Síntese e caraterização de microesferas termossenssíveis e magnéticas, à base de pectina para aplicação de liberação controlada de curcumina

• Ano de defesa: 2013
• Autor(a) principal: Almeida, Elizângela Aparecida Messias Soares de
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Estadual de Maringá; Brasil; Departamento de Química; Programa de Pós-Graduação em Química; UEM; Maringá, PR; Centro de Ciências Exatas
• Palavras-chave em Português: Microesferas; Pectina; Anidrido maleico; Poli(N-isopropilacrilamida) (PNIPAAm); Magnetita; Liberação controlada; Fármacos; Curcumina; Células Caco-2; PNIPAAm; Sistemas de liberação controlada de fármacos; Brasil.; Microspheres; Pectin; Maleic anhydride; Magnetite; Systems controlled drug release; Curcumin; Caco-2 cells; Brazil.; Ciências Exatas e da Terra; Química
• Link de acesso: http://repositorio.uem.br:8080/jspui/handle/1/3909

Researches dedicated to the development of systems for controlled drug release have focused in devices based on polysaccharides because, usually, such polymers are of low cost, nontoxic, biodegradable and from renewed resources. Therefore, the main target of this work was to obtain hydrogels based on Pectin to be used as devices for controlled drug release. For this, the Pectin (Pec) was chemically modified by reacting with maleic anhydride (MA), aiming to insert vinyl groups on Pec that are essential to the formation of Pec-based hydrogels. The reaction was adequately characterized by FTIR and NMR (¹H and ¹³C-CP/MAS) spectroscopies. Based on modified pectin (PecMA) microspheres-typed hydrogels were obtained with size between 20-36 μm using a reaction induced by ultrasound and a specific emulsion method and using PVA as stabilizer. The formation of crosslinked matrix was confirmed by ¹H NMR analysis, in which was possible to observe the disappearance of the signals related to the vinylic hydrogen atoms and the appearance of signs related to the hydrogen atoms due to CH and CH2 bonds. The spheric geometry and micro dimension (microspheres, μP) were observed by SEM images. PecAM-co-PNIPAm/Magnetite (μPPM) microspheres were obtained, sized from 0.5 to 26 μm. The presence of Magnetite was confirmed by XRD, EDX and FTIR. The quantification was performed by flame atomic absorption spectrometry (FAAS) and the sensibility to the magnetic field was measured by use of a vibrating sample magnetometer (VSM). The presence of PNIPAm was confirmed by NMR ¹H through of the appearance of signals related to the methylene and methyl terminals groups. The thermal sensitivity (LCST) of microspheres was evaluated by measures of transmitted light intensity and Zeta potential. Depending on the used formulation, the LCST fall between 31 to 43 °C. Tests of controlled release of Curcumin (CUR) were performed in simulated gastric fluid (SGF) and simulated intestinal fluid (SIF) employing, as devices, microspheres type μP-1 and μPPM-4. The results revealed the potential for the use of these systems as devices for drug delivery in intestine environments. Kinetic studies carried out revealed that the mechanisms of release from the microspheres are the matrix-solute-external fluid partition together the diffusion and macromolecular relaxation phenomena as suggested by Reis et. al. and Ritger-Pepas, respectively. Furthermore, the samples, especially the PecAM, showed an inhibitory effect on the growth of Caco-2 cells. The results indicate that these materials possess desirable properties and characteristics for use in anticancer treatment.