Macromolecular semi-rigid nanocavities for cooperative recognition of specific large molecular shapes

Design of Synthetic Polymer Nanoparticles Specifically Capturing Indole, a Small Toxic Molecule

Synthetic polymers are of interest as stable and cost-effective biomolecule-affinity reagents, since these polymers interact with target biomolecules both in vitro and in the bloodstream. However, little has been reported about orally administered polymers capable of capturing a target molecule and inhibiting its intestinal absorption. Here, we describe the design of synthetic polymer nanoparticles (NPs) specifically capturing indole, a major factor exacerbating chronic kidney disease, in the intestine. N-isopropylacrylamide-based NPs were prepared with various hydrophobic monomers. The amounts of indole captured by NPs depended on the structures and feed ratios of the hydrophobic monomers and the polymer density but not on the particle size. The combination of hydrophobic and quadrupole interaction was effective to enhance the affinity and specificity of NPs for indole. The optimized NPs specifically inhibited intestinal absorption of orally administered indole in mice. These results showed the potential of synthetic polymer NPs for inhibiting the intestinal absorption of a target molecule.

Epitaxially Grown Ultra-Flat Self-Assembling Monolayers with Dendrimers

Mono-molecular films formed by physical adsorption and dendrimer self-assembly were prepared on various substrate surfaces. It was demonstrated that a uniform dendrimer-based monolayer on the subnanometer scale can be easily constructed via simple dip coating. Furthermore, it was shown that an epitaxially grown monolayer film reflecting the crystal structure of the substrate (highly ordered pyrolytic graphite (HOPG)) can also be formed by aligning specific conditions.

Bismuth Complexes in Phenylazomethine Dendrimers: Controllable Luminescence and Emission in the Solid State

Dendritic phosphors were obtained by the stepwise integration of BiCl₃ in phenylazomethine dendrimers. The bismuth-coordinated phenylazomethines displayed photoluminescence at 500-800 nm, and the intensity could be tuned by changing the stoichiometry of BiCl₃ and the dendrimer. This phosphor did not show serious luminescence quenching even though the local concentration of BiCl₃ in the dendrimer was as high as 20 M, and luminescence was also observed in the solid state. The absorption and emission properties could be reversibly switched by addition of a Lewis base or under electrochemical redox control, which induced the reversible complexation of BiCl₃ in the dendrimer.

The study of electron transfer reactions in a dendrimeric assembly: proper utilization of dendrimer fluorescence

Sensing applications of dendrimers: trapping of explosive nitroaromatic compounds within the dendrimer-cage followed by efficient quenching of its fluorescence.

A potential gradient along the layer-by-layer architecture for electron transfer rectification

Electrochemical and photochemical measurements demonstrated that dendritic phenylazomethines, which can make complexes with SnCl2 by a stepwise process, only permit an outbound electron transfer. The unique dendrimer effect allows efficient production of photo-generated radical ion pairs by suppressing their charge recombination. In sharp contrast, the phenylenevinylene or benzylether dendrimers, which lack a heteroatom or π-conjugation, did not exhibit such non-symmetric characters.

A self-assembling dendritic reactor: versatile formation of characteristic patterns with nanoscale dimension

Spherical dendrimers with phenylazomethine backbones are modified onto atomically flat mica or graphite substrates with a simple solvent based spin-coating method, and the resulting surfaces are observed by atomic force microscopy. Especially on the mica substrate, dendrimers form very fine and highly regular patterns with aligned nano-dot arrays and lines. An important observation is that the interval of each dot or line is ≈400 nm whereas previously reported self-assembling patterns exhibit longer intervals than 5 μm. It is revealed that spherical dendrimers with relatively low intermolecular interactions without any terminal modifications are suitable for the fine self-assembling pattern formation. This fact suggests that the regular pattern arises from a physical dissipative structure formation due to a fingering instability induced by Marangoni convection but not by anisotropic intermolecular interactions.