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Cationic polymers

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https://www.readbyqxmd.com/read/28731685/lipophilic-polycation-vehicles-display-high-plasmid-dna-delivery-to-multiple-cell-types
#1
Yaoying Wu, Adam E Smith, Theresa M Reineke
A class of cationic poly(alkylamidoamine)s (PAAAs) containing lipophilic methylene linkers were designed and examined as in vitro plasmid DNA (pDNA) delivery agents. The PAAAs were synthesized via step-growth polymerization between a diamine monomer and each of four different diacid chloride monomers with varying methylene linker lengths, including glutaryl chloride, adipoyl chloride, pimeloyl chloride, and suberoyl chloride, which served to systematically increase the lipophilicity of the polymers. The synthesized polymers successfully complexed with pDNA in reduced serum medium at N/P ratios of 5 and greater, resulting in polyplexes with hydrodynamic diameters of approximately 1 μm...
July 21, 2017: Bioconjugate Chemistry
https://www.readbyqxmd.com/read/28725139/hybrid-polymeric-matrices-for-oral-modified-release-of-desvenlafaxine-succinate-tablets
#2
Wael Samy, Ayman Elnoby, Hanan M El-Gowelli, Nazik Elgindy
Purpose: Desvenlafaxine succinate (DSV) is a water soluble anti-depressant drug, which is rapidly absorbed after oral administration exaggerating its side effects. The current work aimed to prepare controllable release DSV matrix to reduce DSV side effects related to its initial burst. Methods: Fifteen DSV matrix formulations were prepared using different polymers, polymer/drug ratios and matrix excipients and characterized using Differential Scanning Calorimetry (DSC), infrared (IR) spectroscopy, water uptake and in vitro DSV release...
July 2017: Saudi Pharmaceutical Journal: SPJ: the Official Publication of the Saudi Pharmaceutical Society
https://www.readbyqxmd.com/read/28723082/mixed-valency-in-a-3d-semiconducting-iron-fluoranilate-coordination-polymer
#3
Ryuichi Murase, Brendan F Abrahams, Deanna M D'Alessandro, Casey G Davies, Timothy A Hudson, Guy N L Jameson, Boujemaa Moubaraki, Keith S Murray, Richard Robson, Ashley L Sutton
A pair of coordination polymers of composition (NBu4)2[M2(fan)3] (fan = fluoranilate; M = Fe and Zn) were synthesized and structurally characterized. In each case the compound consists of a pair of interpenetrating three-dimensional, (10,3)-a networks in which metal centers are linked by chelating/bridging fluoranilate ligands. Tetrabutylammonium cations are located in the spaces between the two networks. Despite the structural similarity, significant differences exist between (NBu4)2[Fe2(fan)3] and (NBu4)2[Zn2(fan)3] with respect to the oxidation states of the metal centers and ligands...
July 19, 2017: Inorganic Chemistry
https://www.readbyqxmd.com/read/28722515/construction-of-a-plga-based-targeted-sirna-delivery-system-for-treatment-of-osteoporosis
#4
Deniz Sezlev Bilecen, Jose Carlos Rodriguez-Cabello, Hasan Uludag, Vasif Hasirci
Osteoporosis is a systemic skeletal disorder which occurs when the bone turnover balance is disrupted. With the identification of the genes involved in the pathogenesis of the disease, studies on development of new osteoporosis treatments has intensified. RNA interference (RNAi) mechanism uses short interfering RNA (siRNA) to knockdown disease related gene expression as a treatment approach. Targeting while protecting siRNA against hydrolysis by nucleases in vivo is, however, challenging. The maintenance of therapeutic plasma level is also hampered by the clearance of siRNA from the body...
July 19, 2017: Journal of Biomaterials Science. Polymer Edition
https://www.readbyqxmd.com/read/28722040/a-new-set-of-cd-ii-coordination-polymers-with-mixed-ligands-of-dicarboxylate-and-pyridyl-substituted-diaminotriazine-selective-sorption-towards-co2-and-cationic-dyes
#5
Santanu Chand, Syed Meheboob Elahi, Arun Pal, Madhab C Das
On the basis of a mixed ligand system of L(NH2)2 (6-(pyridin-4-yl)-1,3,5-triazine-2,4-diamine) and dicarboxylic acids, three new Cd(ii) coordination polymers viz. {[Cd0.5(tdc)0.5(L(NH2)2)0.5(H2O)]·DMF·H2O}n (1), {[Cd0.5(bdc)0.5(L(NH2)2)(H2O)]·DMF·H2O}n (2), and {[Cd(ipa)(L(NH2)2)(DMF)]·H2O}n (3) (tdcH2 = thiophene-2,5-dicarboxylic acid, bdcH2 = benzene-1,4-dicarboxylic acid, ipaH2 = benzene-1,3-dicarboxylic acid) were synthesized under diverse reaction conditions and characterized by single crystal X-ray diffraction, PXRD, elemental analysis, IR spectroscopy and TGA...
