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Application of polymer

Christoph Bernhard, Kristin N Bauer, Mischa Bonn, Frederik Roman Wurm, Grazia Gonella
Synthetic polymers are commonly used as protein repelling materials for a variety of biomedical applications. Despite their widespread use, the fundamental mechanism underlying protein repellence is often elusive. Such insights are essential for improving existing, and developing new materials. Here, we investigate how subtle differences in the chemistry of hydrophilic polyphosphoesters influence the adsorption of the human blood proteins serum albumin and fibrinogen. Using thermodynamic measurements, surface-specific vibrational spectroscopy and Brewster angle microscopy, we investigate protein adsorption, hydration as well as the steric repulsion properties of the polyphosphoester polymers...
December 5, 2018: ACS Applied Materials & Interfaces
Cuiping Jiang, Zitong Qi, Hengbo Jia, Yilei Huang, Yunbo Wang, Wenli Zhang, Zimei Wu, Hu Yang, Jianping Liu
In this work, we report on an ATP-responsive low-molecular-weight polyethylenimine (LMW-PEI)-based supramolecular assembly. It formed via host-guest interaction between PEI (MW=1.8 kDa)-α-cyclodextrin (α-CD) conjugates and PEI1.8k-phenylboronic acid (PBA) conjugates. The host-guest interaction between PEI1.8k-α-CD and PEI1.8k-PBA was confirmed by the 2D-NOESY chromatogram experiment and competition test. The ATP-responsive property of the supramolecular assembly was evaluated by a series of ATP-triggered degradation and siRNA release studies in terms of fluorescence resonance energy transfer, agarose gel electrophoresis assay and the time course monitoring of the particle size and morphology...
December 5, 2018: Biomacromolecules
Ni Ya Li, Dong Liu
The assembly of coordination polymers from metal ions and organic moieties is currently attracting considerable attention in crystal engineering due to their intriguing architectures and potential applications as functional materials. A new coordination polymer, namely poly[[μ2 -trans-1,2-bis(pyridin-3-yl)ethylene-κ2 N:N']bis(μ4 -4,4'-oxydibenzoato-κ6 O:O,O':O'':O'',O''')dicadmium(II)], [Cd2 (C14 H8 O5 )2 (C12 H10 N2 )]n or [Cd2 (4,4'-OBB)2 (3,3'-BPE)]n , has been synthesized by the the self-assembly of Cd(NO3 )2 ·4H2 O, 4,4'-oxydibenzoic acid (4,4'-H2 OBB) and trans-1,2-bis(pyridin-3-yl)ethene (3,3'-BPE) under hydrothermal conditions...
December 1, 2018: Acta Crystallographica. Section C, Structural Chemistry
Pan He, Satoshi Shimano, Krishnachary Salikolimi, Takashi Isoshima, Yohei Kakefuda, Takao Mori, Yasujiro Taguchi, Yoshihiro Ito, Masuki Kawamoto
Four thermally-cleavable polythiophene derivatives containing carbonate and solubilizing groups were synthesized for non-covalent modification of single-walled carbon nanotubes (SWCNTs). A well-dispersed polythiophene/SWCNTs composite was obtained by adsorption of the polymer at the SWCNTs surface. The solution-processed composite film exhibited solid-state thermal cleavage of the insulating solubilizing group through decarboxylation, producing an insoluble composite film. The thermally-cleavable composite film was evaluated for potential application as a thermoelectric (TE) material...
December 5, 2018: ACS Applied Materials & Interfaces
Min Yang, Nannan Li, Suxiao Yang, Yuan Yu, Zhenlian Han, Li Li, Haijin Mou
Understanding the effect of conserved domains reconstruction of alginate lyases on action mode is essential for their application and in-depth study. We report the expression and action mode of recombinant alginate lyase (AlyM) and its conserved domain reconstruction forms (AlyMΔCBM, cAlyM, and AlyMΔ58C). The enzymatic activities of AlyM, AlyMΔCBM, cAlyM, and AlyMΔ58C were 61.77, 150.57, 388.97, and 308.21 U/mg, respectively. The transcription level of cAlyM was 49.89-fold of AlyM. cAlyM and AlyMΔ58C showed higher thermal stability than AlyM, indicating that the removal of F5_F8_type_C domain was beneficial for the increase of thermal stability...
December 4, 2018: Applied Microbiology and Biotechnology
Paulo Ronaldo Sousa Teixeira, Ana Siqueira do Nascimento Marreiro Teixeira, Emanuel Airton de Oliveira Farias, Edson Cavalcanti da Silva Filho, Helder Nunes da Cunha, José Ribeiro Dos Santos Júnior, Lívio César Cunha Nunes, Handerson Rodrigues Silva Lima, Carla Eiras
There are increasing concerns regarding the risks arising from the contamination of manipulators of antineoplastic drugs promoted by occupational exposure or even in the dosage of drugs. The present work proposes the use of an electrochemical sensor based on a biopolymer extracted from the babassu coconut (Orbignya phalerata) for the determination of an antineoplastic 5-fluorouracil (5-FU) drug as an alternative for the monitoring of these drugs. In order to reduce the cost of this sensor, a flexible gold electrode (FEAu) is proposed...
