Efeito da massa molar da galactomanana de Dimorphandra gardneriana na formação de nanopartículas de copolímeros de galactomanana/poli-N-isopropilacrilamida

• Ano de defesa: 2020
• Autor(a) principal: Gomes, Raelle Ferreira
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Palavras-chave em Português: Galactomanana; Despolimerização; Copolímero; N-isopropilacrilamida
• Link de acesso: http://www.repositorio.ufc.br/handle/riufc/64378

Dimorphandra gardneriana (DG) galactomannan is a neutral, water-soluble polysaccharide composed of a linear chain of mannose units with branches of galactose units. Due to its high molar mass, depolymerization processes using enzymatic hydrolysis, ultrasound and acid hydrolysis were used to decrease the molar mass and the viscosity of the polysaccharide, enabling its use um the formation of nanoparticles. This work aimed to evaluate the effect of the molar mass of galactomannan of Dimorphandra gardneriana modified by different depolymerization processes in the synthesis of thermosensitive copolymer with Nisopropylacrylamide (NIPAM) and its potential as a drug carrier. Acid hydrolysis was the method that resulted in the least reduction in molar mass. The depolymerized materials were analyzed FT-IR and 1H NMR and results shows that chemical structures were similar to DG, however an increase in the mannose/galactose ratio was observed. The synthesis of copolymers was confirmed by FT-IR and 1H NMR with the appearance of poly-Nisopropylacrylamide (PNIPAM) functional groups. Copolymers formed with galactomannan of lower molar mass showed higher NIPAM grafting content, lower critical aggregation concentration (CAC) and particle size at 25 and 50 ºC, indicating the influence of molar mass. The copolymers showed a transition temperature higher than that of the homopolymer (PNIPAM) and a reduction in particle size with increasing temperature. Nanoparticles with sizes smaller than 300 nm were obtained and these materials showed indomethacin encapsulation efficiency ranging from 29 to 63%. The nanoparticle with greater encapsulation efficiency showed a controlled release with a maximum of 55,3 ± 3,2% in 72 hours of study. Nanoparticles formed by copolymers based on PNIPAM and galactomannan depolymerized by acid hydrolysis, have potential application in controlled drug delivery systems. Foi bolsista durante o curso? *