July 19, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
https://www.readbyqxmd.com/read/28719858/interfacial-analysis-of-sirna-complexes-with-poly-ethylenimine-pei-or-pamam-dendrimers-in-gene-delivery
#6
Patrick K C Chang, Clive A Prestidge, Kristen E Bremmell
Solution and interfacial analysis has been employed to gain insight into the complexation of siRNA using either G4 PAMAM dendrimers or 25kDa branched poly-ethylenimine (bPEI). The size, charge and shape/structure of the complexing agents were probed using atomic force microscopy (AFM), circular dichroism spectrometry (CD), dynamic light scattering (DLS), and gel electrophoresis (GE). The binding capability of these cationic polymers to the siRNA molecule, subsequently controls the surface/adsorption behaviour of the complexes to a negatively charged surface...
July 8, 2017: Colloids and Surfaces. B, Biointerfaces
https://www.readbyqxmd.com/read/28715017/multipodal-dynamic-coordination-involving-cation-%C3%AF-interactions-to-control-the-structure-of-helical-polymers
#7
Mohammad Alzubi, Sandra Arias, Iria Louzao, Emilio Quiñoá, Ricardo Riguera, Félix Freire
A precise tuning of the four possible states of a helix (P/M helical sense and stretched/compressed helical backbone) is attained by controlling the complexation between Li(+) and a poly(phenylacetylene) that bears amide, ester and phenyl ring functionalities at the pendant group. Depending on the MeOH ratio that is present as a cosolvent, different coordination sites are involved in interactions leading to complexes I-III, each one with a characteristic structure (tri-, bi-, and unipodal) and an associated helical state...
July 17, 2017: Chemical Communications: Chem Comm
https://www.readbyqxmd.com/read/28714572/surface-modified-mesh-filter-for-direct-nucleic-acid-extraction-and-its-application-to-gene-expression-analysis
#8
Jae Bem You, Yong Tae Kim, Kyoung G Lee, Yunho Choi, Seongkyun Choi, Chi Hyun Kim, Kyung Hoon Kim, Sung Jin Chang, Tae Jae Lee, Seok Jae Lee, Sung Gap Im
Rapid and convenient isolation of nucleic acids (NAs) from cell lysate plays a key role for onsite gene expression analysis. Here, this study achieves one-step and efficient capture of NA directly from cell lysate by developing a cationic surface-modified mesh filter (SMF). By depositing cationic polymer via vapor-phase deposition process, strong charge interaction is introduced on the surface of the SMF to capture the negatively charged NAs. The NA capturing capability of SMF is confirmed by X-ray photoelectron spectroscopy, fluorescent microscopy, and zeta potential measurement...
July 17, 2017: Advanced Healthcare Materials
https://www.readbyqxmd.com/read/28707806/selective-adsorption-and-separation-of-organic-dyes-with-spherical-polyelectrolyte-brushes-and-compressed-co2
#9
Rui Zhang, Zhenchuan Yu, Yuan Yao, Xiaoyan Hou, Qizhe Shen, Lei Wang, Xuhong Guo, Junwei Wang, Xuedong Zhu
Direct discharge of industry organic dyes has caused serious environmental pollution. Herein, we proposed a rational designed spherical polyelectrolyte brushes (SPB) with cationic charges, polystyrene-poly(2-aminoethylmethacrylate hydrochloride) (PS-PAEMH), as the absorbent and compressed carbon dioxide as the anti-solvent to separate the anionic dye, eosin Y (EY) from a solution of mixed dyes. The adsorption behavior of EY onto PS-PAEMH was highly dependent on CO2 pressure, contact time and initial concentration, and the maximum adsorption capacity of PS-PAEMH was 335...
