IRANIAN POLYMER JOURNAL
·
2019
·Vol. 28
·期 2
·173-182
·
IF 1.707
Huang Chongxing,Dang Xiujie,Bei Ronghua,Zhao Yuan,Li Cuicui,Chen Qiang,Wang Shuangfei
Polyethylene terephthalate (PET) is widely used in food packaging, but the processing aids that include materials such as plasticizers and antioxidants may migrate to food, thereby harming the food quality and human health. To develop packaging materials with lesser plasticizer migration and to understand the anti-migration mechanism, a SiO x layer was deposited by plasma-enhanced chemical vapor deposition (PECVD) on a PET substrate to prepare a composite film. The effects of SiO x layers with different thicknesses on blocking the migration of dioctyl phthalate (DEHP, a plasticizer) and Irganox 1010 (an antioxidant) from the PET substrate into the food simulant were investigated at three temperatures. The migration of additives from both pristine and SiO x -coated films increased with an increase in the contact time and temperature. However, compared with the pristine film, the specific migration rates of DEHP can be reduced by up to 88.57% in the 320-nm SiO x /PET composite film, while that of Irganox 1010 can reach 82.61%. For a fixed SiO x layer thickness, the DEHP migration is not greatly affected by temperature, while that of Irganox 1010 migration decreased at higher temperatures. In addition, a 320-nm SiO x layer effectively retarded the transmission of water vapor and oxygen through the composite film to 77.3% and 79.3% lesser than those of the pristine PET film, respectively. The SEM image showed that the surface of the composite film was denser and more uniform than a pristine PET film, which also confirmed that the SiO x layer can block the migration of additives.
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JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY
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2019
·
IF 3.202
Nan Zhao,Mengchun Cheng,Shuai Huang,Dan Liu,Qiang Zhao,Yunpeng Bai,Xiaozhe Zhang
When characterizing components from ginseng, we found a vast number of multicharged anions presented in the liquid chromatography–mass spectrometry (LC-MS) chromatograms. The source of these anions is unclear yet, while ginsenosides, the major components of ginseng, are the main suspected type of molecules because of their sugar moiety. Our investigation using 14 pure ginsenosides affirmed that the multicharged anions were formed by ginsenosides rather than other types of ingredients in ginseng. Various anions could be observed for each ginsenoside. These anions contain ions ([M-2H]2−, [M+Adduct]2−), as well as those formed by polymerization of at least two ginsenosides, such as [nM-2H]2−, [nM-H+Adduct]2−, and [nM-3H]3−. The presence of so different types of ions from a ginsenoside explains the reason for the large number of anions in the LC-MS analysis of ginseng. We further found that formation of [nM-2H]2− ions was influenced by the number of sugar chains: ginsenosides containing two sugar chains produced all [nM-2H]2− ion types, whereas ginsenosides containing one sugar chain did not produce [2M-2H]2−. Thus, [2M-2H]2− and [3M-2H]2− can be utilized to rapidly identify monodesmosidic and/or bidesmosidic ginsenosides as joint diagnostic anions. The position of the glycosyl radical might be the key factor affecting the formation of multicharged multimer ions from monodesmosidic ginsenosides. Consequently, three groups of ginsenoside isomers were differentiated by characteristic [nM-2H]2− anions. Using concentration-dependent characteristics and collision-induced dissociation (CID), we confirmed that [nM-2H]2− ions are non-covalently bound multimers whose aggregation has marked distinction between monodesmosidic and bidesmosidic ginsenosides, accounting for the differentiated formation of [nM-2H]2− between them.
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MICROCHIMICA ACTA
·
2019
·Vol. 186
·期 2
·1-8
·
IF 5.479
Yang Hongmei,Su Rui,Wishnok John S.,Liu Ning,Chen Changbao,Liu Shuying,Tannenbaum Steven R.
