Chemistry - An Asian Journal最新文献

Chemically powered colloidal motors exhibit significant potential for applications in oral cleaning and antimicrobial treatment. The integration of MnO₂-based colloidal motors with common mouth-rinsing H₂O₂ solutions for sterilization and disinfection via reactive oxygen species (ROS) represents an ideal approach. In this study, we fabricate uniform dumbbell-shaped (DS-MnO₂-motor), spherical (S-MnO₂-motor), and silver half-coated spherical Janus Ag-MnO₂ colloidal motors (JS-MnO₂-motor) using hydrothermal, co-precipitation, and sputtering methods, respectively. These motors are propelled by O₂ bubble ejection generated from the catalytic decomposition of low-concentration H₂O₂ by peroxidase-like MnO₂ components. Notably, the JS-MnO₂-motors achieve a maximum speed of 146.4 µm s^-1 in gargle containing 1.5% H₂O₂. In vitro and in vivo antimicrobial trials demonstrated that the JS-MnO₂-motor gargle exhibits superior sterilization rates of 98.1% and 97.4% against both planktonic and biofilm-forming P. gingivalis and F. nucleatum. Consequently, it significantly enhances the therapeutic efficacy in treating periodontitis in Wistar rats, as evidenced by a marked reduction in inflammatory cells. The mechanical force exerted by these colloidal motors, along with cation adhesion to bacterial membranes and the antimicrobial effects of ROS, collectively contribute to this enhanced performance. Our findings introduce a novel strategy for the treatment of chronic inflammatory diseases.

A convenient route for the mechanochemical synthesis of fluorinated aromatic compounds, that is, fluoro, trifluoromethyl, and trifluoromethoxy arenes, has been developed via pyrylium tetrafluoroborate (Pyry-BF₄)-mediated desulfonamidative cross-coupling of primary sulfonamides under the synergy of a piezoelectric material BaTiO₃, and Ru-catalysis. This is the first-ever report on the selective transformation of sulfonamide (SO₂NH₂) functionality to CF₃/OCF₃/F group in a single step under mechanochemical ball-milling conditions. Considering the importance of primary sulfonamides as the valuable pharmacophores, the present desulfonamidative cross-coupling approach could have potential to get synthetic utility in pharmaceutical industries for the late-stage functionalization of sulfonamide drugs and related active pharmaceutical ingredients (APIs).

Hydrogels have emerged as flexible biomaterials with enormous potential in biomedical applications due to their outstanding biocompatibility and ability to hold a high water concentration. Hydrogels have low toxicity and are biodegradable. This review begins with a look at the various riveting characteristics and classifications of hydrogel nanocomposites reinforced with various metallic and ceramic components. A distinct focus is offered on thoroughly deliberating surface modification techniques with special attention on fabrication, patterning, and their applications in biomedical fields. The review describes the value of novel cross-linking techniques including physical, chemical, and physical-chemical dual cross-linking in adapting hydrogel characteristics to specific applications. This review also explains the major bioapplication of functionalized hydrogels. It emphasizes the importance of nanocomposite hydrogels and multifunctional self-assembled monolayers in solving contemporary biological difficulties such as infection control, medication delivery, and tissue regeneration. It explains the need for interdisciplinary collaboration and ongoing research efforts to realize the full potential of hydrogels and nanomaterials in biomedical applications. Overall, this review gives useful insights into current advances and future possibilities for hydrogels grafted with metals and ceramic additives in biomedical applications, highlighting the need for multidisciplinary cooperation and ongoing research in nano(bio)technology.

MXene is a cationic 2D material made of transition metal carbides known for its diverse structure and multifunctionality. It faces challenges like stacking, oxidation, and weak mechanical properties that limit its use. By integrating MXene with self-supporting porous materials, it can be stabilized and converted from fragile 2D sheets to strong 3D structures. Wood, due to its natural structure and stability, is ideal for depositing MXene, which adheres to wood via adsorption, hydrogen bonding, or reactions with wood fibers. New MXene-wood composites with improved functions have been created and show great potential for interdisciplinary research. This review covers preparation methods, applications, potential development, and challenges of MXene-wood composites, aiming to provide a research framework and progressive direction for their future development.

Molecular cages are distinguished supramolecular structures with stable cavities, enabling applications in molecular recognition, catalysis, and drug delivery. While the synthesis of purely organic cages is less common and often hindered by entropy-related challenges in irreversible reactions. In this study, we present a novel single-precursor strategy featuring dual aldehyde and hydrazine units to facilitate ring closure via hydrazone chemistry. This approach yielded a double-layered aromatic arylhydrazone macrocycle with 88% yield. Furthermore, this macrocycle with electron-rich properties showed strong binding to the electron-donor fullerene guest C₆₀ and C₇₀.

