Nanopartículas de sulfato de dextrana enxertada com poli (N- isopropilacrilamida) para o encapsulamento de metotrexato

• Ano de defesa: 2019
• Autor(a) principal: Santos, Aline Teixeira dos
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Palavras-chave em Português: Sulfato de dextrana; N-isopropilacrilamida; Metotrexato
• Link de acesso: http://www.repositorio.ufc.br/handle/riufc/48020

Rheumatoid arthritis (RA) is an autoimmune disease, affecting about 1% of the world's population. It generates joint deformity and destruction due to the occurrence of bone and cartilaginous erosion. Nanoparticles of amphiphilic copolymers based on polysaccharides and their derivatives have been widely studied because they are biocompatible and biodegradable, which makes them promising materials for biomedical applications. N-isopropylacrylamide-grafted thermo- responsive copolymers (NIPAM) are candidates for drug release because they are able to change their structure rapidly and reversibly as a response to temperature rise. The dextran sulphate (DS) has biocompatibility with the macrophages responsible for the inflammatory complexes in rheumatoid arthritis, in addition to being obtained by bacteria that favors the control of structure in industrial scale. This work aims to synthesize and characterize thermosensitive nanoparticles based on DS grafted with NIPAM for the treatment of rheumatoid arthritis. The copolymers were synthesized by radical copolymerization and the influence of the amount of NIPAM was analyzed. The products were characterized by FTIR and RMN. The copolymers showed bands characteristic of the DS and PNIPAM. 1H NMR detected the presence of signals characteristic of the DS and the PNIPAM, confirming the grafting. The copolymers showed phase transition with increasing temperature. Transition temperatures were lower for the DS-g-3PNIPAM (33 ºC) and DS-g-PNIPAM (34 ºC) copolymers because of the lower PNIPAM content. The Dynamic Light Scattering (DLS) showed that of the copolymers obtained, the DS-g-3PNIPAM presented a greater hydrodynamic radius and better homogeneity. The DS-g-3PNIPAM copolymer had a critical association concentration (CAC) of 0.176 mg / mL, being lower than that of DS-g-PNIPAM at 50 ºC. The nanoparticles formed by the DS-g-3PNIPAM copolymer showed spherical structure and size smaller than that observed by DLS. Among the copolymers studied, DS-g- 3PNIPAM was shown to be the most suitable for the incorporation of methotrexate, presenting an encapsulation efficiency of 27,6 and as a drug content a value of 5,7.