Navegando por Autor "Ruiz, Ana Lucia Tasca Gois"
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Item In vitro and in vivo acute toxicity of a novel citrate-coated magnetite nanoparticle.(2022) Rocha, José Marcos Vieira; Souza, Valeria Barbosa de; Panunto, Patricia Costa; Nicolosi, Jacqueline Spacagna; Silva, Emanueli do Nascimento da; Cadore, Solange; Londono, Oscar Moscoso; Muraca, Diego; Tancredi, Pablo; Brot, Marina de; Nadruz, Wilson; Ruiz, Ana Lucia Tasca Gois; Knobel, Marcelo; Schenka, André AlmeidaMagnetic nanoparticles (MNps) have become powerful tools for multiple biomedical applications such as hyperthermia drivers, magnetic resonance imaging (MRI) vectors, as well as drug-delivery systems. However, their toxic effects on human health have not yet been fully elucidated, especially in view of their great diversity of surface modifications and functionalizations. Citrate-coating of MNps often results in increased hydrophilicity, which may positively impact their performance as drug-delivery systems. Nonetheless, the consequences on the intrinsic toxicity of such MNps are unpredictable. Herein, novel magnetite (Fe3O4) nanoparticles covered with citrate were synthesized and their potential intrinsic acute toxic effects were investigated using in vitro and in vivo models. The proposed synthetic pathway turned out to be simple, quick, inexpensive, and reproducible. Concerning toxicity risk assessment, these citrate-coated iron oxide nanoparticles (IONps) did not affect the in vitro viability of different cell lines (HaCaT and HepG2). Moreover, the in vivo acute dose assay (OECD test guideline #425) showed no alterations in clinical parameters, relevant biochemical variables, or morphological aspects of vital organs (such as brain, liver, lung and kidney). Iron concentrations were slightly increased in the liver, as shown by Graphite Furnace Atomic Absorption Spectrometry and Perls Prussian Blue Staining assays, but this finding was considered non-adverse, given the absence of accompanying functional/clinical repercussions. In conclusion, this study reports on the development of a simple, fast and reproducible method to obtain citrate-coated IONps with promising safety features, which may be used as a drug nanodelivery system in the short run.Item Lupeol and its esters : NMR, powder XRD data and in vitro evaluation of cancer cell growth.(2018) Silva, Aline Teixeira Maciel; Magalhães, Cássia Gonçalves; Duarte, Lucienir Pains; Mussel, Wagner da Nova; Ruiz, Ana Lucia Tasca Gois; Shiozawa, Larissa; Carvalho, João Ernesto de; Trindade, Izabel Cristina; Vieira Filho, Sidney AugustoThe triterpene lupeol (1) and some of its esters are secondary metabolites produced by species of Celastraceae family, which have being associated with cytotoxic activity. We report herein the isolation of 1, the semi-synthesis of eight lupeol esters and the evaluation of their in vitro activity against nine strains of cancer cells. The reaction of carboxylic acids with 1 and DIC/DMAP was used to obtain lupeol stearate (2), lupeol palmitate (3) lupeol miristate (4), and the new esters lupeol laurate (5), lupeol caprate (6), lupeol caprilate (7), lupeol caproate (8) and lupeol 3’,4’-dimethoxybenzoate (9), with high yields. Compounds 1-9 were identified using FT-IR, 1H, 13C-NMR, CHN analysis and XRD data and were tested in vitro for proliferation of human cancer cell activity. In these assays, lupeol was inactive (GI50> 250μg/ mL) while lupeol esters 2 -4 and 7 - 9 showed a cytostatic effect. The XRD method was a suitable tool to determine the structure of lupeol and its esters in solid state. Compound 3 showed a selective growth inhibition effect on erythromyeloblastoid leukemia (K-562) cells in a concentration-dependent way. Lupeol esters 4 and 9 showed a selective cytostatic effect with low GI50 values representing promising prototypes for the development of new anticancer drugs.