Mechanochromic polymers have potential in visualization of microscopic damages in materials, and the integration of non-invasive switching into mechanochromic polymers can enable rich on-demand functionality of polymer materials. In this work, we report the development of a mechanoresponsive fluorescent polymer with photogated properties, comprising poly(methyl acrylate) (PMA) and the photoswitchable mechanophore S₂A₂, which features two anthracene groups linked by a disilane spacer. The mechanochromic polymer PMA-S₂A₂ exhibits ratiometric fluorescence response upon mechanical deformation, which arises from the monomer and excimer emission ratio of anthracene controlled by the polymer strain. The mechanochromic property of the polymer can be switched off by irradiation with 365 nm UV light which induces [4 + 4] cycloaddition of the anthracene groups between and within the polymer chains. Importantly, the anthracene dimers can be reversibly dissociated in situ within the polymer film by irradiation with 254 nm UV, restoring the mechanochromic function. Furthermore, intermolecular photodimerization of anthracene increases the molecular weight and forms an entanglement network, significantly enhancing the material toughness. This reversible photocontrolled switch design offers a novel strategy for developing mechanochromic materials with modulated responses and mechanical properties.

Cancer remains a critical global issue, marked by its high mortality rates. Despite achieving remarkable progress in cancer treatments, conventional chemotherapeutic drugs face numerous limitations. To this end, nanomaterial-based targeted drug delivery systems have emerged as a hope of promise. In this study, we report the design and development of transferrin (Tf) tethered naphthalene-diimide-based fluorescent organic nanoparticles (NDI-OH-Tf) for targeted delivery of paclitaxel to cancer cells with over expressed transferrin receptors (TfR). Spherical NDI-OH FONPs were fabricated through J-type of aggregation of NDI-OH amphiphiles in a 1:99 (v/v) DMSO-H₂O mixture. These NDI-OH FONPs exhibited aggregation induced emission (AIE) at an emission wavelength of λ_em = 594 nm. The hydroxyl groups on the surface of the NDI-OH FONPs were conjugated with carboxyl groups of transferrin, forming NDI-OH-Tf FONPs. These NDI-OH-Tf FONPs were successfully used for targeted bioimaging and drug delivery to TfR+ cancer cells through ligand receptor interaction between transferrin and TfR. Notably, paclitaxel loaded NDI-OH-Tf exhibited ∼2.9-fold higher efficacy toward TfR+ cancer cells compared to normal cells and ∼3.3-fold higher cytotoxicity than free PTX due to transferrin mediated targeted accumulation of PTX in cancer cells.

The chemoenzymatic synthesis of oligosaccharides presents a highly attractive methodology with significant potential for diverse applications, particularly through using various glycosidases. In this study, the O-glycan core 6 disaccharide moiety, GlcNAcβ1-6GalNAc, was successfully synthesized via enzymatic glycosylation using an N-acetyl-β-D-glucosaminidase from Bacteroides thetaiotaomicron (BtOGA), a member of glycoside hydrolase family 84 (GH84), alongside an N-acetyl-D-glucosamine oxazoline derivative (GlcNAc-oxa) as the glycosyl donor. Furthermore, an investigation into glycosyl acceptor recognition in BtOGA-catalyzed enzymatic glycosylation indicated that the presence of an aromatic group at the anomeric position and an axial hydroxy group at the 4-position of the saccharide moiety is crucial for effective recognition of BtOGA as a glycosyl acceptor. The protecting-group-free chemoenzymatic synthesis of the core 6 disaccharide moiety was achieved by integrating the direct synthesis of GlcNAc-oxa thorough Shoda activation method using a water-soluble dehydration condensing agent in an aqueous medium, followed by BtOGA-catalyzed enzymatic glycosylation.

Charge delocalization through spiro-conjugation provides insights for the rational design of next-generation charge transport materials. We have previously conducted studies using terminally alkyl-protected cyclic [3]spirobifluorenylene compound 1-[3], which features a cyclic structure composed of bifluorenyl units. ESR studies on this radical cation species have shown that its electron is delocalized over approximately three bifluorenyl units, meaning that it is delocalized across the entire molecule. In this study, we newly synthesized cyclic [n]spirobifluorenylene compounds 1-[4] and 1-[5] and investigated their spectroscopic and electrochemical properties, and chemical oxidation behavior. Additionally, DFT calculations were performed not only for the neutral species but also for the radical cation species. Furthermore, we examined the influence of the number of perpendicular π-conjugated units on electron delocalization in their radical cation species. As a result, ESR spectral analysis of the radical cation species 1-[4]^·+ and 1-[5]^·+ revealed that electrons were delocalized over 3.37 and 3.87 units, respectively, when considering bifluorenyl as the unit structure.

The unconventional ionic solid, K₆[Rh₄Zn₄(L-cys)₁₂O]·nH₂O, exhibited excellent formability as well as high ionic conductivity. These features enabled a straightforward assembly of all-solid-state potassium-ion battery: A cold-pressed solid sample of K₆[Rh₄Zn₄(L-cys)₁₂O]·nH₂O, which was sandwiched by solid samples of K₂Ni[Fe(CN)₆] and chloranil as cathode, and anode, respectively, displayed an initial discharge capacity of 21.6 mAh g^-1-electrodes at 25 °C at a current density of 0.5 mA cm^-2 (∼0.34C). Energy dispersive X-ray spectroscopy analysis confirmed that K⁺ ions swiftly conduct through K₆[Rh₄Zn₄(L-cys)₁₂O]·nH₂O between the cathode and anode during charge-discharge cycles.