Papers by Keyword: Polyethylene Glycol (PEG)

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Authors: Xiu Yun Li, Li Yang, De Chun Liu
Abstract: The crystallization of isotactic polypropylene (iPP) and polypropylene/polyethylene-glycol (iPP/PEG) blends were investigated by in situ Fourier transform infrared spectroscopy (FTIR) and wide angle X-ray diffraction (WAXD). It was found that the existence of polyethylene-glycol(PEG) does not destroy the helical structure of iPP in the melt, but changes the crystal structure of iPP in the bends. Moreover, the variation tendency of ratios of intensity A998 cm-1/A1460 cm-1 for iPP and iPP/PEG blends showed that the the onset crystallization temperature of iPP is improved by addition of PEG until the PEG content reaches to 5 wt%, and beyond this content, the crystallization point decreases.
Authors: Damra E. Mustafa, Hua Fan, Xuan Zhou, Hai Yang Tu, Ai Dong Zhang
Abstract: Non-adsorption of water dispersible gold nanoparticles (GNPs) is a major concern in its widely labeling applications. This paper presents the investigation of the adsorption properties of GNPs with superficially tethered ferrocene functions to different surfaces. The GNPs were coated with a mixed monolayer of PEG-thiol and progargyl PEG-thiol, and the later was linked with a ferrocene moiety (Fc) through the alkyne-azide click reaction. The adsorption behaviors of the Fc-GNP to glassy carbon, gold and platinum electrodes, in the absence and presence of a self-assembled monolayer (SAM) or protein layer, were studied by cyclic voltammetry (CV). It was found that the bare gold electrode possessed higher adsorption capacity. However, the adsorption was either reduced or completely prevented when the gold electrode was modified with monolayers of 2-mercaptoethanol (ME), dodecanethiolate (DT) and PEG-thiol. The electroactive and water dispersible GNPs with Fc labels allows us to use CV to explore the interaction between these GNP and bovine serum albumin (BSA). The BSA modified electrode resulted in better resistant to adsorption compared to other modifiers coated electrodes. Thus, the study of non-specific interaction by CV was found effective when compared to results obtained by surface plasmon resonance (SPR) and FTIR.
Authors: Takao Hanawa, Harumi Sakamoto, Yuta Tanaka
Abstract: Application of metals will be expanded to new medical devices, scaffold for tissue engineering, artificial organs, etc. with the addition of biofunction. Therefore, immobilization or combination of functional polymers to metals is significant subject for the application of metals to biofunctional materials and sensors. Metal-polymer hybrid materials are promising biomaterials future, especially for artificial organs. To form metal-polymer hybrid for biomedical devices, two techniques are predominant according to the purpose: Immobilization of biofunctional polymers to metals and bonding of biopolymers with metals. In the first case, poly(ethylene glycol: PEG) is a biofuctional molecule on which adsorption of proteins is inhibited. Control of immobilization mode of PEG modified with NH2 to titanium surface by electrodeposition is feasible and the adsorption of proteins is inhibited by the deposited PEG. This technique could be applied to all metallic materials. In the other case, we attempted to form a composite of titanium with segmentated polyurethane (SPU) thorough silane-coupling agent (γ-MPS). This composite material is applied to texture of titanium covered by SPU as artificial organs.
Authors: Maryam Jokar, Russly Abdul Rahman, Nor Azowa Ibrahim, Luqman Chuah Abdullah, Tan Chin Ping
Abstract: Silver nanoparticles are of interest due to their unique physicochemical and antimicrobial properties. The nanoparticles were produced by chemical reduction using short chain polyethylene glycol (PEG) as reducing agent, solvent and stabilizer in absence of other chemicals. Silver nanoparticles were separated from colloidal dispersion by ultra centrifuge at 14000 rpm. The reduction of silver ion (Ag+) to silver nanoparticles (Agº) was monitored by pH measurement and UV-visible spectroscopy of colloidal dispersion at fixed intervals. Silver nanoparticles were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM) and diphenyl-picrylhydrazyl (DPPH) radical scavenging method. Antimicrobial activity of silver nanoparticles was investigated against Escherichia coli, Staphylococcus aureus and Vibrio parahaemolyticus by agar plate test. Results indicated 51.5% conversion efficiency of silver ions to silver nanoparticles. Colloidal dispersion containing 4.12 mg/ml silver nanoparticles showed uniform size of 5.5 ± 1.1 nm with a typical visible spectra band at 447 nm. Silver nanoparticles showed significant (p < 0.05) antimicrobial efficiency and with concentration of 100 ppm resulted in 46.22%, 66.51% and 69.06% inhibition against S. aureus, E. coli and V. parahaemolyticus, respectively. The nanoparticles were also found to reduce DPPH free radical up to 88.9%. Results of this study proved that the silver nanoparticles produced by polyethylene glycol possess antimicrobial and antioxidant activity.
