Reverse Vesicles of Ferrum Laurate Metallosurfactant in Non‐Aqueous Solution Dried to Produce Solid Shells

Ferrum laurate [Fe(OOCC₁₁H₂₃)₃] metallosurfactant can successfully self‐assemble into reversed vesicles in organic media such as pure CHCl₃ and a mixed solvent of CHCl₃ and CH₃OH. Deformed solid vesicles, including collapsed erythrocyte‐like and broken hollow shells, were obtained directly by slectively drying the organic solvents. The morphology of the reversed vesicles of metallosurfactant in the organic media to hardly solid shells is maintained and it is ascribed to the evaporation rate of the solvents and the interactions between ferrum laurate and solvents.     

Aqueous Self‐Assembly of Y‐Shaped Amphiphilic Block Copolymers into Giant Vesicles

The preparation and aqueous self‐assembly of newly Y‐shaped amphiphilic block polyurethane (PUG) copolymers are reported here. These amphiphilic copolymers, designed to have two hydrophilic poly(ethylene oxide) (PEO) tails and one hydrophobic alkyl tail via a two‐step coupling reaction, can self‐assemble into giant unilamellar vesicles (GUVs) (diameter ≥ 1000 nm) with a direct dissolution method in aqueous solution, depending on their Y‐shaped structures and initial concentrations. More interesting, the copolymers can self‐assemble into various distinct nano‐/microstructures, such as spherical micelles, small vesicles, and GUVs, with the increase of their concentrations. The traditional preparation methods of GUVs generally need conventional amphiphilic molecules and additional complicated conditions, such as alternating electrical field, buffer solution, or organic solvent. Therefore, the self‐assembly of Y‐shaped PUGs with a direct dissolution method in aqueous solution demonstrated in this study supplies a new clue to fabricate GUVs based on the geometric design of amphiphilic polymers.

     

Sugar‐Decorated Sugar Vesicles: Lectin–Carbohydrate Recognition at the Surface of Cyclodextrin Vesicles

An artificial glycocalix self‐assembles when unilamellar bilayer vesicles of amphiphilic β‐cyclodextrins are decorated with maltose and lactose by host–guest interactions. To this end, maltose and lactose were conjugated with adamantane through a tetra(ethyleneglycol) spacer. Both carbohydrate–adamantane conjugates strongly bind to β‐cyclodextrin (K_a≈4×10⁴ M ^?1). The maltose‐decorated vesicles readily agglutinate (aggregate) in the presence of the lectin concanavalin A, whereas the lactose‐decorated vesicles agglutinate in the presence of peanut agglutinin. The orthogonal multivalent interaction in the ternary system of host vesicles, guest carbohydrates, and lectins was investigated by using isothermal titration calorimetry, dynamic light scattering, UV/Vis spectroscopy, and cryogenic transmission electron microscopy. It was shown that agglutination is reversible, and the noncovalent interaction can be suppressed and eliminated by the addition of competitive inhibitors, such as D ‐glucose or β‐cyclodextrin. Also, it was shown that agglutination depends on the surface coverage of carbohydrates on the vesicles.