International Journal of Nanomedicine
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2013
·
IF 3.463
Yan Xiao,Huafang Zhang,Zhaoguo Zhang,Mina Yan,Ming Lei,Ke Zeng,Chunshun Zhao
For the purposes of obtaining a hepatocyte-selective drug delivery system, a novel tetravalent galactosylated diethylenetriaminepentaacetic acid-distearoyl phosphatidylethanolamine (4Gal-DTPA-DSPE) was synthesized. The chemical structure of 4Gal-DTPA-DSPE was confirmed by proton nuclear magnetic resonance and mass spectrometry. The four galactose-modified liposomes (4Gal-liposomes) were prepared by thin-film hydration method, then doxorubicin (DOX) was encapsulated into liposomes using an ammonium sulfate gradient loading method. The liposomal formulations with 4Gal-DTPA-DSPE were characterized by laser confocal scanning microscopy and flow cytometry analysis, and the results demonstrated that the 4Gal-liposomes facilitated the intracellular uptake of DOX into HepG2 cells via asialoglycoprotein receptor-mediated endocytosis. Cytotoxicity assay showed that the cell proliferation inhibition effect of 4Gal-liposomes was higher than that of the conventional liposomes without the galactose. Additionally, pharmacokinetic experiments in rats revealed that the 4Gal-liposomes displayed slower clearance from the systemic circulation compared with conventional liposomes. The organ distributions in mice and the study on frozen sections of liver implied that the 4Gal-liposomes enhanced the intracellular uptake of DOX into hepatocytes and prolonged the circulation. Taken together, these results indicate that liposomes containing 4Gal-DTPA-DSPE have great potential as drug delivery carriers for hepatocyte-selective targeting.
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POSTHARVEST BIOLOGY AND TECHNOLOGY
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2015
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IF 2.223
Jingxin Chen,Linchun Mao,Hongbo Mi,Wenjing Lu,Tiejin Ying,Zisheng Luo
Fruits are prone to suffer water-deficit stress and accelerated senescence after harvest. To understand the effect of postharvest water-deficit on the senescence progress of strawberry fruit, fruit peduncles were dipped into water or abscisic acid solution and stored at 20 °C with 50% relative humidity in the dark. The results showed that detached fruit without water supply through the peduncles suffered serious water-deficit stress with great weight loss and low moisture content. However, fruit absorbing water through their peduncles successfully avoided the water-deficit stress with a slight change of weight loss and moisture content. Water-deficit significantly promoted anthocyanin levels with increased PAL, C4H and DFR activities. The expressions of transcriptional factors that regulate anthocyanin biosynthesis ( FaMYB1 , FabHLH3 and FaTTG1 ) were also up-regulated under water-deficit stress. Meanwhile, stress elevated the abscisic acid level as well as FaNCED1 and FaASR expression in strawberry fruit. Furthermore, exogenous ABA application exhibited the similar features with water-deficit stress. These results suggested that postharvest water-deficit would accelerate anthocyanin accumulation in strawberry fruit and that abscisic acid may play a role in the response to water-deficit stress.
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INTERNATIONAL JOURNAL OF MASS SPECTROMETRY
·
2013
·
IF 2.142
Qing Yang,Yongjun Hu,Yanchun Wei,Honglei Wang,Jiwen Guan,Yanjiao Zhang,Shaoxin Li
Laser desorption postionization mass spectrometry (LDPI-MS) is a novel mass spectrometry. In present report, LDPI-MS method with 10.5 eV vacuum ultraviolet (VUV 118 nm) single photon ionization (VUV-SPI-MS) is firstly used to detect medicinal chemicals (taking the methylene blue (MB) as the example) in situ in intact tissues, where MB is dosed into the tissue in advance. The neutral species of tissue and dosed MB are vaporized under 1064 nm IR radiation firstly, and followed by VUV (118 nm) light for postionization. The optimal delay time between the desorption laser and ionization laser is between 18 and 35 μs. The results show that a variety of the fragments of amino acids and other biological species below m / z 100 can be detected in the tissue which do not interfere the signal of MB detected in the MB-dosed tissue. The method, termed laser desorption postionization mass spectrometry with 10.5 eV vacuum ultraviolet (VUV 118 nm) single photon ionization, promises to be an approach toward in situ detection of medicinal chemicals in intact tissues.
