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Blanka Bucsella, Antoine Fornage, Catherine Le Denmat, Franka Kálmán
In biotechnological processes the intracellular level of nucleotides and nucleotide sugars have a direct impact on the post-translational modification (glycosylation) of the therapeutic protein products and on the exopolysaccharide pattern of the cells. Thus, they are precursors and also key components in the production of glycoproteins and glycolipids. All four nucleotides (at different phosphorylation stages) and their natural sugar derivatives coexist in biological samples. Their relative ratios depend on the actual conditions under which the cells are grown...
October 2016: Chimia
Eun Ji Park, Dong Hee Na
The separation mechanism of PEGylated peptides in reversed-phase high-performance liquid chromatography (RP-HPLC) is complex, because the PEGylated molecules exhibit physicochemical properties that are different from those of the parent molecules and have heterogeneous structure. Since most separation studies have focused on the hydrophobicity of the peptide relative to poly(ethylene glycol) (PEG), the role of PEG in the separation of PEGylated peptides on RP-HPLC is not clear. To elucidate the effect of the attached PEG on the retention of PEGylated peptides on RP-HPLC, the mono-PEGylated forms of collagen pentapeptide and octreotide were fractionated drop-by-drop from the outlet of the HPLC system and each drop was subjected to matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS)...
October 25, 2016: Analytical Chemistry
Maria Giovanna Sabbieti, Alessandra Dubbini, Fulvio Laus, Emanuele Paggi, Andrea Marchegiani, Melania Capitani, Luigi Marchetti, Fabrizio Dini, Tina Vermonden, Piera Di Martino, Dimitrios Agas, Roberta Censi
The present study reports on the biocompatibility in vivo after intramuscular and subcutaneous administration in Balb/c mice of vinyl sulphone bearing p(HPMAm-lac1-2)-PEG-p(HPMAm-lac1-2)/thiolated hyaluronic acid hydrogels, designed as novel injectable biomaterials for potential application in the fields of tissue engineering and regenerative medicine. Ultrasonography, used as a method to study hydrogel gelation and residence time in vivo, showed that, upon injection, the biomaterial efficiently formed a hydrogel by simultaneous thermal gelation and Michael Addition cross-linking forming a viscoelastic spherical depot at the injection site...
October 24, 2016: Journal of Tissue Engineering and Regenerative Medicine
John D Fisher
In the words of the legendary late John Messenger, pacemakers have evolved from the equivalent of a pirate's peg leg that simply prevents you from falling down, to a fully articulated prosthesis. Each "ultimate" step has been succeeded by ever more sophisticated devices. Very early attempts at providing atrioventricular synchrony included metal wire connections between atrium and ventricle, and His bundle pacing with large screw-in electrodes. These efforts failed, largely because of poor conductivity, excessive fibrosis and loss of capture...
October 24, 2016: Pacing and Clinical Electrophysiology: PACE
Erick Yu, Allison Lo, Linda Jiang, Bradley Petkus, Nazar Ileri Ercan, Pieter Stroeve
Novel pore-expanded mesoporous silica nanoparticles (MSNs) with pore sizes of approximately 11nm were synthesized and modified with thermoresponsive, poly(n-isopropylacrylamide) (PNIPAM) gating groups on the nanoparticle exterior surface and in addition with poly(ethylene-glycol) (PEG) within the porous interior to minimize protein adsorption. PEG traditionally has been grafted to the nanoparticle exterior to minimize non-specific binding and interactions with the biological environment, but due to the templating mechanism of MSN synthesis, both the pore interior and nanoparticle surface can be separately modified...
