Read by QxMD icon Read

Cationic polymers

Hashem Shahroosvand, Saeid Abaspour, Babak Pashaei, Eros Radicchi, Filippo De Angelis, Francesco Bonaccorso
We report on the exploitation of a new tetrazole-substituted 1,10-phenanthroline and a 2,2'-bipyridine (bpy) ancillary ligand modified with an electron-donating group in cationic ruthenium complexes. This complex, placed in between two electrodes without any polymer, demonstrates high efficiency near-infrared (NIR) electroluminescence (EL). The comparison between bpy and its methyl-substituted ancillary ligand shows that the cationic Ru tetrazolate complex containing methyl groups exhibits a red shift in the EL wavelength from 620 to 800 nm compared to [Ru(bpy)3](2+) and an almost twofold reduction in the turn-on voltage, i...
May 23, 2017: Chemical Communications: Chem Comm
Weiwei Cao, Yu Zhang, Xi Wang, Yinyan Chen, Qiang Li, Xiaodong Xing, Yuhong Xiao, Xuefeng Peng, Zhiwen Ye
Research on the incorporation of cutting-edge nano-antibacterial agent for designing dental materials with potent and long-lasting antibacterial property is demanding and provoking work. In this study, a novel resin-based dental material containing photocurable core-shell AgBr/cationic polymer nanocomposite (AgBr/BHPVP) was designed and developed. The shell of polymerizable cationic polymer not only provided non-releasing antibacterial capability for dental resins, but also had the potential to polymerize with other methacrylate monomers and prevented nanoparticles from aggregating in the resin matrix...
July 2017: Journal of Materials Science. Materials in Medicine
Qiaoyun Zhang, Suniti Singh, David C Stuckey
Using adsorbents/flocculants in anaerobic membrane bioreactors (AnMBRs) to reduce membrane fouling is comparatively rare. This study evaluated 8 additives: 3 powdered activated carbons, 2 granular activated carbons, 1 cationic polymer, and 2 metal salts to identify the best additive and dose to minimise membrane fouling. Small cross flow filtration tests showed 400mg/L PAC SAE2, or 150mg/L FeCl3, reduced the transmembrane pressure (TMP) rise from 0.94 to 0.06kPa/h, indicating excellent fouling reduction. The best filtration performance correlated with a significant reduction in supernatant supracolloidal particles, colloids and SMPs...
May 5, 2017: Bioresource Technology
Jingxiao Tian, Jiangyan Zhang, Jiangtao Yang, Lingyun Du, Hao Geng, Yongqiang Cheng
The emergence of drug-resistance bacteria severely challenges the antimicrobial agents and antibacterial strategy. Here we demonstrate a novel, simple and highly efficient combination therapy strategy by direct combinations of cationic conjugated polymers (CCPs) with polypeptide antibiotics against gram-negative and gram-positive bacteria based on a synergistic antibacterial effect. The combination therapy method enhances the antibacterial efficacy with significantly reduced antibiotic dosage. Also the highly efficient and synergistically killing of drug-resistant bacteria is realized...
May 18, 2017: ACS Applied Materials & Interfaces
Gonzalo Pérez-Mitta, Waldemar A Marmisollé, Christina Trautmann, María Eugenia Toimil-Molares, Omar Azzaroni
The design of an all-plastic field-effect nanofluidic diode is proposed, which allows precise nanofluidic operations to be performed. The fabrication process involves the chemical synthesis of a conductive poly(3,4-ethylenedioxythiophene) (PEDOT) layer over a previously fabricated solid-state nanopore. The conducting layer acts as gate electrode by changing its electrochemical state upon the application of different voltages, ultimately changing the surface charge of the nanopore. A PEDOT-based nanopore is able to discriminate the ionic species passing through it in a quantitative and qualitative manner, as PEDOT nanopores display three well-defined voltage-controlled transport regimes: cation-rectifying, non-rectifying, and anion rectifying regimes...
