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Cationic polymers

Bong Jik Kim, Sung Woo Cho, Yung Jin Jeon, Sujin An, Ara Jo, Jae Hyun Lim, Dong-Young Kim, Tae-Bin Won, Doo Hee Han, Chae-Seo Rhee, Hyun Jik Kim
We studied the contribution of Duox2 in mucosal host defense against influenza A virus (IAV) infection in in vivo lung. We found that Duox2 was required for the induction of type I and III interferon (IFN)s and transient Duox2 overexpression using cationic polymer polyethyleneimine (PEI) leads to suppression of IAV infection in in vivo lung. Twenty mice (C57BL/6J) were anesthetized and challenged by intranasal administration of 213 pfu/30 μl of IAV (WS/33/H1N1), and IAV-infected mice were euthanized at 1, 3, 5, 7, 10, 14 days post infection (dpi)...
September 21, 2017: Applied Microbiology and Biotechnology
Jay-Ar Bendo, Jonathan Martens, Giel Berden, Jos Oomens, Thomas Hellman Morton
Evidence is presented for cyclization to yield 2-bora-1,3-diazacycloalkanium cations in the gas phase. While the neutral compounds in solution and solid phase are known to possess an acyclic structure (as revealed by X-ray diffraction), the gaseous cations (from which borohydride BH4- ion has been expelled) have a cyclic structure, as revealed by InfraRed Multiple Photon Dissociation (IRMPD) spectroscopy and collisionally activated decomposition (CAD). The IRMPD decomposition of the monocyclic ions proceeds principally via H2 expulsion, although CAD experiments show additional pathways...
September 22, 2017: Journal of Physical Chemistry. A
Thaiesha A Wright, Melissa Lucius Dougherty, Benjamin Schmitz, Kevin M Burridge, Katherine Makaroff, Jamie M Stewart, Henry D Fischesser, Jerry T Shepherd, Jason A Berberich, Dominik Konkolewicz, Richard C Page
A thermophilic cellulase, FnCel5a, from Fervidobacterium nodosum was conjugated with various functional polymers including cationic, anionic, and strongly and weakly hydrogen bonding polymers. The activity of FnCel5a toward a high molecular weight carboxymethyl cellulose substrate was enhanced by polymer conjugation. Activity enhancements of 50% or greater observed for acrylamide and mixed N,N-dimethyl acrylamide/2-(N,N-dimethylamino)ethyl methacrylate polymers suggesting that the greatest enhancements were caused by polymers capable of non-covalent interactions with the substrate...
September 21, 2017: Bioconjugate Chemistry
Miharu Eguchi, Masako Momotake, Fumie Inoue, Takayoshi Oshima, Kazuhiko Maeda, Masayoshi Higuchi
A chemically inert, insulating layered silicate (saponite; SP) and an iron(II)-based metallo-supramolecular complex polymer (polyFe) were combined via electrostatic attraction to improve the electrochromic properties of polyFe. Structural characterization indicated that polyFe was intercalated into the SP nanosheets. Interestingly, the redox potential of polyFe was lowered by combining it with SP, and the current was measurable despite the insulating nature of SP. X-ray photoelectron spectroscopy showed that the decrease of the redox potential observed in the SP-polyFe hybrid was caused by electrostatic neutralization of the Fe cation in polyFe by the negative charge on SP...
September 21, 2017: ACS Applied Materials & Interfaces
Pierre Thuéry, Jack Harrowfield
An overview is given of recent structural studies on heterometallic uranyl-containing species, with particular emphasis on those formed with carboxylate ligands, showing the effect of the additional metal cations and ancillary ligands on the dimensionality, geometry and topology of the assemblies generated. These examples illustrate the level of elaboration which is now possible in the design and synthesis of both uranyl clusters and coordination polymers, properties and potential applications of which are also briefly discussed...
September 21, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
Phil Liebing
The mol-ecular and crystal structure of the l-proline-derived di-thio-carbamate-carboxyl-ate compound poly[tri-μ-aqua-(μ-2-carboxyl-atopyrrolidine-1-carbodi-thio-ato)dipotassium], [K2(C6H7NO2S2)(H2O)3] n or K2(SSC-NC4H7-COO)·3H2O, has been determined. The di-thio-carbamate moiety displays a unique coordination mode, comprising a 'side-on' π-coordinated K(+) cation besides a commonly σ-chelated K(+) cation. By bridging coordination of the CSS group, COO group and water mol-ecules, the K(+) cations are linked into a two-dimensional coordination polymer extending parallel to the ab plane...
September 1, 2017: Acta Crystallographica. Section E, Crystallographic Communications
Mengmeng Wu, Zhong Shi, Haidong Huang, Jianmei Qu, Xiaohui Dai, Xuefeng Tian, Weiying Wei, Guoqiang Li, Ting Ma
The micro-network structure and functional properties of sanxan, a novel polysaccharide produced by Sphingomonas sanxanigenens NX02, were investigated. Transparent hydrogel sanxan was a high acyl polymer containing 8.96% acetyl and 4.75% glyceroyl. The micro-network structure of sanxan was mainly cyclic configurations composed of side-by-side intermolecular associations, with many rounded nodes found. Sanxan exhibited predominant gelation behavior at concentrations above 0.1%, which was enhanced by adding cations, especially Ca(2+)...
