Materials Science & Engineering C-Materials for Biological Applications
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2016
·
IF 3.42
Dakun Ma,Gang An,Min Liang,Yugang Liu,Bin Zhang,Yansong Wang
Given the fabulous potential of promoting bone regeneration, BMP-2 has been investigated widely in the bone tissue engineering field. A sophisticated biomaterial loaded with BMP-2, which could avoid the required supraphysiological dose leading to high medical costs and risks of complications, has been considered as a promising strategy to treat non-healing bone defects. In this study, we developed a simple approach to engineer a composited hydrogel consisting polymeric particles (PLA/PLGA) used as a BMP-2 delivery vehicle. Compared with other groups, the introduction of PLA into PEG-silk gels endowed the hydrogel new physicochemical characteristics especially hydrophobicity which inhibited the burst release of BMP-2 and enhanced gel's structural stability. Moreover, such composited gels could stabilize entrapped proteins and maintain their bioactivity fully in vitro. In vivo, the bio-degradability experiment demonstrated this system was biocompatible and the reinforced hydrophobicity significantly decreased degradation rate, and in rat critical-sized cranial defects model, the gel containing PLA promoted the most bone formation. These findings demonstrated the introduction of PLA changed physicochemical features of gels more suitable as a BMP-2 carrier indicated by inducing bone regeneration efficiently in large bone defects at low delivered dose and this system may own translational potential.
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高影响因子
MACROMOLECULES
·
2017
·
IF 5.835
Dongdong Zhou,Shaoyong Huang,Jingru Sun,Xinchao Bian,Gao Li,Xuesi Chen
The crystallization behaviors and microstructures of poly(l-2-hydroxyl-3-methylbutanoic acid)/poly(l-lactide) blends [P(L-2H3MB)/PLLA] were investigated by OM, DSC, SAXS, in situ temperature-dependent WAXD, and in situ synchrotron WAXS. The blends exhibited a homogeneous state at 250 °C. In the cooling process, P(L-2H3MB), with higher melting temperature, crystallized first at 166.7 °C and drove the formation of the phase separation and microstructure. And the amorphous P(L-2H3MB) and PLLA were excluded into the interlamellar and interfibrillar regions of the former P(L-2H3MB) crystallites. For P(L-2H3MB)/PLLA (5/5), the amorphous P(L-2H3MB) in the interfibrillar regions continued to form crystallites sequentially at 134.6 °C, which clearly confirmed the fractional crystallization of P(L-2H3MB). In our knowledge, this unique fractional crystallization has not been reported yet, of the component in miscible blend, which crystallized first under little confinement. This work provided a new viewpoint and understanding of the relationship between fractional crystallization and microstructures in crystalline/crystalline blends.
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高影响因子
GREEN CHEMISTRY
·
2017
·Vol. 19
·期 4
·1102-1108
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IF 9.125
Chunqing Lou,Ning Zhu,Ronghua Fan,Hailong Hong,Limin Han,Jianbin Zhang,Quanling Suo
A convenient and efficient method for the synthesis of 2-mercaptobenzothiazoles from disulfide and CS2 mediated by a metal sulfide in water is described. This synthetic methodology could be used to prepare diverse 2-mercaptobenzothiazole derivatives in good to excellent yields. In this paper, the concept of metal sulfide–disulfide dynamic interchange reaction was put forward. Then the intermediates of the interchange reaction between NaHS and a disulfide were detected by LC-MS, which demonstrated that the S–S bond of the disulfide could be broken by the metal sulfide through the dynamic interchange reaction. In addition, NaHS was eventually transformed into sulfur S8 by the dynamic interchange reaction. Moreover, the underlying mechanism of 2-mercaptobenzothiazole formation is proposed, in which NaHS not only acts as an S–S bond cleaving agent but also as an activator of CS2. As a result, a novel synthetic route for the preparation of sulfur-containing heterocycles from a disulfide is developed.
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高影响因子
INTERNATIONAL JOURNAL OF ANTIMICROBIAL AGENTS
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2017
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IF 4.307
Hong-Yan Luo,Ma-Feng Liu,Ming-Shu Wang,Xin-Xin Zhao,Ren-Yong Jia,Shun Chen,Kun-Feng Sun,Qiao Yang,Ying Wu,Xiao-Yue Chen,Francis Biville,Yuan-Feng Zou,Bo Jing,An-Chun Cheng,De-Kang Zhu
The Gram-negative bacterium Riemerella anatipestifer CH-2 is resistant to lincosamides, having a lincomycin (LCM) minimum inhibitory concentration (MIC) of 128 µg/mL. The G148_1775 gene of R. anatipestifer CH-2, designated lnu (H), encodes a 260-amino acid protein with ≤41% identity to other reported lincosamide nucleotidylyltransferases. Escherichia coli Rosetta TM (DE3) containing the pBAD24- lnu (H) plasmid showed four- and two-fold increases in the MICs of LCM and clindamycin (CLI), respectively. A kinetic assay of the purified Lnu(H) enzyme for LCM and CLI showed that the protein could inactive lincosamides. Mass spectrometry analysis demonstrated that the Lnu(H) enzyme catalysed adenylylation of lincosamides. In addition, an lnu (H) gene deletion strain exhibited 512- and 32-fold decreases in LCM and CLI MICs, respectively. The wild-type level of lincosamide resistance could be restored by complementation with a shuttle plasmid carrying the lnu (H) gene. The transformant R. anatipestifer ATCC 11845 [ lnu (H)] acquired by natural transformation also exhibited high-level lincosamide resistance. Moreover, among 175 R. anatipestifer field isolates, 56 (32.0%) were positive for the lnu (H) gene by PCR. In conclusion, Lnu(H) is a novel lincosamide nucleotidylyltransferase that inactivates LCM and CLI by nucleotidylylation, thus conferring high-level lincosamide resistance to R. anatipestifer CH-2.
