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Item Photodynamic therapy of cationic and anionic BSA-curcumin nanoparticles on amastigotes of Leishmania braziliensis and Leishmania major and Leishmania amazonensis(Photodiagnosis and Photodynamic Therapy, Elsevier) Marcolino, Luciana Maria Cortez; Ambrósio, Jéssica Aparecida Ribeiro; Pinto, Juliana Guerra; Ferreira, Isabelle; Simioni, Andreza Ribeiro; Ferreira-Strixino, JulianaCutaneous leishmaniasis is a neglected disease prevalent in tropical countries, and conventional treatment can cause several serious side effects. Photodynamic therapy (PDT) can be considered a promising treatment alternative, as it is non-invasive therapy that has no side effects and uses accessible and low-cost substances, such as curcumin. This study evaluated the PDT response with cationic and anionic BSA nanoparticles encapsulated with curcumin in macrophages infected with L. braziliensis, L. major, and L. amazonensis. The nanoparticle system was characterized using a steady-state technique, scanning electron microscopy (SEM) study, and its biological activity was evaluated using macrophage cell lines infected with different Leishmania species. All spectroscopy measurements demonstrated that BSA curcumin (BSACur) has good photophysical properties, and confocal microscopy shows that macrophages and protozoa internalized the nanoparticles. The viability test demonstrated that at low concentrations, such as 0.1, 0.7, and 1.0 μmol. L 1, there was a decrease in cell viability after PDT application. Furthermore, a decrease in the number of parasites recovered was observed in the PDT groups. The results allowed us to conclude that curcumin loaded into BSA nanoparticles may have potential application in drug delivery systems for PDT protocols, demonstrating reduced cell viability at lower concentrations than free curcumin.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.