RSC Advances
·
2015
·Vol. 5
·期 22
·17194-17201
·
IF 3.84
Zhiping Du,Xiaofeng Sun,Xiumei Tai,Guoyong Wang,Xiaoying Liu
Thermosensitive SiO2 nanoparticles were prepared with graft-on poly(ethylene glycol) methyl ether methacrylate (POEGMA, Mn ∼ 300 or 500 g mol−1) via atom transfer radical polymerization with activators generated through electron transfer (AGET ATRP). CuBr2/PMDETA and ascorbic acid (AA) were employed as the catalyst and reducing agent respectively in the fabrication process. The structure and surface composition of our hybrid materials were analyzed using Fourier Transform Infrared (FTIR) spectroscopy and X-ray Photoelectron Spectroscopy (XPS) in detail. The results of Thermogravimetric Analysis (TGA) show that AGET-ATRP could provide a higher surface grafting density to get more pronounced thermosensitive properties. The morphology of our hybrid SiO2 nanoparticles was characterized by Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy (SEM). measurements of turbidity, Dynamic Light Scattering (DLS), and phase transfer were conducted to investigate the thermal responses of the hybrid material. In addition, Pickering emulsions were prepared using such hybrid SiO2-POEGMA as an emulsifier. Moreover, its fast de-emulsification above a lower critical solution temperature (LCST) may be exploited for the efficient separation and recycling of catalysts in future.
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POLYMER INTERNATIONAL
·
2015
·Vol. 64
·期 10
·1415-1424
·
IF 2.409
Weijuan Sheng,Teng Liu,Shouxin Liu,Qinqin Wang,Xuan Li,Naer Guang
A novel temperature responsive copolymer, poly[2-(2-methoxyethoxy)ethyl methacrylate- co -oligo(ethylene glycol)methacrylate- co-N -hydroxymethyl acrylamide] [P(MEO 2 MA- co -OEGMA- co -HMAM)], was synthesized by atom transfer radical polymerization. pH responsive poly(methacrylic acid) (PMAA) was synthesized by reversible addition-fragmentation chain transfer polymerization. After the hydroxyl groups on P(MEO 2 MA- co -OEGMA- co -HMAM) were transformed into azide groups and the carboxyl groups on PMAA were transformed into alkyne groups respectively, a novel temperature and pH responsive hydrogel was fabricated by click chemistry between the azide-P(MEO 2 MA- co -OEGMA- co -HMAM) and alkyne-PMAA in the presence of CuSO 4 and sodium ascorbate in aqueous solution. The rheological kinetics of gel formation demonstrated that gelation had commenced within 5 min at 25 °C, since then the storage modulus ( G ′) was higher than the loss modulus ( G ″). SEM images of hydrogel morphology and the swelling ratios of hydrogel at different temperatures and pH proved that the formed hydrogel had temperature and pH sensitivities. Bovine serum albumin was used as a model to evaluate the sustained release of the hydrogel; the results indicated that the hydrogel was a promising candidate for controlling protein drug delivery. © 2015 Society of Chemical Industry
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RSC Advances
·
2015
·Vol. 5
·期 99
·81115-81122
·
IF 3.84
Xinzhen Zhao,Huixia Xuan,Chunju He
Branched polyethylene glycol (PEG) was anchored onto a membrane surface by efficient covalent self-assembly to optimize the separation and antifouling properties of polyvinylidene fluoride (PVDF) ultrafiltration membranes based on its excellent hydrophilic and antifouling properties. The results showed that the surface self-assembly method could effectively improve the stability of PEG and the surface wetting ability of the PVDF membrane, and simultaneously enhanced the water flux and rejection of modified membranes. Meanwhile, the fouling results showed the anchored PEG segments on the separation interface contributed to improve the antifouling performance of the PVDF ultrafiltration membrane with significantly improved anti-adsorption capacity for bovine serum albumin (BSA) and expectant water flux recovery ratios for BSA and humic acid (HA), two typical pollutants. This paper provides a sample modification idea and demonstrated covalent self-assembly was an effective method for surface modification.