July 14, 2017: Chemistry: a European Journal
https://www.readbyqxmd.com/read/28704679/ph-sensitive-polymer-modified-liposome-based-immunity-inducing-system-effects-of-inclusion-of-cationic-lipid-and-cpg-dna
#10
Yuta Yoshizaki, Eiji Yuba, Naoki Sakaguchi, Kazunori Koiwai, Atsushi Harada, Kenji Kono
Efficient vaccine carriers for cancer immunotherapy require two functions: antigen delivery to dendritic cells (DCs) and the activation of DCs, a so-called adjuvant effect. We previously reported antigen delivery system using liposomes modified with pH-sensitive polymers, such as 3-methylglutarylated hyperbranched poly(glycidol) (MGlu-HPG), for the induction of antigen-specific immune responses. We reported that inclusion of cationic lipids to MGlu-HPG-modified liposomes activates DCs and enhances antitumor effects...
July 3, 2017: Biomaterials
https://www.readbyqxmd.com/read/28704064/nucleic-acid-extraction-from-synthetic-mars-analog-soils-for-in-situ-life-detection
#11
Angel Mojarro, Gary Ruvkun, Maria T Zuber, Christopher E Carr
Biological informational polymers such as nucleic acids have the potential to provide unambiguous evidence of life beyond Earth. To this end, we are developing an automated in situ life-detection instrument that integrates nucleic acid extraction and nanopore sequencing: the Search for Extra-Terrestrial Genomes (SETG) instrument. Our goal is to isolate and determine the sequence of nucleic acids from extant or preserved life on Mars, if, for example, there is common ancestry to life on Mars and Earth. As is true of metagenomic analysis of terrestrial environmental samples, the SETG instrument must isolate nucleic acids from crude samples and then determine the DNA sequence of the unknown nucleic acids...
July 13, 2017: Astrobiology
https://www.readbyqxmd.com/read/28702634/controlling-biomineralisation-with-cations
#12
K K Sand, C S Pedersen, J Matthiesen, S Dobberschütz, S L S Stipp
The production of polymers for controlling calcite growth is a well-known approach in biomineralising organisms. Numerous studies have shown that polymers significantly influenced the growth rate and morphology of CaCO3 but little is known about how the polymers are actually controlled by the organisms. Here we show that cations control the effect of polysaccharides and that these processes have been in place for at least 60 million years. We studied the interaction between cleaved samples of pure calcite and ancient coccolith associated polysaccharides (aPS) that we had extracted from the samples of Cretaceous chalk, in solutions that contained one of the common seawater cations, K(+), Ca(2+), Mg(2+) and Sr(2+)...
July 12, 2017: Nanoscale
https://www.readbyqxmd.com/read/28702622/mechanism-of-ion-transport-in-perfluoropolyether-electrolytes-with-a-lithium-salt
#13
Ksenia Timachova, Mahati Chintapalli, Kevin R Olson, Sue J Mecham, Joseph M DeSimone, Nitash P Balsara
Perfluoropolyethers (PFPEs) are polymer electrolytes with fluorinated carbon backbones that have high flash points and have been shown to exhibit moderate conductivities and high cation transference numbers when mixed with lithium salts. Ion transport in four PFPE electrolytes with different endgroups was characterized by differential scanning calorimetry (DSC), ac impedance, and pulsed-field gradient NMR (PFG-NMR) as a function of salt concentration and temperature. In spite of the chemical similarity of the electrolytes, salt diffusion coefficients measured by PFG-NMR and the glass transition temperature measured by DSC appear to be uncorrelated to ionic conductivity measured by ac impedance...
July 12, 2017: Soft Matter
https://www.readbyqxmd.com/read/28692282/design-and-applications-of-metastable-state-photoacids
#14
Yi Liao
Proton transfer is one of the most common processes in nature, and many chemical, material, and biological processes are sensitive to proton concentration, from acid-catalyzed reactions to the activities of many enzymes. Photoacids that reversibly undergo proton dissociation upon irradiation promise remote spatial and temporal control over proton-sensitive processes and could provide a way to convert photoenergy into other types of energy. The recently discovered metastable-state photoacids can produce a large proton concentration with high efficiency and good reversibility...
July 10, 2017: Accounts of Chemical Research
https://www.readbyqxmd.com/read/28690305/determination-of-nonvolatile-amines-in-foods-by-improved-dansyl-derivatization-reaction
#15
Ayami Handa, Hitomi Kawanabe, Akihiro Ibe
An analytical method for the determination of nonvolatile amines (putrescine, cadaverine, histamine, tyramine, and spermidine) in foods was developed, using an improved dansyl derivatization technique. The five amines were extracted from food with 1% trichloroacetic acid. Three milliliter of extract was applied to a polymer-based strong cation exchange resin mini-column, which was washed with 5 mL of water, and eluted with 5 mL of 1 mol/L potassium carbonate solution. The eluate was dansylated, then 5 mL of toluene was added with shaking...