May 18, 2017: Advanced Materials
Jong Hoon Choi, Jung Seok Lee, Kyung Min Park, Jin Woo Bae, Yunki Lee, Ki Dong Park
We describe a facile and effective poly(ethylene glycol) (PEG) coating method that has not been used previously for decoration of nanogels. Layer-by-layer (LbL) assembly was the technique of choice to introduce PEG onto the surface of multi-layered nanogels (MLNGs). Pegylated MLNGs were prepared simply by sequentially dispersing nanogels in solutions of cationic polymer, anionic polymer, and modified PEGs, and each coating step was validated by measuring changes in size and surface charge. Particularly, a peptide linker that is cleavable by matrix metalloproteinase-2 (MMP-2) in the tumor microenvironment was introduced between PEG layer and nanogels because it is known that PEG reduces the uptake of nanoparticles in tumor cells due to its high mobility...
May 3, 2017: Colloids and Surfaces. B, Biointerfaces
Dan Zhang, Thomas Thundat, Ravin Narain
Temperature-responsive copolymer with cationic charge was prepared with N-isopropylacrylamide (NIPAM) and 2-aminoethyl methacrylamide hydrochloride (AEMA) by conventional free-radical polymerization. The flocculation performance of the copolymer, poly(AEMA-st-NIPAM), was compared to five different mixture ratios of polyNIPAM and cationic poly(acrylamide-st-diallyldimethylammonium chloride) (poly(AAm-st-DADMAC)). The effects of polymer mixture ratios, polymer dosages, and temperature on solid-liquid separation as a function of initial settling rates (ISR), supernatant turbidity, sediment solids content and water recovery were investigated...
May 17, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
Matthew L Brown, Jeffrey S Ovens, Daniel B Leznoff
The first series of uranyl ([UO2](2+))-dicyanoaurate coordination polymers and molecular complexes has been synthesized. Reactions of [A][Au(CN)2] (A = [(n)Bu4N](+) or [(Ph3P)2N](+) ([PPN])) and uranyl nitrate in alcoholic solvents in ambient light led to [A]2[(UO2)2(μ-η(2):η(2)-O2)(NO3)2(μ-Au(CN)2)2], which incorporates peroxo ligands into a one-dimensional ladder topology with alternating aurophilic and peroxo rungs. Conducting the reaction with non-alcoholic solvents formed two polymorphs of a one-dimensional chain, [PPN][UO2(NO3)2Au(CN)2], from acetone, and a molecular analogue, [PPN]2[UO2(NO3)2(Au(CN)2)2], from acetonitrile, none of which exhibited aurophilic interactions...
May 16, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
Fangyuan Zhao, Nicolas Plumeré, Marc M Nowaczyk, Adrian Ruff, Wolfgang Schuhmann, Felipe Conzuelo
In the development of photosystem-based energy conversion devices, the in-depth understanding of electron transfer processes involved in photocurrent generation and possible charge recombination is essential as a basis for the development of photo-bioelectrochemical architectures with increased efficiency. The evaluation of a bio-photocathode based on photosystem 1 (PS1) integrated within a redox hydrogel by means of scanning photoelectrochemical microscopy (SPECM) is reported. The redox polymer acts as a conducting matrix for the transfer of electrons from the electrode surface to the photo-oxidized P700 centers within PS1, while methyl viologen is used as charge carrier for the collection of electrons at the reduced FB site of PS1...
May 16, 2017: Small
Shaokui Zheng, Xiaofeng Li, Xueyu Zhang, Wei Wang, Shengliu Yuan
This study investigated the potential effect of four frequently used inorganic regenerant properties (i.e., ionic strength, cation type, anion type, and regeneration solution volume) on the desorption and adsorption performance of 14 pharmaceuticals, belonging to 12 therapeutic classes with different predominant chemical forms and hydrophobicities, using polymeric anion exchange resin (AER)-packed fixed-bed column tests. After preconditioning with NaCl, NaOH, or saline-alkaline (SA) solutions, all resulting mobile counterion types of AERs effectively adsorbed all 14 pharmaceuticals, where the preferential magnitude of OH(-)-type = Cl(-) + OH(-)-type > Cl(-)-type...
