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https://www.readbyqxmd.com/read/27910990/a-ph-responsive-sequential-disassembly-nanohybrid-for-mitochondrial-targeting
#1
Lijia Li, Wei Sun, Lian Li, Yuanyuan Liu, Lei Wu, Fengling Wang, Zhou Zhou, Zhirong Zhang, Yuan Huang
Cationic materials have been reported as promising tools for targeting to mitochondria which are the "power houses" and "metabolic garbage keepers" of cells. However, their positive nature also restricts their in vivo application due to the quick clearance. Herein, we fabricated a nanohybrid consisting of the pH-responsive N-(2-hydroxypropyl)methacrylamide (HPMA) co-polymer (R-P) shells and positive mesoporous silica nanoparticle cores via electrostatic interaction. The anticancer drug, docetaxel (DTX), was encapsulated in the positive MSN cores (MSN-DTX)...
December 2, 2016: Nanoscale
https://www.readbyqxmd.com/read/27908097/molecular-dynamics-analysis-of-the-effect-of-electronic-polarization-on-the-structure-and-single-particle-dynamics-of-mixtures-of-ionic-liquids-and-lithium-salts
#2
Volker Lesch, Hadrián Montes-Campos, Trinidad Méndez-Morales, Luis Javier Gallego, Andreas Heuer, Christian Schröder, Luis M Varela
We report a molecular dynamics study on the effect of electronic polarization on the structure and single-particle dynamics of mixtures of the aprotic ionic liquid 1-ethyl-3-methylimidazolium bis-(trifluoromethylsulfonyl)-imide ([EMIM][TFSI]) doped with a lithium salt with the same anion at 298 K and 1 bar. In particular, we analyze the effect of electron density fluctuations on radial distribution functions, velocity autocorrelation functions, cage correlation functions, mean-squared displacements, and vibrational densities of states, comparing the predictions of the quantum-chemistry-based Atomistic Polarizable Potential for Liquids, Electrolytes, & Polymers (APPLE&P) with those of its nonpolarizable version and those of the standard non-polarizable Optimized Potentials for Liquid Simulations-All Atom (OPLS-AA)...
November 28, 2016: Journal of Chemical Physics
https://www.readbyqxmd.com/read/27902930/modulating-micrornas-in-cardiac-surgery-patients-novel-therapeutic-opportunities
#3
REVIEW
Giovanni Biglino, Massimo Caputo, Cha Rajakaruna, Gianni Angelini, Eva van Rooij, Costanza Emanueli
This review focuses on microRNAs (miRs) in cardiac surgery, where they are emerging as potential targets for therapeutic intervention as well as novel clinical biomarkers. Identification of the up/down-regulation of specific miRs in defined groups of cardiac surgery patients can lead to the development of novel strategies for targeted treatment in order to maximise therapeutic results and minimise acute, delayed or chronic complications. MiRs could also be involved in determining the outcome independently of complications, for example in relation to myocardial perfusion and fibrosis...
November 27, 2016: Pharmacology & Therapeutics
https://www.readbyqxmd.com/read/27899629/enhanced-non-viral-gene-delivery-by-coordinated-endosomal-release-and-inhibition-of-%C3%AE-tubulin-deactylase
#4
Yoon Khei Ho, Li Han Zhou, Kam C Tam, Heng Phon Too
Efficient non-viral gene delivery is highly desirable but often unattainable with some cell-types. We report here that non-viral DNA polyplexes can efficiently transfect differentiated neuronal and stem cells. Polyplex transfection centrifugation protocols was enhanced by including a simultaneous treatment with a DOPE/CHEMS lipid suspension and a microtubule inhibitor, Tubastatin A. Lipoplex transfection protocols were not improved by this treatment. This mechanism of action was unravelled by systematically identifying and rationally mitigating barriers limiting high transfection efficiency, allowing unexpected improvements in the transfection of mesenchymal stem cells (MSC), primary neuron and several hard-to-transfect cell types beyond what are currently achievable using cationic polymers...
