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https://www.readbyqxmd.com/read/28821146/evaluation-of-carboxymethyl-moringa-gum-as-nanometric-carrier
#1
Rimpy, Abhishek, Munish Ahuja
In the present study, carboxymethylation of Moringa oleifera gum was carried out by reacting with monochloroacetic acid. Modified gum was characterised employing Fourier-transform infrared spectroscopy, differential scanning calorimetry, X-ray diffraction, scanning electron microscopy, and Rheology study. The carboxymethyl modification of moringa gum was found to increase its degree of crystallinity, reduce viscosity and swelling, increase the surface roughness and render its more anionic. The interaction between carboxymethyl moringa gum and chitosan was optimised by 2-factor, 3-level central composite experimental design to prepare polyelectrolyte nanoparticle using ofloxacin, as a model drug...
October 15, 2017: Carbohydrate Polymers
https://www.readbyqxmd.com/read/28821135/exploring-pullulan-poly-vinyl-alcohol-interpenetrating-network-microspheres-as-controlled-release-drug-delivery-device
#2
Saundray Raj Soni, Animesh Ghosh
In the present study, interpenetrating polymeric network (IPN) microsphere was prepared using glutaraldehyde assisted water-in-oil emulsion crosslinking method for controlled delivery of pirfenidone, the only chemical entity approved by US FDA for the treatment of Idiopathic Pulmonary Fibrosis (IPF). In our study, the natural biopolymer pullulan was harnessed in combination with synthetic polymer PVA for drug delivery applications. The prepared microspheres were characterized by Fourier transform infrared spectroscopy, Raman spectroscopy, solid state (13)C nuclear magnetic resonance and field emission scanning electron microscopy...
October 15, 2017: Carbohydrate Polymers
https://www.readbyqxmd.com/read/28821133/single-helix-in-v-type-starch-carrier-determines-the-encapsulation-capacity-of-ethylene
#3
Linfan Shi, Xiong Fu, Qiang Huang, Bin Zhang
V-type starch carriers with different single helix contents were prepared using alcoholic-alkaline treatment followed by ethanol precipitation. Ethylene gas was entrapped into V-type starch carriers using a solid encapsulation method. The morphological and structural properties of inclusion complexes (ICs) were characterized using scanning electron and light microscopy, X-ray diffractometry, (13)C solid-state nuclear magnetic resonance (NMR) and Raman spectroscopy. Aqueous ethanol treatment resulted in swelling and aggregation of starch granules, and B-type diffraction reflections were either reduced or completely lost with evolution of V-type pattern...
October 15, 2017: Carbohydrate Polymers
https://www.readbyqxmd.com/read/28821116/active-release-coating-of-multilayer-assembled-branched-and-ionic-%C3%AE-cyclodextrins-onto-poly-ethylene-terephthalate
#4
Leyre Pérez-Álvarez, Leire Ruiz-Rubio, Erlantz Lizundia, Estíbaliz Hernáez, Luis M León, Jose Luis Vilas-Vilela
Branched ionic cyclodextrins multilayers were assembled onto the surface of previously aminolyzed poly(ethylene terephthalate) in order to construct local drug delivery tailored platforms with potential applicability as materials for indwelling medical devices. The construction of the multilayers took place by the alternate deposition of ionic cyclodextrin derivatives and was characterized by surface zeta-potential measurements, X-ray photoelectron spectroscopy and, after fluorescent labeling of anionic branched cyclodextrins, by UV-vis spectroscopy and confocal fluorescence spectroscopy...
October 15, 2017: Carbohydrate Polymers
https://www.readbyqxmd.com/read/28821111/a-facile-sodium-alginate-based-approach-to-improve-the-mechanical-properties-of-recycled-fibers
#5
Yuan-Yuan Bai, Yan-Hao Lei, Xiao-Jun Shen, Jing Luo, Chun-Li Yao, Run-Cang Sun
The application of recycled fibers is steadily increasing in various paper products recently. It is necessary to improve the mechanical properties of paper products made from these fibers. An eco-friendly polymeric additive, sodium alginate (SA), was prepared from waste seaweeds and developed as functional additives. The properties of SA were characterized by proton nuclear magnetic resonance, Fourier transform infrared spectroscopy, thermal gravity analysis, gel permeation chromatography, and compared with the commercial SA...
