Oliveira, Ana Isabel de Freitas Tavares deMoreira, Fernando Xavier FerreiraCarvalho, Daniel José Teixeira2024-01-292023-11-17http://hdl.handle.net/10400.22/24798Flavanol quercetin has shown numerous therapeutic potentialities, although its application in the pharmaceutical industry is limited, making it necessary to use various methodologies such as nanotechnology to overcome this problema. The main aim of this work was to develop a method for preparing quercetin-loaded polymeric nanoparticles. Quercetin was incorporated into polycaprolactone nanoparticles using the nanoprecipitation method, after diferente parameters had been optimized. Different ratios of polycaprolactone:quercetin were evaluated, and stable nanoparticles with the best characteristics were obtained at a ratio of 1:0.07, with na average size of 220nm, polydispersity indexo f 0.218, and a zeta potential of -24mV. An association efficiency of 45% was obtained by the indirect method and 12% by the direct method after optimization of the extraction process. The association efficiency was assessed using a properly validated high-performance liquid chromatography method with a linearity range of 0.14-245 µg/mL, a correlation corfficient of 0.999, good precision (˂10%), accuracy (88.6-110.7%) and specificity.With regard to the activity of the nanoparticles on HaCaT cells, the quercetin-loaded nanoparticles were shown to reduce the cytotoxicity of quercetin at high concentrations, as well as having a protective Effect against aggressive agentes at the same concentrations.engQuercetinNanoparticlesNanoprecipitationPolycaprolactoneHPLCmaster thesis203473418