November 29, 2016: Nucleic Acids Research
https://www.readbyqxmd.com/read/27899572/c3-symmetric-opioid-scaffolds-are-ph-responsive-dna-condensation-agents
#5
Natasha McStay, Zara Molphy, Alan Coughlan, Attilio Cafolla, Vickie McKee, Nicholas Gathergood, Andrew Kellett
Herein we report the synthesis of tripodal C3-symmetric opioid scaffolds as high-affinity condensation agents of duplex DNA. Condensation was achieved on both supercoiled and canonical B-DNA structures and identified by agarose electrophoresis, viscosity, turbidity and atomic force microscopy (AFM) measurements. Structurally, the requirement of a tris-opioid scaffold for condensation is demonstrated as both di- (C2-symmetric) and mono-substituted (C1-symmetric) mesitylene-linked opioid derivatives poorly coordinate dsDNA...
November 28, 2016: Nucleic Acids Research
https://www.readbyqxmd.com/read/27895261/photochemistry-of-framework-supported-m-diimine-co-3x-complexes-in-three-dimensional-lithium-carboxylate-metal-organic-frameworks-monitoring-the-effect-of-framework-cations
#6
Thomas J Reade, Thomas S Murphy, James A Calladine, Raphael Horvath, Ian P Clark, Gregory M Greetham, Michael Towrie, William Lewis, Michael W George, Neil R Champness
The structures and photochemical behaviour of two new metal-organic frameworks (MOFs) are reported. Reaction of Re(2,2'-bipy-5,5'-dicarboxylic acid)(CO)3Cl or Mn(2,2'-bipy-5,5'-dicarboxylic acid)(CO)3Br with LiCl or LiBr, respectively, produces single crystals of {Li2(DMF)2 [(2,2'-bipy-5,5'-dicarboxylate)Re(CO)3Cl]}n ( RELI: ) or {Li2(DMF)2[(2,2'-bipy-5,5'-dicarboxylate)Mn(CO)3Br]}n ( MNLI: ). The structures formed by the two MOFs comprise one-dimensional chains of carboxylate-bridged Li(I) cations that are cross-linked by units of Re(2,2'-bipy-5,5'-dicarboxylate)(CO)3Cl ( RELI: ) or Mn(2,2'-bipy-5,5'- dicarboxylate)(CO)3Br ( MNLI: )...
January 13, 2017: Philosophical Transactions. Series A, Mathematical, Physical, and Engineering Sciences
https://www.readbyqxmd.com/read/27894825/designing-chitosan-tripolyphosphate-microparticles-with-desired-size-for-specific-pharmaceutical-or-forensic-applications
#7
Ezzeddin M A Hejjaji, Alan M Smith, Gordon A Morris
Chitosan (CS) is a natural cationic polymer obtained by the partial N-deacetylation of chitin. Chitosan microparticles can be prepared by cross-linking with tripolyphosphate (TPP) via the ionic interaction between positively charged amino groups (CS) and negatively charged counter ions (TPP). This can be controlled by the charge density of CS and TPP, which depend on the pH and ionic strength of the solution. The purpose of this study is to investigate the combined effects of three independent variables (pH, ionic strength and CS: TPP ratio) on three important physico-chemical properties (viscosity, zeta potential and particle size) during the preparation of microparticles...
November 25, 2016: International Journal of Biological Macromolecules
https://www.readbyqxmd.com/read/27892545/erythrocyte-membrane-based-cationic-polymer-mcdna-complexes-as-an-efficient-gene-delivery-system
#8
Ping Huang, Jing Zhao, Chiju Wei, Xiaohu Hou, Pingzhang Chen, Yan Tan, Cheng-Yi He, Zhiyong Wang, Zhi-Ying Chen
Gene therapy has great promise for the treatment of obtained and inherited serious diseases. However, the lack of safe and efficient gene delivery systems remains a barrier for their clinical application. Here, we reported a potential gene delivery vehicle composed of the erythrocyte membrane and cationic polymers, for example the XtremeGENE from Roche and the ε-caprolactone modified polyethylenimine. In addition to high efficiency, this system showed negligible cytotoxicity compared to the two cationic polymers alone in various cell lines, including human embryonic kidney cells (293T), human liver cancer cells (Huh7 and HepG2), murine dendritic cells (DC2...
