DRUG DELIVERY
·
2017
·
IF 6.402
Yanpu Wu,Luming Wang,Kaili Zhang,Lixiao Zhou,Xiaobing Zhang,Xuecheng Jiang,Chenggang Zhu
The local delivery of chemotherapeutic drugs to tumor sites is an effective approach for achieving therapeutic drug concentrations in solid tumors. Injectable implants with the ability to form in situ represent one of the most promising technologies for intratumoral chemotherapy. However, many issues must be resolved before these implants can be applied in clinical practice. Herein, we report a novel injectable in situ-forming implant system composed of n-butyl-2-cyanoacrylate (NBCA) and ethyl oleate, and the sol–gel phase transition is activated by anions in body fluids or blood. This newly developed injectable NBCA ethyl oleate implant (INEI) is biodegradable, biocompatible, and non-toxic. INEI solidifies in several seconds after exposure to body fluids or blood, and the implant’s in vivo degradation time can be controlled. In addition, the pore sizes formed by the polymerization of NBCA can be decreased by increasing the NBCA concentration in the implants. Therefore, the drug retention/release time can be adjusted from a few weeks to several months by changing the concentration of NBCA in the implant formulation. Anti-tumor experiments in animal models showed that the average growth inhibition rate of xenografted human breast cancer cells by the paclitaxel-loaded INEI (40% NBCA) was 80%, and they also indicated that tumors in some of the mice were completely eliminated by just a single dosage injection. For the epirubicin-loaded INEI (50% NBCA), the average growth inhibition rate of xenografted human liver cancer cells was 58%. Thus, the chemotherapeutic drug-loaded INEIs exhibited excellent therapeutic efficacy for local chemotherapy.
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高影响因子
Small
·
2016
·Vol. 13
·期 3
·1602507
·
IF 8.315
Feng Hu,Hongchao Yang,Changhong Wang,Yejun Zhang,Huan Lu,Qiangbin Wang
Rational design of cost-effective, nonprecious metal-based catalysts with desirable oxygen reduction reaction (ORR) performance is extremely important for future fuel cell commercialization, etc. Herein, a new type of ORR catalyst of Co-N-doped mesoporous carbon hollow sphere (Co-N-mC) was developed by pyrolysis from elaborately fabricated polystyrene@polydopamine-Co precursors. The obtained catalysts with active Co sites distributed in highly graphitized mesoporous N-doped carbon hollow spheres exhibited outstanding ORR activity with an onset potential of 0.940 V, a half-wave potential of 0.851 V, and a small Tafel slope of 45 mV decade −1 in 0.1 m KOH solution, which was comparable to that of the Pt/C catalyst (20%, Alfa). More importantly, they showed superior durability with little current decline (less than 4%) in the chronoamperometric evaluation over 60 000 s. These features make the Co-N-mC one of the best nonprecious-metal catalysts to date for ORR in alkaline condition.
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RSC Advances
·
2016
·Vol. 6
·期 89
·85735-85744
·
IF 3.289
Bin Cai,Qin Zou,Yi Zuo,Limei Li,Boyuan Yang,Yubao Li
Composite microspheres based on nano-hydroxyapatite (n-HA)/chitosan (CS) with different weight ratios were fabricated by an emulsion method and using natural vanillin as a cross-linking agent. FT-IR, XRD, TGA, SEM and laser particle size analysis were used to characterize their physico-chemical properties. Live-dead cell staining and MTT assay were used to evaluate cell viability and cytocompatibility. The results showed that the rod-like n-HA crystals could be incorporated into the CS matrix in a relatively high level up to 29.57 wt%. The encapsulation efficiency of n-HA in the composite microspheres was between 29.50–73.93%. The composite microspheres with a diameter of 10.9–55.0 μm and good swelling properties should be easy to inject into irregular bone defects. The studies of in vitro biodegradation and cell culture using MG63 cells demonstrated that the vanillin-crosslinked n-HA/CS microspheres could be degraded in a sustained and controlled behavior while supporting cell growth, thus acting as worthy candidates for a multifunctional injectable matrix in bone tissue engineering.