May 10, 2017: Chemosphere
Susan Oliver, Aziidah Jofri, Donald S Thomas, Orazio Vittorio, Maria Kavallaris, Cyrille Boyer
In this contribution, we present a strategy to functionalise three natural carbohydrate polymers (dextran - a neutral polymer, sodium alginate - an anionic polymer and chitosan - a cationic polymer) with catechin with excellent degrees of functionality. In a first step, the carbohydrate polymers were oxidised by sodium periodate to yield aldehyde functionalised carbohydrate polymers. The presence of aldehyde groups was exploited to attach catechin by an acid catalysed nucleophilic reaction. The degree of catechin functionalisation could be easily tuned by varying the acid concentration in the reaction mixture, achieving catechin functionalisation levels of up to 48% for dextran aldehyde catechin, 35% for chitosan-aldehyde-catechin and 22% for sodium alginate aldehyde catechin...
August 1, 2017: Carbohydrate Polymers
Philipp Heller, Dominika Hobernik, Ulrich Lächelt, Meike Schinnerer, Benjamin Weber, Manfred Schmidt, Ernst Wagner, Matthias Bros, Matthias Barz
Therapeutic nucleic acids such as pDNA hold great promise for the treatment of multiple diseases. These therapeutic interventions are, however, compromised by the lack of efficient and safe non-viral delivery systems, which guarantee stability during blood circulation together with high transfection efficiency. To provide these desired properties within one system, we propose the use of reactive triblock copolypept(o)ides, which include a stealth-like block for efficient shielding, a hydrophobic block based on reactive disulfides for cross-linking and a cationic block for complexation of pDNA...
May 10, 2017: Journal of Controlled Release: Official Journal of the Controlled Release Society
Jiao Cai, Gang-Tian Zhu, Xiao-Mei He, Zheng Zhang, Ren-Qi Wang, Yu-Qi Feng
In this work, a polyoxometalate (POM) incorporated polymer monolith microextraction (PMME) was successfully proposed and employed in the selective extraction of basic antidepressants in undiluted urine sample. This hybrid monolith exhibited strong cation-exchange interaction (SCX) with positively charged antidepressants when pH was 3.0, because of the multiple ionizable moieties on polyanionic POM. As such, antidepressants in complex sample matrices were efficiently extracted by the monolith, and the matrix effect was significantly reduced...
August 1, 2017: Talanta
Myosotys Rodriguez, Jessica Lapierre, Chet Raj Ojha, Ajeet Kaushik, Elena Batrakova, Fatah Kashanchi, Seth M Dever, Madhavan Nair, Nazira El-Hage
We previously reported that activation of the host autophagic protein, Beclin1, by HIV-1 infection represents an essential mechanism in controlling HIV replication and viral-induced inflammatory responses in microglial cells. Existing antiretroviral therapeutic approaches have been limited in their ability to cross the blood-brain barrier effectively and recognize and selectively eliminate persistent HIV-infected brain reservoirs. In the present study and for the first time, the bio-distribution and efficacy of noninvasive intranasal delivery of small interfering RNA (siRNA) against the Beclin1 gene using the cationic linear polyethylenimines (PEI) as a gene carrier was investigated in adult mouse brain...
May 12, 2017: Scientific Reports
Nor Akma Mamat, Hong Heng See
A new electric-field driven extraction approach based on the integration of a bubbleless electrode into the electromembrane extraction (EME) across hollow polymer inclusion membranes (HPIMs) was demonstrated for the first time. The bubbleless electrode was prepared based on an in-situ synthesised polyacrylamide within a fused silica capillary. The electrode functions as a salt bridge, which conducts the electrical current between the acceptor phase in the lumen of the HPIM and the acceptor solution in the reservoir connected to a high voltage supply through a platinum electrode...
May 3, 2017: Journal of Chromatography. A
Hyejin Lee, Jin Yong Kim, Woonjin Choi, Myeong Hee Moon
In this study, ultrahigh-molecular-weight (MW) (>10(7)Da) cationic polyacrylamides (C-PAMs), which are water-soluble polymers used in waste water treatment, were characterized using frit-inlet asymmetrical flow field-flow fractionation coupled with multi-angle light scattering and differential refractive detection. C-PAMs copolymerized with acryloxyethyltrimethyl ammonium chloride (DAC) were prepared by varying the feed amount of cationic monomer, polymerization method (solution vs. emulsion), and degree of branching...
