable alternative. This work aimed to analyze, in vitro and in vivo, the action of aPDT with PS Photodithazine® (PDZ) on the methicillin-resistant S. aureus (MRSA) strain. In the in vitro method, the S. aureus biofilm was incubated with PDZ at 50 and 75 μg.mL−1 for 15 min, adopting the light dose of 25, 50, and 100 J/cm2. In addition, PS interaction, formation of reactive oxygen species (ROS), bacterial metabolism, adhesion, bacterial viability, and biofilm structure were evaluated by scanning electron microscopy. Subsequently, the strain was inoculated into models of Galleria mellonella, and the survival curve, health scale, blood cell analysis, and CFU/mL of S. aureus in the hemolymph were analyzed after aPDT. In the in vitro results, bacterial reduction was observed in the different PDZ concentrations, highlighting the parameters of 75 μg.mL−1 of PDZ and 100 J/cm2. As for in vivo results, aPDT increased survival and stimulated the immune system of G. mellonella infected by S. aureus. aPDT proved effective in both models, demonstrating its potential as an alternative therapy in treating MRSA bacterial infections.Item Photodynamic treatment in glioma: Metabolic and structural evaluation after therapy(Wiley) Teixeira, Marina Gabriela; Marcolino, Luciana Maria Cortez; Pinto, Juliana Guerra; Almeida, Rainara Moreno Sanches de; Ferreira, Isabelle; Ferreira-Strixino, JulianaGliomas are malignant tumors of the central nervous system, and one severe variant is called gliosarcoma. Photodynamic therapy (PDT) is a technique that stands out in the oncology area for minimizing side effects for the patient, triggering cell death at the site of irradiation, and can be used concomitantly with conventional treatments. This study aimed to evaluate the interaction of chlorine e6 with the cytoskeleton and mitochondria, as well as morphological changes and the death mechanism trig- gered after PDT. Chlorin e6 was used at concentrations of 200, 12.5, and 6.25 μg/mL, and cytoskeletal changes were analyzed by alpha-tubulin staining and mitochondrial membrane potential (MMP) analysis by JC-1 and Rhodamine 123 in flow cytom- etry. Surface features were examined using scanning electron microscopy, and the type of cell death mechanism was determined by flow cytometry with annexin and propidium iodide. Changes in the cytoskeleton were observed after PDT. Cytometry showed that cell death occurred predominantly via the apoptosis pathway, followed by the necrosis pathway. Chlorin e6 associated with PDT causes damage to gliosar- coma cells, regardless of concentration, showing cytoskeletal disruption, a decrease in MMP, and the percentage of cell death varies according to the concentration of PS.