Magnetic silica nanoparticles (MSNPs) were prepared and applied for the first time as a matrix in MALDI MS for analysis of small thermally labile biomolecules including oligosaccharides, amino acids, peptides, nucleosides, and ginsenosides. The matrix was characterized by scanning electron microscopy and UV-vis spectroscopy. It displays good performance in analyses of such biomolecules in the positive ion mode. In addition, the method generates significantly less energetic ions compared to the use of carbon nanotubes or graphene-assisted LDI MS and thus produces intact molecular ions with little or no fragmentation. In addition, the MSNPs have better surface homogeneity and better salt tolerance and cause lower noise. It is assumed that the soft ionization observed when using MSNPs as a matrix is due to the specific surface area and the homogenous surface without large clusters. The matrices were applied to the unambiguous identification and relative quantitation of the water extract of Panax ginseng roots. Any false-positive results as obtained when using graphene and carbon nanotubes as a matrix were not observed.
Schematic presentation of the application of magnetic silica nanoparticles in laser desorption ionization mass spectrometry. Their use results in little or no fragmentation during analysis of small labile biomolecules with some advantages such as better surface homogeneity, high salt tolerance, and lower noise.
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JOURNAL OF POLYMER RESEARCH
·
2019
·Vol. 26
·期 2
·1-11
·
IF 1.53
Li Fan,Liu Jinhua,Luo Yue,Li Daqi,Zhang Fengying,Liu Sihai
Hydroxypropyl acrylate-N-diethyl-perfluorooctane sulfonamide (HAF), a novel surface active cationic fluorinated monomer, is designed and synthesized in this study. The structure of HAF and its intermediate product are characterized by FT-IR and 1 H-NMR. Then the hydrophobically associating polyacrylamide (PMHAF) is prepared by free radical polymerization of acrylamide, 2-Acrylamido-2- methylpropane sulfonic acid and HAF in an aqueous solution. The structure and composition of PMHAF are characterized by FT-IR, 1 H-NMR, XPS and Tg. Macroscopic and microscopic self-assembly associative properties in solutions of PMHAF are studied via viscosimetry, SEM and AFM. The result show that with the polymer concentration increase, the viscosity increased and the critical association concentration (CAC) is about 1.09 g.L −1 . Moreover, the active of PMHAF solution are examined with surface tension, interfacial tension (IFT) and contact angle. The CAC values of PMHAF in water and in salt from surface tension are 1.39 g.L −1 and 1.22 g.L −1 respectively. Copolymers can reduce the interfacial tension between crude oil from Xinjiang Oilfield /water, and the final values of IFT is around 0.0243 mN.m −1 and PMHAF solution has good potential on change of wettability. All of these properties indicate that the fluorinated hydrophobically associating polyacrylamide is an excellent chemical for chemical enhanced oil recovery.
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CHINESE JOURNAL OF POLYMER SCIENCE
·
2019
·Vol. 37
·期 6
·548-559
·
IF 2.804
Xu Wei-Ke,Tang Jing-Yu,Yuan Zhang,Cai Cai-Yun,Chen Xiao-Bin,Cui Shu-Quan,Liu Peng,Yu Lin,Cai Kai-Yong,Ding Jian-Dong
Bacterial infection is a very troublesome issue in wound treatment, which stimulates exudate formation and severely delays the healing process. Herein, a thermogelling dressing system composed of two triblock copolymers of poly(D,L-lactic acid- co -glycolic acid)- b -poly(ethylene glycol)- b -poly(D,L-lactic acid- co -glycolic acid) (PLGA-PEG-PLGA) with different block lengths was developed to deliver teicoplanin (TPN), a glycopeptide antibiotic, for cutaneous wound repair. The TPN-loaded thermogel was a free-flowing sol at room temperature and formed a semi-solid gel at physiological temperature. In vitro studies demonstrated that the TPN-loaded thermogel system exhibited desired tissue adhesiveness and realized the sustained release of TPN in a fast-followed-slow manner for over three weeks. Furthermore, a full-thickness excision wound model in Sprague-Dawley (SD) rats was constructed to assess the efficacy of TPN-loaded thermogel formulation. Gross and histopathologic observations implied that treatment with the thermogel formulation reduced inflammation response, promoted disposition of collagen, enhanced angiogenesis, and accelerated wound closure and maturity of SD rats. The combination of the bioactivity of TPN and the acidic nature of the thermogel matrix was responsible for such an enhanced wound healing process. Consequently, the TPN-loaded PLGA-PEG-PLGA thermogel is a good candidate of wound dressing for full-thickness excision wound healing.