April 28, 2017: Journal of Chromatography. A
Minghuey Shieh, Chia-Chi Yu, Chia-Yeh Miu, Chang-Hung Kung, Chung-Yi Huang, Yu-Hsin Liu, Hsiang-Lin Liu, Chih-Chiang Shen
A series of semiconducting cluster-incorporated Cu-based coordination polymers, namely, 1D zigzag polymers [[{TeFe3(CO)9Cu2}(L)]n (L = 1,2-bis(4-pyridyl)ethane (bpea), 1; L = 1,2-bis(4-pyridyl)ethylene (bpee), 5), 2D honeycomb-like polymers [{TeFe3(CO)9Cu}Cu(L)2.5]n (L = bpea, 2; L =bpee, 6), and 2D wave-like cation-anion polymer [{Cu2(L)4}{{TeFe3(CO)9Cu}2(L)}]n (L = 1,3-bis(4-pyridyl)propane (bpp), 4), as well as the macrocycle [{TeFe3(CO)9Cu2}2(bpp)2] (3) have been quantitatively synthesized via the liquid-assisted grinding from the pre-designed cluster [TeFe3(CO)9Cu2(MeCN)2] with conjugated or conjugation-interrupted dipyridyl linkers...
May 11, 2017: Chemistry: a European Journal
Shigehiro Kagaya, Tomonori Maeno, Kazuma Ito, Makoto Gemmei-Ide, Robert W Cattrall, Spas D Kolev
An important reason for the inefficient extraction of Cr(VI) from its acidic solutions into polymer inclusion membranes (PIMs), consisting of poly(vinyl chloride) as the base-polymer and Aliquat 336 as the carrier, was found to be associated with the leaching of Aliquat 336 from the PIMs into the solutions, where it subsequently reduced the anionic Cr(VI) species to cationic Cr(III) species. The PIM extraction efficiency for Cr(VI) was significantly improved by the addition of NaNO3 to the solutions, which suppressed the leaching of Aliquat 336 and the reduction of Cr(VI) to Cr(III)...
2017: Analytical Sciences: the International Journal of the Japan Society for Analytical Chemistry
Noha Nafee, Noha Gouda
The restless endeavors revealing the molecular pathways underlying many neurodegenerative diseases and brain tumors have paved the way for the introduction of the selective exogenous gene-based therapeutics. The implicated active biomolecules encompass mainly negatively-charged nucleic acids ranging from DNA, mRNA, non-coding RNAs (small-interfering RNA, siRNA, and microRNA, miRNA), to antisense oligonucleotides. They selectively interfere with the genes translational and/or transcriptional processes. Although many reviews previously addressed brain targeting, a thorough correlation between the molecular properties of these biomacromolecules, the nature of blood brain barrier (BBB) in the accompanying pathological condition, the intracellular targets, as well as the design of the delivery system which will transport the bioactive cargo to the target cells attempting efficient delivery to the active sites in the brain will be appraised...
May 10, 2017: Current Gene Therapy
Jonathan C Pegg, Adam Czajka, Gavin Hazell, Christopher Hill, Jocelyn Peach, Sarah E Rogers, Julian Eastoe
HYPOTHESIS: Reports of random copolymers capable of solubilising hydrophobic oils are rare. This is primarily because random copolymers are unlikely to self-assemble into suitable aggregates (or micelles) in water. A random copolymer with a "blocky" (or lumpy) microstructure may have potential to solubilise hydrophobic oils in water. This type of polymer would have advantages over block copolymers which are more laborious and costly to synthesise. EXPERIMENTS: The solubilising capacity of a blocky random copolymer, namely poly(methyl methacrylate-co-2-dimethylaminoethyl methacrylate) (PMMA-co-PDMAEMA) is assessed by UV-visible spectroscopy and compared with common reference surfactants...
May 2, 2017: Journal of Colloid and Interface Science
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"