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CANADIAN JOURNAL OF CHEMICAL ENGINEERING
·
2016
·Vol. 95
·期 2
·364-371
·
IF 1.066
Wenling Hu,Xiaolong Han,Liangliang Liu,Xin Zhang,Juanqin Xue,Baoyi Wang,Peng Zhang,Xingzhong Cao
Polyethylene glycol (PEG) of three different molecular weights was used to prepare PEG/PVDF composite membranes for separating organosulphur compounds from n -heptane by pervaporation. All the composite membranes were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X-ray diffraction (XRD), and positron annihilation spectroscopy (PAS). The effects of operating temperature, feed sulphur content, and organosulphur species on performance of PEG/PVDF composite membranes with different molecular weights were investigated. When the feed organosulphur was thiophene, the fluxes decreased with an increase in PEG molecular weight, however, the enrichment factors were in a different order: PEG membrane with molecular weight of 35 000 exhibited the highest enrichment factor of 12.59 for thiophene at 85 °C. When the feed organosulphur was 2-methylthiophene or 2,5-dimethylthiophene, it was found that the PEG membrane with molecular weight of 100 000 showed the highest enrichment factor. The results showed that PEG molecular weight has a considerable effect on separation performance for pervaporation desulphurization.
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APPLIED SURFACE SCIENCE
·
2017
·
IF 3.387
Yan Liu,Pengpeng Chen,Wangyan Nie,Yifeng Zhou
A temperature-responsive, recyclable nanocatalyst was fabricated by composting the exfoliated molybdenum disulfide (MoS 2 ) nanosheets with poly ( N -isopropylacry lamide) (PNIPAM). The structure and morphology of MoS 2 /PNIPAM nanocatalyst was fully characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), Thermogravimetry analysis (TGA), Scanning electron microscope (SEM) and Transmission electron microscopy (TEM). The temperature-responsive properties of the MoS 2 /PNIPAM nanocatalyst were confirmed by Dynamic Light Scattering (DLS) and Ultraviolet–visible ((UV–vis)) absorption spectroscopy. The catalytic activities of the MoS 2 /PNIPAM nanocatalyst were studied using the reduction reaction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) as the model reaction. Results showed that the catalytic activity of the MoS 2 /PNIPAM nanocatalyst could be regulated by temperature. Furthermore, when the temperature went higher than the low critical solution temperature (LCST) of PNIPAM, the MoS 2 /PNIPAM nanocatalyst tended to aggregated to form bulk materials from homogeneous suspension.
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SCIENCE OF THE TOTAL ENVIRONMENT
·
2017
·
IF 4.9
Nai-Xian Feng,Jiao Yu,Ce-Hui Mo,Hai-Ming Zhao,Yan-Wen Li,Bing-Xiao Wu,Quan-Ying Cai,Hui Li,Dong-Mei Zhou,Ming-Hung Wong
Phthalic acid esters (PAEs) are a group of recalcitrant and hazardous organic compounds that pose a great threat to both ecosystem and human beings. A novel endophytic strain YJB3 that could utilize a wide range of PAEs as the sole carbon and energy sources for cell growth was isolated from Canna indica root tissue. It was identified as Bacillus megaterium based on morphological characteristics and 16S rDNA sequence homology analysis. The degradation capability of the strain YJB3 was investigated by incubation in mineral salt medium containing di-n-butyl-phthalate (DBP), one of important PAEs under different environmental conditions, showing 82.5% of the DBP removal in 5 days of incubation under the optimum conditions (acetate 1.2 g·L − 1 , inocula 1.8%, and temperature 34.2 °C) achieved by two-step sequential optimization technologies. The DBP metabolites including mono-butyl phthalate (MBP), phthalic acid (PA), protocatechuic acid (PCA), etc. were determined by GC–MS. The PCA catabolic genes responsible for the aromatic ring cleavage of PCA in the strain YJB3 were excavated by whole-genome sequencing. Thus, a degradation pathway of DBP by the strain YJB3 was proposed that MBP was formed, followed by PA, and then the intermediates were further utilized till complete degradation. To our knowledge, this is the first study to show the biodegradation of PAEs using endophyte. The results in the present study suggest that the strain YJB3 is greatly promising to act as a competent inoculum in removal of PAEs in both soils and crops.