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ELECTROCHIMICA ACTA
·
2015
·
IF 4.504
Pei Song,Lei Liu,Ai-Jun Wang,Xi Zhang,Si-Yuan Zhou,Jiu-Ju Feng
In this work, three-dimensional trimetallic Pt–Pd–Co alloyed nanoflowers are fabricated by a facile one-pot solvothermal strategy, with the assistance of oleylamine as the solvent, surfactant, and reducing agents, along with cetylpyridinium chloride (CPC) as the co-surfactant and shape-directing agents. Their morphology and crystal structure were investigated by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning transmission electron microscope (STEM), and X-ray photoelectron spectra (XPS) in details. The respective electrochemically active surface area (ECSA) is estimated to be 32.53 m 2 g −1 , and current density is 132.91 mA cm −2 for the electrooxidation of ethylene glycol (EG). These values are much higher than those of PtPdCo nanoparticles, PtPd nanoparticles, commercial Pt black, and Pd black under the identical conditions, showing the improved catalytic activity of Pt–Pd–Co nanoflowers. The excellent performances are attributed to the specific structure and synergistic interactions of the trimetallic alloy. The as-prepared nanoflowers can serve as a promising electrocatalyst in fuel cells.
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Journal of Materials Chemistry B
·
2013
·Vol. 1
·期 43
·5933-5941
·
IF 0
Hua Guo,Chengling Yang,Zhenpeng Hu,Wei Wang,Yukun Wu,Quanyong Lai,Zhi Yuan
The high viscosity of sodium alginate (ALG) causes its insufficient drug loading and limits its application as a drug carrier. In the present work, we synthesized poly(ethylene glycol) oligomer (mOEG)-modified sodium alginate (ALG–mOEG) and characterized its properties as a drug delivery system. Our results showed that ALG–mOEG displayed a greatly reduced viscosity (0.024 Pa s at 2.0 wt%) with a significantly improved drug loading capacity (18.0% (w/w)) compared with unmodified ALG (6.9% (w/w)). In addition, DOX–ALG–mOEG nanoparticles (DOX–ALG–mOEG NPs) with high drug loading were more cytotoxic for HepG2 cells in vitro and showed a higher antitumor activity in vivo compared with the control group (DOX–ALG NPs) at the same dose of DOX. DOX–ALG–mOEG NPs inhibited HepG2 proliferation in vitro with an IC50 value of 220.0 ng mL−1 and reduced tumor growth in vivo by 75.6%, while DOX–ALG NPs showed activities of 443.9 ng mL−1 and 62.7%, respectively. Meanwhile, we did not observe the “accelerated blood clearance (ABC)” phenomenon in these mOEG-modified ALG nanoparticles. In view of most biologic and chemical molecules used for the biological function being hydrophobic, we thought the ALG–mOEG scaffold also might serve as an efficient long-duration carrier for other hydrophobic molecules with minimal immunogenicity.
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PubMed
JOURNAL OF BIOMATERIALS SCIENCE-POLYMER EDITION
·
2013
·
IF 1.7
Wanyun Liu,Junchao Wei,Ping Huo,Yunhua Lu,Yiwang Chen,Yen Wei
A diblock copolymer of monomethoxy-poly(ethylene glycol)-b-poly(L-lactide) (MePEG-PLLA)/brefeldin A (BFA) conjugate was synthesized by the reaction of carboxyl-terminated copolymer MePEG-PLLA with BFA in the presence of dicyclohexylcarbodiimide and dimethylaminopyridine. The conjugation efficiency was found to be 95%. Its structure was confirmed by 1H nuclear magnetic resonance and gel permeation chromatography. The MePEG-PLLA/BFA conjugate could self-assemble into micelles in aqueous solutions with a low critical micelle concentration of 1.8 × 10−3 g/L. Dynamic light scattering and transmission electron microscopy analyses of the MePEG-PLLA/BFA micelles revealed their spherical structure with an average diameter of 120 nm. The release profiles of BFA in PBS were measured by high performance liquid chromatography (HPLC), demonstrating that the controlled release of BFA can be gained for long time. The in vitro antitumor activity of the conjugate micelles against human liver carcinoma HepG2 cells was evaluated by 3-(4,5-dimethylthiazolyl-2)-2,5-diphenyl tetrazolium bromide method, and the results showed that BFA can be released from the conjugate micelles without losing cytotoxicity.
