Navegando por Assunto "Leishmania braziliensis"

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    Biochemical changes in Leishmania braziliensis after photodynamic therapy with methylene blue assessed by the Fourier transform infrared spectroscopy
    (Springer Nature Link) Sakane, Kumiko Koibuchi; Bhattacharjee, Tanmoy; Fagundes, Jaciara; Marcolino, Luciana Maria Cortez; Ferreira, Isabelle; Pinto, Juliana Guerra; Ferreira-Strixino, Juliana
    Photodynamic therapy (PDT) with photosensitizer methylene blue was applied to Leishmania braziliensis, and Fourier transform infrared (FTIR) spectroscopy was used to study biochemical changes in the parasite after PDT in comparison to untreated (C), only irradiation (I), and only photosensitizer (PS). Spectral analysis suggests increase in lipids, proteins, and protein secondary structures in PDT compared with C and decrease in nucleic acids and carbohydrates. Interestingly, these trends are different from PDT of Leishmania major species, wherein lipids decrease; there are minimal changes in secondary structures and increase in nucleic acids and carbohydrates. The study thus suggests possibility of different biomolecular players/pathways in PDT-induced death of L. braziliensis and L. major.
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    Methylene blue functionalized ZnO nanoparticles: a promising approach for photodynamic therapy in the treatment of leishmaniasis
    (Sage) Gouvea, Thainara Alves; Ambrósio, Jéssica Aparecida Ribeiro; Carvalho, Janicy Arantes; Marmo, Vitor Luca Moura; Marcolino, Luciana Maria Cortez; Pinto, Juliana Guerra; Ferreira-Strixino, Juliana; Simioni, Andreza Ribeiro; Gonçalves, Erika Peterson
    Zinc oxide (ZnO) has wide application in engineering, but its use in medical sciences has aroused growing interest. In this context, ZnO nanoparticles were investigated as vehicles for the delivery of methylene blue (MB), a photosensitizer (PS) used in photodynamic therapy (PDT) against Leishmania braziliensis. ZnO-NPs were produced by a coprecipitation method and characterized by several techniques, including scanning electron microscopy (SEM), UV-VIS spectroscopy, Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). The results showed that the ZnO-NPs presented uniform spheroidal morphology with open porosity, allowing an efficient methylene blue (MB) encapsulation without significant structural changes, ensuring stability and the absence of aggregation. The PS was adsorbed on the porous surface of the ZnO nanoparticles, characterized by scanning electron microscopy (SEM) and steady-state analysis techniques. Spectroscopic analysis confirmed the maintenance of the photosensitizing properties of MB. The biological activity was evaluated in vitro using the trypan blue exclusion method in macrophages infected with Leishmania braziliensis. After loading with the photosensitizer, they maintained their photophysical properties, ensuring the proper location of the dye within the cells. In vitro assays demonstrated the internalization of ZnO/MB-NPs by infected macrophages and a significant reduction in parasite viability after light activation. Thus, the results showed that the developed system exhibits a promising photodynamic activity with relevant therapeutic potential in treating macrophages infected by Leishmania braziliensis.
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    Photodynamic Activity of Photogem® in Leishmania Promastigotes and Infected Macrophage
    (Taylor & Francis) Pinto, Juliana Guerra; Marcolino, Luciana Maria Cortez; Ferreira-Strixino, Juliana
    Objectives: This study aimed to evaluate the effect of photodynamic therapy (PDT) with Photogem⃝R in promastigotes of Leishmania braziliensis and Leishmania major, and in infected macrophages. Materials & methods: The following parameters were analyzed: Photogem⃝R internalization, mitochondrial activ- ity, viability, tubulin marking and morphological alterations in promastigotes and viability in infected macrophages. Results: Photogem⃝R accumulated in the cytosol and adhered to the flagellum. Changes were observed in the mitochondrial activity in groups maintained in the dark, with no viability alteration. After PDT, viability decreased up to 80%, and morphology was affected. Conclusion: The results point out that PDT with Photogem⃝R can reduce parasite and macrophage viability. Lay abstract: Cutaneous Leishmaniasis is a disease that can cause deforming lesions, the treatment of which is highly toxic. It is considered a neglected disease and little progress has been made in the treatment of this disease. Photodynamic therapy can be an alternative treatment which is less costly, and involves local treatment of the lesion, thereby reducing side effects for the patient. The present study aims to test the photodynamic therapy with Photogem, a photo sensitive drug, and to verify if the parasites can be affected by this therapy, aiming to apply this therapy in lesions in patients in the near future.