November 28, 2016: Biomaterials Science
https://www.readbyqxmd.com/read/27884774/esponsive-multifunctional-drug-delivery-nanoparticles-for-elastic-matrix-regenerative-repair
#9
Balakrishnan Sivaraman, Ganesh Swaminathan, Lee Moore, Jonathan Fox, Dhruv Seshadri, Shataakshi Dahal, Ivan Stoilov, Maciej Zborowski, Robert Mecham, Anand Ramamurthi
: Arresting or regressing growth of abdominal aortic aneurysms (AAAs), localized expansions of the abdominal aorta are contingent on inhibiting chronically overexpressed matrix metalloproteases (MMPs)-2 and -9 that disrupt elastic matrix within the aortic wall, concurrent with providing a stimulus to augmenting inherently poor auto-regeneration of these matrix structures. In a recent study we demonstrated that localized, controlled and sustained delivery of doxycycline (DOX; a tetracycline-based antibiotic) from poly(lactic-co-glycolic acid) nanoparticles (PLGA NPs), enhances elastic matrix deposition and MMP-inhibition at a fraction of the therapeutically effective oral dose...
November 21, 2016: Acta Biomaterialia
https://www.readbyqxmd.com/read/27884715/improved-sustained-release-of-antigen-from-immunostimulatory-dna-hydrogel-by-electrostatic-interaction-with-chitosan
#10
Yumiko Ishii-Mizuno, Yuka Umeki, Yoshinori Onuki, Hiroshi Watanabe, Yuki Takahashi, Yoshinobu Takakura, Makiya Nishikawa
Immunostimulatory DNA hydrogel (sDNA hydrogel) containing unmethylated cytosine-phosphate-guanine (CpG) sequences has been demonstrated to be a useful antigen delivery system, which can effectively induce an antigen-specific immune response through stimulation of the innate immune system. However, relatively rapid release of antigens from the sDNA hydrogel limits its potential. To enhance the potency of the sDNA hydrogel via improvement of its sustained release property, we selected chitosan, a biocompatible cationic polymer which electrostatically interacts with DNA, and mixed it with the sDNA hydrogel...
November 21, 2016: International Journal of Pharmaceutics
https://www.readbyqxmd.com/read/27884714/carrier-particle-design-for-stabilization-and-isolation-of-drug-nanoparticles
#11
Teresa Tierney, Katalin Bodnár, Åke Rasmuson, Sarah Hudson
Nanoparticles of poorly water-soluble drugs were prepared in suspension via antisolvent precipitation in order to improve their dissolution behaviour. Insoluble, surface-functionalized, micron-range, clay carrier particles were employed for the dual purpose of stabilizing the nanoparticles in suspended state, and facilitating their unhindered isolation to solid state; often a challenging step in nanoparticle production. The carrier particles, which were functionalized with an optimal level of cationic polymer (protamine), attracted negatively-charged nanoparticles to their surface as a uniform and segregated nanoparticle layer, at drug loadings up to 9% w/w...
November 21, 2016: International Journal of Pharmaceutics
https://www.readbyqxmd.com/read/27879056/in-vitro-drug-and-gene-delivery-using-random-cationic-copolymers-forming-stable-and-ph-sensitive-polymersomes
#12
Partha Laskar, Joykrishna Dey, Payel Banik, Mahitosh Mandal, Sudip Kumar Ghosh
Stimuli-sensitive polymeric vesicles or polymersomes as self-assembled colloidal nanocarriers have received paramount importance for their integral role as delivery system for therapeutics and biotherapeutics. This work describes spontaneous polymersome formation at pH 7, as evidenced by surface tension, steady state fluorescence, dynamic light scattering, and microscopic studies, by three hydrophilic random cationic copolymers synthesized using N,N-(dimethylamino)ethyl methacrylate (DMAEM) and methoxy poly(ethylene glycol) monomethacrylate in different mole ratios...
