Navegando por Palavras-chave "Electron Paramagnetic Resonance"

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    Caracterização biofísica de vesículas catiônicas de dodab contendo C24:1 beta-glicosilceramida (βGlcCer)
    (Universidade Federal de São Paulo (UNIFESP), 2019-05-30) Martins, Leticia de Souza [UNIFESP]; Rozenfeld, Julio Henrique Kravcuks [UNIFESP]; http://lattes.cnpq.br/4232139220639334; http://lattes.cnpq.br/8580993475540515; Universidade Federal de São Paulo (UNIFESP)
    Objective: To characterize the structure of DODAB vesicles containing βGlcCer using differential scanning calorimetry (DSC), electron paramagnetic resonance (EPR) spectroscopy and fluorescence microscopy. Methods: Pure vesicles of DODAB, βGlcCer, and also mixed vesicles of DODAB plus βGlcCer were prepared from lipid films resulting from the evaporation of chloroform: methanol solutions. EPR, DSC and fluorescence microscopy experiments were performed using 5 mol%, 9 mol% and 16 mol% of βGlcCer in relation to the total lipid concentration. Results: It was shown that βGlcCer destabilized the gel phase of DODAB vesicles by decreasing the gel phase packing. Thus, βGlcCer induced a decrease in the phase transition temperature and cooperativity of DODAB vesicles, as seen in DSC thermograms. EPR spectra also showed that βGlcCer induced an increase in the order and / or rigidity of the DODAB fluid phase. Despite their different structures, a similar effect of loosening of the gel phase and stiffening of the fluid phase was observed when low cholesterol fractions were incorporated into the DODAB vesicles. Conclusion: βGlcCer is completely miscible with DODAB at all fractions tested, since no domains were observed by fluorescence microscopy or ESR spectra. Structural characterization of DODAB vesicles containing βGlcCer may be important for the development of novel immunotherapeutic tools such as vaccine adjuvants.