Phase Separation and Nanodomain Formation in Hybrid Polymer/Lipid Vesicles.

Hybrid polymer/lipid large unilamellar vesicles (LUVs) were studied by small angle neutron scattering (SANS), time-resolved Förster resonance energy transfer (TR-FRET), and cryo-transmission electron microscopy (cryo-TEM). For the first time in hybrid vesicles, evidence for phase separation at the nanoscale was obtained, leading to the formation of stable nanodomains enriched either in lipid or polymer. This stability was allowed by using vesicle-forming copolymer with a membrane thickness close to the lipid bilayer thickness, thereby minimizing the hydrophobic mismatch at the domain periphery.

Polymersome shape transformation at the nanoscale.

Polymer vesicles, also named polymersomes, are valuable candidates for drug delivery and micro- or nanoreactor applications. As far as drug delivery is concerned, the shape of the carrier is believed to have a strong influence on the biodistribution and cell internalization. Polymersomes can be submitted to an osmotic imbalance when injected in physiological media leading to morphological changes.