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JOURNAL OF APPLIED POLYMER SCIENCE
·
2013
·Vol. 130
·期 2
·1415-1420
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IF 1.395
Zuolong Yu,Jiadong Zhou,Fei Cao,Binbin Wen,Xuan Zhu,Ping Wei
Poly(ethylene 2,5-furandicarboxylate- co -ethylene succinate) (PEFS) copolymers of 2,5-furandicarboxylic acid (FDCA) and succinic acid with 11.98–91.32 mol % FDCA composition were synthesized via melt polycondensation in the presence of ethylene glycol using tetrabutyl titanate as a catalyst. PEFSs' molecular weight, thermal properties, and molar composition were determined by Fourier transform infrared spectroscopy, gel permeation chromatography, intrinsic viscosity, 1 H NMR, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and wide-angle X-ray diffraction (WAXD) measurements. From experimental conditions, we obtained random copolymers with number-average molecular weights exceeding 25,600, determined by GPC and 1 H NMR analyses. DSC analysis revealed that PEFS copolymers' melting temperatures differed depending on EF units' percentage. TGA studies confirmed that all PEFS copolymers' thermal stability exceeded 300°C. From WAXD analysis, it is observed that the PEFS copolymer crystal structure was similar to that of PES when EF unit was 11.98 mol % and to that of PEF when EF units were 74.35 and 91.32 mol %. These results benefit this novel biodegradable copolymer to be used as a potential biomaterial. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 1415-1420, 2013
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RSC Advances
·
2016
·Vol. 6
·期 9
·7413-7418
·
IF 3.289
Xiaomeng Liu,Lili Ren
Molybdenum phosphide (MoP), synthesized by combining with polyethylene glycol (PEG), shows 4 to 5 times superior activity than conventional MoP for hydrodechlorination of trichloroethylene (TCE). We investigated the effect of PEG average molecular mass on the catalytic activity of MoP, and found that when the average molecular mass of PEG was 8000, the MoP catalyst gave the highest activity. Through X-ray diffraction (XRD), N2 adsorption–desorption, transmission electron microscopy (TEM), scanning electron microscopy (SEM), and H2 temperature-program reduction (H2-TPR), the effect of PEG was investigated. The results showed that the addition of PEG changed MoP from the original flat structure to a lamellar structure, and indeed improved the growth of the (101) and (102) crystal planes (the possible crystal planes of high activity) and restrained the (100) and (201) crystal planes (the possible crystal planes of low activity). This leads to the high catalytic performance of MoP modified with PEG.
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PHYSICS AND CHEMISTRY OF LIQUIDS
·
2017
·
IF 1.145
Bosheng Zhao,Lihua Liu,Xiaoxia Yang,Chang Liu,Feng Sha,Jianbin Zhang
Thermophysical properties for binary mixture of tetraethylene glycol (T4EG) (1) + 1,2-ethanediamine (EDA) (2), a potential scrubbing solution for the absorption of CO2, are very important as well as lacking in the literatures. This work reports densities and viscosities over the entire concentration range for the binary mixture at T = (293.15-318.15) K under atmospheric pressure. According to the experimental density and viscosity values, the mixtures’ excess molar volume (VmE), absolute viscosity deviation (∆η), excess free energies of activation (∆G*E), apparent molar volumes, partial molar volumes and isobaric thermal expansion coefficient were calculated, respectively. Meanwhile, the VmE, ∆η and ∆G*E values were fitted by a Redlich–Kister equation to obtain coefficients. To further study, the Fourier transform infrared, UV-Vis and fluorescence spectra of T4EG + EDA mixtures with various concentrations were measured, and the intermolecular interaction of T4EG with EDA was also discussed as the formation of –OCH2CH2O–H···N(H2)CH2CH2(H2)N···.
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高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2016
·
IF 2.74
Hai-lin Zhu,Zhi-yong Hu,Dong Liang,Jian-long Wang,Duan-lin Cao
Aggregation behavior and thermodynamics of micellization of diester-bonded cationic gemini surfactants (12-Z1-12, 14-Z1-14, 12-Z2-12, 14-Z2-14) have been studied in ethylene glycol–water (EG–water) binary mixtures by conductometric method in the temperatures ranging from 298.15 to 313.15 K. With increasing length of hydrophobic chain and spacer, the values of critical micelle concentration (CMC) decrease, and degree of counterion association (β) increases. While with increasing temperature and concentration of ethylene glycol , the values of CMC increase, and β decrease. The thermodynamic parameters of micellization were determined from the temperature dependence of CMC values. The Gibbs energy values were found to be negative, and the negative values increased with the increase in the length of hydrophobic chain and spacer of surfactant, and with the decrease in temperature and volume fraction of ethylene glycol.