October 17, 2016: Colloids and Surfaces. B, Biointerfaces
Damián Rodríguez Sartori, Cristian R Lillo, Juan J Romero, María Laura Dell Arciprete, Alejandro Miñán, Mónica Fernández Lorenzo de Mele, Mónica C Gonzalez
Grafting of polyethylene glycol (PEG) to ultrasmall photoluminescent silicon dots (SiDs) is expected to improve and expand the applications of these particles to aqueous environments and biological systems. Herein we report a novel one-pot synthesis of robust, highly water compatible PEG-coated SiDs (denoted as PEG-SiDs) of (3.3 ± 0.5) nm size. The nanoparticles' synthesis is based on the liquid phase oxidation of magnesium silicide using PEG as reaction media and leading to high PEG density grafting. PEG-SiDs enhanced photophysical, photosensitising, and solution properties in aqueous environments are described and compared to those of 2 nm size PEG-coated SiDs with low PEG density grafting (denoted as PEG-NHSiDs) obtained from a multistep synthesis strategy...
October 24, 2016: Nanotechnology
Etienne Borré, Stéphane Bellemin-Laponnaz, Matteo Mauro
A series of amphiphilic metallopolymers is described that features zinc(II) bis-terpyridine coordination nodes and a backbone with hydrophobic azoaryl moieties and hydrophilic phenylene-ethynylene units decorated with PEG brushes. Using such metallopolymers at very low concentration, stable, photo-responsive and self-healable hydrogels are obtained. UV irradiation of the gel allows modulation of the degree of hydrophobic π-π interactions between photo-isomerizable azoaryl units and polarity switch that overall induces a fast gel-to-sol transition...
October 24, 2016: Chemistry: a European Journal
Hongbo Chen, Yinan Yao, Yifan Wang, Hua Zhou, Tianxiang Xu, Jing Liu, Guocheng Wang, Yongfeng Zhang, Xiang Chen, Qingwei Liu, Peng Huang, Rongbin Yu
BACKGROUND: HLA-DM gene, which is related to antigen processing and presentation and located in the non-classical class-II region of human leukocyte antigen (HLA) region, may play a crucial role in chronic hepatitis C virus (HCV) infection treatment outcomes. The study was conducted to evaluate the role of the variant of several single nucleotide polymorphisms (SNPs) in HLA-DM gene in HCV treatment outcomes. METHODS: We genotyped four SNPs from the candidate genes (HLA-DMA and DMB) in 336 patients who were treated with pegylated interferon-alpha and ribavirin (PEG IFN-α/RBV)...
October 20, 2016: International Journal of Environmental Research and Public Health
Qinglei Zhang, Xiaolong Lu, Qingzhao Zhang, Lei Zhang, Suoding Li, Shaobin Liu
In this study, Polyvinylidene fluoride (PVDF) hollow fiber hemodialysis membranes were prepared by non-solvent induced phase separation (NIPS) with compound addtive. The compound additive was made with polyvinyl pyrrolidone (PVP) and Poly ethylene glycol (PEG). The results showed that the modified PVDF membrane had better separation performance than virgin PVDF membrane. The UF flux of modified PVDF membrane can reach 684 L·h(-1)·m(-2) and lysozyme (LZM) passage is 72.6% while virgin PVDF membrane is 313 L·h(-1)·m(-2) and 53...
October 19, 2016: Membranes
Søren B van Witteloostuijn, Søren L Pedersen, Knud J Jensen
Peptides and proteins constitute a vast pool of excellent drug candidates. Evolution has equipped these molecules with superior drug-like properties such as high specificity and potency. However, native peptides and proteins suffer from an inadequate pharmacokinetic profile, and their outstanding pharmacological potential can only be realized if this issue is addressed during drug development. To overcome this challenge, a variety of half-life extension techniques relying on covalent chemical modification have been developed...
October 24, 2016: ChemMedChem
Byung-Chul Kim, Sung-Min Jun, So Yeon Kim, Yong-Dae Kwon, Sung Chul Choe, Eun-Chul Kim, Jae-Hyung Lee, Jinseok Kim, Jun-Kyo Farancis Suh, Yu-Shik Hwang
The in vitro generation of cell-based three dimensional (3D) nerve tissue is an attractive subject to improve graft survival and integration into host tissue for neural tissue regeneration or to model biological events in stem cell differentiation. Although 3D organotypic culture strategies are well established for 3D nerve tissue formation of pluripotent stem cells to study underlying biology in nerve development, cell-based nerve tissues have not been developed using human postnatal stem cells with therapeutic potential...
