Transição vesícula-micela em mistura aquosa de sais dialquilados de amônio quaternário com Pluronic® F127

• Ano de defesa: 2015
• Autor(a) principal: Lemos, Monique [UNESP]
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Estadual Paulista (Unesp)
• Palavras-chave em Português: Biologia molecular; Biofísica; Sistemas de entrega de drogas; Lipídios; Polieletrolitos; Potencial zeta
• Link de acesso: http://hdl.handle.net/11449/127754

It has been studied the effects of the alkyl chain length (C12 and C18) and counterion (Br - and Cl-) of the vesicle-forming quaternary ammonium cationic lipids from didodecyldimethylammonium bromide (DDAB), dioctadecyldimethylammonium bromide (DODAB) and dioctadecyldimethylammonium chloride (DODAC), on the interaction with the micelle-forming triblock copolymer Pluronic® F127(F127). Thermal and structural properties of vesicles and micelles formed were investigated. The lipid concentration was fixed at 1 mM at which predominantly unilamellar vesicles are formed in aqueous dispersion and varied the F127 concentration up to 5 mM. The samples were monitored by turbidimetry, differential scanning calorimetry (DSC), dynamic light scattering (DLS) and dynamic electrophoretic light scattering (DELS) techniques. The results indicate vesicle-micelle transition, which occurs in three stages: in the first stage there is predominance of mixed vesicles; in the second stage there co-exist mixed vesicles and micelles; and in the third stage the system is dominated by mixed micelles. The complexes formed consist of mixed vesicles or micelles from lipidF127, respectively at low and high copolymer concentrations. These vesicle and micelle complexes can serve as template for lipoplexes and polyplexes in the interaction of mixed micelles and vesicles with nucleic acid (DNA or RNA), respectively.