November 23, 2016: Macromolecular Bioscience
https://www.readbyqxmd.com/read/27877903/the-novel-functional-nucleic-acid-ired-effectively-regulates-target-genes-following-cytoplasmic-delivery-by-faint-electric-treatment
#13
Mahadi Hasan, Noriko Tarashima, Koki Fujikawa, Takashi Ohgita, Susumu Hama, Tamotsu Tanaka, Hiroyuki Saito, Noriaki Minakawa, Kentaro Kogure
An intelligent shRNA expression device (iRed) contains the minimum essential components needed for shRNA production in cells, and could be a novel tool to regulate target genes. However, general delivery carriers consisting of cationic polymers/lipids could impede function of a newly generated shRNA via electrostatic interaction in the cytoplasm. Recently, we found that faint electric treatment (fET) of cells enhanced delivery of siRNA and functional nucleic acids into the cytoplasm in the absence of delivery carriers...
2016: Science and Technology of Advanced Materials
https://www.readbyqxmd.com/read/27875623/biophysical-characterization-of-quaternary-pyridinium-functionalized-polynorbornenes-for-dna-complexation-and-their-cellular-interactions
#14
Zeliha Guler, Semra Zuhal Birol, Tarık Eren, Sebnem Ercelen Ceylan
Cationic polymers with hydrophobic side chains have gained great interest as DNA carriers since they form a compact complex with negatively charged DNA phosphate groups and interact with the cell membrane. Amphiphilic polyoxanorbornenes with different quaternary alkyl pyridinium side chains with ethyl-p(OPy2) and hexyl units-p(OPy6) bearing 10 kDa MWT were synthesized by living Ring-Opening Metathesis Polymerization method. The physicochemical characteristics: critical micellar concentration, size distribution, surface charge and condensation of polymer/DNA complex were investigated...
November 22, 2016: Biopolymers
https://www.readbyqxmd.com/read/27872011/aminoclay-as-a-highly-effective-cationic-vehicle-for-enhancing-adenovirus-mediated-gene-transfer-through-nanobiohybrid-complex-formation
#15
Soo-Yeon Kim, Sang-Jin Lee, Hyo-Kyung Han, Soo-Jeong Lim
: Electrostatic complexation of adenovirus (Ad) with cationic lipids or polymers has been shown to be an effective means for overcoming the limitations of adenoviral vectors and enhancing gene-transfer efficacy. However, such complexation causes cytotoxicity, limiting the use of this strategy. The present study explored the potential of 3-aminopropyl functionalized magnesium phyllosilicate (aminoclay) as a cationic vehicle for improving Ad-mediated gene transfer without inducing cytotoxicity...
November 18, 2016: Acta Biomaterialia
https://www.readbyqxmd.com/read/27870135/independent-assessment-of-matrix-assisted-laser-desorption-ionization-mass-spectrometry-maldi-ms-sample-preparation-quality-effect-of-sample-preparation-on-maldi-ms-of-synthetic-polymers
#16
Pieter C Kooijman, Sander Kok, Maarten Honing
RATIONALE: Matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) provides detailed and in-depth information about the molecular characteristics of synthetic polymers. To obtain the most accurate results the sample preparation parameters should be chosen to suit the sample and the aim of the experiment. Because the underlying principles of MALDI are still not fully known, a priori determination of optimal sample preparation protocols is often not possible. METHODS: Employing an automated sample preparation quality assessment method recently presented by us we quantified the sample preparation quality obtained using various sample preparation protocols...
