Amphiphilic hyaluronic acid (HA) derivatives bearing hydrophobic indocyanine green dye derivatives and hydrophilic poly(ethylene glycol) were synthesized through the use of condensation and copper-catalyzed click cyclization reactions. The amphiphilic HA derivatives dissolved in water and formed self-assemblies in which the near-infrared dyes were tightly packed and arranged to form dimers or H-aggregates. By irradiating an aqueous solution of HA derivatives with near-infrared light, photoacoustic signals were detected along with fluorescence emission. Self-assemblies consisting of HA derivatives could smoothly accumulate in tumor tissues by passive tumor targeting. By utilizing HA derivatives as a contrast agent, tumor sites were clearly visualized by optical imaging as well as by photoacoustic tomography.

Amphiphilic brush-like copolymers having simple amino acids or oligopeptides and poly(ethylene glycol) as side chains were synthesized via ring-opening metathesis polymerization and further transformations. All of the synthesized copolymers formed spherical self-assemblies in water and their hydrodynamic diameters were 100–250 nm, as measured by dynamic light scattering. Amphiphilic polymers bearing leucine and valine can form stable spherical self-assemblies in water because of the synergistic effects of intermolecular hydrogen bonding and hydrophobic interaction. The oligomerization of leucine moieties and capping with the proper length of fatty acyl groups at an N-terminus could significantly affect both the stability and fluorescence intensity of near-infrared fluorescent (NIRF) dye-containing polymeric self-assemblies. All of the self-assemblies consisting of leucine- and oligoleucine-grafted copolymers with a NIRF indocyanine green dye and hydrophilic targeting agents showed low cytotoxicity in cell viability tests. Furthermore, self-assemblies consisting of N-acetylleucine-grafted copolymers with strong fluorescence could visualize a tumor site with high-contrast in vivo, while low contrast images were obtained by utilizing oligoleucine-grafted self-assemblies because of their weak fluorescence. These results indicate that the precise control of both the number of leucine moieties and the length of the fatty acyl groups is important to produce highly functionalized tumor-targeting vehicles delivering a NIRF dye.

Here we explore the buried talent interested in molecular recognition abilities on ZnO nanowires uniformly grown on the inner surface of an open tubular fused silica capillary via liquid chromatography....

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A simple approach to the synthesis of heterocyclophane consisting of two 4,4’‐bithiazoles has been developed in mild conditions. The heterocyclophane with two short chains was conveniently prepared by Hantzsch thiazoles synthesis using the reaction of 3‐tert‐butoxycarbonyl‐3‐azapentanethiocarboxamide with 1,4‐dibromobutane‐2,3‐dione in methanol under reflux for only 15 min. Amino groups at the linkers of this heterocyclophane can be functionalized to give acylated and carbamate derivatives. Their properties as protein kinase inhibitors were investigated, and one of the heterocyclophanes exhibited specific anti‐activity for c‐mesenchymal epithelial transition factor (IC50=603 nm), among seven types of protein kinases investigated. The computational site identification by ligand competitive saturation method was used to determine why the one heterocyclophane exhibited strong anti‐activity for c‐mesenchymal epithelial transition factor.