Acta Biomaterialia
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2017
·
IF 6.319
Huicong Zhou,Huanjiao Sun,Shixian Lv,Dawei Zhang,Xuefei Zhang,Zhaohui Tang,Xuesi Chen
Traditional chemotherapy strategy exists undesirable toxic side-effects to normal tissues due to the low selectively to cancer cells of micromolecule cytotoxic drugs. One considered method to realizing the targeted delivery and increasing the specificity to tumor tissues of the cytotoxic drug is to transporting and discharging it through an environment-sensitive mechanism. In this study, a novel enzyme-sensitive polymer-doxorubicin conjugate was designed to delivery chemotherapeutic drug in a tumor-specific behavior and selectively activated in tumor tissue. Briefly, doxorubicin (DOX) was conjugated to carboxyl-terminated 4-arm poly(ethylene glycol) through a tetrapeptide linker, alanine-alanine-asparagine-leucine (AANL), which was one of the substrates of legumain , an asparaginyl endopeptidase that was found presented in plants, mammals and also highly expressed in human tumor tissues. Hereinafter, the polymer-DOX conjugate was termed as 4-arm PEG-AANL-DOX. Dynamic laser scattering (DLS) and transmission electron microscopy (TEM) measurements indicated that the 4-arm PEG-AANL-DOX could self-assemble into micelles in aqueous solution. Drug release and in vitro cytotoxicity studies revealed that the 4-arm PEG-AANL-DOX could be cleaved by legumain. Ex vivo DOX fluorescence imaging measurements demonstrated that the 4-arm PEG-AANL-DOX had an improved tumor-targeting delivery as compared with the free DOX·HCl. In vivo studies on nude mice bearing MDA-MB-435 tumors revealed that the 4-arm PEG-AANL-DOX had a comparable anticancer efficacy with the free DOX·HCl but without DOX-related toxicities to normal tissues as measured by body weight change and histological assessments, indicating that the 4-arm PEG-AANL-DOX had an improved therapeutic index for cancer therapy. Statement of Significance Herein we describe the construction of a novel tumor environment-sensitive delivery system through the instruction of a legumain-cleavable linkage to a polymer-DOX conjugate (4-arm PEG-AANL-DOX). This particular design strategy allows for polymer-DOX conjugates to be delivered in a tumor-specific manner and selectively activable in tumor microenvironment so that it can combine the advantages of tumor-specific delivery and tumor intracellular microenvironment-triggered release systems.
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PubMed
高影响因子
Nanoscale
·
2017
·Vol. 9
·期 43
·17004-17012
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IF 7.367
Hui Xu,Jin Wang,Bo Yan,Shumin Li,Caiqin Wang,Yukihide Shiraishi,Ping Yang,Yukou Du
Highly open metallic nanocages represent a novel class of nanostructures for advanced catalytic applications in direct liquid fuels cells due to their specific capability of providing easy access to reactants in both internal and external active sites and also desirable electronic structures for the adsorption of molecules, which render superior catalytic performances. However, to date, the rational design of trimetallic nanocages with tunable compositions remains a challenge. Herein, we demonstrate a facile method combining seed mediated and galvanic replacement for the preparation of unique trimetallic Pd–Au–Ag nanocages catalysts with tunable compositions. A series of controlled experiments reveal that the reaction time plays a crucial role in affecting the morphology of the final product. Importantly, the newly-generated Pd–Au–Ag nanocages are high-performance electrocatalysts for the oxidation of both ethylene glycol and glycerol with mass activities of 7578.2 and 5676.1 mA mg−1, respectively, which are far superior to that of commercial Pd/C. We firmly believe that the strategy and enhanced electrocatalysts developed in this study can be well applied to boost the commercial development of fuel cell technologies.