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ENVIRONMENTAL TOXICOLOGY
·
2013
·Vol. 29
·期 12
·1460-1470
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IF 2.708
Mingbao Feng,Ruijuan Qu,Ying Li,Zhongbo Wei,Zunyao Wang
Hexabromobenzene (HBB) is a novel brominated flame retardant (BFR) with ample evidence of its ubiquitous existence in the aquatic ecosystems. However, to date, the toxicological effects of this BFR on fish have been inadequately researched. The present study was conducted, based on an in vivo model, to investigate HBB-induced biochemical changes in liver and gill tissues of Carassius auratus after medium-term exposure to different concentrations (10, 150, and 300 mg/kg) for 7, 14, and 25 days. Oxidative stress was evoked evidently for the prolonged exposure, demonstrated by significant inhibition in antioxidant enzymes activities including superoxide dismutase, catalase, glutathione reductase, glutathione peroxidase, and glutathione S-transferase, and a decrease in reduced glutathione level, as well as simultaneous elevation in malondialdehyde content. Moreover, Na + , K + -ATPase activity, and protein level were remarkably reduced in fish tissues. Based on the integrated biomarker response, the toxic potency in each treatment was distinguished, and the more severe stress was mainly noted with the increasing concentrations and the extending durations. It was also observed that liver exhibited more pronounced alterations in biochemical parameters than gill, probably indicating the vulnerability of liver to HBB-triggered oxidative stress. Taken together, the results of this study clearly showed that HBB was capable of inducing oxidative stress and inhibiting Na + , K + -ATPase activity in different tissues of C. auratus after medium-term exposure. © 2013 Wiley Periodicals, Inc. Environ Toxicol 29: 1460–1470, 2014.
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RSC Advances
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2015
·Vol. 5
·期 124
·102811-102817
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IF 3.84
Fengwei Zhang,Shuai Chen,Huan Li,Xian-Ming Zhang,Hengquan Yang
A multi-component mesoporous core–shell structured nanocatalyst was prepared via encapsulation of a hydrophobic mesoporous carbon with amino-functionalized mesoporous silica, followed by coordination of palladium precursors and then reduction with a NaBH4 reagent. The resulting Pd/MCN@MS-NH2 catalyst could be well-dispersed in an aqueous medium owing to the inherent hydrophilic properties of the mesoporous silica shell. The experimental results indicated that the Pd/MCN@MS-NH2 catalyst had high catalytic activity and selectivity for the hydrogenation of phenol to cyclohexanone under 1 atm of H2 at 80 °C for 3 h in pure water (conversion > 99% and selectivity 99%). Furthermore, the catalyst can be easily recovered and reused six times without significant loss of catalytic activity.
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DRUG DEVELOPMENT AND INDUSTRIAL PHARMACY
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2016
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IF 2.429
Zhiyong Wang,Jinhua Wang,Songling Yang,Shuying Hou
In this study, the PEGylated nanostructured lipid carriers (PEG-NLC) were constructed for the intravenous delivery of 17-allylamino-17-demethoxygeldanamycin (17AAG). 17AAG-PEG-NLC was successfully prepared by the method of emulsion evaporation at a high temperature and solidification at a low temperature using a mixture of glycerol monostearate and PEG2000-stearate as solid lipids, and medium-chain triglyceride as the liquid lipid. The results revealed that the morphology of the NLC was spheroidal. The particle size, zeta potential and entrapment efficiency for 17AAG-PEG-NLC were observed as 189.4 nm, −20.2 mV and 83.42%, respectively. X-ray diffraction analysis revealed that 17AAG existed as amorphous structures in the nanoparticles. In the in vitro release study, the 17AAG from 17AAG-PEG-NLC exhibited a biphasic release pattern with burst release initially and sustained release afterwards. In addition, 17AAG-PEG-NLC showed a significantly higher in vitro antitumor efficacy and longer retention time in vivo than 17AAG solution. These results indicated that 17AAG-PEG-NLC may offer a promising alternative to the current 17AAG formulations for the treatment of solid tumors.
