Navegando por Assunto "Vaterite"

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    Hydroxyapatite microspheres used as a drug delivery system for gliosarcoma strain 9l/Lacz treatment by photodynamic therapy protocols
    (Elsevier) Ambrósio, Jéssica Aparecida Ribeiro; Marmo, Vitor Luca Moura; Gonçalves, Érika Peterson; Pinto, Juliana Guerra; Ferreira-Strixino, Juliana; Raniero, Leandro José; Beltrame Junior, Milton; Simioni, Andreza Ribeiro
    Background: Hydroxyapatite (HAp) presents similarities with the human bone structure and presents properties such as biodegradability, biocompatibility, and osteoconductivity, which favors its use in prostheses implants and enables its use as a vehicle for the delivery of photosensitizers (PS) from systems of release (DDS) for photodynamic therapy applications Methods: In this work was to synthesized hydroxyapatite microspheres (meHAp), encapsulated with chloroaluminium phthalocyanine (ClAlPc), for DDS. meHAp was synthesized using vaterite as a template. The drug was encapsulated by mixing meHAp and a 50.0 mg.mL− 1 ClAlPc solution. Photochemical, photophysical, and photobiological studies characterized the system. Results: The images from the SEM analysis showed the spherical form of the particles. All spectroscopic results showed excellent photophysical parameters of the drug studied when served in the meHAp system. The incorporation efficiency was 57.8 %. The trypan blue exclusion test results showed a significant reduction (p < 0.05) in cell viability for the groups treated with PDT at all concentrations above 250 μg.mL− 1 . In 9 L/lacZ gliosarcoma cells, PDT mediated at concentrations from 250 to 62.5 µg.mL− 1 reduced cell viability by more than 98 %. In the cell internalization study, it was possible to observe the internalization of phthalocyanines at 37 ◦C, with the accumulation of PS in the cytoplasm and inside the nucleus in the two tested concentrations. Conclusions: From all the results presented throughout the article, the meHAp system shows promise for use as a modified release system (DSD) in photodynamic therapy.
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    Vaterite microparticle-loaded methylene blue for photodynamic activity in macrophages infected with Leishmania braziliensis
    (Springer Nature) Marmo, Vitor Luca Moura; Ambrósio, Jéssica Aparecida Ribeiro; Gonçalves, Érika Peterson; Raniero, Leandro José; Beltrame Junior, Milton; Pinto, Juliana Guerra; Ferreira-Strixino, Juliana; Simioni, Andreza Ribeiro
    Calcium carbonate (CaCO3) exhibits a variety of crystalline phases, including the anhydrous crystalline polymorphs calcite, aragonite, and vaterite. Developing porous calcium carbonate microparticles in the vaterite phase for the encapsulation of methylene blue (MB) as a photosensitizer (PS) for use in photodynamic therapy (PDT) was the goal of this investigation. Using an adsorption approach, the PS was integrated into the CaCO3 microparticles. The vaterite microparticles were characterized by scanning electron microscopy (SEM) and steady-state techniques. The trypan blue exclusion method was used to measure the biological activity of macrophages infected with Leishmania braziliensis in vitro. The vaterite microparticles produced are highly porous, non-aggregated, and uniform in size. After encapsulation, the MB-loaded microparticles kept their photophysical characteristics. The carriers that were captured allowed for dye localization inside the cells. The results obtained in this study indicated that the MB-loaded vaterite microparticles show promising photodynamic activity in macrophages infected with Leishmania braziliensis.