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高影响因子
RSC Advances
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2016
·Vol. 6
·期 57
·51694-51702
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IF 3.289
Wenwen Deng,Yufeng Lei,Shengwen Zhou,Anqiang Zhang,Yaling Lin
Polydimethylsiloxanes (PDMS) are soft materials with high elasticity and excellent biocompatibility, giving them high potential for widespread applications as biomaterials. However, the application of PDMS to wound dressing is limited due to its shortcomings, particularly its non-absorptive and poor adhesive properties. This work addresses these limitations in two ways: first, a hydrophilic and biocompatible polyethylene glycol (PEG) block was introduced to the PDMS main chain to obtain carboxyl acid terminated PDMS-b-PEG-b-PDMS copolymers (EPMDS–COOH2); second, EPMDS–COOH2 polymers were reacted with diethylenetriamine and urea via a two-stage route to obtain a novel supramolecular elastomer (ESESi) based on multiple hydrogen bond association. Compared with the supramolecular elastomer based on simple PDMS (SESi), the hydrophilicity, water-absorption rate, adhesive ability and rate of water vapor permeation were significantly improved, enhancing the properties of ESESi films for application to wound dressing. After fully evaluating the bio-compatibilities of ESESi films, a full-thickness dermal wound model was chosen to estimate the healing performance, and traditional vaseline gauze, SESi film and commercialized Tegaderm™ film were chosen as controls. The results confirmed that the ESESi polymer could promote the healing of a skin wound to some extent, mainly due to its improved absorption and adhesive properties.
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高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
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2017
·
IF 5.401
Shuo Geng,Shu Min Lin,Nian Bing Li,Hong Qun Luo
As an important heavy metal ion, copper has the negative influence on otherwise healthy individuals, so establishing a valid way for the highly efficient, sensitive, and quantitative determination of Cu 2+ ion becomes an emergency in the environmental analysis. In the present work, water-soluble luminescent ZnO quantum dots (QDs) capped by polyethylene glycol (PEG) have been synthesized by a simple solution method. The PEG capped ZnO QDs (PEG@ZnO QDs) showed yellow fluorescence. High-resolution transmission electron microscopy, UV–vis absorption spectroscopy, Fourier transform infrared spectroscopy, and luminescence spectroscopy were applied to elucidate the properties of the PEG@ZnO QDs. In addition, the yellow fluorescence of the PEG@ZnO QDs was quenched when Cu 2+ ion was added to the PEG@ZnO QDs solutions. Therefore, a novel fluorescent probe was designed to detect Cu 2+ in water solution. The linear relationships were 10–200 nM and 2–10 μM, respectively, with the detection limit for Cu 2+ at 3.33 nM according to 3σ/slope (where σ denotes the standard deviation of the blank measures). The proposed sensor of the PEG@ZnO QDs has also been used in natural water samples to examine the availability of this method. In addition, the quenching mechanism was discussed, which may be attributed to the aggregation induced quenching.
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高影响因子
JOURNAL OF CHEMICAL THERMODYNAMICS
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2016
·
IF 2.196
Shurui Xu,Shuanshi Fan,Haiyuan Yao,Yanhong Wang,Xuemei Lang,Pingping Lv,Songtian Fang
In this paper, the three-phase coexistence points are generated for multicomponent gas hydrate in methanol (MeOH) solution for (0.05, 0.10, 0.15, and 0.35) mass fraction and ethylene glycol (EG) solution for (0.05, 0.10, 0.15, 0.35, 0.40 and 0.55) mass fraction. The phase equilibrium curves of different system were obtained by an isochoric pressure-search method on high pressure apparatus. The phase equilibrium regions of multicomponent gas hydrate were measured using the same composition of natural gas distributed in the South China Sea. And the different concentration solutions were prepared based formation water. The experimental data were measured in a wide range temperature from 267.74 to 298.53 K and a wide range pressure from 4.22 MPa to 34.72 MPa. The results showed that the hydrate phase equilibrium curves shifted to the inhibition region in accordance with the increased inhibitor concentration. In addition, the equilibrium temperature would decrease about 2.7 K when the concentration of MeOH increased 0.05 mass fraction. Besides, the suppression temperature was 1.25 K with the 0.05 mass fraction increase of EG concentration in the range of 0.05 mass fraction to 0.15 mass fraction. While in high EG concentration region, the suppression temperature was 3.3 K with the same increase of EG concentration (0.05 mass fraction).