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Acta Biomaterialia
·
2016
·
IF 6.008
Wen Hu,Lipeng Qiu,Liang Cheng,Qing Hu,Yang Liu,Ziyang Hu,Dawei Chen,Lifang Cheng
To solve the contradiction between long circulation time and effective intracellular drug release, redox and pH-responsive drug delivery system was developed by incorporated redox-sensitive disulfide linkage between poly(amidoamine) dendrimers (PAMAM) and poly(ethylene glycol) (PEG). Doxorubicin (DOX) was loaded into the hydrophobic core of the conjugates to prepare PAMAM-SS-PEG/DOX complexes (PSSP/DOX). In vitro release studies suggested that DOX release from PSSP/DOX complexes followed an redox and acid-triggered manner and increased with increasing PEGylation degree. In vitro cytotoxicity of PSSP/DOX complexes against B16 tumor cells increased with, while cellular uptake decreased with increasing PEGylation degree. Further, intracellular DOX release observation and measurement indicate that the intracellular DOX release played a critical role for the cytotoxicity of DOX-loaded PSSP conjugates. In addition, cellular entry mechanism of the PSSP/DOX study demonstrated that both clathrin- and caveolae-mediated endocytosis were the primary pathways for cellular entry of PSSP/DOX. Finally, in vivo study of PSSP/DOX complexes in B16 tumor-bearing mice indicate that PSSP/DOX could significantly improve antitumor efficiency and present a good safety. The redox and pH-responsive drug delivery system has been demonstrated to be a promising candidate for solid tumor therapy. Statement of Significance In previous research, pH-sensitive diblock polymer of poly(ethylene glycol)-poly(2,4,6-trimethoxybenzylidene-pentaerythritol carbonate) (PEG-PTMBPEC) was synthesized to facilitate the intracellular anticancer drug release. However, the nanoparticles based on PEG-PTMBPEC get into the tumor cells just relying on the EPR-mediated passive targeting resulting in the low drug accumulation. Therefore, cRGD peptide modified PEG-PTMBPEC polymeric micelles were developed for specific targeted delivery of doxorubicin (DOX) to neovascular cells and tumor cells simultaneously. The precise intracellular target site and effective drug concentration will contribute to enhancing the antitumor toxicity and reducing the systematic toxicity of DOX. The cRGD modified pH-sensitive micellar system is a promising vehicle for intracellular drug delivery to αvβ3 integrin receptor overexpressed tumor cells and neovascular cells.
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高影响因子
Journal of Materials Chemistry B
·
2016
·Vol. 4
·期 13
·2338-2350
·
IF 4.872
Yuanyuan Guo,Boning Niu,Qingle Song,Yongdan Zhao,Yuling Bao,Songwei Tan,Luqin Si,Zhiping Zhang
Developing multifunctional nanoparticles (NPs) to improve therapeutic efficacy is highly desirable in cancer therapy. In an attempt to respond to such a challenge, a novel copolymer, D-α-tocopherol polyethylene glycol succinate-SS-poly(lactide) (TPGS-SS-PLA) with a disulfide linkage between the TPGS and PLA units, was synthesized for paclitaxel (PTX) delivery. PTX-loaded NPs were fabricated using a nanoprecipitation method to form a particle size of ∼130 nm with good in vitro stability, which can be disassociated under intracellular reductive conditions to release PTX rapidly. The detached TPGS can further promote the drug retention and cytotoxicity through its P-glycoprotein inhibiting property. Integrin-specific targeting peptide, cyclic RGD (cRGD), was further conjugated to the surface of the NPs for targeting the drug delivery. The RGD-decorated NPs exhibited enhanced cellular uptake, PTX accumulation and cell cytotoxicity as compared to non-targeted NPs on murine melanoma B16F10 cells, PTX-sensitive human ovarian A2780 cells and PTX-resistant A2780/T cells. In vivo evaluation of the targeted NPs further showed an extended half-life, increased AUC (area under the concentration–time curve), and significant tumor growth inhibition in mouse sarcoma S180- and B16F10-tumor bearing mice, with reduced side effects as compared to Taxol® and non-targeted NPs. These results indicate that the RGD decorated redox-sensitive NPs could deliver chemotherapies specifically inside the cell via receptor-mediated endocytosis with enhanced efficacy, especially in integrin αvβ3/αvβ5-rich tumor cells. Such a targeted nanocarrier against receptor clustering prepared from a non-cytotoxic and biodegradable copolymer might have great potential in cancer treatment.
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