Mixed Hybrid Lipid/Polymer Vesicles as a Novel Membrane Platform

Abstract

Vesicles can be individually fabricated from naturally occurring lipid or synthetic block copolymer molecules via self-assembly in aqueous solutions; the blending of both vesicle-forming amphiphiles leads to the formation of hybrid membranes. Their final stabilities and lateral morphologies are strongly determined by the molar composition, size, and charge properties of the interacting components as well as by the lipid chain melting temperature. Upon merging the best properties of lipo- and polymersomal membranes, hybrid lipid/polymer vesicles represent a new scaffold for medical applications combining, e.g., combining the biocompatibility of liposomes with the high thermal and mechanical stability and functional variability of polymersomes within a single vesicle type. Up to now, several hybrid membrane systems and their corresponding vesicular morphologies have been studied, highlighting the attractive properties and features useful in selective delivery receptor scaffolding.

Janus dendrimersomes coassembled from fluorinated, hydrogenated, and hybrid Janus dendrimers as models for cell fusion and fission

“…Diblock copolymers have also been widely used for the development of synthetic vesicles denoted polymersomes, which exhibit excellent stability and mechanical properties (5,6). However, they are polydisperse and sometimes toxic and exhibit bilayers from 8 to 50 nm, which are thicker than those of biological membranes (about 4 nm), making them less suitable for incorporating proteins and other components of biological origin in their bilayers (7)(8)(9)(10). A third class of synthetic vesicles denoted dendrimersomes (DSs) has been elaborated by the self-assembly of amphiphilic JDs (11).…”

“…drug and gene delivery vectors (1,9,10,16). A three-component lipid system consisting of 30% 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC), 50% brain sphingomyelin, and 20% cholesterol was reported to form giant unilamellar, peanut-shaped biphasic liposomes (17,18).…”

Bioactive cell-like hybrids coassembled from (glyco)dendrimersomes with bacterial membranes

“…These vesicles provide models for primitive (12) and contemporary (13,14) cell membranes and drug-delivery devices (15)(16)(17). Recently, hybrid vesicles coassembled from naturally occurring phospholipids and amphiphilic block copolymers (18)(19)(20) have been described; these vesicles eliminated some of the deficiencies of liposomes, such as limited stability under oxidative conditions and general instability over time, and the deficiencies of polymersomes, which possess wide membrane thickness [8-50 nm (20)], exhibit toxicity, and can be tedious to synthesize. These hybrid vesicles combined the desirable feature of liposomes-specifically, their biologically suitable membrane thickness of 4 nm-with that of polymersomes, which are known for their stability.…”

“…In addition, transmembrane proteins (21-23) could be incorporated into the phospholipid fragments of planar membranes derived from these assemblies. However, the variability in the extent of miscibility between the hydrophobic fragments of the phospholipid and the block copolymer (20) generates a complex morphology of the hybrid membrane that requires further characterization to enable practical applications both as drug-delivery devices and cell membrane models. Here, we report the coassembly of the components of DSs and GDSs with those of the bacterial membrane vesicles (BMVs) to generate functional hybrid vesicles.…”

Constraining Polymers into β-Turns: Miscibility and Phase Segregation Effects in Lipid Monolayers

“…Being superior in mechanical performance, with significantly enhanced bending moduli in comparison to lipid-bilayer membranes [2], they also display drawbacks, such as a reduced membrane mobility, a large thickness, or significantly reduced transport properties across the membrane [3,4]. In order to merge the advantages of polymersomes with those of lipid bilayer membranes, mixed-systems between those two components have gained significant attention during the past years, placing the principles of formation, stability, and most of all miscibility of these two systems into the limelight [5][6][7][8].…”