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高影响因子
JOURNAL OF DISPERSION SCIENCE AND TECHNOLOGY
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2017
·
IF 1.591
Jianbin Qin,Guangcheng Zhang,Xuetao Shi
The monodisperse polystyrene (PS) microspheres were prepared by dispersion polymerization. The rheological properties of shear thickening fluid (STF) based on PS microspheres dispersing in polyethylene glycol with different concentrations were studied through the steady and oscillatory shear at different temperatures, respectively. All suspensions successively present the first shear thinning, the shear thickening, and the second shear thinning. The experimental results indicate that the shear thickening behavior of STF is controlled by the concentration of PS microspheres and temperature, as changed from continuous shear thickening (CST) to discontinuous shear thickening (DST) with increasing solid content or decreasing temperature. The STF is affected by shear rate, temperature, and the viscosity of the dispersed medium, and it is reversible absolutely and presents transient response ability. Both CST and DST behave as dilatancy. The PS microsphere aggregations formed under shear stress may result in the shear thickening in STFs.
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高影响因子
COMPOSITES PART A-APPLIED SCIENCE AND MANUFACTURING
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2016
·
IF 3.719
Junjiu Gao,Jiang Zhu,Jingjing Luo,Jie Xiong
The application of electrospun nanofibrous scaffolds in tissue engineering is limited due to their small pore size which leads to the failure of cell infiltration into the scaffolds. Microporous silk fibroin (SF)/gelatin composite scaffolds with biological properties could be fabricated to mimic tissue structure for tissue engineering applications. This study aimed to present a simple method to fabricate the composite scaffolds which is based on the simultaneously electrospraying of microspheres and electrospinning of nanofibers. Different contents of polyethylene glycol (PEG) microspheres were embedded into the SF/gelatin nanofibrous membranes by varying the content of PEG microsphere. Furthermore, microspheres can be selectively leached, obtaining the single SF/gelatin nanofibrous scaffolds and retaining the hierarchical organization of the porous nanofibers. In conclusion, the multilevel microporous and nanofibrous composite scaffolds can be obtained by varying pump flow rate of electrospraying.
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高影响因子
NANO
·
2017
·
IF 1.025
Xuedong Gao,Lulu Liu,Qiyu Wang,Kun Qi,Zhao Jin,Weitao Zheng,Xiaoqiang Cui
Nanodendritic Pt-based bimetallic alloys are one promising catalyst with three-dimensional (3D) networks structure composed of integrating branches for electrochemical catalytic reaction. We successfully synthesized dendrites Pt 6 Ir 4 alloy with small size of 20 nm in oleylamine. The dendritic Pt 6 Ir 4 alloy are characterized by high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The electrochemical tests suggest that the as-prepared dendritic Pt 6 Ir 4 alloy exhibits greatly enhanced ethylene glycol oxidation reaction (EGOR) activity than commercial Pt/C with high EGOR mass activity, anti-poisoning and stability.
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高影响因子
MACROMOLECULAR RESEARCH
·
2017
·Vol. 25
·期 3
·206-213
·
IF 1.405
Fang Qisheng,Chen Tao,Zhong Qi,Wang Jiping
Thermoresponsive P(MEOMA- co -OEGMA) copolymers of Ethylene glycol methyl ether methacrylate (MEOMA) and oligo(ethylene glycol) methacrylate (OEGMA) were synthesized through free-radical copolymerization initiated by azodiisobutyronitrile (AIBN) in solution polymerization. The lower critical solution temperature (LCST) of The P(MEOMA- co -OEGMA) copolymers can be controlled by adjusting the mole fractions of MEOMA and OEGMA. The synthesized copolymers were characterized by proton nuclear magnetic resonance spectroscopy ( 1 H NMR), infrared spectrum (FTIR) and gel permeation chromatography (GPC). The LCST of the synthesized copolymers and diverse results of FTIR and contact angle of the films were examined in different conditions, which can explain the transformation of thermoresponsive polymer with changing temperature. The LCST behavior of the polymers in ethanol/water co-solvent was measured, which contribute to coat polymers onto fabrics substrate conveniently. Modified fabrics showed tunable hydrophilic as so-called “Smart Textiles”.