October 15, 2017: Carbohydrate Polymers
https://www.readbyqxmd.com/read/28821081/direct-characterization-of-cotton-fabrics-treated-with-di-epoxide-by-nuclear-magnetic-resonance
#6
Min Xiao, Joronia Chéry, Ivan Keresztes, David B Zax, Margaret W Frey
A non-acid-based, di-functional epoxide, neopentyl glycol diglycidyl ether (NPGDGE), was used to modify cotton fabrics. Direct characterization of the modified cotton was conducted by Nuclear Magnetic Resonance (NMR) without grinding the fabric into a fine powder. NaOH and MgBr2 were compared in catalyzing the reaction between the epoxide groups of NPGDGE and the hydroxyl groups of cellulose. Possible reaction routes were discussed. Scanning electron microscopy (SEM) images showed that while the MgBr2-catalyzed reaction resulted in self-polymerization of NPGDGE, the NaOH-catalyzed reaction did not...
October 15, 2017: Carbohydrate Polymers
https://www.readbyqxmd.com/read/28821055/improvement-of-silicate-cement-properties-with-bacterial-cellulose-powder-addition-for-applications-in-dentistry
#7
Georgeta Voicu, Sorin-Ion Jinga, Bogdan-Gabriel Drosu, Cristina Busuioc
The goal of this paper was to synthesize a new family of composites starting from mineral binder powders and biocellulose membranes, with applications in endodontics. An important achievement consisted in the crushing of biocellulose 3D structure in a polygranular powder via an hydrothermal treatment. Afterwards, the polymer powder was mixed with silicate cement powders synthesized through the sol-gel technique. The resulting hybrid materials were investigated by thermal analysis, X-ray diffraction, scanning electron microscopy and mechanical measurements...
October 15, 2017: Carbohydrate Polymers
https://www.readbyqxmd.com/read/28821051/a-novel-self-assembly-lentinan-tetraphenylethylene%C3%A2-composite-with-strong-blue%C3%A2-fluorescence-in-water-and-its-properties
#8
Mengxia Li, Pan Chen, Min Xu, Xiaojuan Xu
We report a unique self-assembly of lentinan, a triple helical β-(1→3)-glucan (t-LNT), in water. By molecular dynamics simulation, it was found that t-LNT aggregated preferentially along the chain direction to form long chains, accompanied by side-direction linkage to form branches. Transmission electron microscopy images demonstrated that t-LNT formed dendrite-like fibers, which further formed fishnet-like porous/mesoporous aggregates with increasing concentration. The meshes in the fishnet were ascribed to the intersection of branches...
October 15, 2017: Carbohydrate Polymers
https://www.readbyqxmd.com/read/28821045/production-of-cellulose-nanofibers-using-phenolic-enhanced-surface-oxidation
#9
Iman Beheshti Tabar, Ximing Zhang, Jeffrey P Youngblood, Nathan S Mosier
In this study we demonstrate that lignin monomers formed as byproducts of pulping or bioprocessing of lignocellulosic biomass is an effective enhancer to oxidize cellulose surfaces with ozone for the production of cellulose nanofibers (CNF). Never dried softwood pulp with minimum mercerization was enzymatically treated leading to a homogeneous pulp slurry with a higher reactivity. The slurry was oxidized by ozone gas in the presence of syringic acid, a lignin degradation model compound, as an oxidation enhancer at room temperature and pH 11...
October 15, 2017: Carbohydrate Polymers
https://www.readbyqxmd.com/read/28821043/effect-of-moderate-electric-fields-in-the-properties-of-starch-and-chitosan-films-reinforced-with-microcrystalline-cellulose
#10
Caroline C S Coelho, Miguel A Cerqueira, Ricardo N Pereira, Lorenzo M Pastrana, Otniel Freitas-Silva, António A Vicente, Lourdes M C Cabral, José A Teixeira
Microcrystalline cellulose (MCC) can provide improved properties when the aim is the development of biodegradable packaging materials. In this work the physicochemical properties of polysaccharide-based films (chitosan and starch) with the incorporation of MCC and the application of moderate electric field (MEF) and ultrasonic bath (UB) as treatments, were evaluated. For each treatment, the thickness, moisture content, solubility, water vapor permeability, contact angle, mechanical properties, along with its color and opacity were determined...