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Journal of Materials Chemistry B
·
2014
·Vol. 2
·期 35
·5910-5924
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IF 0
Hongmei Liu,Chenmeng Qiao,Jun Yang,Jie Weng,Xin Zhang
Co-delivery of siRNAs and chemotherapeutic drugs to kill tumors have achieved superior tumor growth inhibition. However, due to siRNAs and chemotherapeutic drugs with different molecular properties, co-delivery carriers use more cationic materials to bind siRNAs and excessive inert materials to embed drugs, causing low drug-loading contents and systemic toxicity. To achieve this goal, doxorubicin (DOX) is chemically conjugated to stearoyl chloride (C18) through N-methyldiethanol amine (N) as cross-linker to form amphiphilic C18–N–DOX. C18–N–DOX contains a tertiary amine that can complex siRNAs at low pH (pH 3) and reduce the density of the positive charges on the surface of NPs at physiological pH (pH 7.4). C18–N–DOX, together with 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-methoxy-poly(ethylene glycol 2000) DSPE-PEG2000, self-assemble into DOX-prodrug nanoparticles (DOX-prodrug NPs), which bind siRNAs in citrate buffer (pH 3) to form DOX-prodrug NPs/siRNA. After replacing citrate buffer (pH 3) with PBS (pH 7.4), DOX-prodrug NPs/siRNA have slight negative charges due to complexed more siRNAs. In this study, clear evidence is shown that DOX-prodrug NPs can deliver siRNA to the same tumor cells both in vitro and in vivo. Moreover, DOX-prodrug NPs/siRNA show a great effect on inhibiting tumor cell growth both in vitro and in vivo. Therefore, the DOX-prodrug NPs are promising candidates as siRNAs delivery system for tumor therapy.
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Polymer Chemistry
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2014
·Vol. 5
·期 21
·6216-6224
·
IF 5.368
Xiao Wang,Yuan Gao,Hui Zhao,Xiao-Qing Liu,Zhengke Wang,Anjun Qin,Qiaoling Hu,Jing Zhi Sun,Ben Zhong Tang
Monosaccharide-functionalized poly(phenylacetylenes) (PPAs) are synthesized with high yield and molecular weight, but it shows no solvating power to multiwalled carbon nanotubes (MWCNTs) by simply blending them together. Polymerization of monosaccharide-functionalized monomers in the presence of MWCNTs (in situ polymerization) leads to the hybrids of monosaccharide-functionalized PPAs/MWCNTs, and the content of MWCNTs is over 2% by weight. The characterization data indicates that the π–π interaction between the styrene-like moieties in the polymer backbone and the MWCNTs plays crucial role in the dispersing capacity. Based on the in situ precipitation method, CS rods containing monosaccharide-functionalized PPAs/MWCNTs hybrids were fabricated. The bending strength and modulus of the hybrid-reinforced CS rods showed substantial improvement in comparison with the CS rods made from pristine and hydroxyapatite-reinforced CS.
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RSC Advances
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2014
·Vol. 4
·期 57
·30004-30012
·
IF 3.708
Yaping Zheng,Ruilu Yang,Fei Wu,Dewang Li,Nan Wang,Aibo Zhang
A multiwall carbon nanotube (MWCNT) derivative with liquid-like behaviour at room temperature was prepared by attaching Fe3O4 on the surface of MWCNT and employing tertiary amine terminated organosilanes as a corona and sulfonic-acid as a canopy. The MWCNT derivative is a Newtonian fluid at low shear rate. It has relative low viscosity at room temperature (3.87 Pa s at 25.7 °C). It shows good solubility in organic solvents such as ethanol, acetone and dichloroethane. Transmission electron microscopy (TEM) images confirmed the good dispersion of the MWCNT derivative in the solvent and the epoxy matrix. The MWCNT derivative is a super-paramagnetic material with a specific magnetization of 2.68 emu g−1. According to the TEM image, the derivative can be aligned in the epoxy matrix under a magnetic field. The MWCNT derivative can improve the impact toughness of pure epoxy by 194% and the glass transition temperature (Tg) by 16.9 °C. The MWCNT derivative has many novel properties and can be used in nanocomposites.
