title: Structural features of interacting complementary liposomes promoting formation of multicompartment structures.
abstract: The structural features of complementary liposomes and factors favoring formation of multicompartment systems are investigated. Specifically, liposomal formulations consisting of PEGylated unilamellar liposomes with guanidinium moieties located at the distal end of polyethylene glycol (PEG) chains interact with complementary multilamellar liposomes bearing phosphate moieties. Furthermore, the number of PEG chains attached to the unilamellar interface of the liposomes is enhanced by incorporating PEGylated cholesterol in their bilayer. While molecular recognition of the liposomes is the driving force for initiating multicompartmentalization, it is the enhanced PEGylation at the liposomal interface that synergistically promotes fusion resulting in large and well-formed multicompartment systems. A mechanism is proposed according to which initial adhesion of the liposomes, followed by reorganization of their membrane lipids, leads to giant bilayer aggregates incorporating large liposomes.
authors.affiliation: Institute of Physical Chemistry, NCSR "Demokritos", 15310 Aghia Paraskevi, Attiki, Greece.
authors.forename: Zili
authors.initials: Z
authors.lastname: Sideratou
authors.forename: Nikoletta
authors.initials: N
authors.lastname: Sterioti
authors.forename: Dimitris
authors.initials: D
authors.lastname: Tsiourvas
authors.forename: Constantinos M
authors.initials: CM
authors.lastname: Paleos
mesh_terms: D002784:Cholesterol; D008051:Lipid Bilayers; D008081:Liposomes / Q000737:chemistry*; D008561:Membrane Fusion; D010710:Phosphates; D011092:Polyethylene Glycols
chemical_list: D008051:Lipid Bilayers; D008081:Liposomes; D010710:Phosphates; D011092:Polyethylene Glycols; D002784:Cholesterol