On the stability of lithocholate derivative supramolecular tubules

Abstract

The self-assembly of a mannose-labelled bile salt derivative gives rise to a metastable nematic phase of\ud monodisperse nanotubes in aqueous solutions that are characterized by a crystalline order. This work is\ud addressed to study the relative stability of these tubular aggregates in order to have full control of such\ud a system for possible applications. By using a static light scattering method we evaluate both the\ud solubilities of the metastable nanotubes and of stable nanocrystals, demonstrating that these are\ud remarkably lower than the critical micellar concentration of typical bile salts and other ionic conventional\ud surfactants. A partial stability map is developed by combining solubility and calorimetry data, where\ud a nematic nanotube phase region is highlighted below 60–65 °C

Wormlike reverse micelles in lecithin/bile salt/water mixtures in oil

“…They often self-assemble in tubes or fibers and behave as low molecular weight gelators [15][16][17][18][19][20][21][22][23][24][25][26]. The tubes have cross section diameters spanning a wide range of values (3-450 nm) [9,19,[27][28][29][30][31][32][33][34] and sometimes they form through appealing pH [35,36] or temperature responsive aggregations [37]. Mixed tubes with tunable composition and related features such as charge [38] and sizes [39] can sometimes be prepared.…”

Gel-to-gel non-variant transition of an organogel caused by polymorphism from nanotubes to crystallites

“…As shown by Gubitosi et al 35 , kinetically stable tubes formed by a lithocholate derivative are thermodynamically metastable. Similar to HUB-4, they transform into crystals above a given temperature or upon aging.…”

Structure of Nanotubes Self-Assembled from a Monoamide Organogelator

“…Given the shape of the aggregates, it is relevant to compare HUB-4 also with lipid compounds self-assembling in metastable nanotubes [ 27 ]. As Gubitosi et al have shown lately, kinetically stable tubes formed by lithocholic acid have been proved to be thermodynamically metastable [ 28 ]. Like these authors did, we will devote our next studies to map the c - T phase diagram of these polymorphs.…”