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RSC Advances
·
2014
·Vol. 4
·期 51
·26653-26661
·
IF 3.708
Liqing Jiang,Meng Li,Lin Lin,Yongfeng Li,Xingquan He,Lili Cui
A series of non-noble-metal catalysts for oxygen reduction reaction (ORR), based on metal 5,10,15,20-tetrakis(4-hydroxyphenyl)porphyrin (M-THPP, M: Fe3+, Co2+, Ni2+, Mn2+) grown on poly(sodium-p-styrenesulfonate) modified reduced graphene oxide (PSS-rGO), were fabricated using an in situ solvothermal synthesis method. The morphology of the M-THPP/PSS-rGO was characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Ultraviolet-visible (UV-vis) absorption spectroscopy and X-ray photoelectron spectroscopy (XPS) techniques were utilized to analyse the unusual interactions between the metalloporphyrins and graphene sheets. Electrochemical measurements using rotating disk electrode (RDE) and rotating ring-disk electrode (RRDE) techniques were employed to study the catalytic activity and the mechanism of the oxygen reduction reaction on the as-synthesised M-THPP/PSS-rGO catalysts in an alkaline medium. The half-wave potential for the ORR on the CoTHPP/PSS-rGO catalyst was found to be around −0.22 V vs. SCE, which was much higher than those on the other M-THPP/PSS-rGO catalysts and similar to that on Pt/C (−0.20 V vs. SCE). RDE and RRDE results show that the ORR process proceeds mainly via an almost 4-electron pathway on CoTHPP/PSS-rGO. The catalyst stability tests disclose that the CoTHPP/PSS-rGO is much more stable than the other M-THPP/PSS-rGO composites. The assembled CoTHPP/PSS-rGO catalyst possesses high activity, good long-term stability, excellent tolerance to the crossover effect of methanol and a facile 4-electron pathway for ORR, which could be used as a promising Pt-free catalyst in an alkaline direct methanol fuel cell.
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Scientific Reports
·
2017
·Vol. 7
·期 1
·1-11
·
IF 4.259
Huang Haiying,Tao Xuanyu,Jiang Yiming,Khan Aman,Wu Qi,Yu Xuan,Wu Dan,Chen Yong,Ling Zhenmin,Liu Pu,Li Xiangkai
Soil contamination by PAH and heavy metals is a growing problem. Here, we showed that a new isolate, Pseudomonas brassicacearum strain LZ-4, can simultaneously degrade 98% of 6 mM naphthalene and reduce 92.4% of 500 μM hexavalent chromium [Cr (VI)] within 68 h. A draft genome sequence of strain LZ-4 (6,219,082 bp) revealed all the genes in the naphthalene catabolic pathway and some known Cr (VI) reductases. Interestingly, genes encoding naphthalene pathway components were upregulated in the presence of Cr (VI), and Cr (VI) reduction was elevated in the presence of naphthalene. We cloned and expressed these naphthalene catabolic genes and tested for Cr (VI) reduction, and found that NahG reduced 79% of 100 μM Cr (VI) in 5 minutes. Additionally, an nahG deletion mutant lost 52% of its Cr (VI) reduction ability compared to that of the wild-type strain. As nahG encodes a salicylate hydroxylase with flavin adenine dinucleotide (FAD) as a cofactor for electron transfer, Cr (VI) could obtain electrons from NADH through NahG-associated FAD. To the best of our knowledge, this is the first report of a protein involved in a PAH-degradation pathway that can reduce heavy metals, which provides new insights into heavy metal-PAH contamination remediation.
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APPLIED MICROBIOLOGY AND BIOTECHNOLOGY
·
2017
·Vol. 101
·期 13
·5325-5332
·
IF 3.42
Cao Hao,Nie Kaili,Li Chengcheng,Xu Haijun,Wang Fang,Tan Tianwei,Liu Luo
Adenosine-5′-triphosphate (ATP) is the energy equivalent of the living system. Polyphosphate (polyP) is the ancient energy storage equivalent of organisms. Polyphosphate kinases (PPKs) catalyze the polyP formation or ATP formation, to store energy or to regenerate ATP, respectively. However, most PPKs are active only in the presence of long polyPs, which are more difficult and more expensive to generate than the short polyPs. We investigated the PPK preference towards polyPs by site-directed mutagenesis and computational simulation, to understand the mechanism and further design enzymes for effective ATP regeneration using short polyPs for in vitro cascade reactions, which are highly desired for research and applications. The results suggest that the short polyPs inhibit PPK by blocking the ADP-binding pocket. Structural comparison between PPK ( Corynebacterium glutamicum ) and PPK ( Sinorhizobium meliloti ) indicates that three amino acid residues, i.e., lysine, glutamate, and threonine, are involved in the activity towards short polyP by fixing the adenosine group of ADP in between the subunits of the dimer, while the terminal phosphate group of ADP still offers an active site, which presents a binding pocket for ADP. A proposed triple mutant PPK (SMc02148-KET) demonstrates significant activity towards short polyP to form ATP from ADP. The obtained high glutathione titer (38.79 mM) and glucose-6-phosphate titer (87.35 mM) in cascade reactions with ATP regeneration using the triple mutant PPK (SMc02148-KET) reveal that the tailored PPK establishes the effective ATP regeneration system for ATP-dependent reactions.
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