BackgroundAfter recognition of 3D printing and injectable hydrogel as a critical issue in tissue/organ engineering and regenerative medicine society, many hydrogels as bioinks have been developed worldwide by using polymeric biomaterials such as gelatin, alginate, hyaluronic acid and others. Even though some gels have shown good performances in 3D bioprinting, still their performances do not meet the requirements enough to be used as a bioink in tissue engineering.MethodIn this study, a hydrogel consisting of three biocompatible biomaterials such as hyaluronic acid (HA), hydroxyethyl acrylate (HEA) and gelatin-methacryloyl, i.e. HA-g-pHEA-gelatin gel, has been evaluated for its possibility as a bioprinting gel, a bioink. Hydrogel synthesis was obtained by graft polymerization of HEA to HA and then grafting of gelatin- methacryloyl via radical polymerization mechanism. Physical and biological properties of the HA-based hydrogels fabricated with different concentrations of methacrylic anhydride (6 and 8%) for gelatin-methacryloylation have been evaluated such as swelling, rheology, morphology, cell compatibility, and delivery of small molecular dimethyloxalylglycine. Printings of HA-g-pHEA-Gelatin gel and its bioink with bone cell loaded in lattice forms were also evaluated by using home-built multi-material (3D bio-) printing system.ConclusionThe experimental results demonstrated that the HA-g-pHEA-gelatin hydrogel showed both stable rheology properties and excellent biocompatibility, and the gel showed printability in good shape. The bone cells in bioinks of the lattice-printed scaffolds were viable. This study showed HA-g-pHEA-Gelatin gel’s potential as a bioink or its tissue engineering applications in injectable and 3D bioprinting forms.

In breast cancer, the cytokine tumor necrosis factor-α (TNF-α) induces cell invasion, although the molecular basis of it has not been clearly elucidated. In this study, we investigated the role of daidzein in regulating TNF-α induced cell invasion and the underlying molecular mechanisms. Daidzein inhibited TNF-α induced cellular migration and invasion in estrogen receptor (ER) negative MCF10DCIS.com human breast cancer cells. TNF-α activated Hedgehog (Hh) signaling by enhancing Gli1 nuclear translocation and transcriptional activity, which resulted in increased invasiveness; these effects were blocked by daidzein and the Hh signaling inhibitors, cyclopamine and vismodegib. Moreover, these compounds suppressed TNF-α induced matrix metalloproteinase (MMP)-9 mRNA expression and activity. Taken together, mammary tumor cell invasiveness was stimulated by TNF-α induced activation of Hh signaling; these effects were abrogated by daidzein, which suppressed Gli1 activation, thereby inhibiting migration and invasion.

No abstract

This study employed the metabolomic approach to identify the key constituent exerting anti-inflammatory activity in murine macrophage RAW 264.7 cells. Among the six different fractions (SF1-SF6) of the strawberry 'Seolhyang', SF4 showed more significant inhibition on iNOS expression than SF3, and ellagic acid was determined as the most significant different component between SF4 and SF3 using orthogonal partial least-squares discriminant analysis. Ellagic acid (0.3 and 1.0 μM) and SF4 (100 μg/mL) were found to regulate the same inflammatory mediators, inhibitory κB (IκB) and mitogen-activated protein kinases (MAPKs), which led to the reduction of tumor necrosis factor (TNF-α), interleukin-1β (IL-1β), and iNOS expressions. These results demonstrate that ellagic acid from strawberry 'Seolhyang' is the major component playing a crucial role in inflammation, suggesting the possible application of metabolomic analysis to determining the key ingredients having biological functions in the complicated food matrix.

Herein we report a novel synthetic entry to the legendary quinuclidine natural products quinine and quinidine. The developed strategy is based on the use of a symmetrical and nonstereogenic precursor to access quinine and quinidine through a “local‐desymmetrization” approach, in stark contrast conceptually to the preparation of stereodefined disubstituted piperidines (or their acyclic precursors) as featured in all past syntheses. The developed strategy also provided quinine and quinidine derivatives that could not be readily obtained through previous total syntheses or by modification of the naturally occurring substances.

In the current research, we performed quantitative characterization of commercially available photo papers with respect to chemical composition and physical properties in order to find the preferred photo paper with the best electrical conductivity through in situ silver nanoparticle sintering. The composition ratio of chloride ions, surface roughness and pore size of the photo papers were quantitatively analyzed. The relationship of the above-mentioned parameters with the conductivity of the silver nanoparticle pattern formed on the printed surface was explored. The experimental results showed that chloride ions on the surface of photo papers activated the decomposition of a capping agent and sintering between the silver nanoparticles. It was also found that the chloride ions above a certain value did not affect the sintering. The surface roughness and pore size of the photo papers were found to be inversely related to the conductivity of electrode pattern. Moreover, it was found that additional heat treatment (for a relatively short time at a low temperature) contributed to the improvement of conductivity. However, this effect varied depending upon the characteristics of the photo papers. This newly developed inexpensive method using a highly accessible substrate will be very helpful for future paper electronics related devices and research.

The recently discovered yttrium oxyfluoride (YOF) coating has been found to be a highly promising plasma-resistant material which can be coated onto the inner wall of the dry etching chambers used in the manufacturing of the three-dimensional stacking circuits of semiconductors, such as vertical NAND flash memory. Here, the coating behavior of the YOF coating which was deposited by suspension plasma spraying was investigated using a high-output coaxial feeding method. Both the deposition rate and density of YOF coatings increased with the plasma power, which was determined by the gas ratio of Ar/H2/N2 and the arc current. The coating thicknesses were 58 ± 3.4, 25.8 ± 2.1, 5.6 ± 0.6, and 0.93 ± 0.4 µm at plasma powers of 112, 83, 67, and 59 kW, respectively, for 20 scans with a feeding rate of the suspension at 0.045 standard liters per minute (slm). The porosities were 0.15% ± 0.01%, 0.25% ± 0.01%, and 5.50% ± 0.40% at corresponding plasma powers of 112, 83, and 67 kW. High-resolution X-ray diffraction (HRXRD) shows that the major and minor peaks of the coatings which were deposited at 112 kW stem from trigonal YOF and cubic Y2O3, respectively. Increasing the flow rate of the atomizing gas from 15 slm to 30 slm decreased the porosity of the YOF coating from 0.22% ± 0.03% to 0.07% ± 0.03%. The Vickers hardness of the YOF coating containing some Y2O3 deposited at 112 kW was 550 ± 70 HV.

We report the boron-catalyzed hydrophosphinylation of N-heteroaryl-substituted alkenes with secondary phosphine oxides that furnishes various phosphorus-containing N-heterocycles. This process proceeds under mild conditions and enables the introduction of a phosphorus atom into multisubstituted alkenylazaarenes. The available mechanistic data can be explained by a reaction pathway wherein the C–P bond is created by the reaction between the activated alkene (by coordination to a boron catalyst) and the phosphorus­(III) nucleophile (in tautomeric equilibrium with phosphine oxide).