An investigation of morphological, microscopic dynamics, fluidity, and physicochemical variations in Cu-decorated metallosomes with cholesterol

Abstract The controlled stoichiometry of single-tailed surfactant cetylpyridinium chloride (CPC) in the presence of Cu ions led to a vesicular assembly known as ‘metallosomes’. Unlike liposomes, their membrane properties such as microscopic dynamics, fluidity, and physicochemical variations, have not been explored. Therefore, metallosomes with a water-soluble metallosurfactant (bishexadecylpyridiniumcopper tetrachloride) with varying cholesterol concentrations were synthesized and explored for the induced effect of cholesterol on different membrane properties. Three different metallosomes were synthesized by varying the metallosurfactant to cholesterol molar ratio to 1:0, 1:0.5, and 1:1 and characterized with cryo-TEM, FESEM, DLS, and ζ-potential. For microscopic dynamics studies, quasielastic neutron scattering (QENS), for bilayer molecular arrangement XRD and SAXS, and for physicochemical properties, three fluorescent probes (ANS, Prodan, and Laurdan) were utilized. The Well Diffusion method was employed for exploring the antimicrobial behavior of empty as well as drug-loaded metallosomes. The spherical morphology of synthesized metallosomes was established with different studies and insertion of cholesterol has been found to lead to more stable and homogeneous suspensions. Also, more restricted, less fluid, and dehydration of membrane was observed with cholesterol. The antimicrobial activity as well as releasing profile was observed to be directly influenced in the presence of cholesterol.