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MICROCHIMICA ACTA
·
2019
·Vol. 186
·期 2
·1-10
·
IF 5.479
Wu Wenqin,Jia Mingming,Wang Zhongzheng,Zhang Wen,Zhang Qi,Liu Guozhen,Zhang Zhaowei,Li Peiwu
A method is described for the simultaneous voltammetric determination of the heavy metal ions cadmium(II), lead(II), mercury(II), zinc(II), and copper(II) using a glassy carbon electrode (GCE) modified with magnetite (Fe 3 O 4 ) nanoparticles and fluorinated multiwalled carbon nanotubes (Fe 3 O 4 /F-MWCNTs). The Fe 3 O 4 /F-MWCNT composite was synthesized by a hydrothermal method and characterized by X-ray photoelectron spectroscopy, X-ray diffraction, transmission electron microscopy, scanning electron microscopy, elemental mapping, electrochemical impedance spectroscopy, and square wave stripping voltammetry. Under the optimum conditions, the electrode displays excellent response to the ions. Figures of merit for Cd(II), Pb(II), Hg(II), Zn(II), and Cu(II), respectively, include (a) high electrochemical sensitivity (29.88, 43.50, 120.86, 47.34 and 90.31 (μA μM −1 cm −2 ), (b) well separated peaks (at −0.70, −0.53, +0.37, −1.11 and + 0.01 V vs. Ag/AgCl); (c) low limits of detection (0.014, 0.0084, 0.0039, 0.012, and 0.0053 μM); and (d) wide linear ranges (0.048–30.0, 0.028–30.0, 0.013–32.5, 0.039–32.5, and 0.017–31.5 μM). The modified GCE displays satisfying selectivity in the presence of potentially interfering other metal ions, stability for 30 days, and reproducibility of electrodes (with a relative standard deviation between 1.2 and 4.8% for n = 6). The modified GCE was applied to the determination of several heavy metal ions in (spiked) water and rice samples, and the results agreed well with data obtained by atomic fluorescence spectrometry or inductively coupled plasma-mass spectrometry. The dramatic performance probably result from the semi-ionic C-F bond on F-MWCNTs surface with a strong negative charge, the good electrical conductivity of the F-MWCNTs and Fe 3 O 4 , the synergistic interaction between Fe 3 O 4 and F-MWCNTs, and the nafion conductive membrane improving the stability of the modified layer and enhanced cation adsorption.
An environmentally-friendly, low-cost, high-throughput Fe 3 O 4 /fluorinated multi-walled carbon nanotube composite (Fe 3 O 4 /F-MWCNTs) modified glassy carbon electrode is described. It was applied to simultaneous electrochemical determination of Cd(II), Pb(II), Hg(II), Zn(II), and Cu(II) by square wave stripping voltammetry
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MICROCHIMICA ACTA
·
2019
·Vol. 186
·期 2
·1-8
·
IF 5.479
He Baoshan,Yan Sasa
A signal-on aptasensor is described for the voltammetric determination of kanamycin (KANA). Au@Pt core-shell nanoparticles with large surface and good electrical conductivity were synthetized and act as both a conductive material and as the carrier for complementary strands (CS2) and thionine (TH). In the presence of KANA, the electrochemical response of TH changes due to hybridization between CS1 immobilized on the electrode and the Au@Pt-CS2/TH system. The peak current increases linearly with the logarithm of the KANA concentration in the range from 1 pM to 1 μM, and the limit of detection is 0.16 pM. The sensor was characterized in terms of selectivity, reproducibility and stability, and satisfactory results were obtained. It was also utilized for the determination of KANA in (spiked) chicken samples. The recoveries (95.8–103.2%) demonstrate the potential of the method for KANA detection in real samples.
