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Cationic polymers

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https://www.readbyqxmd.com/read/28636347/the-structure-and-dynamics-of-alginate-gels-crosslinked-by-polyvalent-ions-probed-via-solid-state-nmr-spectroscopy
#1
Jiří Brus, Martina Urbanová, Jiri Czernek, Miroslava Pavelkova, Katerina Kubova, Jakub Vyslouzil, Sabina Abbrent, Rafal Konefal, Jiri Horsky, David Vetchy, Jan Vysloužil, Pavel Kulich
Alginate gels are an outstanding biomaterial widely applicable in tissue engineering, medicine, and pharmacy for cell transplantation, wound healing and efficient bioactive agent delivery, respectively. This contribution provides new and comprehensive insight into the atomic-resolution structure and dynamics of polyvalent ion-crosslinked alginate gels in microbead formulations. By applying various advanced solid-state NMR (ssNMR) spectroscopy techniques, we verified the homogenous distribution of the crosslinking ions in the alginate gels and the high degree of ion exchange...
June 21, 2017: Biomacromolecules
https://www.readbyqxmd.com/read/28636336/a-mg-cp-with-in-situ-encapsulated-photochromic-guest-as-sensitive-fluorescence-sensor-for-fe-3-cr-3-ions-and-nitro-explosives
#2
Zhao-Feng Wu, Liao-Kuo Gong, Xiao-Ying Huang
Here we report a fluorescent magnesium coordination polymer (Mg-CP), namely, [CH3-dpb]2[Mg3(1,4-NDC)4(μ-H2O)2(CH3OH)(H2O)]·1.5H2O (1, 1,4-H2NDC = 1,4-naphthalene dicarboxylic acid, dpb = 1,4-bis(pyrid-4-yl)benzene). Compound 1 possesses a three-dimensional (3D) host-guest structure constructed by the 1,4-NDC linkers bridging the linear trinuclear secondary building units of [Mg3(COO)8(μ-H2O)2]. The dpb molecules were in situ reacted with CH3OH resulting in photochromic cations of [CH3-dpb](+) that acted as guests located in the channels parallel to the b-axis...
June 21, 2017: Inorganic Chemistry
https://www.readbyqxmd.com/read/28633119/polymer-grafted-magnetic-halloysite-nanotube-for-controlled-and-sustained-release-of-cationic-drug
#3
Meriem Fizir, Pierre Dramou, Kai Zhang, Cheng Sun, Chuong Pham-Huy, Hua He
In this research, novel polymer grafted-magnetic halloysite nanotubes with norfloxacin loaded (NOR-MHNTs) and controlled-release, was achieved by surface-initiated precipitation polymerization. The magnetic halloysite nanotubes exhibited better adsorption of NOR (72.10mgg(-1)) compared with the pristine HNTs (30.80mgg(-1)). Various parameters influencing the drug adsorption of the MHNTs for NOR were studied. Polymer grafted NOR-MHNTs has been designed using flexible docking in computer simulation to choose optimal monomers...
April 6, 2017: Journal of Colloid and Interface Science
https://www.readbyqxmd.com/read/28631882/tuning-surface-polarity-of-microporous-organic-polymers-for-co2-capture
#4
Qihua Yang, Jian Chen, He Li, MingMei Zhong
CO2 capture is very important for reducing CO2 concentration in atmosphere. Herein, we report the preparation of microporous polymers with tunable surface polarity for CO2 capture. -NH2, -SO3H and -SO3Li functionalized porous polymers have been successfully prepared by post-synthesis modification of microporous polymers (P-PhPh3 prepared with 1,3,5-triphenylbenzene as monomer and AlCl3 as catalyst) via chemical transformations such as nitration-reduction, sulfonation and cationic exchange. The CO2 adsorption selectivity (CO2/N2 and CO2/H2) and isosteric heats of the microporous polymers increase markedly after modification, P-PhPh3-NH2 and P-PhPh3-SO3Li afford higher CO2 uptake capacity than P-PhPh3 at pressure less than 0...
