Desenvolvimento de sistemas nanoestruturados à base de óleo de pracaxi contendo ubiquinona e avaliação da citotoxicidade in vitro

• Ano de defesa: 2014
• Autor(a) principal: Mattiazzi, Juliane
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Santa Maria; BR; Farmácia; UFSM; Programa de Pós-Graduação em Ciências Farmacêuticas
• Palavras-chave em Português: Nanocápsulas; Óleo de pracaxi; Ubiquinona; Fotodegradação; Estabilidade; Teste de hemólise; Citotoxicidade; Nanocapsules; Pracaxy oil; Ubiquinone; Photodegradation; Stability; Hemolysis test; Cytotoxicity; CNPQ::CIENCIAS DA SAUDE::FARMACIA
• Link de acesso: http://repositorio.ufsm.br/handle/1/6046

This work aimed the preparation of novel nanocapsules and nanoemulsions based on pracaxy oil loaded with ubiquinone. For nanocapsules, poly(-caprolactone) (PCL) or Eudragit® EPO were employed in the preparation. For comparison purposes, nanospheres containing ubiquinone were prepared with both polymers. The methods employed to prepare these formulations were spontaneous emulsification (nanoemulsions), nanoprecipitation (nanospheres) and interfacial deposition of pre-formed polymer (nanocapsules). An analytical method was validated to the assay of ubiquinone-loaded systems and it was considered specific, linear, precise and accurate. After preparation, the nanostructured systems were characterized regarding particle size, polydispersity index, zeta potential, pH, as well as ubiquinone content and encapsulation efficiency. PCL-nanocapsules presented larger diameters (261 nm), which demonstrates the influence of both oil and polymer in the formulation. Nanocapsules containing the lowest amount of oil (0.15 g) presented polydispersity index more suitable. Zeta potential values of both nanoemulsions (-18 mV) and PCL-nanoparticles (-12 to -21 mV) were negatives, due to the presence of fatty acids in the pracaxy oil and due to the negative density of charge of PCL, respectively. Nanocapsules and nanospheres formulated with Eudragit ® EPO showed positives values of zeta potential (+25 to +45 mV), because of the cationic nature of this polymer. The pH values were slightly acidic for both nanoemulsions and PCL-nanostructures, while the Eudragit® EPO formulations presented pH close to the neutrality, about 7.5. Ubiquinone content of the nanostructured systems was close to the theoretical value, 1.0 mg/mL and the encapsulation efficiency was about 100%. Photodegradation studies showed that nanostructures were able to provide protection to the encapsulated ubiquinone in relation to free-ubiquinone (ethanolic solution), after 4h of exposition to UVC radiation and this protection was more pronounced for nanocapsules and nanoemulsions. The drug degradation followed a first order kinetic for all the systems studied, while the ethanolic solution of ubiquinone fitted better to the second order equation. The stability study of the formulations demonstrated that the systems were instable when stored for 90 days at 40 ± 2ºC e UR 75 ± 5%, especially Eudragit® EPO-nanocapsules, however, when they were stored at room temperature, the formulations appeared to be stable, keeping the initial physico-chemical characteristics. By performing a semi-quantitative hemolysis test, it was demonstrated the hemocompatibility of PCL nanocapsules. The MTT test was used to evaluate the cytotoxicity, and it was verified that free ubiquinone and pracaxi oil were capable to reduce cellular viability in rat glioma (C6) and breast cancer cells (MCF-7) after 48h of incubation, comparing to the control (DMEM). Besides, this cytotoxic potential was more pronounced when the cells were treated with PCL nanocapsules. In this way, the nanocarriers developed are promising systems for vectorization, stabilization and to study therapeutic potentials of ubiquinone.