2017: Shokuhin Eiseigaku Zasshi. Journal of the Food Hygienic Society of Japan
https://www.readbyqxmd.com/read/28688213/multivalent-methionine-functionalized-biocompatible-block-copolymers-for-targeted-sirna-delivery-and-subsequent-reversal-effect-on-adriamycin-resistance-in-human-breast-cancer-cell-line-mcf-7-adr
#16
Yang Wu, Wei Zhang, Tinghan Li, Rong Ma, Dan Chen, Junying Zhang, Jianzhong Wu, Jinhai Tang
BACKGROUND: Cationic polymers are the outstanding representatives of the most efficient siRNA vectors. Low cytotoxicity and siRNA protecting effect can be obtained with these cationic polymers via a variety of structural modifications. Nevertheless, the gap between their efficiency and the requirement for therapeutic processes is still noticeable. METHODS: A cationic polymer vector was synthesized via the copolymerization of N-(1, 3-dihydroxy propan-2-yl) methacrylamide (DHPMA) and N-(3-aminopropyl) methacrylamide (APMA)...
July 8, 2017: Journal of Gene Medicine
https://www.readbyqxmd.com/read/28687984/comparison-of-the-optoelectronic-performance-of-neutral-and-cationic-forms-of-riboflavin
#17
Gözde Murat Saltan, Deniz Aykut Kıymaz, Ceylan Zafer, Haluk Dinçalp
The riboflavin dye 2,3,4,5-tetra-O-acetyl-1-[3-(6-bromohexyl)-7,8-dimethyl-2,4-dioxo-3,4-dihydrobenzo[g]pteridin-10(2H)-yl]-1-deoxypentitol and its pyridinium salt were synthesized, and studied by absorption and fluorescence spectroscopy in solutions and on thin film states. The first absorption band of riboflavin-pyridinium salt derivative is red-shifted by 10 nm compared to neutral one on film. Cationic riboflavin derivative shows significant wavelength changes on its fluorescence emission spectrum in the excited state depending on the solvent polarity and the electronic environment...
July 7, 2017: Journal of Fluorescence
https://www.readbyqxmd.com/read/28686437/mechanisms-underlying-ion-transport-in-polymerized-ionic-liquids
#18
Santosh Mogurampelly, Jordan R Keith, Venkat Ganesan
We report the results of atomistic molecular dynamics simulations informed by quantum-mechanically parametrized force fields, which identify the mechanisms underlying ion motion and diffusivities in poly(1-butyl-3-vinylimidazolium-hexafluorophosphate) polymerized ionic liquid (polyIL) electrolytes. Our results demonstrate that anion transport in polyILs occurs through a mechanism involving intra- and intermolecular ion hopping through formation and breaking of ion-associations involving four polymerized cationic monomers bonded to two different polymer chains...
July 7, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28686016/a-combination-of-guanidyl-and-phenyl-groups-on-a-dendrimer-enables-efficient-sirna-and-dna-delivery
#19
Hong Chang, Jia Zhang, Hui Wang, Jia Lv, Yiyun Cheng
Gene therapy has received considerable attention due to its great potential in the treatment of various diseases; however, the design of efficient and biocompatible carriers for the delivery of siRNA as well as DNA still remains a major challenge. In this study, we developed an efficient carrier for gene delivery by modification of a compound containing both guanidyl and phenyl groups on the surface of a cationic dendrimer. The guanidyl group on the dendrimer facilitates nucleic acid condensation via specific guanidinium-phosphate interactions, whereas the phenyl group on the polymer is critical for efficient endosomal escape...
July 17, 2017: Biomacromolecules
https://www.readbyqxmd.com/read/28685625/preparation-and-characterization-of-self-nano-emulsifying-drug-delivery-system-snedds-for-oral-delivery-of-heparin-using-hydrophobic-complexation-by-cationic-polymer-of-%C3%AE-cyclodextrin
#20
Yasaman Soltani, Navid Goodarzi, Reza Mahjub
OBJECTIVE: The aim of this study was the preparation of a self nano-emulsifying drug delivery system (SNEDDS) for oral delivery of heparin. SIGNIFICANCE: Preparation of hydrophobic complexes between heparin as the hydrophilic macromolecule and cationic polymer of β-cyclodextrin (CPβCD) was considered for preparation of orally administered SNEDDS in which the drug incorporated in internal oil phase of O/W nano-droplets. METHOD: Hydrophobic complexes of heparin-CPβCD were prepared by electrostatic interaction...
July 7, 2017: Drug Development and Industrial Pharmacy
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