obtention-giant-unilamellar-hybrid-vesicles-electroformation

Obtention of Giant Unilamellar Hybrid Vesicles by Electroformation and Measurement of their Mechanical Properties by Micropipette Aspiration

Giant vesicles obtained from phospholipids and copolymers can be exploited in different applications: controlled and targeted drug delivery, biomolecular ...

CNRS, Bordeaux INP, LCPO, UMR 5629

The light-triggered, programmable rupture of cell-sized vesicles is described, with particular emphasis on self-assembled polymersome capsules. The mechanism involves a hypotonic osmotic imbalance created by the accumulation of photogenerated species inside the lumen, which cannot be compensated owing to the low water permeability of the membrane. This simple and versatile mechanism can be adapted to a wealth of hydrosoluble molecules, which are either able to generate reactive oxygen species or undergo photocleavage. Ultimately, in a multi-compartmentalized and cell-like system, the possibility to selectively burst polymersomes with high specificity and temporal precision and to consequently deliver small encapsulated vesicles (both polymersomes and liposomes) is demonstrated.

Polymersome Popping by Light-Induced Osmotic Shock under Temporal, Spatial, and Spectral Control.

Multicompartmentalization is a key feature of eukaryotic cells, allowing separation and protection of species within the membrane walls. During the last years, several methods have been reported to afford synthetic multicompartment lipidic or polymeric vesicles that mimic biological cells and that allow cascade chemical or enzymatic reactions within their lumen. We hereby report on the preparation and study of liposomes in polymersomes (LiPs) systems. We discuss on the loading and coloading of lipidic nanovesicles made of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC), 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC), 1,2-dipentadecanoyl-sn-glycero-3-phosphocholine (diC15-PC), or 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) inside the lumen of giant poly(butadiene)-b-poly(ethylene oxide) (PBut-b-PEO) polymersomes. These LiPs systems were characterized by confocal microscopy and UV-visible spectroscopy. We further demonstrate that we can achieve controlled sequential release of dyes from diC15-PC and DPPC liposomes at defined temperatures inside the giant PBut-b-PEO polymersomes. This controlled release could be used as a means to initiate cascade reactions on demand in confined microreactors.

Liposomes in Polymersomes: Multicompartment System with Temperature-Triggered Release.

Polypeptide nanoparticles were obtained by the miniemulsion polymerization of -(-nitrobenzyl)-l-cysteine (NBC) -carboxyanhydride (NCA). Through process optimization, reaction conditions were identified that allowed the polymerization of the water sensitive NCA to yield nanoparticles of about 220 nm size. Subsequent UV-irradiation of the nanoparticle emulsions caused the  removal of the nitrobenzyl group and particle cross-linking through disulfide bond formation accompanied by the shrinkage of the particles.

Polypeptide Nanoparticles Obtained from Emulsion Polymerization of Amino Acid -Carboxyanhydrides.

Reported here is the first aqueous ring-opening polymerization (ROP) of N-carboxyanhydrides (NCAs) using α-amino-poly(ethylene oxide) as a macroinitiator to protect the NCA monomers from hydrolysis through spontaneous in situ self-assembly (ISA). This ROPISA process affords well-defined amphiphilic diblock copolymers that simultaneously form original needle-like nanoparticles.

Emmanuel Ibarboure

Université de Bordeaux

CNRS, Bordeaux INP, LCPO, UMR 5629

Obtention of Giant Unilamellar Hybrid Vesicles by Electroformation and Measurement of their Mechanical Properties by Micropipette Aspiration

Emmanuel Ibarboure

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CNRS, Bordeaux INP, LCPO, UMR 5629

Obtention of Giant Unilamellar Hybrid Vesicles by Electroformation and Measurement of their Mechanical Properties by Micropipette Aspiration

Université de Bordeaux