October 24, 2016: Biotechnology and Bioengineering
Subhash Chandra Bose Penjuri, Saritha Damineni, Nagaraju Ravouru, Srikanth Reddy Poreddy Reddy Poreddy
BACKGROUND: The objective of this investigation was to develop a self emulsifying drug delivery system (SEDDS) of naproxen, a poorly water soluble drug, which could improve its solubility and oral bioavailability. Methoda: The recent patents on SEDDS of abiraterone acetate (WO2014/009434 A1) and tamoxifen (WO2013/0080083) helped in selecting the naproxen and excipients. Phase diagrams were constructed and the formulations were taken from the micro emulsion region. Formulations were subjected to thermodynamic stability, dispersibility and precipitation tests for optimization...
October 19, 2016: Recent Patents on Drug Delivery & Formulation
Shengnan Yin, Yiran Xia, Qi Jia, Zhao-Sheng Hou, Na Zhang
This study describes the preparation and properties of a novel aliphatic cost-effective segmented polyurethanes (SPUs) based on poly(ether ester) (poly-(ε-caprolactone-co-L-lactide)-poly(ethylene glycol)-poly-(ε-caprolactone-co-L- lactide), PECLA) and uniform-size diurethane diisocyanates (HDI-BDO-HDI). PECLA was synthesized via bulk ring-opening polymerization with poly(ethylene glycol) (PEG) as an initiator and ε-caprolactone, L-lactide as monomers. By chain extension of PECLA diol with HDI-BDO-HDI, three SPUs with different hydrophilic segments content and hard segments content were obtained...
October 23, 2016: Journal of Biomaterials Science. Polymer Edition
Hariane Côco, Larissa Pernomian, Priscila C Pereira, Mayara S Gomes, Katia C Marchi, Alexandre H Lopes, Thiago M Cunha, Carlos R Tirapelli, Ana M de Oliveira
OBJECTIVES: To investigate the mechanisms underlying the effects of chronic restraint stress on the vascular contractile response induced by angiotensin (Ang) II in rat carotid. METHODS: Concentration-response curves for AngII were obtained in endothelium-intact or endothelium-denuded carotid rings, in the absence or presence of SC-560 (COX-1 inhibitor), SC-236 (COX-2 inhibitor), wortmannin (PI3 K-Akt inhibitor), ML171 (NOX-1 inhibitor), VAS2870 (NOX-4 inhibitor), tiron (O2- scavenger) or PEG-catalase (H2 O2 scavenger)...
October 24, 2016: Journal of Pharmacy and Pharmacology
Arvin Eskandari, Janine N Boodram, Paul B Cressey, Chunxin Lu, Peter M Bruno, Michael T Hemann, Kogularamanan Suntharalingam
We report the cancer stem cell (CSC) potency of a novel series of copper(ii)-phenanthroline complexes bearing nonsteriodial anti-inflammatory drugs: naproxen, tolfenamic acid, and indomethacin (2a-3c). Two of the complexes, 2a and 3c, kill breast CSC-enriched HMLER-shEcad cells (grown in both monolayer and three-dimensional cell cultures) to a significantly better extent than salinomycin, a well-established CSC toxin. The most potent complex in the series, 3c induces its cytotoxic effect by generating intracellular reactive oxygen species (ROS) and inhibiting cyclooxgenase-2 (COX-2) activity...
