Fusion and leakage of catanionic surfactant vesicles induced by α-helical peptides: the effect of membrane charge

Abstract

Leakage and fusion of vesicles have triggered great interest because they are important steps in the transportation of materials in living systems. In this paper, we have shown a process of vesicle leakage and fusion induced by a type of α-helical peptide through the adsorption of peptide molecules on or their absorption in the membrane of vesicles. The fusion process was monitored by dynamic light scattering and cryogenic transmission electron microscopy, and the leakage process was tested with fluorescence dequenching of carboxyfluorescein molecules. The mechanism of leakage and fusion was deduced through circular dichroism and ζ-potential measurements. It was found that the positively charged peptides could only interact with negatively charged vesicles and that the interaction between peptides and negative vesicles depended on the charge density of the membrane. This study could enhance the understanding of the transport of materials in vivo and promote potential applications in drug delivery systems.