One-Step Fabrication of Biocompatible Multifaceted Nanocomposite Gels and Nanolayers

Nanocomposite gels are a fascinating class of polymeric materials with an integrative assembly of organic molecules and organic/inorganic nanoparticles, offering a unique hybrid network with synergistic properties. The mechanical properties of such networks are similar to those of natural tissues, which make them ideal biomaterial candidates for tissue engineering applications. Existing nanocomposite gel systems, however, lack many desirable gel properties, and their suitability for surface coatings is often limited. To address this issue, this article aims at generating multifunctional nanocomposite gels that are injectable with an appropriate time window, functional with bicyclononynes (BCN), biocompatible and slowly degradable, and possess high mechanical strength. Further, the in situ network-forming property of the proposed system allows the fabrication of ultrathin nanocomposite coatings in the submicrometer range with tunable wettability and roughness. Multifunctional nanocomposite gels were fabricated under cytocompatible conditions (pH 7.4 and <i>T</i> = 37 °C) using laponite clays, isocyanate (NCO)-terminated sP­(EO-<i>stat</i>-PO) macromers, and clickable BCN. Several characterization techniques were employed to elucidate the structure–property relationships of the gels. Even though the NCO-sP­(EO-<i>stat</i>-PO) macromers could form a hydrogel network in situ on contact with water, the incorporation of laponite led to significant improvement of the mechanical properties. BCN motifs with carbamate links were used for a metal-free click ligation with azide-functional molecules, and the subsequent gradual release of the tethered molecules through the hydrolysis of carbamate bonds was shown. The biocompatibility of the hydrogels was examined through murine macrophages, showing that the material composition strongly affects cell behavior

Microphase Separation and High Ionic Conductivity at High Temperatures of Lithium Salt-Doped Amphiphilic Alternating Copolymer Brush with Rigid Side Chains

An amphiphilic alternating copolymer brush (AACPB), poly­{(styrene-<i>g</i>-poly­(ethylene oxide))-<i>alt</i>-(maleimide-<i>g</i>-poly­{2,5-bis­[(4-methoxy­phenyl)­oxycarbonyl]­styrene})}­(P­{(St-<i>g</i>-PEO)-<i>alt</i>-(MI-<i>g</i>-PMPCS)}), was synthesized by alternating copolymerization of styrene-terminated poly­(ethylene oxide) (St-PEO) and maleimide-terminated poly­{2,5-bis­[(4-methoxy­phenyl)-oxy­carbonyl]­styrene} (MI-PMPCS) macromonomers using the “grafting through” strategy. ¹H NMR and gel permeation chromatography coupled with multiangle laser light scattering were used to determine the molecular characteristics of AACPBs. Although these AACPBs cannot microphase separate with thermal and solvent annealing methods, they can form lamellar structures by doping a lithium salt. This is a first report on lithium salt-induced microphase separation of AACPBs, and the lithium salt-doped AACPBs can serve as solid electrolytes for the transport of lithium ion. For the same AACPB, the ionic conductivity (σ) increases with increasing doping ratio. In addition, σ values of different AACPBs with the same doping ratio become higher for shorter PMPCS side chains. The σ value of the lithium salt-doped AACPB increases with increasing temperature in the range of 25–240 °C, and σ is 1.79 × 10^–4 S/cm at 240 °C. The relatively high σ values of the lithium-doped AACPBs at high temperatures benefit from the rigid PMPCS side chain and the AACPB architecture. The lithium salt-doped AACPBs have the potential to serve as solid electrolytes in high-temperature lithium ion batteries

Bis(oxazolinyl)phenyl-Ligated Rare-Earth-Metal Complexes: Highly Regioselective Catalysts for <i>cis</i>-1,4-Polymerization of Isoprene

NCN-pincer (<i>S,S</i>)-2,6-bis­(4′-isopropyl-2′-oxazolinyl)­phenyl-ligated rare-earth-metal dichlorides [(<i>S,S</i>)-Phebox-^<i>i</i>Pr]­LnCl₂(THF)₂ (Ln = Sc (<b>1</b>); Y (<b>2</b>); Dy (<b>3</b>); Ho (<b>4</b>); Tm (<b>5</b>); Lu (<b>6</b>)) were synthesized via transmetalation between [(<i>S,S</i>)-Phebox-^<i>i</i>Pr]Li and LnCl₃ in THF solvent. Interestingly, treatment of LaCl₃ by the same method generated tris­(ligand) lanthanum complex [(<i>S,S</i>)-Phebox-^<i>i</i>Pr]₃La (<b>7</b>). Molecular structures of complexes <b>1</b>, <b>2</b>, <b>3</b>, and <b>7</b> were established by single-crystal X-ray diffraction study. Pincer ligand (<i>S,S</i>)-Phebox-^<i>i</i>Pr adopts a κC:κN:κN′ tridentate coordination mode to the central metal ion. Upon activation with [PhNHMe₂]­[B­(C₆F₅)₄] and Al^<i>i</i>Bu₃, complexes <b>2</b>–<b>5</b> exhibited highly catalytic activities and more than 98% <i>cis</i>-1,4-selectivity for isoprene polymerization while complexes <b>1</b> and <b>6</b> were inactive for this reaction. When use of the catalyst system consisted of complex <b>2</b>, [PhNHMe₂]­[B­(C₆F₅)₄], and Al^<i>i</i>Bu₃ for isoprene polymerization, the resultant polymer has a high <i>cis</i>-1,4-selectivity up to 99.5%. The reaction temperature had little effect on the regioselectivity, and high <i>cis</i>-1,4-selectivity almost remained even at 80 °C