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高影响因子
JOURNAL OF WUHAN UNIVERSITY OF TECHNOLOGY-MATERIALS SCIENCE EDITION
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2017
·Vol. 32
·期 4
·772-776
·
IF 0.447
Xiang Tao,Wang Qingxiu,Duan Lijie,Liu Fude
A conjugated polymer of poly(4,4'-bis(thien-2-yl)azobenzene-co-3-hexylthiophene) (PTAB-H), bearing azo group in main chain and soluble in THF, chloroform, was synthesized through FeCl3 oxidation copolymerization with 3-hexylthiophene, and the monomer of 4,4'-bis(thien-2-yl)azobenzene was synthesized by Sandmeyer reaction and Suzuki reaction. The UV-Vis spectra of PTAB-H reveal that azo group in the main chain can extend the absorption and lower the band gap. The fluorescent spectra, photoluminescence (PL) spectra, cyclic voltammetry (CV) of PTAB-H were recorded.The gel permeation chromatography (GPC), thermogravimetry analysis (TGA), and differential scanning calorimetry (DSC) measurements indicated that the molecular weight Mn, Mw and polydispersity indices (PDI) of the polymer are 10 876 g/mol, 22 338 g/mol and 2.05 respectively and the temperature of 5% weight-loss is 224.6 °C. No glass transition and crystallization melting peak was observed in the temperature range from 30 °C to 400 °C.
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高影响因子
RSC Advances
·
2017
·Vol. 7
·期 17
·10564-10569
·
IF 3.108
Xiaowen Zhang,Yang Li,Zhongliang Hu,Zhi Chen,Jianrong Qiu
The second near-infrared window (NIR-II, 1000–1400 nm) is ideal for fluorescence imaging owing to negligible tissue scattering and minimal autofluorescence. NIR-II luminescence nanophosphors are promising materials for fluorescence imaging. Mn5+ is emerging as a new luminescent indicator owing to its typical NIR-I (800 nm) to NIR-II (1190 nm) downconversion luminescence. Herein, we report a facile synthesis approach to prepare Mn5+ doped Ba3(MO4)2 (M = V, P) nanoparticles with a remarkably sharp emission peak around 1190 nm in the NIR-II region for the first time to our knowledge. The developed two-step approach based on efficient anion exchange reaction is able to not only stabilize the valence but also keep the controlled morphology and uniform size. It is highly possible that the general approach will provide a new perspective on synthesizing special valence ion doped nanosized materials.
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Scientific Reports
·
2016
·Vol. 6
·期 1
·1-11
·
IF 5.228
Tian Zhen,Liu Jiyuan,Zhang Yalin
Given the advantages of behavioral disruption application in pest control and the damage of Cydia pomonella , due progresses have not been made in searching active semiochemicals for codling moth. In this research, 31 candidate semiochemicals were ranked for their binding potential to Cydia pomonella pheromone binding protein 2 (CpomPBP2) by simulated docking and this sorted result was confirmed by competitive binding assay. This high predicting accuracy of virtual screening led to the construction of a rapid and viable method for semiochemicals searching. By reference to binding mode analyses, hydrogen bond and hydrophobic interaction were suggested to be two key factors in determining ligand affinity, so is the length of molecule chain. So it is concluded that semiochemicals of appropriate chain length with hydroxyl group or carbonyl group at one head tended to be favored by CpomPBP2. Residues involved in binding with each ligand were pointed out as well, which were verified by computational alanine scanning mutagenesis. Progress made in the present study helps establish an efficient method for predicting potentially active compounds and prepares for the application of high-throughput virtual screening in searching semiochemicals by taking insights into binding mode analyses.
