FLUORINATED HYDROGENATED MIXED VESICLES AS CARRIER OF MODEL BIOMOLECULES - A SPECTROSCOPIC STUDY/

Light scattering (LS), small-angle neutron scattering (SANS), electron spin resonance (ESR), and electronic spectroscopy in the UV-vis regio n were used to characterize hydrogenated/fluorinated mixed vesicles to be used as carriers for molecules of biological and pharmaceutical in terest. n-Dodecylbetaine and the ammonium salt of a perfluoropolyether carboxylate are known to spontaneously give mixed stable vesicles. Be cause of its heme-like structure, an octakis (octylthio)tetraazaporphy rin, under the form of the free base and of its Cu(II) metal complex, was utilized as a model cargo to penetrate into the vesicles. The porp hyrins appreciably aggregated, as indicated by their electronic spectr a, without disturbing the bilayer dynamics and polarity as revealed by ESR data using nitroxide probes located in different regions of the v esicle's membrane. Light scattering data showed, conversely, a signifi cant contraction of the vesicle's radius, which is in agreement with t he increased curvature expected from the insertion of polyazamacrocycl es in the bilayer membrane.