November 15, 2017: Carbohydrate Polymers
Ahmed M Elbarbary, Hassan A Abd El-Rehim, Naeem M El-Sawy, El-Sayed A Hegazy, El-Sayed A Soliman
Superabsorbent hydrogels based on polyacrylamide (PAAm) and Na-alginate (Alg) or chitosan (CS) were synthesized by γ-rays. The effect of dose and copolymer composition on gel content and water absorbency of PAAm/Alg, PAAm/CS and PAAm/Alg/CS hydrogels were studied. The gel content and water absorbency follows the order PAAm/Alg>PAAm/Alg/CS>PAAm/CS. The effect of different cations, fertilizers, buffers on water absorbency of the hydrogels was investigated. Water retention capability of swollen hydrogels as a function of time was studied...
November 15, 2017: Carbohydrate Polymers
Delia A Haynes, Laura J van Laeren, Orde Q Munro
Herein we delineate an unusual one-dimensional coordination polymer (CP), 3, prepared from S = ½ Co(TPP), 1, (TPP = 5,10,15,20-tetraphenylporphyrin dianion) and S = ½ 4-(4'-pyridyl)-1,2,3,5-dithiadiazolyl (py-DTDA) radical, 2. The atypically long S-S distance for CP 3 (2.12 Å) reflects fractional electron transfer from the formally Co(II) ion into the antibonding π-SOMO of the metal-bound py-DTDA bridging ligand. The bonding in solid CP 3 involves non-integer redox states in a resonance hybrid repeat unit best formulated as [Co(TPP)](0...
September 19, 2017: Journal of the American Chemical Society
Kevin D Clark, Miranda N Emaus, Marcelino Varona, Ashley N Bowers, Jared L Anderson
The applications of ionic liquids (ILs) and IL-derived sorbents are rapidly expanding. By careful selection of the cation and anion components, the physicochemical properties of ILs can be altered to meet the requirements of specific applications. Reports of IL solvents possessing high selectivity for specific analytes are numerous and continue to motivate the development of new IL-based sample preparation methods that are faster, more selective, and environmentally benign compared to conventional organic solvents...
September 19, 2017: Journal of Separation Science
Alexey N Bilyachenko, Alexander A Korlyukov, Anna V Vologzhanina, Victor N Khrustalev, Alena N Kulakova, Jérôme Long, Joulia Larionova, Yannick Guari, Marina S Dronova, Ulyana S Tsareva, Pavel V Dorovatovskii, Elena S Shubina, Mikhail M Levitsky
Herein, the effect of replacement of the surrounding solvent and/or the partial substitution of sodium ions in the cage-like copper, sodium phenylsilsesquioxane [(PhSiO1.5)12(CuO)4(NaO0.5)4(n-BuOH)6] 1 with a globular structure was investigated; the synthesis of ten new derivatives of complex 1 was performed, and their crystal structures were determined. Solvate replacement of n-butanol in 1 with dimethyl sulfoxide, acetonitrile, 1,4-dioxane/EtOH, and 1,4-dioxane/PhCN afforded the complexes [(PhSiO1.5)12(CuO)4(NaO0...
September 19, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
Yao Tong, Tsogzolmaa Ganbold, Huricha Baigude
Cationic polymers are powerful carriers for intracellular delivery of therapeutic nucleic acids. However, the positively charged macromolecules have considerable cytotoxicity and often induce irreversible damages to the cells and tissues, which greatly negate the clinical application of such materials as drug delivery system. Herein, we report the synthesis of novel amphoteric polymers based on curdlan, and the evaluation of their cytotoxicity as well as the nucleic acid delivery efficiency. β-(1,3)-polyglucuronic acid, a TEMPO-oxidized derivative of curdlan, was chemically modified by conjugation of tetraethylenepentamine...
November 1, 2017: Carbohydrate Polymers
Kai Chi, Jeffrey M Catchmark
As a novel sustainable nanomaterial, crystalline nanocellulose (CNC) possesses many unique characteristics for emerging applications in coatings, emulsions, paints, pharmaceutical formulations, and other aqueous composite systems where interactions with oppositely charged surfactants are commonly employed. Herein, the binding interactions between sulfated CNC and a novel biologically-derived cationic surfactant lauric arginate (LAE) were comprehensively examined. Ionic strength and solution pH are two crucial factors in determining the adsorption of LAE to the CNC surface...
