Navegando por Assunto "Fotoenticine"

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    Action of Photodynamic Therapy at Low Fluence in 9 L/lacZ Cells after Interaction with Chlorins
    (MDPI) Vitorio, Gabrielle dos Santos; Godoi, Bruno Henrique; Pinto, Juliana Guerra; Ferreira, Isabelle; Pacheco Soares, Cristina; Ferreira-Strixino, Juliana
    Gliosarcoma (GS) is a primary malignant neoplasm of the central nervous system, treated with an unfavorable prognosis with surgery, radiotherapy, and chemotherapy. The treatment for GS consists of surgical resection, almost always accompanied by radiotherapy and/or chemotherapy, given the invasive behavior of the tumor. Photodynamic Therapy (PDT) is studied as an alternative method that combines light, a photosensitizer (PS), and molecular oxygen. This study aimed to compare the effects of PDT using the photosensitizers Fotoenticine (FTC) and Photodithazine (PDZ) at low concentrations and fluences. For this study, 9 L/lacZ cells, concentrations of 1.55 µg mL−1 , 12.5 µg mL−1 , and 50 µg mL−1 of chlorins and fluences of 1, 5, and 10 J/cm2 were used. A test was also carried out with Trypan Blue in L929 cells at the mentioned concentrations at 5 J/cm2 . Both chlorins were internalized in the cytoplasm, with a significant reduction in viability (>95%) in almost all groups and altered cell adhesion and morphology after PDT. HSP70 expression decreased in both PS, while HSP27 increased only in PDT with FTC, and although there was a change in cell adhesion in the 9 L/LacZ lineage it was not observed in the L929 fibroblast lineage. Both chlorins were effective, highlighting the concentration of 50 µg mL−1 at the fluence of 5 J/cm2 ; according to the present study, the PDZ showed better results.
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    Antimicrobial effects of photodynamic therapy with Fotoenticine on Streptococcus mutans isolated from dental caries
    (Elsevier) Terra-Garcia, Maíra; Souza, Cheyenne Marçal de; Gonçalves, Nathalia Maria Ferreira; Pereira, André Henrique Correia; Barros, Patrícia Pimentel de; Borges, Alessandra Bühler; Miyakawa, Walter; Ferreira-Strixino, Juliana; Junqueira, Juliana Campos
    Photodynamic therapy (PDT) is a promising strategy to control cariogenic pathogens, such as Streptococcus mutans. Seeking to reach the total bacterial elimination from dental surfaces, novel photosensitizers have been investigated, such as Fotoenticine (FTC) derived from chlorin e6. The objective of this study was to investigate the photodynamic effects of FTC against several clinical strains of S. mutans. Clinical isolates were obtained from patients with active carious lesions, identified by molecular analysis and subjected to PDT using laser irradiation (660 nm and 39.5 J/cm2) in planktonic and biofilm stages. We identified 11 S. mutans strains from cervical, occlusal and proximal caries. PDT mediated by FTC has totally eliminated the S. mutans cells in planktonic growth for all analyzed strains. In biofilms, PDT with FTC reached statistically significant reductions compared with the non-treated control group, at 5.4, 5.5 and 6.5 Log10 (CFU/mL), respectively, for the strains from proximal, occlusal and cervical caries. The scanning electron microscopy evaluations confirmed that PDT mediated by FTC was able to disaggregate and kill the S. mutans cells adhered to enamel surface, suggesting its potential to disinfect the dental tissues.
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    Antimicrobial Photodynamic Therapy Mediated by Fotenticine and Methylene Blue on Planktonic Growth, Biofilms, and Burn Infections of Acinetobacter baumannii
    (MDPI) Figueiredo-Godoi, Lívia Mara Alves; Garcia, Maíra Terra; Pinto, Juliana Guerra; Ferreira-Strixino, Juliana; Faustino, Eliseu Gabriel; Pedroso, Lara Luise Castro; Junqueira, Juliana Campos
    Antimicrobial photodynamic therapy (aPDT) is considered a promising alternative strategy to control Acinetobacter baumannii infections. In this study, we evaluated the action of aPDT mediated by a new photosensitizer derivative from chlorin e-6 (Fotoenticine—FTC) on A. baumannii, comparing its effects with methylene blue (MB). For this, aPDT was applied on A. baumannii in planktonic growth, biofilms, and burn infections in Galleria mellonella. The absorption of FTC and MB by bacterial cells was also evaluated using microscopic and spectrophotometric analysis. The results of planktonic cultures showed that aPDT reduced the number of viable cells compared to the non-treated group for the reference and multidrug-resistant A. baumannii strains. These reductions varied from 1.4 to 2 log10 CFU for FTC and from 2 log10 CFU to total inhibition for MB. In biofilms, aPDT with MB reduced 3.9 log10 CFU of A. baumannii, whereas FTC had no effect on the cell counts. In G. mellonella, only MB-mediated aPDT had antimicrobial activity on burn injuries, increasing the larvae survival by 35%. Both photosensitizers were internalized by bacterial cells, but MB showed a higher absorption compared to FTC. In conclusion, MB had greater efficacy than FTC as a photosensitizer in aPDT against A. baumannii.
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    Susceptibility of Dental Caries Microcosm Biofilms to Photodynamic Therapy Mediated by Fotoenticine
    (MDPI) Garcia, Maíra Terra; Ward, Rafael Araújo da Costa; Gonçalves, Nathália Maria Ferreira; Pedroso, Lara Luise Castro; Silva Neto, José Vieira da; Ferreira-Strixino, Juliana; Junqueira, Juliana Campos
    Photodynamic therapy (PDT) mediated by Fotoenticine® (FTC), a new photosensitizer derived from chlorin e-6, has shown in vitro inhibitory activity against the cariogenic bacterium Streptococcus mutans. However, its antimicrobial effects must be investigated on biofilm models that represent the microbial complexity of caries. Thus, we evaluated the efficacy of FTC-mediated PDT on microcosm biofilms of dental caries. Decayed dentin samples were collected from different patients to form in vitro biofilms. Biofilms were treated with FTC associated with LED irradiation and analyzed by counting the colony forming units (log10 CFU) in selective and non-selective culture media. Furthermore, the biofilm structure and acid production by microorganisms were analyzed using microscopic and spectrophotometric analysis, respectively. The biofilms from different patients showed variations in microbial composition, being formed by streptococci, lactobacilli and yeasts. Altogether, PDT decreased up to 3.7 log10 CFU of total microorganisms, 2.8 log10 CFU of streptococci, 3.2 log10 CFU of lactobacilli and 3.2 log10 CFU of yeasts, and reached eradication of mutans streptococci. PDT was also capable of disaggregating the biofilms and reducing acid concentration in 1.1 to 1.9 mmol lactate/L. It was concluded that FTC was effective in PDT against the heterogeneous biofilms of dental caries.