Additional file 1: of WIPF1 antagonizes the tumor suppressive effect of miR-141/200c and is associated with poor survival in patients with PDAC

Table S1. The primer sequences used for polymerase chain reaction. Table S2. The nucleotide sequence of the primers used for qRT-PCR. Table S3. The sequence of miR-200c mimic, miR-141 mimic, anti-miR-200c mimic (Has-miR-200c inhibitor), and anti-miR-141 mimic (Has-miR-141 inhibitor) used for lentivirus transfection and luciferase reporter assay. Table S4. Characteristics of patients with pancreatic cancer (N = 37). Table S5. Characteristics of patients with pancreatic cancer from the TCGA database (N = 177). Figure S1. Identifying miR-141/200c target genes using the TargetScan software program. Figure S2. The levels of CpG methylation of the promoter region of miR-200a/200b/429 in PDAC. Figure S3. Lentiviral expression of miR-141 and miR-200c and their inhibitors in pancreatic cancer cell lines. Figure S4. The effect of miR-141 and miR-200c inhibitors on cell migration and invasion in vitro and tumor growth in xenograft. Figure S5. miR-141 and miR-200c inhibit the expression of WIPF1 in HPDE cell line. Figure S6. Lentiviral expression of shWIPF1 in pancreatic cancer cell lines. Figure S7. WIPF1 antagonizes the inhibitory effect of miR-141/200c on cell migration, invasion and metastasis of PDAC. (DOCX 17513 kb

Direct Multitier Synthesis of Two-Dimensional Semiconductor 2H-MoTe₂

Two-dimensional (2D) 2H-MoTe2 is an emerging semiconductor with promising electronic and optoelectronic properties. Meanwhile, the in-plane 2D epitaxy mechanism via the 1T′ to 2H phase transition allows the synthesis of 2H-MoTe2 on arbitrary surfaces. Here, we demonstrate two routes for tier-by-tier growth and one-step growth to synthesize multitier 2H-MoTe2 isolated by atomic layer deposition aluminum oxide (Al2O3). Raman, scanning transmission electron microscopy, and other characterizations show that the periodic 2H-MoTe2/Al2O3 multilayer structure exhibits the characteristics of large-area preparation and high crystallinity. Our direct multitier growth routes move the first step toward realizing 3D-ICs and nonvolatile memories based on semiconducting 2H-MoTe2

Infection efficiency of recombinant baculovirus in hESCs and hiPSCs.

<p><b>A</b> and <b>B</b>: Fluorescence microscopy images of hESCs and hiPSCs, respectively, which were seeded at 1×10⁵ cells per well and infected with Bac-GFP at MOI = 200 (40×). <b>C</b>: GFP⁺ % of Bac-GFP-infected hESCs and hiPSCs at 24 hpi with different MOIs. Results are means ± SD (n = 3). <b>Abbreviations</b>: hESCs, human embryonic stem cells; hiPSCs, human induced pluripotent stem cells.</p

Remarkable Stereochemistry Control in the Polymerization of α‑Olefins Using a Simple Scandium Catalyst System

A convenient approach to highly isotactic poly­(α-olefin)­s (<i>mmmm</i> > 99%) was realized using a simple scandium-based catalyst system consisting of ScCl₃(THF)₃, Al^<i>i</i>Bu₃, and [Ph₃C]­[B­(C₆F₅)₄] under mild conditions. The resultant polymers possess ultrahigh molecular weight (<i>M</i>_n > 10⁶) and relatively narrow molecular weight distribution. Especially, the excellent stereoselectivity still remains even at an elevated reaction temperature of 80 °C. Aluminum alkyls and organic borates, as well as their loadings significantly affected both the catalyst activity and product stereochemistry. The initial mechanistic exploration was carried out by means of NMR and ICP–AES spectroscopy, suggesting that a kind of incompact ion pair might be the active species. Further efforts to elucidate the real active sites and stereochemistry control mechanism of the catalytic system are underway

Remarkable Stereochemistry Control in the Polymerization of α‑Olefins Using a Simple Scandium Catalyst System