November 1, 2017: Carbohydrate Polymers
Paula Cucos, Lorenzo Sorace, Catalin Maxim, Sergiu Shova, Delia Patroi, Andrea Caneschi, Marius Andruh
The reactions of cobalt(II) perchlorate with a diazine tetratopic helicand, H4L, in the presence of sodium carbonate afford two coordination polymers constructed from tetranuclear anionic helicates as building blocks: ∞(3)[Co4L3Na4(H2O)4]·4H2O (1) and ∞(2)[Co5L3Na2(H2O)9]·2.7H2O·DMF (2). The tetranuclear triple-stranded helicates, {Co(II)4L3}(4-), are connected in 1 by sodium(I) ions and in 2 by sodium(I) and cobalt(II) ions (H4L results from the condensation reaction between 3-formylsalicylic acid and hydrazine)...
September 15, 2017: Inorganic Chemistry
Shaozhe Yang, Xiaoling Zhou, Rongxiang Li, Xiuhong Fu, Pingnan Sun
Polyethyleneimine (PEI), a cationic polymer vehicle, forms a complex with DNA which then can carry anionic nucleic acids into eukaryotic cells. PEI-based transfection is widely used for transient transfection of plasmid DNA. The efficiency of PEI-based transfection is affected by numerous factors, including the way the PEI/DNA complex is prepared, the ratio of PEI to DNA, the concentration of DNA, the storage conditions of PEI solutions, and more. Considering the major influencing factors, PEI-based transfection has been optimized to improve its efficiency, reproducibility, and consistency...
September 14, 2017: Current Protocols in Chemical Biology
Cem Varan, Erem Bilensoy
Background: Brain tumors are the most common tumors among adolescents. Although some chemotherapeutics are known to be effective against brain tumors based on cell culture studies, the same effect is not observed in clinical trials. For this reason, the development of drug delivery systems is important to treat brain tumors and prevent tumor recurrence. The aim of this study was to develop core-shell polymeric nanoparticles with positive charge by employing a chitosan coating. Additionally, an implantable formulation for the chemotherapeutic nanoparticles was developed as a bioadhesive film to be applied at the tumor site following surgical operation for brain glioma treatment...
2017: Beilstein Journal of Nanotechnology
Patrick Midoux, Lucie Pigeon, Cristine Gonçalves, Chantal Pichon
Synthetic vectors such as cationic polymers and cationic lipids remain attractive tools for non-viral gene transfer which is a complex process whose effectiveness relies on the ability to deliver a plasmid DNA (pDNA) into the nucleus of non-dividing cells. Once in the cytosol, the transport of pDNAs towards the nuclear envelop is strongly impaired by their very low cytosolic mobility due to their large size. To promote their movement towards the cell nucleus, few strategies have been implemented to exploit dynein, the microtubule's motor protein, for propagation of cytosolic pDNA along the microtubules (MTs) towards the cell nucleus...
September 12, 2017: Bioscience Reports
Konstantin Rodygin, Irina Werner, Valentine P Ananikov
Synthesizing chemicals and materials based on renewable sources is one of the main tasks of modern science. Carbohydrates represent excellent renewable natural raw materials, that are eco-friendly, inexpensive and biologically compatible. Herein, we developed a green vinylation procedure for carbohydrates using readily available calcium carbide. Various carbohydrates were utilized as starting materials resulting in mono-, di- and tetra-vinyl ethers in high to excellent yields (81-92 %). The synthesized bio-based vinyl ethers were utilized as monomers in free radical and cationic polymerizations...
September 12, 2017: ChemSusChem
Devrah A Arndt, Emily K Oostveen, Judy Triplett, D Allan Butterfield, Olga V Tsyusko, Blanche Collin, Daniel L Starnes, Jian Cai, Jon B Klein, Richard Nass, Jason M Unrine
This study examined the impact of surface functionalization and charge on ceria nanomaterial toxicity to Caenorhabditis elegans. The examined endpoints included mortality, reproduction, protein expression, and protein oxidation profiles. Caenorhabditis elegans were exposed to identical 2-5nm ceria nanomaterial cores which were coated with cationic (diethylaminoethyl dextran; DEAE), anionic (carboxymethyl dextran; CM), and non-ionic (dextran; DEX) polymers. Mortality and reproductive toxicity of DEAE-CeO2 was approximately two orders of magnitude higher than for CM-CeO2 or DEX-CeO2...
September 6, 2017: Comparative Biochemistry and Physiology. Toxicology & Pharmacology: CBP
Chunnuan Du, Yufang Hu, Qingqing Zhang, Zhiyong Guo, Guoping Ge, Sui Wang, Chunyang Zhai, Mingshan Zhu
A novel, label-free and convenient strategy for thrombin assay has been developed based on the fluorescence resonance energy transfer (FRET) from a cationic conjugated polymer (CCP) to Ir(III) complex. The energy donor (CCP) and acceptor (Ir(III) complex) were taken into close proximity through π-π stacking interaction and electrostatic interaction, leading to the occurrence of FRET. However, the introduction of the thrombin aptamer upset the status and blocked the FRET process, but afterwards the reappearance of FRET phenomenon was confirmed by the special binding interaction between aptamer and thrombin, thus achieving the quantitative detection of thrombin...
August 10, 2017: Biosensors & Bioelectronics
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