Hirotaka Ejima 교수

The development of facile and versatile strategies for thin-film and particle engineering is of immense scientific interest. However, few methods can conformally coat substrates of different composition, size, shape, and structure. We report the one-step coating of various interfaces using coordination complexes of natural polyphenols and Fe(III) ions. Film formation is initiated by the adsorption of the polyphenol and directed by pH-dependent, multivalent coordination bonding. Aqueous depositio

Polyphenols are building blocks with many advantages for engineering biomaterials because they are abundant in nature, biocompatible, biodegradable, and capable of assembly through different mechanisms. A variety of biomaterials across different length scales can be made with different physical/chemical properties and unique stimuli responses using modular and straightforward synthesis routes. We review the recent progress of biomaterials engineering based on polyphenols under three broad catego

Adhesion occurs by covalent bonding, as in reactive structural adhesives, or through noncovalent interactions, which are nearly ubiquitous in nature. A classic example of the latter is gecko feet, where hierarchical features enhance friction across the contact area. Biomimicry of such structured adhesion is regularly achieved by top-down lithography, which allows for direction-dependent detachment. However, bottom-up approaches remain elusive given the scarcity of building blocks that yield stro

Growing metal–organic frameworks (MOFs) around biomolecules has recently emerged as a promising method to combine natural and synthetic materials. In parallel, cellulose nanocrystals (CNCs) have found use for forming a wide range of renewable nano- and macroscopic materials because of their bio-derived nature, high surface area, and high strength. Herein, we demonstrate the continuous nucleation of MOFs from the surface of CNCs, thereby forming hybrid hydrogels, aerogels, and porous assemblies t

Extracellular vesicles, including exosomes, shuttle proteins and genetic information between cells and are recently regarded as a promising class of nanoparticles for biomedical applications. Collecting exosomes from patients and amplifying the signal from the exosome cargo could enable new liquid biopsies owing to the exosome’s strong correlation with disease progression. A promising strategy to develop personalized therapeutic carriers is through surface engineering the exosomes and hijacking

Ordered porous materials are of great technological interest for use as separation, catalysis, adsorbents, and electronic devices. We report here a fabrication of honeycomb-patterned porous films from fluorescent hyperbranched poly(phenylene vinylene) (hypPPV) by breath figure method and the thermal conversion of this film to macroporous carbon. This hexagonal porous film is very thermally stable and retained its structure at up to >600 °C. After the heating, carbonization of hypPPV occurred, an

Faceted polymer microcapsules are prepared from metal-organic framework (MOF) templates. The MOF templates are removable under mild aqueous conditions. The obtained microcapsules are stiffer than their spherical counterparts, reflecting the near-incompressibility of the facet edges, and indicating that the faceting might be a useful strategy for controlling the mechanical properties of polymer microcapsules.

Peptides that bind to poly(phenylene vinylene) (PPV) were identified by the phage display method. Aromatic amino acids were enriched in these peptide sequences, suggesting that a π-π interaction is the key interaction between the peptides and PPV. The surface plasmon resonance (SPR) experiments using chemically synthesized peptides demonstrated that the Hyp01 peptide, with the sequence His-Thr-Asp-Trp-Arg-Leu-Gly-Thr-Trp-His-His-Ser, showed an affinity constant (7.7 × 10(5) M(-1)) for the target

Despite high demands from various industries, strong adhesion in a wet environment remains challenging. We investigated the underwater adhesion of gallol-functionalized polymers as a function of molecular weight and gallol content. By optimizing these parameters, the underwater adhesion strength of aluminium substrates exceeded 4 MPa. Therefore, the biomimetic molecular design of phenolic polymers is effective for the development of strong underwater adhesives.

Abstract Exosomes are cell‐derived extracellular vesicles that hold promise for diagnosis and therapy. The surface characteristics of exosomes dictate their biological fate and are therefore important for various applications, however surface modification strategies are generally either limited in scope or require complex equipment or experimental procedures. Herein, we employ a simple and fast method to control the surface properties of exosomes via polydopamine coating. Specifically, the polyd

Low-fouling phospholipid polymer was conjugated with bio-inspired tethering groups. Immobilization efficiencies of these polymers onto various surfaces were investigated.

The development of antimicrobial fabrics and textiles that can sustainably inhibit a broad spectrum of microbes is crucial for protecting against pathogens in various environments. However, engineering antimicrobial textiles is challenging due to issues with discoloration and inhibited breathability, the use of harmful or harsh reagents and synthesis conditions, and complex and/or time-consuming processing. Herein, we develop a facile and rapid approach to deposit antimicrobial coatings using un

Stereoselective total synthesis of tabtoxinine-β-lactam has been achieved. The vinylogous Mukaiyama aldol reaction with vinylketene silyl N,O-acetal and α-keto-β-lactam proceeded to afford the adduct possessing a TβL-skeleton with a tert-alcohol in high yield and stereoselectivity. Stereoselective introduction of the amino group has been accomplished by azidation at the α position of the imide followed by hydrogenolysis. A straightforward method to achieve the potent inhibitor of glutamine synth