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JOURNAL OF ASIA-PACIFIC ENTOMOLOGY
·
2017
·
IF 1.046
Yunhua Zhang,Jinyun Ji,Xiao Zhao,Ruoheng Jin,Jianhong Li,Hu Wan
A previous study demonstrated that a β- N -acetyl- d -hexosaminidase ( NlHex4 ) from the brown planthopper could serve as a new potential target for biopesticides due to its requirement for molting, and lethal phenotypes were observed via RNA interference . However, the enzymatic properties of NlHex4 remain unclear. In the present study, NlHex4 was expressed, purified and characterized. Recombinant NlHex4 was functionally expressed in baculovirus-infected insect cells and purified with a molecular weight of approximately 70 kDa. Recombinant NlHex4 had an optimal pH and temperature of 6.0 and 60 °C, respectively. Moreover, recombinant NlHex4 exhibited thermal stability at 50 °C for at least 1 h. Furthermore, the activity of recombinant NlHex4 was inhibited by the metal ions Fe 2 + and Fe 3 + and the serine protease inhibitor phenylmethanesulfonyl fluoride. These results reveal the enzymatic properties of NlHex4 and provide a basis for future investigation of the interaction between HEX and chitin oligosaccharide .
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CARBON
·
2016
·
IF 6.198
Jingyue Zhu,Dan Xu,Cancan Wang,Wenjing Qian,Jun Guo,Feng Yan
This work reports a facile strategy for the preparation of Nitrogen-doped porous carbons via carbonization of a mixture containing ferric citrate (FC) and ammonium chloride (NH 4 Cl). FC provides carbon and iron element sources, while ammonium chloride acts as both the porogen and nitrogen dopant during the carbonization process . The formed hierarchical porous structures facilitate the ion diffusion/transport, and nitrogen-doping provides more active sites, which contribute to both oxygen reduction reaction (ORR) and supercapacitor applications. Compared with KOH and NaCl, the utilization of NH 4 Cl as porogen shows the best ORR performance in this work might due to the dual functions of NH 4 Cl. Ferric citrate-NH 4 Cl carbonized at 700 °C exhibits good capacity of 242 F g −1 and stability in 6 M KOH at a current density of 1 A g −1 . Since both FC and NH 4 Cl are cheap and easily available, this work provides a facile and effective method to obtain carbons with superb electrochemical performances.
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LANGMUIR
·
2016
·
IF 3.993
Defeng Li,Ang Wu,Guangyin Xu,Hua Lai,Zhongjun Cheng,Yuyan Liu
In this paper, we report a simple method based on assembling n-alkanoic acids on hierarchical structured copper toward preparing surfaces with tunable oil wetting performance in water. Surface wettability from superoleophobicity to superoleophilicity in water can be regulated through tuning the chain length of n-alkanoic acids. Importantly, even in strongly acid and basic water, such phenomena can still be observed. The cooperation between the hierarchical structures and the surface chemical composition variation is responsible for the controllability. Meanwhile, the tunable ability is universal and the controllability is suitable for various oils including silicon oil, n-hexane, and chloroform. Moreover, the method was also used on copper mesh substrates, and we reported the related application of selective oil/water separation. This paper provides a flexible strategy toward preparing surfaces with tunable oil wetting performances, which can also be suitable for other materials, and offers some fresh ideas in manipulating underwater oil wetting performances on surfaces.