June 20, 2017: Chemistry, An Asian Journal
https://www.readbyqxmd.com/read/28631252/synthesis-and-characterization-of-novel-carboxymethyl-assam-bora-rice-starch-for-the-controlled-release-of-cationic-anticancer-drug-based-on-electrostatic-interactions
#5
Sharmistha Mohapatra, Anees Ahmad Siddiqui, Mohammed Anwar, Neha Bhardwaj, Sohail Akhter, Farhan Jalees Ahmad
Carboxymethyl Assam Bora rice starch (CM-ABRS) was chemically synthesized in non-aqueous medium with the optimum degree of substitution (DS) of 1.23, and physicochemically characterized by FT-IR, DSC, XRD, and SEM analysis. Comparative evaluation of CM-ABRS with native starch (ABRS) for powder flow characteristics, swelling index, apparent solubility, rheological properties, textural properties, and mucoadhesive studies were carried out. The aim of the current work was to investigate the potential of CM-ABRS as a novel carrier for the water-soluble chemotherapeutic, doxorubicin hydrochloride (DOX)...
June 19, 2017: AAPS PharmSciTech
https://www.readbyqxmd.com/read/28629980/polymer-nanoassemblies-with-hydrophobic-pendant-groups-in-the-core-induce-false-positive-sirna-transfection-in-luciferase-reporter-assays
#6
Steven Rheiner, Derek Reichel, Piotr Rychahou, Tadahide Izumi, Hsin-Sheng Yang, Younsoo Bae
Poly(ethylene glycol)-conjugated polyethylenimine (PEG-PEI) is a widely studied cationic polymer used to develop non-viral vectors for siRNA therapy of genetic disorders including cancer. Cell lines stably expressing luciferase reporter protein typically evaluate the transfection efficacy of siRNA/PEG-PEI complexes, however recent findings revealed that PEG-PEI can reduce luciferase expression independent of siRNA. This study elucidates a cause of the false positive effect in luciferase assays by using polymer nanoassemblies (PNAs) made from PEG, PEI, poly-(L-lysine) (PLL), palmitate (PAL), and deoxycholate (DOC): PEG-PEI (2P), PEG-PEI-PAL (3P), PEG-PLL (2P'), PEG-PLL-PAL (3P'), and PEG-PEI-DOC (2PD)...
June 16, 2017: International Journal of Pharmaceutics
https://www.readbyqxmd.com/read/28629093/novel-pemulen-pullulan-blended-hydrogel-containing-clotrimazole-loaded-cationic-nanocapsules-evaluation-of-mucoadhesion-and-vaginal-permeation
#7
Julia A de Lima, Thamiris C Paines, Mariana H Motta, Watussi B Weber, Sara S Dos Santos, Letícia Cruz, Cristiane de B da Silva
In this work, hydrogels containing clotrimazole-loaded nanocapsules were developed through the innovative association of two mucoadhesive polymers: Pemulen® TR1 and Pullulan. Furthermore, the hydrogels macroscopic characteristics, pH and spreadability were evaluated. The formulations showed homogeneous appearance and pH compatible with vaginal application (around 5.0). Similar spreadability profiles were found in hydrogels containing clotrimazole-loaded nanocapsules and in the free drug as well. Hydrogels were evaluated considering their mucoadhesive potential by the falling liquid film method and the permeation/penetration capacity through cow vaginal mucosa in Franz cell...
