Characterization of DDAB/Cholesterol Vesicles and Its Comparison with Lipid/Cholesterol Vesicles

Vesicles prepared by synthetic surfactant, DDAB (dilauryldimethylammonium bromide), were modified with cholesterol and their membrane surface properties of the vesicle were characterized through the analyses of fluorescent probes, such as Laurdan (6-lauroyl-2-dimethylaminonaphthalene) and DPH (1,6-diphenyl-1,3,5-hexatriene). The self-assembly of DDAB with cholesterol showed stable vesicle structure with a mean diameter of 127 nm through the dynamic light scattering analysis. While the DDAB vesicle showed high polarity and high fluidity, the modification of the DDAB vesicle with cholesterol lead to the formation of "heterogeneous phase" on the vesicle membrane. DDAB:cholesterol = 70:30 vesicle showed unique characteristics that represents polar environment but lower fluidity. A novel platform for the chemical process in aqueous media can be expected by using the artificial surfactant vesicles modified with cholesterol.