December 5, 2018: Analytical and Bioanalytical Chemistry
Maija-Liisa Mattinen, Guillaume Riviere, Alexander Henn, Robertus Wahyu N Nugroho, Timo Leskinen, Outi Nivala, Juan José Valle-Delgado, Mauri A Kostiainen, Monika Österberg
Lignin has interesting functionalities to be exploited in adhesives for medicine, foods and textiles. Nanoparticles (NPs) < 100 nm coated with poly (L -lysine), PL and poly(L -glutamic acid) PGA were prepared from the laccase treated lignin to coat nanocellulose fibrils (CNF) with heat. NPs ca. 300 nm were prepared, β-casein coated and cross-linked with transglutaminase (Tgase) to agglutinate chamois. Size exclusion chromatography (SEC) and Fourier-transform infrared (FTIR) spectroscopy were used to characterize polymerized lignin, while zeta potential and dynamic light scattering (DLS) to ensure coating of colloidal lignin particles (CLPs)...
December 3, 2018: Nanomaterials
Shenggui Chen, Junzhong Yang, Yong-Guang Jia, Bingheng Lu, Li Ren
With the rapid application of light-curing 3D printing technology, the demand for high-performance polymer resins is increasing. Existing light-curable resins often have drawbacks limiting their clinical applications. This study aims to develop a new type of polymethyl methacrylate (PMMA) composite resins with enhanced mechanical properties, high antibacterial activities and excellent biocompatibilities. A series of reinforced composite resins were prepared by mechanically mixing PMMA with modified cellulose nanocrystals (CNCs), which were coated with polydopamine and decorated by silver nanoparticles (AgNPs) via Tollen reaction...
December 3, 2018: Materials
Tuanwei Li, Lifeng Yan
Photodynamic therapy (PDT) is an appealing therapeutic modality in management of some solid tumors and other diseases for its minimal invasion and non-systemic toxicity. However, the hydrophobicity and non-selectivity of the photosensitizers, inherent serious hypoxia of tumor tissues and limited penetration depth of light restrict PDT further applications in clinic. Functional polymer nanoparticles can be used as a nanocarrier for accurate PDT. Here, we elucidate the mechanism and application of PDT in cancer treatments, and then review some strategies to administer the biodistribution and activation of photosensitizers (PSs) to ameliorate or utilize the tumor hypoxic microenvironment to enhance the photodynamic therapy effect...
November 30, 2018: Pharmaceuticals
Carol Korzeniewski, Jay P Kitt, Saheed Bukola, Stephen E Creager, Shelley D Minteer, Joel M Harris
Single layer graphene (SLG), with its angstrom-scale thickness and strong Raman scattering cross section, was adapted for measurement of the axial (Z-direction) probe beam profile in confocal Raman microscopy depth-profiling experiments. SLG adsorbed to a glass microscope coverslip (SLG/SiO2 ) served as a platform for estimation of axial spatial resolution. Profiles were measured by stepping the confocal probe volume through the SLG/SiO2 interface while measuring Raman scattering from the sample. Using a high numerical aperture (1...
December 4, 2018: Analytical Chemistry
Daniele Martella, Sara Nocentini, Filippo Micheletti, Diederik S Wiersma, Camilla Parmeggiani
Light represents a very versatile stimulus and its use to control the deformation in shape-changing polymers can take advantage of multiple parameters (such as wavelength, intensity and polarization) to be explored in order to obtain differentiated responses. Polymers with selected color responsiveness are commonly prepared by using different dyes, while a polarization-dependent control can be introduced exploiting trans-cis isomerization of azobenzenes. As shape-changing polymers driven by a photothermal effect are gaining more and more attention in many application fields, exploring polarization to modulate their response could enlarge the tuning parameter space and provide an insight into the material optical properties...
December 4, 2018: Soft Matter
Yongli Qi, Xin Li, Yao He, Deyuan Zhang, Jiandong Ding
Strong and biodegradable materials are the key to the development of next-generation medcial devices for interventional treatment. Biodegradable polymers such as polylactide (PLA) have controllable degradation profiles, but the mechanical strength is much weaker than some metallic materials such as iron; on the other hand, tuning the corrosion rate of iron to a proper time range for biomedical applications has always been a challenge. Very recently, we have achieved a complete corrosion of iron stent in vivo within clinically required time frame by combining a PLA coating, which provides a new biomaterial type for the next-generation biodegradable coronary stents termed as metal-polymer composite stent (MPS)...
December 4, 2018: ACS Applied Materials & Interfaces
P Blake J St Onge, Michael U Ocheje, Mariia Selivanova, Simon Rondeau-Gagné
Organic bulk heterojunction solar cells are promising candidates as future photovoltaic technologies for large-scale and low-cost energy production. It is, therefore, not surprising that research on the design and preparation of these types of organic photovoltaics has attracted a lot of attention since the last two decades, leading to constantly growing values of energy conversion and efficiency. Combined with the possibility of a large-scale production via roll-to-roll printing techniques, bulk heterojunction solar cells enable the fabrication of conformable, light-weight and flexible light-harvesting devices for point-of-use applications...