October 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
https://www.readbyqxmd.com/read/28629080/efficient-megalin-targeted-delivery-to-renal-proximal-tubular-cells-mediated-by-modified-polymyxin-b-polyethylenimine-based-nano-gene-carriers
#8
Fatemeh Oroojalian, Ali Hossein Rezayan, Faramarz Mehrnejad, Azadeh Hashem Nia, Wayne Thomas Shier, Khalil Abnous, Mohammad Ramezani
Non-viral vectors have attracted great interest, as they are simple to prepare, easy to modify and relatively safe, compared to viral vectors. Kidney-targeted gene delivery systems depict a promising technology to improve drug efficacy in renal diseases treatments. In order to develop a novel kidney-targeted gene delivery system, we synthesized polyamine-PEI conjugates using polymyxin B as ligand and investigated their potential targeting efficiency. After grafting either PEI25 kDa or PEI10 kDa with polymyxin B through amidation reaction, the modified-polymyxin-PEI/DNA-nanoplexes were produced via electrostatic attraction between the cationic polymers and EGFP plasmid...
October 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
https://www.readbyqxmd.com/read/28629045/chitosan-based-in-situ-forming-polyelectrolyte-complexes-a-potential-sustained-drug-delivery-polymeric-carrier-for-high-dose-drugs
#9
Niharika Lal, Juhi Dubey, Praveen Gaur, Navneet Verma, Anurag Verma
The present study investigated the feasibility of using combination of Cationic and anionic polymers as sustained release carrier for the delivery of high dose gastric acid soluble model drug Paracetamol. Various formulations were prepared using wet granulation technique. Briefly a cooled (4°C) neutral solution of chitosan (CH) was combined with cooled aqueous solution (4°C) of anionic polymer such as Gum Ghatti (GG) and Xanthan gum (XG). This polyelectrolyte solution was then used to granulate the model drug Paracetamol...
October 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
https://www.readbyqxmd.com/read/28627875/preparation-of-gemini-surfactant-conjugated-polymer-aggregates-for-enhanced-fluorescence-and-bioimaging-application
#10
Hua Wang, Lingyun Zhou, Chengcheng Zhou, Weiwei Zhao, Jianwu Wang, Libing Liu, Shu Wang, Yilin Wang
Conjugated polymers have great potential applications in bioimaging. However, the aggregation of conjugated polymers driven by electrostatic and hydrophobic interactions in aqueous media results in the reduction of photoluminescence quantum efficiency. In present work we synthesized a carboxylate gemini surfactant (SDHC) to adjust the aggregation behaviors and fluorescence properties of conjugated polymers (anionic MPS-PPV and cationic PMNT). This gemini surfactant shows very low critical micellar concentration (CMC) in aqueous solution and forms vesicles above CMC...
June 19, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28623473/increasing-the-bile-acid-sequestration-performance-of-cationic-hydrogels-by-using-an-advanced-controlled-polymerization-technique
#11
Patrícia V Mendonça, André Matos, Andreia F Sousa, Arménio C Serra, Sérgio Simões, Jorge F J Coelho
PURPOSE: To investigate the influence of the polymerization technique and the content of hydroxyl groups on the performance of new bile acid sequestrants based on PAMPMTA-co-PHEA (PAMPTMA: poly((3-acrylamidopropyl)trimethylammonium chloride); PHEA: poly(2-hydroxyethyl acrylate)) hydrogels. METHODS: PAMPMTA-co-PHEA hydrogels were prepared using either free radical polymerization or supplemental activator and reducing agent atom transfer radical polymerization. The chemical structure and composition of the hydrogels was confirmed by both FTIR and ssNMR...
June 16, 2017: Pharmaceutical Research
https://www.readbyqxmd.com/read/28619643/superior-transfection-efficiency-of-phagocytic-astrocytes-by-large-chitosan-dna-nanoparticles
#12
Fanqiang Kong, Guoping Liu, Shumin Zhou, Jie Guo, Song Chen, Zhiyun Wang
PURPOSE: Mechanism study of why astrocytes isolated from experimental autoimmune encephalomyelitis (EAE)-induced B6 mice or after being exposed to inflammatory factors had the highest transfection efficiency to larger-sized, but not compacted, pspCS/pDNA particles. METHODS: Phosphorylatable short peptide conjugated chitosan (pspCS) was compounded with plasmid DNA (pDNA) at different N:P ratios to form pspCS/pDNA particles of different size and zeta potentials. These pspCS/pDNA particles were used for the transfection of astrocytes isolated from either EAE induced or healthy B6 mice...
