COLLOIDS AND SURFACES B-BIOINTERFACES
·
2016
·
IF 3.902
Ming-Mao Chen,Huan Cao,Yuan-Yuan Liu,Yan Liu,Fei-Fei Song,Jing-Di Chen,Qi-Qing Zhang,Wen-Zhi Yang
Wound treatment should meet the challenge both of preventing infection and promoting wound healing. To design a sequential delivery system for wound healing, PLGA-glycol chitosan (GC) core-shell microspheres containing chlorhexidine acetate (CHA) at the GC shell and bFGF in the core of PLGA microspheres were fabricated using emulsion-solvent evaporation method. SEM showed that the microspheres were all spherical in shape with a smooth surface. The average size of PLGA-GC microspheres increased due to the GC coating on the surface. The results of release profiles and fluorescence images indicated that PLGA-GC microspheres had an ability to deliver drugs in sequence. The CHA was rapidly released, whereas the proteins presented a sustained release. The release behavior could be modulated by changing the GC amount. Antibacterial assay and cell proliferation tests suggested that the released CHA and bFGF retained their antimicrobial activity and bioactivity during preparation. The microspheres exhibited non-cytotoxicity against 3T3 cells and had a good biocompatibility. These results demonstrated that PLGA-GC core-shell microspheres could be a promising controlled release system of delivering drugs and proteins in sequence for wound healing.
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高影响因子
MACROMOLECULAR CHEMISTRY AND PHYSICS
·
2016
·Vol. 217
·期 14
·1607-1613
·
IF 2.495
Xianjing Gong,Dean Shi,Huihui Zeng,Yingkui Yang,Tao Jiang,Qunchao Zhang,Shichun Jiang,Robert K. Y. Li,Yiu-Wing Mai
Comb-like polyethylene glycol (PEG)-based copolymer electrolytes with given crosslinking density are synthesized using PEG as the main chain segments (denoted as MC-PEG), methoxy polyethylene glycol (MPEG) as side chain segments (denoted as SC-PEG), and hexamethylene-1,6-diisocyanate homopolymer (HDI trimer) as bridging and/or crosslinking agent. In this study, the effects of molecular weight of MC-PEG and SC-PEG on Li ion conductivities of the copolymer have been examined. If MC-PEG and/or SC-PEG do not crystallize, the ion conductivities of graft copolymer electrolyte increase with either decreasing MC-PEG or increasing SC-PEG segment length. The highest ion conductivity of the copolymer electrolyte at room temperature reaches up to 7.7 × 10 −4 S cm −1 when the molecular weight of MC-PEG is 400 g mol −1 and SC-PEG is 1000 g mol −1 (denoted as GC400-1000). However, when the MC-PEG and/or SC-PEG segments begin to crystallize (i.e., GC400-2000), where the flexibility of the related PEG molecular chains is largely reduced, the ion conductivity drops by almost two orders comparing to that of GC400-1000 copolymer electrolyte. Meanwhile, crosslinked GC400-1000 electrolyte has good thermal and electrochemical stability as well as high mechanical properties, making it suitable for commercial applications in Li ion secondary batteries.
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高影响因子
Waste and Biomass Valorization
·
2016
·Vol. 8
·期 7
·2443-2450
·
IF 0.915
Zhang Kai,Wu Shubin,Yang He,Li Gang
Cassava residue was proposed as a raw material for the production of ethylene glycol (EG) via a one-pot hydrothermal reaction in the present study. Various mixed catalysts consisting of activated carbon supported Ru (Ru/AC) and a tungsten species were used for the conversion of cassava residues, and the effects of various reaction conditions on the catalytic performance were investigated. When the reaction was carried out at 245 °C for 60 min, the Ru/AC–H 2 WO 4 mixed catalyst showed a EG yield of 53.1 % with a total polyols yield of 80 %, which was confirmed to be the most active among the prepared catalysts. The excellent catalytic performance using cassava residue as the feedstock mainly resulted from a high content of carbohydrates and a low amount of lignin in cassava residues. Furthermore, the Ru/AC–H 2 WO 4 catalyst also showed reasonable stability during the hydrothermal conversion of cassava residues for EG production.
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高影响因子
Biointerphases
·
2017
·Vol. 12
·期 2
·
IF 2.603
Wang Hanqi,Cheng Fang,He Wei,Zhu Jiaohui,Cheng Gang,Qu Jingping
This paper reported a facile strategy for the one-pot synthesis of vinyl sulfone (VS) group terminated hydrogel precursors [poly(ethylene) glycol (PEG)-VS] and PEG hydrogels via catalytic oxa-Michael reaction. Nine potential catalysts were investigated for the reaction between PEG and divinyl sulfone, among which 4-dimethylaminopyridine (DMAP) prevailed for its high catalytic activity. DMAP produced PEG-VS with a conversion of more than 90% in 2 h under a solvent-free condition at room temperature, which significantly simplifies the synthesis of PEG-VS. The preparation of PEG hydrogels was realized by adding glycerol as a crosslinker, and the physical and the mechanical properties were easily controlled by changing the crosslinker concentration as well as the PEG chain length. This strategy can also be applied to other polyhydroxy compounds as crosslinkers, and thus, a library of hydrogels with designed structures and desired properties could be prepared. The PEG hydrogels showed good antifouling properties, low cytotoxicity, and ability to release drugs at a tunable rate, indicating versatile potential bioapplications.
