Preparation and Properties of Vesicles Made of Nonpolar/Polar/Nonpolar Fullerene Amphiphiles

Abstract

Twenty potassium complexes of penta-[(4-substituted)phenyl][60]fullerene anions were synthesized and examined for their ability to form bilayer vesicles in water. The 4-substituents include alkyl groups ranging from methyl to icosanyl groups and perfluoromethyl, perfluorobutyl, and perfluorooctyl groups. The overall structure of the amphiphiles can be described as a nonpolar/polar/nonpolar (n-p-n') motif as opposed to the usual polar/nonpolar motif of lipid amphiphiles. Despite the hydrophobicity of the fullerene moiety (n-part) and alkyl/perfluoroalkyl chains (n'-part), all compounds except for the one with perfluoromethyl groups were soluble in water because of the centrally located fullerene cyclopentadienide (p-part) and spontaneously formed a vesicle of 25- to 60-nm diameter with a narrow unimodal size distribution. The vesicles are stable upon heating to 90 °C or standing over one year in air, as well as on a solid substrate in air or in vacuum, maintaining their spherical form. The vesicle membrane consists of an interdigitated bilayer of the amphiphile molecules, in which the fullerene n-part is inside and the n'-side is exposed to water. These vesicles, in particular the one bearing icosanyl chains, exhibit the smallest water permeability coefficient ever found for a self-assembled membrane in water.

siRNA delivery targeting to the lung via agglutination-induced accumulation and clearance of cationic tetraamino fullerene

“…This accumulation often causes toxic effects such as chronic obstructive pulmonary emphysema and arterial embolism. Fullerene is both hydrophobic and lipophobic29, and thus the TPFE aggregates do not fuse with the lipophilic erythrocyte membrane but prefer to aggregate with plasma proteins. As a result, spontaneous clearance from the lung capillaries via dissociation of the TPFE–siRNA complexes must have taken place.…”

High‐Density Display of Protein Ligands on Self‐Assembled Capsules via Noncovalent Fluorous Interactions

“…Upon mixing with V1 ([F8K]:[1] = 1:1 mole ratio), the aggregates mostly disappeared, and instead a uniform solution of V2 was formed that showed a DLS peak with an average diameter of 32.8 AE 0.8 nm (polydispersity index of 0.15, Figure 3 a, black), which is larger than that of V1 by 5.8 AE 0.7 nm (1 on V1 shown in column 1 in Table 1). Such a size increase was also seen for FT-Man 4 on V1, 1 on alkyl-covered vesicle V1C made from C8K ( Figure 1), [12] and 5 on V1C, thus suggesting that the sugar moiety in the FT-sugar is exposed on the vesicle surface. On the other hand, the size increase for the water-soluble AT-Man 5 on the fluorous vesicle V1 was negligible, indicating that 5 hardly binds on the vesicle surface.…”

Self‐Assembled Giant Vesicles Formed by Type I [3:3]‐Hexakis Adducts of C60 Equipped with Enantiomerically Pure cyclo‐Monomalonate Addends

“…Larger vesicles with diameters varying from 80 to 150 nm and membrane thickness varying from ca. [16] No ordered superstructures were observed upon dispersing a ca. Notably, the supramolecular assemblies were found to be mostly clustered under all the concentrations studied (see the Supporting Information), behavior that might be attributed to attractive interactions between the exposed polar substituents (1,2-glycol groups) of the fullerene amphiphiles.…”