A convenient approach to highly isotactic poly­(α-olefin)­s (<i>mmmm</i> > 99%) was realized using a simple scandium-based catalyst system consisting of ScCl₃(THF)₃, Al^<i>i</i>Bu₃, and [Ph₃C]­[B­(C₆F₅)₄] under mild conditions. The resultant polymers possess ultrahigh molecular weight (<i>M</i>_n > 10⁶) and relatively narrow molecular weight distribution. Especially, the excellent stereoselectivity still remains even at an elevated reaction temperature of 80 °C. Aluminum alkyls and organic borates, as well as their loadings significantly affected both the catalyst activity and product stereochemistry. The initial mechanistic exploration was carried out by means of NMR and ICP–AES spectroscopy, suggesting that a kind of incompact ion pair might be the active species. Further efforts to elucidate the real active sites and stereochemistry control mechanism of the catalytic system are underway

Bis(oxazolinyl)phenyl-Ligated Rare-Earth-Metal Complexes: Highly Regioselective Catalysts for <i>cis</i>-1,4-Polymerization of Isoprene

NCN-pincer (<i>S,S</i>)-2,6-bis­(4′-isopropyl-2′-oxazolinyl)­phenyl-ligated rare-earth-metal dichlorides [(<i>S,S</i>)-Phebox-^<i>i</i>Pr]­LnCl₂(THF)₂ (Ln = Sc (<b>1</b>); Y (<b>2</b>); Dy (<b>3</b>); Ho (<b>4</b>); Tm (<b>5</b>); Lu (<b>6</b>)) were synthesized via transmetalation between [(<i>S,S</i>)-Phebox-^<i>i</i>Pr]Li and LnCl₃ in THF solvent. Interestingly, treatment of LaCl₃ by the same method generated tris­(ligand) lanthanum complex [(<i>S,S</i>)-Phebox-^<i>i</i>Pr]₃La (<b>7</b>). Molecular structures of complexes <b>1</b>, <b>2</b>, <b>3</b>, and <b>7</b> were established by single-crystal X-ray diffraction study. Pincer ligand (<i>S,S</i>)-Phebox-^<i>i</i>Pr adopts a κC:κN:κN′ tridentate coordination mode to the central metal ion. Upon activation with [PhNHMe₂]­[B­(C₆F₅)₄] and Al^<i>i</i>Bu₃, complexes <b>2</b>–<b>5</b> exhibited highly catalytic activities and more than 98% <i>cis</i>-1,4-selectivity for isoprene polymerization while complexes <b>1</b> and <b>6</b> were inactive for this reaction. When use of the catalyst system consisted of complex <b>2</b>, [PhNHMe₂]­[B­(C₆F₅)₄], and Al^<i>i</i>Bu₃ for isoprene polymerization, the resultant polymer has a high <i>cis</i>-1,4-selectivity up to 99.5%. The reaction temperature had little effect on the regioselectivity, and high <i>cis</i>-1,4-selectivity almost remained even at 80 °C

Bis(oxazolinyl)phenyl-Ligated Rare-Earth-Metal Complexes: Highly Regioselective Catalysts for <i>cis</i>-1,4-Polymerization of Isoprene

NCN-pincer (<i>S,S</i>)-2,6-bis­(4′-isopropyl-2′-oxazolinyl)­phenyl-ligated rare-earth-metal dichlorides [(<i>S,S</i>)-Phebox-^<i>i</i>Pr]­LnCl₂(THF)₂ (Ln = Sc (<b>1</b>); Y (<b>2</b>); Dy (<b>3</b>); Ho (<b>4</b>); Tm (<b>5</b>); Lu (<b>6</b>)) were synthesized via transmetalation between [(<i>S,S</i>)-Phebox-^<i>i</i>Pr]Li and LnCl₃ in THF solvent. Interestingly, treatment of LaCl₃ by the same method generated tris­(ligand) lanthanum complex [(<i>S,S</i>)-Phebox-^<i>i</i>Pr]₃La (<b>7</b>). Molecular structures of complexes <b>1</b>, <b>2</b>, <b>3</b>, and <b>7</b> were established by single-crystal X-ray diffraction study. Pincer ligand (<i>S,S</i>)-Phebox-^<i>i</i>Pr adopts a κC:κN:κN′ tridentate coordination mode to the central metal ion. Upon activation with [PhNHMe₂]­[B­(C₆F₅)₄] and Al^<i>i</i>Bu₃, complexes <b>2</b>–<b>5</b> exhibited highly catalytic activities and more than 98% <i>cis</i>-1,4-selectivity for isoprene polymerization while complexes <b>1</b> and <b>6</b> were inactive for this reaction. When use of the catalyst system consisted of complex <b>2</b>, [PhNHMe₂]­[B­(C₆F₅)₄], and Al^<i>i</i>Bu₃ for isoprene polymerization, the resultant polymer has a high <i>cis</i>-1,4-selectivity up to 99.5%. The reaction temperature had little effect on the regioselectivity, and high <i>cis</i>-1,4-selectivity almost remained even at 80 °C