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高影响因子
Polymer Chemistry
·
2017
·Vol. 8
·期 10
·1680-1688
·
IF 5.375
Jian Sheng,Ying Wang,Lu Xiong,Qiaojie Luo,Xiaodong Li,Zhiquan Shen,Weipu Zhu
Dendron-like multifunctional β-cyclodextrin–poly(ethylene glycol) (CD–PEG) conjugates were synthesized from amino functionalized β-cyclodextrins and poly(ethylene glycol) diacrylate through the Michael addition reaction. The resultant conjugates contain several PEG arms terminated with acrylates, which originated from the same glucopyranose unit of CD. These dendron-like CD–PEG conjugates can incorporate adamantane-modified doxorubicin (AD–DOX) by host–guest interactions between CD and AD moieties, to give a reactive supramolecular polymeric prodrug, which can be further crosslinked by poly[oligo(ethylene glycol) mercaptosuccinate] (POEGMS) via thiol–ene “click” reaction under physiological conditions. These kinds of in situ forming drug-loaded hydrogels can be utilized as injectable gelling carriers for localized drug delivery.
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高影响因子
RSC Advances
·
2017
·Vol. 7
·期 5
·2810-2816
·
IF 3.108
Zhaogan Wang,Peng Long,Yiyu Feng,Chengqun Qin,Wei Feng
Hydroxyl functionalized carbon dots (H-CDs) were prepared by monoesterification of ethylene glycol. The H-CDs exhibit a narrow size distribution of 1–4 nm and enhanced photoluminescent (PL) intensity due to an increased amount of electron donor hydroxyl groups. According to fluorescence spectra, the H-CDs exhibit a high sensitivity to Fe3+ with a detection limit of 2.56 nM, which is superior to the detection limit of CDs (7.4 μM). The quenching fluorescence is primarily controlled by the formation of a chelate compound based on the complexation between Fe3+ and the hydroxyl on the surface of the H-CDs. Furthermore, we demonstrate that paper impregnated with H-CDs exhibits a high sensitivity to Fe3+ by fluorescence quenching. In the future, the modified CDs can be developed for high sensitivity fluorescent probes by optimizing the chemical structures and microstructures.
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高影响因子
CHINESE JOURNAL OF POLYMER SCIENCE
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2016
·Vol. 34
·期 12
·1436-1447
·
IF 1.811
Fu Xiao-hui,Ma Yi-nan,Sun Jing,Li Zhi-bo
A series of poly( L -glutamate)s grafted with oligo(ethylene glycol) (OEG) side-chains through the thioether linkages (PALG
n
- g -EG
x
, x = 2, 3 and 4) were prepared by ring-opening polymerization (ROP) of γ-allyl- L -glutamate N -carboxyanhydride (ALG-NCA) and thiol-ene photoaddition. The chemical structures and physical properties were characterized by 1 H-NMR, Fourier transform infrared (FTIR), circular dichroism (CD), etc . The PALG
n
-g-EG
x
samples with x = 3 and 4 displayed lower critical solution temperature (LCST) in water due to the presence of OEG units. The clouding point (CP) of polypeptides can be finely tuned by changing the side chain structures, molecular weights and sample concentrations. In addition, the thioether linkages in the side chains offer additional redox-responsive properties. The influence of both OEG units and thioether linkages on the LCST behavior was systematically investigated. This work provides an efficient way to prepare multi-stimuli responsive materials with highly tunable properties.
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高影响因子
MACROMOLECULAR BIOSCIENCE
·
2016
·Vol. 17
·期 4
·1600295
·
IF 3.68
Caiyan Zhao,Leihou Shao,Jianqing Lu,Chenying Zhao,Yujie Wei,Junxing Liu,Mingjun Li,Yan Wu
Stimuli-responsive nanocarriers with the ability to respond to tumorous heterogeneity have been extensively developed for drug delivery. However, the premature release during blood circulation and insufficient intracellular drug release are still a significant issue. Herein, three disulfide bonds are introduced into the amphiphilic poly(ethylene glycol)-polycaprolactone copolymer blocks to form triple-sensitive cleavable polymeric nanocarrier (tri-PESC NPs) to improve its sensitivity to narrow glutathione (GSH) concentration. The tri-PESC NPs keep intact during blood circulation due to the limited cleaving of triple-disulfide bonds, whereas the loaded drug is efficiently released at tumor cells with the increased concentration of GSH. In vitro studies of doxorubicin-loaded tri-PESC NPs show that the nanocarriers achieve sufficient drug release in cancerous cells and inhibit the tumor cells growth, though they only bring minimum damage to normal cells. Therefore, the tri-PESC NPs with triple-sensitive cleavable bonds hold great promise to improve the therapeutic index in cancer therapy.
