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Item Zinc phthalocyanine tetrasulfonate-loaded polyelectrolytic PLGA nanoparticles for photodynamic therapy applications(Elsevier) Toledo, Maria Cristina Modesto Clementino de; Abreu, Alexandro da Silva; Carvalho, Janicy Arantes; Ambrósio, Jéssica Aparecida Ribeiro; Godoy, Daniele da Silva; Pinto, Bruna Cristina dos Santos; Beltrame Junior, Milton; Simioni, Andreza RibeiroBackground: Photodynamic Therapy (PDT) is a modality for the treatment of neoplastic tissues, which is based on the administration of a phototherapeutic agent and light irradiation at an appropriate wavelength, aiming to locate and destroy the target cell with the formation of reactive oxygen species. Nanoencapsulation technology presents itself as a tool for incorporation of bioactive substances aiming to improve their solubility in physiological environment, obtain a longer circulation time in the organism, administration of lower dosages and the minimization of side effects. The present work aimed at the development of poly (lactic acid-glycolic acid) (PLGA) nanoparticles coated with polyelectrolyte film layers for encapsulating zinc phthalocyanine tetrasulfonated (ZnPcSO4) as a bioactive substance model. Methods: PLGA nanoparticles were produced by the double emulsion/solvent evaporation technique and polyelectrolytic coating was performed using polyalkylamine hydrochloride (PAH) as a weak polycation and poly (4- styrene sulfonate) (PSS) as a strong polyanion by layer-by-layer self-assembly technique (known as layer-by-layer-LbL). The nanoparticulate system was studied by scanning electron microscopy, steady-state, and their biological activity was evaluated using in vitro cancer cell lines by classical MTT assay. Results: The polyelectrolytic PLGA nanoparticles had an average diameter of 384.7 ± 138.6 nm, restricted distribution size with a polydispersity index. The obvious change in zeta potential indicates successful alternation in polycation (PAH) and polyanion (PSS) deposition directly in PLGA nanoparticles. Scanning electron microscopy (SEM) analysis showed that the formed system had morphology spherical, typical of these release systems. The loading efficiency was 82.1 % ± 1.2 %. The polyelectrolytic nanoparticles loaded with phthalocyanine maintained their photophysical behavior after encapsulation. Cell viability was determined, obtaining 90 % cell death. Conclusions: Therefore, the presented work depicts ZnPcSO4-loaded polyelectrolytic PLGA nanoparticles as a promise drug delivery system for phototherapeutic agent, which are thus expected to have superior therapeutic efficiency than free drug.Item Gelatin nanoparticles via template polymerization for drug delivery system to photoprocess application in cells(Taylor & Francis) Trindade, Agnes Cecheto; Castro, Pedro Augusto Rodrigues Ribeiro de; Pinto, Bruna Cristina dos Santos; Ambrósio, Jéssica Aparecida Ribeiro; Oliveira Junior, Benedito Marcio de; Beltrame Junior, Milton; Gonçalves, Erika Peterson; Pinto, Juliana Guerra; Ferreira-Strixino, Juliana; Simioni, Andreza RibeiroPhotodynamic therapy (PDT) is a clinical treatment based on the activation of light-absorbing photosensitizers (PS) to generate reactive oxygen species, which are toxic to the targeted disease cells. Because most PS are hydrophobic with poor water solubility, it is necessary to encapsulate and solubilize PS in aqueous condi- tions to improve the photodynamic action for this compound. In this work, gelatin-poly(acrylic acid) nanoparticles (PAA/gelatin nanoparticles) via template polymerization for incorporation alu- minum chloride phthalocyanine (ClAlPc) as a model drug for PDT application were developed. Biocompatible core-shell polymeric nanoparticles were fabricated via template polymerization using gelatin and acrylic acid as a reaction system. The nanoparticulate system was studied by scanning electron microscopy, steady- state, and their biological activity was evaluated using in vitro cancer cell lines by classical MTT assay. The obtained nanopar- ticles had a spherical shape and DLS particle size were deter- mined further and was found to be around 170nm. The phthalocyanine-loaded-nanoparticles maintained their photophysi- cal behaviour after encapsulation. It is found that ClAlPc can be released from the nanoparticles in a sustained manner with a small initial burst release. In vitro cytotoxicity revealed that ClAlPc- loaded nanoparticles had similar cytotoxicity to free ClAlPc with mouse