December 4, 2018: Chemical Record: An Official Publication of the Chemical Society of Japan ... [et Al.]
Feng Liu, Mao Wang, Xue Wang, Pengfei Wang, Wenhao Shen, Siyuan Ding, Yugang Wang
With the development of the nano-fabrication and nanofluidics, nanoporous membranes have shown great potential in applications such as molecular separation, energy conversion, and molecular sensing. However, their performance has often been limited by the trade-off between selectivity and permeability and the lack of scalability. The prospect of overcoming these problems with nanoporous polymer ion-track membranes is promising. Focusing on these membranes, this review provides a comprehensive overview of fabrication methods, including the traditional track-etching technique and the recently developed track-UV technique; characterization methods; transport mechanisms; and major properties and applications...
December 4, 2018: Nanotechnology
Yongjian Wang, Kelly A Burke
Liquid crystalline polymer networks (LCNs) couple polymer chain organization to molecular ordering, the switching of which has been shown to impart stimuli-responsive properties, including actuation and one-way shape memory, to the networks. While LCNs have long been proposed as artificial muscles, recent reports have also suggested potential as dynamic biomaterial substrates. In contrast to many existing LCNs synthesized using hydrophobic spacers, this work investigates networks synthesized using more hydrophilic spacers to promote interaction with water...
December 4, 2018: Soft Matter
Yangwei Shi, Junwei Ye, Ye Qi, Muhammad Awais Akram, Abdul Rauf, Guiling Ning
An anionic layered coordination polymer [Eu(BTEC)0.5(HCOO)(H2O)2] (1) has been successfully synthesized via a solvothermal method (H4BTEC = 1,2,4,5-benzenetetracarboxylic acid, HCOOH = formic acid). Compound 1 possesses two-dimensional layers, which further generate a three-dimensional supramolecular network by hydrogen bonds existing between carboxylic oxygen, formate anion and H2O molecules of two adjacent layers. Interestingly, 1 shows high luminescence quenching efficiency upon addition of Fe3+ ions when it was dispersed in water even in the presence of interfering ions such as Na+, Ag+, Ca2+, Cd2+, Co2+, Cu2+, Mg2+, Mn2+, Zn2+ and Al3+...
December 4, 2018: Dalton Transactions: An International Journal of Inorganic Chemistry
Steffen Sydow, Dominik de Cassan, Robert Hänsch, Thomas R Gengenbach, Christopher D Easton, Helmut Thissen, Henning Menzel
Nanogels were prepared by ionotropic gelation of chitosan (CS) with tripolyphosphate (TPP). The use of such nanogels to prepare coatings by layer-by-layer deposition (LbL) was studied. The nanogels were characterized in terms of particle size, zeta-potential and stability. Nanogel suspensions were used to build polyelectrolyte multilayers on silicon wafers and on PCL fiber mats by LbL-deposition. Three different polysaccharides were used as polyanions, namely chondroitin sulfate, alginate and hyaluronic acid...
December 4, 2018: Biomaterials Science
Natalia V Lukasheva, Dmitry A Tolmachev, Mikko Karttunen
Cellulose can be phosphorylated to produce organic matrices with highly adsorptive properties for, e.g., biocompatible materials for biomedical applications. We focus on the effects of phosphorylation of surfaces of crystalline nanocellulose and, in particular, on the competitive adsorption of mono- and divalent cations (Na+ and Ca2+) typically contained in mineralizing salt mixtures using all-atom molecular dynamics (MD) simulations. Phosphorylation was applied at 12% and 25% both in water and CaCl2 solutions...
December 4, 2018: Physical Chemistry Chemical Physics: PCCP
Ruijiao Dong, Ruiyi Liu, Piers R J Gaffney, Marc Schaepertoens, Patrizia Marchetti, Christopher M Williams, Rongjun Chen, Andrew G Livingston
Synthetic chemists have devoted tremendous effort towards the production of precision synthetic polymers with defined sequences and specific functions. However, the creation of a general technology that enables precise control over monomer sequence, with efficient isolation of the target polymers, is highly challenging. Here, we report a robust strategy for the production of sequence-defined synthetic polymers through a combination of liquid-phase synthesis and selective molecular sieving. The polymer is assembled in solution with real-time monitoring to ensure couplings proceed to completion, on a three-armed star-shaped macromolecule to maximize efficiency during the molecular sieving process...
December 3, 2018: Nature Chemistry
Nobuhiko Hosono, Aya Terashima, Shinpei Kusaka, Ryotaro Matsuda, Susumu Kitagawa
The ability of porous coordination polymers to undergo reversible structural transformations in response to the presence of guest molecules has been intensively investigated for applications such as molecular separation, storage, sensing and signalling processes. Here we report on the direct observation of the highly guest-responsive nature of the surface of a single-crystalline porous coordination polymer, which consists of paddlewheel zinc clusters and two types of ligand, by in situ liquid-phase atomic force microscopy...
December 3, 2018: Nature Chemistry
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