A signal-on aptasensor for kanamycin (KANA) was developed by using Au@Pt core-shell nanoparticles as nanocarrier for probe aptamer and as a sensing probe.
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JOURNAL OF MATERIALS SCIENCE-MATERIALS IN MEDICINE
·
2019
·Vol. 30
·期 1
·1-11
·
IF 2.467
Zhou Feilong,Song Zhimei,Wen Yi,Xu Hongmei,Zhu Li,Feng Runliang
Curcumin (CUR) is a hydrophobic polyphenol with anti-inflammatory activity. However, its low water-solubility and poor skin permeation limited its application in the treatment of dermititis. CUR-loaded micelles were prepared using thin membrane hydration method with methoxy poly (ethylene glycol)-block-poly (ε-caprolactone) (MPEG-PCL) as carrier material. The drug loading capacity and encapsulation efficiency were 12.14 ± 0.33 and 93.57 ± 1.67%, respectively. CUR-loaded micelles increased CUR’s water-solubility to 1.87 mg/mL, being 1.87 × 10 6 -folds higher than native CUR. CUR-loaded supramolecular hydrogels (CUR-H) were prepared through mixing the CUR-loaded micelles solution with α-cyclodextrin (α-CD) solution. The CUR-H presented continuous dissolution behaviour in aqueous medium for 4.5 h. The ex vivo skin permeation test and confocal fluorescence microscopy evaluation confirmed that CUR-H obviously enhanced skin deposition of CUR without drug flux from skin. In vivo experimental results confirmed that the CUR-H was more effective than dexamethasone ointments against croton oil-induced ear edema. The CUR-H composed of MPEG-PCL and α-CD is a promising formulation for skin inflammatory treatment.
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MICROCHIMICA ACTA
·
2019
·Vol. 186
·期 2
·1-9
·
IF 5.479
Chen Jia,Li Yunchun,Huang Yanni,Zhang Haijuan,Chen Xingguo,Qiu Hongdeng
The authors describe a fluorometric strategy for the determination of dopamine (DA). It is based on the use of aptamer-functionalized MoS 2 quantum dots (QDs) and MoS 2 nanosheets (NSs). The QDs and NSs were extensively characterized with regard to their physical and chemical properties using methods such as TEM, XRD, FT-IR, EDX and molecular spectroscopies. The aptamer against dopamine was labeled with QDs acting as the energy donor in an energy transfer system, while the NSs serve as the energy acceptor. Under the optimal conditions, the fluorescence (FL) intensity (best measured at excitation/emission peaks of 315/412 nm) increases with increasing DA concentration in the range from 0.1 nM to 1000 nM, with a lower detection limit of 45 pM. The method was successfully applied to the determination of DA in complex matrices. In our perception, the method has a wide scope in that it may be extended to other biomolecules for which respective aptamer are available. The QDs show excellent optical properties, good stability, low cytotoxicity, and may also be applied to fluorometric imaging of live cells.
A “turn-on” fluorometric aptasensor for the determination of dopamine (DA) was established based on aptamer-functionalized molybdenum disulfide quantum dots (MoS 2 QDs) and MoS 2 nanosheets. This assay exhibits high selectivity and sensitivity with a detection limit as low as 45 pM.