November 21, 2016: Rapid Communications in Mass Spectrometry: RCM
https://www.readbyqxmd.com/read/27865931/multifunctional-adhesive-polymers-preactivated-thiolated-chitosan-edta-conjugates
#17
Kesinee Netsomboon, Wongsakorn Suchaoin, Flavia Laffleur, Felix Prüfert, Andreas Bernkop-Schnürch
AIM: The aim of this study was to synthesis preactivated thiolated chitosan-EDTA (Ch-EDTA-cys-2MNA) conjugates exhibiting in particular high mucoadhesive, cohesive and chelating properties. METHODS: Thiol groups were coupled with chitosan by carbodiimide reaction and further preactivated by attachment with 2-mercaptonicotinic acid (2MNA) via disulfide bond formation. Determinations of primary amino and sulfhydryl groups were performed by TNBS and Ellman's tests, respectively...
November 16, 2016: European Journal of Pharmaceutics and Biopharmaceutics
https://www.readbyqxmd.com/read/27865455/analysis-of-ustiloxins-in-rice-using-polymer-cation-exchange-cleanup-followed-by-liquid-chromatography-tandem-mass-spectrometry
#18
Zhao-Yun Cao, Li-Hua Sun, Ren-Xiang Mou, Xiao-Yan Lin, Rong Zhou, You-Ning Ma, Ming-Xue Chen
Ustiloxins are cyclopeptide mycotoxins produced by the pathogenic fungus Ustilaginoidea virens of rice false smut. Quantification of ustiloxins is essential to assess the food safety of rice infected by rice false smut disease. This paper describes a sensitive method for the simultaneous quantification of ustiloxins A, B, C, D and F in rice grains using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Since notable matrix enhancement effects (21%-78%) occurred for all of the target analytes (except for ustiloxin A), several solid phase extraction materials were tested for their ability to retain ustiloxins from aqueous solutions prior to the LC-MS/MS analysis, including C18 sorbents, polymer anion exchange sorbents resin (PAX), and polymer cation exchange resin (PCX)...
December 9, 2016: Journal of Chromatography. A
https://www.readbyqxmd.com/read/27862821/growth-kinetics-in-layer-by-layer-assemblies-of-organic-nanoparticles-and-polyelectrolytes
#19
Maziar Mohammadi, Ali Salehi, Ryan J Branch, Lucas J Cygan, Cagri G Besirli, Ronald G Larson
We systematically measure the growth rate of layer-by-layer (LbL) assemblies of polyelectrolytes (PEs) with oppositely charged polystyrene (PS) nanoparticles (NPs) as a function of molecular weight (MW) of PEs, ionic strength of the media, and NP size and charge. To optimize the LbL growth, we assess the effects of suspension concentration, pH of the media, and deposition time on the growth rate of multilayers. Both linear and exponential growth behaviors are observed, and under optimal conditions films of up to around 1 μm thickness can readily be assembled after 10 or so bilayers have been deposited...
November 10, 2016: Chemphyschem: a European Journal of Chemical Physics and Physical Chemistry
https://www.readbyqxmd.com/read/27851933/sizes-of-long-rna-molecules-are-determined-by-the-branching-patterns-of-their-secondary-structures
#20
Alexander Borodavka, Surendra W Singaram, Peter G Stockley, William M Gelbart, Avinoam Ben-Shaul, Roman Tuma
Long RNA molecules are at the core of gene regulation across all kingdoms of life, while also serving as genomes in RNA viruses. Few studies have addressed the basic physical properties of long single-stranded RNAs. Long RNAs with nonrepeating sequences usually adopt highly ramified secondary structures and are better described as branched polymers. To test whether a branched polymer model can estimate the overall sizes of large RNAs, we employed fluorescence correlation spectroscopy to examine the hydrodynamic radii of a broad spectrum of biologically important RNAs, ranging from viral genomes to long noncoding regulatory RNAs...
November 15, 2016: Biophysical Journal
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