October 15, 2017: Carbohydrate Polymers
https://www.readbyqxmd.com/read/28821023/preparation-and-crystallization-behavior-of-poly-ethylene-2-5-furandicarboxylate-cellulose-composites-by-twin-screw-extrusion
#11
Amandine Codou, Nathanaël Guigo, Jesper Gabriël van Berkel, Ed de Jong, Nicolas Sbirrazzuoli
Poly(ethylene 2,5-furandicarboxylate) (PEF), an emerging biobased polyester, was compounded with cellulose via twin-screw extrusion. Different extrusion parameters such as mixing time, screw speed and temperature were employed. Composite thin films containing 1, 2 and 4% cellulose w/w were prepared and compared with neat PEF films. The morphology of PEF/cellulose composites was examined by scanning electron microscopy (SEM) and the molecular weight after extrusion was controlled by means of size exclusion chromatography (SEC)...
October 15, 2017: Carbohydrate Polymers
https://www.readbyqxmd.com/read/28820997/nh2fe3o4-sio2-supported-peroxidase-catalyzed-h2o2-for-degradation-of-endocrine-disrupter-from-aqueous-solution-roles-of-active-radicals-and-noms
#12
Jing Ai, Weijun Zhang, Guiying Liao, Hua Xia, Dongsheng Wang
In this work, magnetic Fe3O4 was utilized to immobilize horseradish peroxidase (IM-HRP) in order to improve its stability and reusability by crosslinking method process with glutaraldehyde. The physicochemical properties of NH2Fe3O4@SiO2 and IM-HRP were characterized by powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Thermo-gravimetric Analysis (TGA) and Transmission electron microscopy (TEM). The thermal stability of immobilized-HRP was considerably improved in comparison with free counterpart...
August 13, 2017: Chemosphere
https://www.readbyqxmd.com/read/28820941/a-photoactivatable-probe-for-super-resolution-imaging-of-enzymatic-activity-in-live-cells
#13
Elias A Halabi, Zacharias Thiel, Nils Trapp, Dorothea Pinotsi, Pablo Rivera-Fuentes
A dual-activatable, fluorogenic probe was developed to sense esterase activity with single-molecule resolution. Without enzymatic pre-activation, the diazoindanone-based probe has an electron poor core and, upon irradiation, undergoes Wolff rearrangement to give a ring-expanded xanthene core that is non-emissive. If the probe is pre-activated by carboxylesterases, the tricyclic core becomes electron-rich and the photoinduced Wolff rearrangement produces a highly emissive rhodol dye. Live-cell and solution studies confirmed the selectivity of the probe and revealed that the photoactivated dye does not diffuse away from the original location of activation because the intermediate ketene forms a covalent bond with surrounding macromolecules...
August 18, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28820526/silica-nanoparticle-monolayers-on-a-macroion-modified-surface-formation-mechanism-and-stability
#14
M Morga, Z Adamczyk, D Kosior
Even though silica nanoparticles and their monolayers find a broad field of applications, only a few studies providing a quantitative description of silica nanoparticle deposition at solid/liquid interfaces have been reported in the literature. Given the deficit of reliable experimental data, the goal of this work is to acquire thorough physicochemical characteristics of amorphous silica nanoparticle deposition. Silica nanoparticle monolayers of controlled coverage were formed on macroion (PAH)-modified mica...
August 18, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28820488/phase-behaviour-and-miscibility-studies-of-collagen-silk-fibroin-macromolecular-system-in-dilute-solutions-and-solid-state
#15
Ima Ghaeli, Mariana A de Moraes, Marisa M Beppu, Katarzyna Lewandowska, Alina Sionkowska, Frederico Ferreira-da-Silva, Maria P Ferraz, Fernando J Monteiro
Miscibility is an important issue in biopolymer blends for analysis of the behavior of polymer pairs through the detection of phase separation and improvement of the mechanical and physical properties of the blend. This study presents the formulation of a stable and one-phase mixture of collagen and regenerated silk fibroin (RSF), with the highest miscibility ratio between these two macromolecules, through inducing electrostatic interactions, using salt ions. For this aim, a ternary phase diagram was experimentally built for the mixtures, based on observations of phase behavior of blend solutions with various ratios...