Authors: Xi Feng Xiao, Lei Ji Zhou
Abstract: Polyethylene glycol (PEG) fixation has been proved to significantly decrease nonspecific protein adsorption on varied substrates. Here, a strategy of surface modification using two kinds of PEGs with different chain lengths was developed to improve the surface ability of protein resistance. We designed different reaction routes and investigated their reaction conditions. The amount of nonspecific protein adsorption on the substrates after modification was measured by UV-Vis spectrometry. The results showed that higher performance of protein resistance on the solid surface was acquired from the two-step modification than other methods. A competitive mechanism of reaction was proposed to elucidate the interaction between distinct PEGs on the substrates.
Authors: Mei Ling Shao, Qing Yang, Lu Chen
Abstract: Aligned PHBV/PEG ultrafine fibers are fabricated for potential applications in tissue repair. In this paper we find that the optimum spinning parameters to prepare aligned PHBV/PEG fibers is as follows: the concentration of 8wt%, voltage at 10kv, receiving distance at 18cm, the boost speed at 0.8ml/h and the best linear velocity of the rotating drum at 9.5m/s. The content of PEG is less than 50%. In addition, we investigate the interaction between PHBV and PEG in its entirety; we also discuss the surface morphology of the blends, compatibility, thermal decomposition and crystallization behavior by the help of different test methods.
Authors: Ji Xin Su, Ming Bo Zhang, Li Yuan Ma, Shen Ping Zhang, Fei Fei Dong
Abstract: Ordered mesoporous silica SBA-15 with controlled pore size and wall thickness was synthesized using polypropylene glycol (PPG) and polyethylene glycol (PEG) as different additives. The final samples were characterized by low-angle X-ray diffraction, N2 adsorption-desorption and transmission electron microscopy. The SBA-15 used PPG or PEG as additive all could maintain the two-dimensional hexagonal structure. The addition of PPG could expand the pore size and decrease the wall thickness and the addition of PEG could reduce the pore size and increase the wall thickness of SBA-15.
Authors: Fei Qiu, Lin Wei
Abstract: Curcumin is a kind of compound with various biological activities. However, curcumin suffers from low aqueous solubility, instability and poor bioavailability in vivo, which restrained it from clinical application. In this paper, novel water soluble curcumin prodrug monomer was synthesized by reacting curcumin with methacryloyl polyethylene glycol (MA-PEG), and succinic anhydride. IR, MS and 1H NMR spectroscopy were carried out to verify the products. We studied and modified the reaction conditions. The drug load rate of the monomer was 26.9%, which was 2-4-fold than previous report, and the solubility of it could be increased to 1.17g/L, which was about 150 times higher than previous report. The monomer is used to prepare comb-like polymer prodrugs.
Authors: M. Zainab, Jeefferie Abd Razak, A.K. Masrom, Zulkifli Mohd Rosli
Abstract: This research, deals with modification of sol gel process for the synthesis of porous TiO2-PEG thin films with good structural integrity for environmental self-cleaning applications. Relatively, by adding the PEG with various molecular weights (300, 400, and 600) could influence the formation of TiO2 films structure and adhesion. Moreover, the formation of porous TiO2 associated with larger pores will accelerate the mass transfer of the treated contaminants in the larger pore channels. The advantages of the unique structures of as-prepared TiO2₂ films in the application of environmental self-cleaning systems are extensively studied by characterizing the produced films using various advanced characterization tools. Adhesion of TiO2 thin films become smooth and better surface with increasing the coating layers. The X-ray Diffraction spectrum of prepared coating shows present of anatase phase as major phase.
Authors: Takeshi Miki, Kaori Nishizawa, Kazuyuki Suzuki, Kazumi Kato
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