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Catalysis Science & Technology
·
2015
·Vol. 6
·期 6
·1913-1920
·
IF 5.426
Renfeng Nie,Hezhan Jiang,Xinhuan Lu,Dan Zhou,Qinghua Xia
N-doped active carbon (N-AC) has been synthesized via heat treatment of a mixture consisting of dicyandiamide as the nitrogen source and commercial active carbon as the precursor. This material is especially adapted for anchoring ultrafine Pd nanoparticles by a very clean strategy using H2 as the reductant. The physicochemical properties of materials were investigated by powder X-ray diffraction (XRD), Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The results reveal that the variation of the treatment temperature can assist the tuning of the content of N and the dispersion of Pd on xN-AC, by which Pd nanoparticles with a narrow size distribution centered at around 1.8 nm can be obtained. These robust catalysts show very high catalytic activity for the aromatic ring hydrogenation of acidic substrates, such as electron-deficient benzoic acid or electron-rich phenol, under mild conditions in aqueous media. Excellent catalytic results (9.2 times higher activity in comparison to non-doped catalyst for benzoic acid hydrogenation), high stability and easy recyclability of the catalyst were achieved. The strong interaction between the pyridinic nitrogen group and Pd species will lower the reducibility of the Pd species and result in the formation of relatively electron-deficient and ultra-small sized Pd clusters, thus leading to high hydrogenation activity.
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JOURNAL OF MATERIALS SCIENCE
·
2015
·Vol. 50
·期 14
·4914-4925
·
IF 2.371
Cheng Cui,Xia Dandan,Zhang Xiuli,Chen Li,Zhang Qiqing
The therapeutic concentration of cisplatin (CDDP) is usually associated with dose-limiting side effects. To avoid these harmful effects, a biocompatible hydrogel carrier which consisted of poly( N -isopropylacrylamide) and carboxymethyl chitosan was designed to deliver CDDP to the local environment of a solid tumor. The poly( N -isopropylacrylamide)-g-carboxymethyl chitosan hydrogels were synthesized by chemical crosslinking. Scanning electronic microscopy images showed that the hydrogels exhibited a cross-linked structure with the average pore size from 100 to 200 µm. Water contact angles and swelling studies suggested that the hydrogels had good hydrophilicity and the lower critical solution temperature lay in the vicinity of 32 °C. The MTT assays implied that the hydrogels were non-cytotoxic on NIH3T3 cells. In vitro release experiment demonstrated that the release of CDDP was controllable and sustained over a long period. Moreover, the released CDDP retained its anticancer activity on A549 cells. The hydrogels are promising carriers for sustained release of cisplatin.
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COLLOIDS AND SURFACES B-BIOINTERFACES
·
2015
·
IF 4.152
Shixuan Chen,Junbin Shi,Xiaolin Xu,Jianyang Ding,Wen Zhong,Lu Zhang,Malcolm Xing,Lin Zhang
The mechanical miss-match between the host and an implanted foreign body is one of the primary causes for implantation failure. To enhance the efficacy in wound repair, we developed stiffness-tunable temperature-sensitive hydrogels composed of poly(amidoamine) (PAA)-based poly( n -isopropyl acrylamide) (PNIPAM). PNIPAM-PAA hydrogels with three different stiffness fabricated by varying the concentrations of poly(amidoamine) were chosen for morphology and rheology tests. The degradation rate and cell compatibility of gels were also characterized. The PAA-PNIPAM hydrogels were then tested in a wound healing model of mice with full-thickness skin loss. We found that the stiffness of hydrogels has an impact on the wound healing process mainly by regulating the cell activities in the proliferation phase. PNIPAM-PAA hydrogels with appropriate stiffness reduce scar formation and improve wound healing by promoting myofibroblast transformation, keratinocytes proliferation, extracellular matrix synthesis and remodeling. Moreover, the stiffness of hydrogels impact on the secretion of TGF-β1 and bFGF, which play an important role in skin wound healing. These results suggest that the therapeutic effects of hydrogels in skin wound healing can by regulated by hydrogels’ stiffness.
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