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高影响因子
RSC Advances
·
2016
·Vol. 6
·期 81
·77499-77506
·
IF 3.289
Kai Zhang,Shubin Wu,He Yang,Huimin Yin,Gang Li
As promising and environmentally friendly catalysts, tungsten-containing heteropoly acids combined with supported noble metals were used for one-pot hydrothermal conversion of cellulose into polyols in the presence of pressurized hydrogen. The microcrystalline cellulose was completely converted over a mixed catalyst consisting of a low concentration of phosphotungstic acid (PTA) (0.03 wt%) and Ru/activated carbon (Ru/AC) via an one-pot hydrothermal reaction, with an ethylene glycol (EG) yield of up to 53.1% under optimal conditions. The catalytic activity of the mixed catalyst gradually decreased with increasing reaction runs, which could be mainly ascribed to the aggregation of Ru/AC particles, and to the coverage of the active sites of Ru due to the deposition of organic materials. Cellobiose was used as a model feedstock for a comparative study on the reaction pathways of the conversion of cellulose, and the results revealed that catalytic conversion of cellobiose consisted of at least three important parallel reactions under the present hydrothermal conditions, which were also most likely involved during the catalytic conversion of cellulose for EG production. Effective control of these reactions would be helpful to further maximize the EG yield during the catalytic conversion of cellulose.
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高影响因子
GREEN CHEMISTRY
·
2016
·Vol. 19
·期 3
·682-691
·
IF 8.506
Naixu Li,Yu Zheng,Lingfei Wei,Hongcheng Teng,Jiancheng Zhou
Although the conversion of cellulose to polyols is currently well-developed, the production of the considerably valuable ethylene glycol (EG) is still challenging. Reactions have long relied on the design of suitable catalysts to obtain a high selectivity and yield of EG. Herein, using well-shaped rectangular tungsten trioxide nanosheets as the substrate, we investigated the catalytic performances of various metal supported catalysts for the convertion of cellulose to EG. Results show that Ru/WO3 is more favorable for EG production, with the highest EG yield of 76.3% over the 1% Ru/WO3 nanosheet catalyst. Our characterizations and activity tests suggest that the embedding of Ru nanoparticles onto the WO3 nanosheets produces more W5+ active sites under the same reduction conditions (NaBH4 or H2), which act as Lewis base sites to promote the glucose retro-aldol condensation reaction. Moreover, the Ru/WO3 catalyst holds a portion of Ru in the form of amorphous RuOxδ+ phases, which could further increase the H+ released into an aqueous solution for cellulose hydrogenolysis. A possible catalytic mechanism for this hydrogenolysis process is accordingly proposed.
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高影响因子
JOURNAL OF POLYMER RESEARCH
·
2017
·Vol. 24
·期 6
·1-11
·
IF 1.615
Wang Hongxun,Ying Xiaoguang,Liu Jiangquan,Li Xiao,Zhang Weiying
Bovine serum albumin imprinted polyethylene glycol 600 (PEG600) grafted Calcium alginate (CaA) hydrogel microspheres were prepared and characterized. The adsorption and recognition properties of PEG600 grafted calcium alginate (CaA- g -PEG600) microspheres were evaluated and the results showed that the crosslinking structure of CaA- g -PEG600 microspheres exerted an obvious effect on the adsorption capacity and imprinting properties for bovine serum albumin. The adsorption isotherms and recognition properties indicated that the imprinted modified microspheres had excellent rebinding affinity toward target proteins and the imprinting efficiency varied according to PEG600 grafting degree. The adsorption capacity and the imprinting factor were 5.5 mg g −1 and 3.6, respectively. Adsorption kinetics of CaA- g -PEG600 microspheres in accordance with the molecular weight between crosslinks ( M c) was investigated and the structural influence on protein selective rebinding was discussed. Furthermore, the binary solution separation performance of CaA- g -PEG600 microspheres with different M c was investigated by selective binding bovine serum albumin from protein mixture solution.
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高影响因子
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