August 18, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/28820482/in-situ-synthesis-of-silver-nanoparticles-on-the-polyelectrolyte-coated-sericin-pva-film-for-enhanced-antibacterial-application
#16
Rui Cai, Gang Tao, Huawei He, Pengchao Guo, Meirong Yang, Chaoxiang Ding, Hua Zuo, Lingyan Wang, Ping Zhao, Yejing Wang
To develop silk sericin (SS) as a potential antibacterial biomaterial, a novel composite of polyelectrolyte multilayers (PEMs) coated sericin/poly(vinyl alcohol) (SS/PVA) film modified with silver nanoparticles (AgNPs) has been developed using a layer-by-layer assembly technique and ultraviolet-assisted AgNPs synthesis method. Ag ions were enriched by PEMs via the electrostatic attraction between Ag ions and PEMs, and then reduced to AgNPs in situ with the assistance of ultraviolet irradiation. PEMs facilitated the high-density growth of AgNPs and protected the synthesized AgNPs due to the formation of a 3D matrix, and thus endowed SS/PVA film with highly effective and durable antibacterial activity...
August 18, 2017: Materials
https://www.readbyqxmd.com/read/28820312/architecture-of-the-atg2b-wdr45-complex-and-an-aromatic-y-hf-motif-crucial-for-complex-formation
#17
Jing-Xiang Zheng, Yan Li, Yue-He Ding, Jun-Jie Liu, Mei-Jun Zhang, Meng-Qiu Dong, Hong-Wei Wang, Li Yu
PtdIns3P signaling is critical for dynamic membrane remodeling during autophagosome formation. Proteins in the Atg18/WIPI family are PtdIns3P-binding effectors which can form complexes with proteins in the Atg2 family, and both families are essential for macroautophagy/autophagy. However, little is known about the biophysical properties and biological functions of the Atg2-Atg18/WIPI complex as a whole. Here, we demonstrate that an ortholog of yeast Atg18, mammalian WDR45/WIPI4 has a stronger binding capacity for mammalian ATG2A or ATG2B than the other 3 WIPIs...
August 18, 2017: Autophagy
https://www.readbyqxmd.com/read/28820220/real-time-plasmon-spectroscopy-study-of-the-solid-state-oxidation-and-kirkendall-void-formation-in-copper-nanoparticles
#18
Mariano D Susman, Yishai Feldman, Tatyana A Bendikov, Alexander Vaskevich, Israel Rubinstein
Oxidation and corrosion reactions have a major effect on the application of non-noble metals. Kinetic information and simple theoretical models are often insufficient for describing such processes in metals at the nanoscale, particularly in cases involving formation of internal voids (nano Kirkendall effect, NKE) during oxidation. Here we study the kinetics of solid-state oxidation of chemically-grown copper nanoparticles (NPs) by in situ localized surface plasmon resonance (LSPR) spectroscopy during isothermal annealing in the range 110-170 °C...
August 18, 2017: Nanoscale
https://www.readbyqxmd.com/read/28820208/positive-zeta-potential-of-nanodiamonds
#19
Laia Ginés, Soumen Mandal, Ashek-I-Ahmed, Chia-Liang Cheng, Maabur Sow, Oliver A Williams
In this paper, the origin of positive zeta potential exhibited by nanodiamond particles is explained. Positive zeta potentials in nano-structured carbons can be explained by the presence of graphitic planes at the surface, which leave oxygen-free Lewis sites and so promotes the suppression of acidic functional groups. Electron Microscopy and Raman Spectroscopy have been used to show that positive zeta potential of nanodiamond is only exhibited in the presence of sp(2) carbon at the surface.
August 18, 2017: Nanoscale
https://www.readbyqxmd.com/read/28820142/nanomelatonin-triggers-superior-anticancer-functionality-in-a-human-malignant-glioblastoma-cell-line
#20
Sanjeev Kumar Yadav, Anup Kumar Srivastava, Atul Dev, Babita Kaundal, Subhasree Roy Choudhury, Surajit Karmakar
Melatonin (MEL) has promising medicinal value as an anticancer agent in a variety of malignancies, but there are difficulties in achieving a therapeutic dose due to its short half-life, low bioavailability, poor solubility and extensive first-pass metabolism. In this study chitosan/tripolyphosphate (TPP) nanoparticles were prepared by an ionic gelation method to overcome the therapeutic challenges of melatonin and to improve its anticancer efficacy. Characterization of the melatonin-loaded chitosan (MEL-CS) nanoformulation was performed using transmission and scanning electron microscopies, dynamic light scattering, Fourier transform infrared spectroscopy, Raman spectroscopy and x-ray diffraction...
August 18, 2017: Nanotechnology
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