June 12, 2017: International Journal of Biological Macromolecules
https://www.readbyqxmd.com/read/28617608/anti-ice-nucleating-activity-of-surfactants-against-silver-iodide-in-water-in-oil-emulsions
#13
Takaaki Inada, Toshie Koyama, Hiroyuki Tomita, Takuya Fuse, Chikako Kuwabara, Keita Arakawa, Seizo Fujikawa
Various water-soluble substances are known as anti-ice nucleating agents (anti-INAs), which inhibit heterogeneous ice nucleation initiated by ice nucleating agents (INAs). Among them, several surfactants are reportedly effective as anti-INAs especially against silver iodide (AgI), which is a typical inorganic INA that induces heterogeneous ice nucleation at relatively high temperatures. In this study, the anti-ice nucleating activities of seven surfactants were examined in emulsified surfactant solutions containing AgI particles...
June 15, 2017: Journal of Physical Chemistry. B
https://www.readbyqxmd.com/read/28617605/arginine-based-polymer-brush-coatings-with-hydrolysis-triggered-switchable-functionalities-from-antimicrobial-cationic-to-antifouling-zwitterionic
#14
Gang Xu, Xianneng Liu, Peng Liu, Dicky Pranantyo, Koon Gee Neoh, En-Tang Kang
Arginine polymer-based coatings with switchable properties were developed on the glass slides (GS) to demonstrate the smart transition from antimicrobial (cationic) to fouling-resistant (zwitterionic) surfaces. L-arginine methyl ester-methacryloylamide (Arg-Est) and L-arginine-methacryloylamide (Arg-Me) polymer brushes were grafted from the GS surface via surface-initiated reversible addition-fragmentation chain-transfer (SI-RAFT) polymerization. In comparison to the pristine GS and Arg-Me graft polymerized GS (GS-Arg-Me) surfaces, the Arg-Est polymer brushes-functionalized GS surfaces exhibit a superior antimicrobial activity...
June 15, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
https://www.readbyqxmd.com/read/28617279/rotating-belt-sieves-for-primary-treatment-chemically-enhanced-primary-treatment-and-secondary-solids-separation
#15
B Rusten, S S Rathnaweera, E Rismyhr, A K Sahu, J Ntiako
Fine mesh rotating belt sieves (RBS) offer a very compact solution for removal of particles from wastewater. This paper shows examples from pilot-scale testing of primary treatment, chemically enhanced primary treatment (CEPT) and secondary solids separation of biofilm solids from moving bed biofilm reactors (MBBRs). Primary treatment using a 350 microns belt showed more than 40% removal of total suspended solids (TSS) and 30% removal of chemical oxygen demand (COD) at sieve rates as high as 160 m³/m²-h. Maximum sieve rate tested was 288 m³/m²-h and maximum particle load was 80 kg TSS/m²-h...
June 2017: Water Science and Technology: a Journal of the International Association on Water Pollution Research
https://www.readbyqxmd.com/read/28607014/np108-an-antimicrobial-polymer-with-activity-against-methicillin-and-mupirocin-resistant-staphylococcus-aureus
#16
Derry K Mercer, Laura K Katvars, Fiona Hewitt, Daniel W Smith, Jennifer Robertson, Deborah A O'Neil
Staphylococcus aureus is a clinically significant human pathogen that causes infectious diseases ranging from skin and soft tissue infections (SSTI), healthcare associated infections (HAI) to potentially fatal bacteraemia and endocarditis. Nasal carriage of S. aureus, especially persistent carriage, is associated with an increased risk of subsequent infection, particularly nosocomial and surgical site infections (SSI), usually via autoinfection. NP108 is a cationic antimicrobial polymer composed of Generally Recognized as Safe (GRAS) amino acid building blocks...