October 24, 2016: Dalton Transactions: An International Journal of Inorganic Chemistry
Ana Filipa M Cláudio, Jorge F B Pereira, Parker D McCrary, Mara G Freire, João A P Coutinho, Robin D Rogers
An extensive study on the formation of aqueous biphasic systems (ABS) using aqueous solutions of protic ionic liquids (PILs) and polyethylene glycol (PEG) was performed in order to understand the mechanisms underlying the phase separation. Aqueous solutions of PEG polymers with different molecular weights (600, 1000, 2000, and 3400 g mol(-1)) and several N-alkyl-, dialkyl-, and trialkyl-ammonium salts of acetate, propanoate, butanoate, hexanoate and octanoate were prepared and their ability to form ABS at several temperatures assessed...
October 24, 2016: Physical Chemistry Chemical Physics: PCCP
C I Fiedler, E A Aisenbrey, J A Wahlquist, C M Heveran, V L Ferguson, S J Bryant, R R McLeod
Current hydrogels used for tissue engineering are limited to a single range of mechanical properties within the replicated tissue construct. We show that repeated in-swelling by a single hydrogel pre-cursor solution into an existing polymerized hydrogel followed by photo-exposure increases hydrogel mechanical properties. The process is demonstrated with a photo-clickable thiol-ene hydrogel using a biocompatible precursor solution of poly(ethylene glycol) dithiol and 8-arm poly(ethylene glycol) functionalized with norbornene...
October 24, 2016: Soft Matter
Jeong Yeon Kang, Jieming Gao, Dae Hwan Shin, Celeste Alvarez, Weixiong Zhong, Glen S Kwon
BACKGROUND: Delivery of monomeric Amphotericin B (AmB), i.e. deaggregated AmB, has been a major tactic in the reduction of renal toxicity at a membrane level, taking advantage of the selectivity of monomeric AmB for binding ergosterol over cholesterol. OBJECTIVE: The aim of this study was to characterize the pharmacokinetic (PK) and renal toxicity of monomeric AmB in rats following a multiple dose regimen. METHOD: AmB existed primarily in a monomeric state in poly(ethylene glycol)-block-poly(N-hexyl stearate L-aspartamide) (PEG-b-PHSA) micelles (mAmB) at 2:1 ratio (mol:mol), whereas AmB as its standard formulation, Fungizone(®), was highly self-aggregated based on absorption spectroscopy...
2016: Pharm Nanotechnol
Dawei Xu, Qian Ran, Yang Xiang, Jiang Linhai, Britannia M Smith, Fadi Bou-Abdallah, Reidar Lund, Zhongjun Li, He Dong
A significant challenge associated with systemic delivery of cationic antimicrobial peptides and polymers lies in their limited hemocompatibility toward vast numbers of circulating red blood cells (RBCs). Supramolecular assembly of cationic peptides and polymers can be an effective strategy to develop an array of antimicrobial nanomaterials with tunable material structures, stability and thus optimized bioactivity to overcome some of the existing challenges associated with conventional antimicrobials. In this work, we will demonstrate the supramolecular design of self-assembling antimicrobial nanofibers (SAANs) which have tunable supramolecular nanostructures, stability, internal molecular packing and surface chemistry through self-assembly of de novo designed cationic peptides and peptide-PEG conjuguates...
2016: RSC Advances
Nicole M Gatto, Kimberly C Paul, Janet S Sinsheimer, Jeff M Bronstein, Yvette Bordelon, Rebecca Rausch, Beate Ritz
We and others have suggested that vitamin D receptor gene (VDR) polymorphisms influence susceptibility for Parkinson's disease (PD), Alzheimer's disease (AD), mild cognitive impairment (MCI) or overall cognitive functioning. Here we examine VDR polymorphisms and cognitive decline in patients with PD. Non-Hispanic Caucasian PD patients (n=190) in the Parkinson Environment Gene (PEG) study were successfully genotyped for seven VDR polymorphisms. Cognitive function was assessed with the Mini-Mental State Exam (MMSE) at baseline and at a maximum of three follow-up exams...
November 15, 2016: Journal of the Neurological Sciences
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