melanoma cancer cell line (B16-F10). In vitro photoeffects assay indicated that the nanoparticle formulation was superior in anticancer effect to free ClAlPc on mouse melanoma cancer cell line B16-F10. The results indicate that ClAlPc encapsulated in gel- atin-poly(acrylic acid) nanoparticles are a successful delivery sys- tem for improving photodynamic activity in the target tissue.Item Polyelectrolytic gelatin nanoparticles as a drug delivery system for the promastigote form of Leishmania amazonensis treatment(Taylor & Francis) Souza, Catarina de; Carvalho, Janicy Arantes; Abreu, Alexandro da Silva; Paiva, Lucas Prudente de; Ambrósio, Jéssica Aparecida Ribeiro; Beltrame Junior, Milton; Oliveira, Marco Antonio de; Mittmann, Josane; Simioni, Andreza RibeiroIn this study, phthalocianato[bis(dimethylaminoethanoxy)] silicon (NzPC) was loaded onto gelatin nanoparticles functionalized with polyelectrolytes (polystyrene sulfonate/polyallylamine hydrochlor- ide) by layer-by-layer (LbL) assembly for photodynamic therapy (PDT) application in promastigote form of Leishmania amazonensis treatment. The process yield, and encapsulation efficiency were 80.0% ± 1.8 and EE 1⁄4 87.0% ± 1.1, respectively. The polyelectro- lytic gelatin nanoparticles (PGN) had a mean diameter of 437.4±72.85nm, narrow distribution size with a polydispersity index of 0.086. The obvious switching of zeta potential indicates successful alternating deposition of the polyanion PSS and polyca- tion PAH directly on the gelatin nanoparticles. Photosensitizer photophysical properties were shown to be preserved after gel- atin nanoparticle encapsulation. The impact of the PDT in the via- bility and morphology of Leishmania amazonensis promastigote in culture medium was evaluated. The PGN-NzPc presented low tox- icity at the dark and the PDT was capable of decreasing the via- bility in more than 80% in 0.1mmol.L 1 concentration tested. The PDT also triggered significant morphological alterations in the Leishmania promastigotes. These results reinforce the idea that the use of PGN as photosensitizers carriers is useful for PDT of Leishmania promastigotes.Item Curcumin-loaded bovine serum albumin (BSA) nanoparticles: photoreactivity and photodynamic action against Acinetobacter baumannii and Staphylococcus aureus(Royal Society of Chemistry) Pinto, Juliana Guerra; Laneri, Francesca; Brambilla, Isabelle de Paula Ribeiro; Azevedo, Maria Clara Barbosa Silva de; Ambrósio, Jéssica Aparecida Ribeiro; Simioni, Andreza Ribeiro; Fraix, Aurore; Sortino, Salvatore; Ferreira-Strixino, JulianaCurcumin (CUR) is a naturally occurring pigment, poorly soluble in water and an object of intense interest due to its multifaceted therapeutic and phototherapeutic activity. In this contribution, bovine serum albumin nanoparticles (BSA-NPs) with oppositely charged surfaces have been used as suitable nanocarriers both to overcome the poor water solubility of CUR and to encourage its interaction with Gram-positive and Gram-negative bacteria. The different surface charges of the BSA-NPs do not affect either the spectroscopic or the photochemical behaviour of the encapsulated CUR which in all cases is almost exclusively present in a diketo form rather than the enolic one. This strictly dictates the response of CUR to blue light excitation which, under these conditions, exhibits the usual reactivity of carbonyl compounds toward molecules that behave as hydrogen donors such as the BSA-NP components. Steady-state and time-resolved photochemical experiments show that the encapsulated CUR under- goes photodecomposition with rate basically independent of the presence of oxygen. The photo- decomposition seems to be mediated mainly by an intermolecular H-abstraction from the components of the nanocarrier by the lowest excited triplet state of CUR with the formation of the corresponding ketyl radical occurring in less than 0.5 ms. This radical is oxidized by molecular oxygen, likely leading to peroxyl and hydroperoxyl radical species, probably responsible for the photodynamic action. Accordingly, with the short triplet lifetime, no singlet oxygen photogeneration is observed. Concentrations of 0.2, 0.3 and 0.4 mM were selected for in vitro tests. Internalization of both formulations was observed in strains of A. baumannii and S. aureus, after 15 minutes of interaction. After irradiation, a reduction in the viability of bacteria was observed, at the different concentrations tested, with concentrations of 0.4 and 0.3 mM being the most efficient.