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Nanoscale Research Letters
·
2019
·Vol. 14
·期 1
·1-14
·
IF 3.159
Cen Chaode,Wu Jun,Zhang Yong,Luo Cong,Xie Lina,Zhang Xin,Yang Xiaolan,Li Ming,Bi Yang,Li Tingyu,He Tongchuan
This study aimed to improve the magnetofection of MG-63 osteoblasts by integrating the use of a novel uniform magnetic field with low molecular weight polyethylenimine modified superparamagnetic iron oxide nanoparticles (PEI-SPIO-NPs). The excellent characteristics of PEI-SPIO-NPs such as size, zeta potential, the pDNA binding and protective ability were determined to be suitable for gene delivery. The novel uniform magnetic field enabled polyethylenimine-modified superparamagnetic iron oxide nanoparticles/pDNA complexes (PEI-SPIO-NPs/pDNA complexes) to rapidly and uniformly distribute on the surface of MG-63 cells, averting local transfection and decreasing disruption of the membrane caused by the centralization of positively charged PEI-SPIO-NPs, thereby increasing the effective coverage of magnetic gene carriers during transfection, and improving magnetofection efficiency. This innovative uniform magnetic field can be used to determine the optimal amount between PEI-SPIO-NPs and pDNA, as well as screen for the optimal formulation design of magnetic gene carrier under the homogenous conditions. Most importantly, the novel uniform magnetic field facilitates the transfection of PEI-SPIO-NPs/pDNA into osteoblasts, thereby providing a novel approach for the targeted delivery of therapeutic genes to osteosarcoma tissues as well as a reference for the treatment of other tumors.
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Nanoscale Research Letters
·
2019
·Vol. 14
·期 1
·1-11
·
IF 3.159
Zhang Jijun,Chen Zexiang,Wang Yan,Yan Xinyu,Zhou Zhiyu,Lv Huifang
High electrochemical performance of asymmetric supercapacitor (ASC) depends on exquisite nanostructure design and synthesis of electrodes, including structural controllable design and synthesis of high theoretical performance materials and nanocomposite materials. Herein, a template-free hierarchical core-shell nanostructure of CoNiO 2 @NiAl-layered double hydroxide (NiAl-LDH) and α-Fe 2 O 3 with a hollow spherical structure composed of nanoparticles are successfully prepared. The CoNiO 2 @NiAl-LDH as the cathode electrode and the hollow spherical α-Fe 2 O 3 as the anode electrode of the ASC devices exhibit superior electrochemical performance. The gel of polyvinyl alcohol (PVA) and KOH acts as the solid electrolyte and the separator to assemble into the all-solid-state flexible ASC devices. Two of the CoNiO 2 @NiAl-LDH//α-Fe 2 O 3 ASC devices in series are fabricated to meet the voltage requirement of mobile energy equipment, which exhibit a maximum energy density of 65.68 Wh kg −1 at the power density of 369.45 W kg −1 . Interestingly, in addition to many advantages that the solid electrolyte in ASC devices already have, we find that it can be an alternative way of solving the problem of iron oxide cycling performance, and of course it can also be used as a reference for other materials with poor cycling performance.
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MICROCHIMICA ACTA
·
2019
·Vol. 186
·期 4
·1-9
·
IF 5.479
Jin Xin,Zhang Hong,Li Yu-Tao,Xiao Meng-Meng,Zhang Zhi-Ling,Pang Dai-Wen,Wong Gary,Zhang Zhi-Yong,Zhang Guo-Jun
The authors describe a field effect transistor (FET) based immunoassay for the detection of inactivated ebola virus (EBOV). An equine antibody against the EBOV glycoprotein was immobilized on the surface of the FET that was previously modified with reduced graphene oxide (RGO). The antibody against EBOV was immobilized on the modified FET, and the response to EBOV was measured as a function of the shift of Dirac voltage. The method can detect the EBOV over the concentration range from 2.4 × 10 −12 g·mL −1 to 1.2 × 10 −7 g·mL −1 and with a limit of detection as low as 2.4 pg·mL −1 . The assay has satisfactory specificity and was applied to the quantitation of inactivated EBOV in spiked serum.
Schematic presentation of the field effect transistor (FET) modified with reduced graphene oxide (RGO) for Ebola Virus (EBOV) detection. Specific binding between EBOV and the anti-EBOV antibody (Ab) on the FET device leads to obvious current change.
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