Pre-chromonic organization in the solid crystalline state and true chromonic phases in a water solution of new unconventionally shaped chiral Ag(i) bis chelated bipyridine ionic complexes.

Cryogenic transmission electron microscopy (cryo-TEM) has become a powerful tool for probing the structures of soft-matter materials at nanometer or sub-nanometer scale. For many complex molecular fluids (CMFs), the limiting factor in such studies is the preparation of a cryo-TEM specimen that represents the native structure. Plunge freezing of electron-transparent thin films has been widely used, but it is often influenced or even dominated by surface effects and mechanical disturbances of the CMF. In this article, we use liquid crystals as model CMF systems and present the general procedures and typical results of cryo-ultramicrotomy of rapidly frozen “bulk” samples.

The aim of this study was to determine whether exosomes from Nicotinamide phosphoribosyltransferase (NAMPT)-overexpressing mesenchymal stem cells (MSC NAMPT-Exo) can attenuate aortic stenosis (AS) and explored the underlying mechanism. NAMPT expression was examined in EC CXCR4 KO (AS) mouse hearts. Six-week-old AS mice received weekly injections of NAMPT-Exo, MSC-Exo, or PBS for three weeks, followed by echocardiography and histological examination of the valves (H&E, Alizarin Red, immunofluorescence). Cardiac ECs from control, AS, and NAMPT-Exo-treated mice were analyzed for miRNA expression (miR-146a-3p/5p, miR-125b-5p, miR-142a-5p). NAMPT expression was decreased in AS hearts. Treatment with NAMPT-Exo reduced aortic valve peak velocity, valvular thickening, and microcalcifications, while improving ejection fraction, fractional shortening, and ventricular dimensions. AS endothelial cells showed elevated levels of miR-146a-3p, miR-146a-5p, and miR-142a-5p, NAMPT-Exo specifically normalized miR-146a-3p. Histology revealed EndMT in AS valves, which was diminished by NAMPT-Exo. In vitro, inhibiting miR-146a-3p suppressed TGF-β-induced EndMT. Our results demonstrate that NAMPT-enriched MSC-derived exosomes effectively slow the progression of AS. Additionally, our findings highlight miR-146a-3p as a key regulator of EndMT, suggesting it as a potential molecular target for future therapies.

Self-assembly of amphiphilic molecules is an important phenomenon attracting a broad range of research. In this work, we study the self-assembly of KTOF₄ sphere–rod amphiphilic molecules in mixed water–dioxane solvents. The molecules are of a T-shaped geometry, comprised of a hydrophilic spherical Keggin-type cluster attached by a flexible bridge to the center of a hydrophobic rod-like oligodialkylfluorene (OF), which consists of four OF units. Transmission electron microscopy (TEM) uncovers self-assembled spherical structures of KTOF₄ in dilute solutions. These spheres are filled with smectic-like layers of KTOF₄ separated by layers of the solution. There are two types of layer packings: (i) concentric spheres and (ii) flat layers. The concentric spheres form when the dioxane volume fraction in the solution is 35–50 vol%. The flat layers are formed when the dioxane volume fraction is either below (20 and 30 vol%.) or above (55 and 60 vol%.) the indicated range. The layered structures show no in-plane orientational order and thus resemble thermotropic smectic A liquid crystals and their lyotropic analogs. The layered packings reveal edge and screw dislocations. Evaporation of the solvent produces a bulk birefringent liquid crystal phase with textures resembling the ones of uniaxial nematic liquid crystals. These findings demonstrate that sphere–rod molecules produce a variety of self-assembled structures that are controlled by the solvent properties.

Self-assembly of amphiphilic molecules is an important phenomenon attracting a broad range of research. In this work, we study the self-assembly of KTOF₄ sphere-rod amphiphilic molecules in mixed water-dioxane solvents. The molecules are of a T-shaped geometry, comprised of a hydrophilic spherical Keggin-type cluster attached by a flexible bridge to the center of a hydrophobic rod-like oligodialkylfluorene (OF), which consists of four OF units. Transmission electron microscopy (TEM) uncovers self-assembled spherical structures of KTOF₄ in dilute solutions. These spheres are filled with smectic-like layers of KTOF₄ separated by layers of the solution. There are two types of layer packings: (i) concentric spheres and (ii) flat layers. The concentric spheres form when the dioxane volume fraction in the solution is 35-50 vol%. The flat layers are formed when the dioxane volume fraction is either below (20 and 30 vol%.) or above (55 and 60 vol%.) the indicated range. The layered structures show no in-plane orientational order and thus resemble thermotropic smectic A liquid crystals and their lyotropic analogs. The layered packings reveal edge and screw dislocations. Evaporation of the solvent produces a bulk birefringent liquid crystal phase with textures resembling the ones of uniaxial nematic liquid crystals. These findings demonstrate that sphere-rod molecules produce a variety of self-assembled structures that are controlled by the solvent properties.