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高影响因子
ELECTROCHIMICA ACTA
·
2017
·
IF 4.798
Mengke Guo,Menglan Zhang,Dan He,Ji Hu,Xiaoen Wang,Chunli Gong,Xiaolin Xie,Zhigang Xue
Solid polymer electrolytes based on a novel comb-like copolymer , polyethylene glycol-grafted sulfonated polyether ether ketone (SPEEK- g -PEG), was designed and synthesized through the reaction between partially hydroxyl-functionalized sulfonated polyether ether ketone (SPEEK) and epoxy-functionalized PEG. The resulting SPEEK- g -PEG was fully characterized by FTIR, 1 H NMR, TGA , and DSC . All data proved the successful grafting of PEG onto the SPEEK main chain. The resulting comb-like structure effectively inhibited the crystallization of PEG. After doping with a lithium salt , the obtained SPEEK- g -PEG polymer electrolyte membrane showed an improved ionic conductivity . The effects of chain length and PEG grafting ratio on the ionic conductivity of SPEEK- g -PEG were also investigated by electrochemical impedance spectroscopy (EIS). Moreover, the effect of this comb-like structure on increasing the ionic conductivity is higher than that of SPEEK/PEG blends, making these comb-like SPEEK- g -PEG copolymers attractive for an application in LIBs .
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高影响因子
ACS Applied Materials & Interfaces
·
2017
·
IF 7.504
Peng Long,Yiyu Feng,Yu Li,Chen Cao,Shuangwen Li,Haoran An,Chengqun Qin,Junkai Han,Wei Feng
Solid-state fluorescent carbon quantum dots (QDs) can be used for the encryption of security information. Controlling the dispersion and aggregation of the QDs is crucial for switching their solid-state fluorescence “on” and “off.” The use of polymers has been proposed to slightly separate the QDs inside aggregates to trigger their fluorescence. However, the complex interactions between the QDs and flexible polymer chains make this process challenging. Here, fluorine-modified carbon nanodots (FCDs) were used in a solution as the printing ink. After printing, the FCDs were aggregated on paper via hydrogen bonds, thereby quenching the fluorescence. After a poly(ethylene glycol) (PEG) treatment, the FCDs exhibited yellow solid-state fluorescence due to an increased interdot spacing. The fluorescence intensity and emission wavelength could be tuned by varying the molecular weight and quantity of PEG used. Finally, we demonstrated a high-resolution encryption and decryption system based on the PEG-triggered fluorescence of FCDs.
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高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2012
·Vol. 129
·期 2
·773-778
·
IF 1.289
Changdao Mu,Xinying Li,Jimin Guo,Caixia Bi,Defu Li
To improve the thermal and mechanical properties of gelatin-polyethylene glycol (PEG) composite fibers, montmorillonite (MMT) is incorporated into gelatin-PEG composite fibers during gel-spinning process. The effects of MMT on the structure and properties of gelatin-PEG composite fibers are investigated. The viscosimetry analysis and transmission electron microscopy measurements show that MMT has a good dispersion in spinning solution at low loading, while serious aggregation is observed with excess amount of MMT adding. The data of X-ray diffraction (XRD) show that MMT can be intercalated and exfoliated in gelatin-PEG-MMT nanocomposite fibers. Fourier transform infrared (FTIR) studies show the hydrogen bonding interactions between gelatin and MMT. The mechanical properties, differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) measurements indicate that the mechanical and thermal properties of nanocomposite fibers are improved as expected at low loading of MMT. However, excess amount of MMT decreases the mechanical and thermal properties of nanocomposite fibers due to poor dispersion and clay cluster induced gelatin chains aggregation. Moreover, it is found that the mechanical properties of gelatin-PEG-MMT nanocomposite fibers may be more sensitive to conformational change of gelatin molecules caused by the addition of MMT. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
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高影响因子
Biomed Research International
·
2014
·
IF 0
Yihang Huang,Jun Liu,Yani Cui,Huanan Li,Yong Sun,Yujiang Fan,Xingdong Zhang
Reduction-triggered breakable polymeric micelles incorporated with MTX were prepared using amphiphilic PAA-g-PEG copolymers having S–S bonds in the backbone. The micelles were spherical with diameters less than 70 nm. The micelles could encapsulate the hydrophobic MTX in the hydrophobic core. The drug loading content and drug loading efficiency of the micelles were highly dependent on the copolymer chemical structure, ranging from 2.9 to 7.5% and 31.9 to 82.5%, respectively. Both the drug loading content and drug loading efficiency increased along with more hydrophobic segments in the copolymers. In normal circumstance, these micelles were capable of keeping stable and hold most of the MTX in the core, stabilizing the incorporated MTX through the
stacking with the phenyl groups in the backbone of the copolymers. In reductive environments that mimicked the intracellular compartments, the entire MTX payload could be quickly released due to the reduction-triggered breakage of the micelles. These micelles showed good antiproliferative activity against several cancer cell lines, including KB, 4T-1 and HepG2, especially within the low drug concentration scope.
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