June 12, 2017: Antimicrobial Agents and Chemotherapy
https://www.readbyqxmd.com/read/28604907/solvent-dependent-selective-cation-exchange-in-anionic-frameworks-based-on-cobalt-ii-and-triphenylamine-linkers-reactor-dependent-synthesis-and-sorption-properties
#17
Oluseun Akintola, David Hornig, Axel Buchholz, Helmar Görls, Winfried Plass
Two cobalt(ii) coordination polymers with anionic networks of formulae {(Me2NH2)2[CoCl(ntb)]}n (JUMP-2) and {(Me2NH2)2[Co5(ntb)4(H2O)3(Me2NH)]}n (previously reported as MIL-144 by Livage et al., Microporous Mesoporous Mater., 2012, 157, 37) have been obtained via a solvothermal reaction of cobalt chloride and 4,4',4''-nitrilotribenzoic acid (H3ntb) in DMF employing two differently-sized reactors, while using the same absolute amount of reactants. Structure analysis revealed that JUMP-2 crystallized in the monoclinic space group P21/n and displays a two-dimensional (2D) network, which by topological analysis was characterized as a layered 3-connected hcb net...
June 12, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
https://www.readbyqxmd.com/read/28602136/in-situ-forming-hydrogels-with-long-lasting-mir-21-enhances-the-therapeutic-potential-of-msc-by-sustaining-stimulation-of-target-gene
#18
Xianwei Zhang, Yufa Sun, Jianfeng Liu, Zhiyong Yi, Feng Gao, Qiaowei Liu, Yundai Chen
Regulating stem cells by microRNA (miRNA) is promising in regenerative medicine. However, non-viral transfection is usually transient while stably lentiviral transfection is accompanied with oncogenic risk. In the study, we explored the feasibility to retain the microRNAs within biopolymer hydrogels for their long-lasting working and sustaining stimulation of target gene. miRNA-21 (MiR-21), a reported microRNA enhancing the therapeutic potential of mesenchymal stem cells (MSCs) was used. We demonstrated that miR-21 could be efficiently retained within collagen hydrogel after forming complex with cationic polymer polyethylenimine (PEI)...
June 10, 2017: Journal of Biomaterials Science. Polymer Edition
https://www.readbyqxmd.com/read/28602081/spectroscopic-studies-of-the-interactions-between-a-cationic-cyanine-dye-and-synthetic-phyllosilicate-from-photophysics-to-hybrid-materials
#19
Christian Ley, Jocelyne Brendlé, Moise Miranda, Xavier Allonas
The interaction of cationic organic dye Astrazon Orange with the synthetic phyllosilicate Laponite® leads to very interesting hybrid materials. Indeed, the Laponite® nanoparticles modify the photophysical properties of Astrazon Orange inducing a stabilization of its excited emissive state by preventing ultrafast isomerisation. The long lived emissive Clay-dye hybrid complex can be used to develop efficient photoinitiating systems leading to organic-inorganic hybrid crosslinked polymer materials.
June 12, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
https://www.readbyqxmd.com/read/28600130/highly-antibacterial-polypeptide-based-amphiphilic-copolymers-as-multifunctional-non-viral-vectors-for-enhanced-intracellular-sirna-delivery-and-anti-infection
#20
Li Zhou, Yuewei Xi, Meng Yu, Min Wang, Yi Guo, Peng Li, Peter X Ma, Bo Lei
For next-generation regenerative medicine and cancer therapy applications, the development of multifunctional biodegradable biomaterials with good antibacterial activity, biocompatibility and gene delivery capability is showing increased interests. As a natural cationic polypeptide, poly(ε-L-lysine) (EPL) has been as attractive antibacterial agent and non-viral gene vectors, however, its gene therapy is still limited probably due to the cytotoxicity, low stability in physiological environment and poor transfection efficiency...
June 6, 2017: Acta Biomaterialia
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