The design and preparation of safe wound dressings with antibacterial and controlled drug release abilities is valuable in medicine. This research focuses on the fabrication of a hydrogel carrier with graphene oxide (GO)-triggered ibuprofen (IBU) release to control inflammation. The hydrogel was prepared by cross-linking the base polymer sodium alginate (SA) and functionalized GO.
View Article and Find Full Text PDFThirteen new sirenin derivatives named eupenicisirenins C-O (1-13), along with a biosynthetically related known one (14), were isolated from the mangrove sediment-derived fungus Penicillium sp. SCSIO 41410. The structures, which possessed a rare cyclopropane moiety, were confirmed by extensive analyses of the spectroscopic data, quantum chemical calculations, and X-ray diffraction.
View Article and Find Full Text PDFTWIK2 channel plays a critical role in NLRP3 inflammasome activation and mice deficient in TWIK2 channel are protected from sepsis and inflammatory lung injury. However, inhibitors of TWIK2 channel are currently in an early stage of development, and the molecular determinants underlying the chemical modulation of TWIK2 channel remain unexplored. In this study, we identified NPBA and the synthesized derivative NPBA-4 potently and selectively inhibited TWIK2 channel by using whole-cell patch clamp techniques.
View Article and Find Full Text PDFRecently, two-dimensional materials are widely concerned because of their novel physical properties. CrGeTe(CGT) has been studied extensively due to its intrinsic ferromagnetism and ferromagnetic order. In this investigation, the electronic and magnetic performances of organic molecules (TCNE, TCNQ and TTF) adsorbed on CGT monolayer were studied based on the first-principles calculations systematically.
View Article and Find Full Text PDFMulti-stimuli-responsive hydrogels are intelligent materials that present advantages for application in soft devices compared with conventional machines. In this paper, we prepared a bilayer hydrogel consisting of a poly(2-(dimethylamino)ethyl methacrylate) layer and a poly(-isopropylacrylamide) layer. The hydrogel responded to temperature, pH, NaCl, and ethanol by undergoing bending deformation.
View Article and Find Full Text PDFThe enzyme cyclic GMP-AMP synthase (cGAS) senses cytosolic DNA and catalyzes the formation of 2'3'-cyclic-GMP-AMP (cGAMP), which in turn triggers interferon (IFN) production. Inappropriate activation of cGAS and production of cGAMP have been linked to a diversity of autoimmune diseases. The volume-regulated anion channels (VRACs) have been recently demonstrated to permeate cGAMP, thus making the channel essential for the activation of the cGAS-cGAMP-STING axis.
View Article and Find Full Text PDFPlatinum nanozymes exhibiting highly efficient and robust oxidase-like activity are successfully synthesized and modified using sodium alginate (SA-PtNPs). According to a steady-state dynamic assay, Michaelis-Menton constant ( ) is calculated as 11.6 μM, indicating that the affinity of SA-PtNPs toward the substrate, 3, 3', 5, 5'-tetramethylbenzidine (TMB), is high.
View Article and Find Full Text PDFIn this study, a colorimetric sensing assay of isoniazid based on excellent oxidase-like activity of heparin sodium stabilized platinum nanoparticles (HS-PtNPs) has been demonstrated. The newly prepared HS-PtNPs exhibit a great dispersion with an average size distribution of 4.8 ± 0.
View Article and Find Full Text PDFIt is found that catechol inhibits the oxidase-mimicking activity of chitosan-protected platinum nanoparticles (Chit-PtNPs) by competing with the substrate for the active site of the Ch-PtNPs. The inhibition mechanism of catechol is different from that of ascorbic acid in that it neither reacts with O nor reduces the oxidized 3,3',5,5'-tetramethylbenzidine (TMB). Tyrosinase (TYRase) catalyzes the oxidation of catechol, thus restoring the activity of oxidase-mimicking Chit-PtNPs.
View Article and Find Full Text PDFOver the past few years, three photorespiratory bypasses have been introduced into plants, two of which led to observable increases in photosynthesis and biomass yield. However, most of the experiments were carried out using Arabidopsis under controlled environmental conditions, and the increases were only observed under low-light and short-day conditions. In this study, we designed a new photorespiratory bypass (called GOC bypass), characterized by no reducing equivalents being produced during a complete oxidation of glycolate into CO catalyzed by three rice-self-originating enzymes, i.
View Article and Find Full Text PDFWe herein report the intrinsic alkaline peroxidase-like activity exhibited by CuO nanoparticles when 3-(4-hydroxyphenyl)propionic acid was employed as a substrate. Based on this observation, a fluorometric assay method with a low detection limit of 0.81 μM was established for HO determination under alkaline conditions.
View Article and Find Full Text PDFCapping molecules on the surface of nanomaterials not only enhance the dispersion and stability of nanomaterials but also greatly facilitate their surface modification and biological applications. However, most capping molecules can severely block the active sites of the catalytic core, thereby decreasing the enzymatic activity of nanomaterial-based enzyme mimics. This work demonstrates the superiority of chitosan (Ch) as a capping molecule for synthesizing catalytic platinum nanoparticles (PtNPs).
View Article and Find Full Text PDFIt is desirable but challenging to assemble various biomimetic properties into a functional catalytic cascade system. In this work, cupric oxide nanoparticles were investigated as oxidase mimics for the aerobic oxidation of cysteine to cystine with the generation of hydrogen peroxide. Coupling this property with the peroxidase-like activity of CuO nanoparticles, we constructed a self-organized cascade reaction system based on a single-component nanozyme, which includes the oxidation of cysteine to yield cystine and hydrogen peroxide and the hydrogen peroxide-mediated oxidation of terephthalic acid to produce a fluorescence change.
View Article and Find Full Text PDFA thermo- and pH-sensitive copolymer of poly(N-isopropylacrylamide)-co-poly(acrylic acid) (P(NIPAAm-co-AAc)) with an adjusted lower critical solution temperature (LCST)(at 37 °C) in an aqueous medium and pH of 7.4 was synthesized by a radical copolymerization, and was characterized by Fourier-transform infrared (FTIR) spectroscopy and H nuclear magnetic resonance (H-NMR) spectroscopy. Then, nanofibers composed of P(NIPAAm-co-AAc) and polyurethane (PU) were fabricated by the single-spinneret electrospinning technique and used as drug carriers by co-spinning with the water insoluble drug nifedipine (NIF).
View Article and Find Full Text PDFObjectives: Electrospun micro- and nanofibres are increasingly being investigated for drug delivery. The components of nanofibres are important influences on the drug release behaviour. The aim of this study was to investigate the self-assembly and release behaviour of drug from nanofibres.
View Article and Find Full Text PDFElectrospinning micro- and nanofibers are being increasingly investigated for drug delivery. The components and their stimuli-responsive properties of fibers are important factors influencing the drug release behavior. The aim of this study is to fabricate thermoresponsive poly(N-isopropylacrylamide) (PNIPAAm)/poly(2-acrylamido-2-methylpropanesulfonic acid) (PAMPS) nanofibers by single-spinneret electrospinning technique.
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