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高影响因子
JOURNAL OF BIOMATERIALS SCIENCE-POLYMER EDITION
·
2016
·
IF 1.733
Bingjie Niu,Bin Li,Yong Gu,Xiaofeng Shen,Yong Liu,Liang Chen
Bone tissue engineering by using osteoinductive scaffolds seeded with stem cells to promote bone extracellular matrix (ECM) production and remodeling has evolved into a promising approach for bone repair and regeneration. In order to mimic the ECM of bone tissue structurally and compositionally, nanofibrous silk fibroin (SF) scaffolds containing hydroxyapatite (HAP) nanoparticles and bone morphogenetic protein 2 (BMP-2) were fabricated in this study using electrospinning technique. The microstructure, mechanical property, biocompatibility, and osteogenic characteristics were examined. It was found that the HAP nanoparticles were successfully incorporated in the SF nanofibers (diameter, 200–500 nm). The mechanical properties of SF/HAP/BMP-2 composite scaffolds increased with HAP content when it was less than 20 wt%, after which the mechanical properties dropped as HAP content increased. Cell culture tests using bone marrow mesenchymal stem cells (BMSCs) showed that the scaffolds had good biocompatibility and promoted the osteogenic differentiation of BMSCs. Therefore, the electrospun SF/HAP/BMP-2 scaffolds may serve as a promising biomaterial for bone tissue engineering.
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高影响因子
ACS Catalysis
·
2016
·
IF 9.307
Da Lei,Kai Yu,Meng-Ru Li,Yuling Wang,Qi Wang,Tong Liu,Pengkun Liu,Lan-Lan Lou,Guichang Wang,Shuangxi Liu
Single-crystalline Pd nanocrystals enclosed by {111} or {100} facets with controllable sizes were synthesized and originally employed as catalysts in the aerobic oxidation of 5-hydroxymethyl-2-furfural (HMF). The experimental results indicated that the particle size and exposed facet of Pd nanocrystals could obviously influence their catalytic performance. The size-dependent effect of Pd nanocrystals in this reaction could only be derived from the different Pd dispersions. Therefore, the facet effect of Pd nanocrystals was first investigated in this work through experimental and theoretical approaches. It was found that Pd-NOs enclosed by {111} facets were more efficient than Pd-NCs enclosed by {100} facets for the aerobic oxidation of HMF, especially for the oxidation step from 5-hydroxymethyl-2-furancarboxylic acid (HMFCA) toward 5-formyl-2-furancarboxylic acid (FFCA). The TOF value of Pd-NOs(6 nm) was 2.6 times as high as that of Pd-NCs(7 nm) and 5.2 times higher than that of commercial Pd/C catalyst for HMF oxidation. Through density functional theory (DFT) calculations, the notably enhanced catalytic performance of Pd-NOs could be mainly attributed to the lower energy barrier in the alcohol oxidation step (from HMFCA to FFCA) and higher selectivity for O2 hydrogenation to produce peroxide.
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高影响因子
PURE AND APPLIED CHEMISTRY
·
2017
·Vol. 89
·期 7
·921-929
·
IF 2.626
Zhi Peng Cai,Wen Li Wang,Louis Conway,Kun Huang,Faisal Nureldin Awad,Li Liu,Josef Voglmeir
We herein demonstrate the use of 1,3-di(2-dipyridyl)propan-1,3-dione (DPPD) as a fluorogenic label for oligosaccharides. A number of milk-derived oligosaccharide standards were successfully labeled with this reagent, with the advantage of greatly simplified sample preparation compared to other commonly used fluorescent tags. DPPD shows a selectivity for oligosaccharides which do not possess a 2-acetamido-2-deoxy-hexose moiety at the reducing terminus, potentially aiding in the identification of complex mixtures of carbohydrates. The use of DPPD for the structural determination of oligosaccharides through exoglycosidase treatment, quantitative analysis of reactions, and in the synthesis of labeled oligosaccharides was also explored. This reagent has, in addition to the analysis of individual and mixed oligosaccharides, potential applications in the study of glycosidases and glycosyltransferases and as such represents a valuable addition to the tools available to the glycoscientist.
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高影响因子
AUSTRALIAN JOURNAL OF CHEMISTRY
·
2016
·Vol. 69
·期 11
·1254-1260
·
IF 1.427
Jiequn Wu,Tianxiang Yin,Shaoxiong Shi,Weiguo Shen
The systematic investigation of the aggregation behaviours of newly synthesised surface-active ionic liquids 1-alkyl-3-methylimidazolium bis(2-ethylhexyl)sulfosuccinate ([Cnmim][AOT], n = 2, 3, 5, 6, 7) by various techniques is reported. The critical aggregation concentrations (CACs) and the standard Gibbs free energies of aggregation () were determined from measurements on conductivity, fluorescence, and surface tension, which suggested a stronger self-assembly ability in the bulk solution for [Cnmim][AOT] surfactants with longer alkyl chain cations. An interesting structure transition driven by the penetration of the imidazolium cation into the aggregate when n > 4 was found by analysis of the variations of the values of CAC, , the degree of counter ion binding (β), and the micropolarity (I1/I3) immediately after the CAC with changing alkyl chain length of the imidazolium cation, which was further confirmed by 1H NMR measurements.
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高影响因子
Progress in Natural Science-Materials International
·
2017
·
IF 2.038
Xuezhang Xiao,Teng Qin,Yiqun Jiang,Fulei Jiang,Meng Li,Xiulin Fan,Shouquan Li,Hongwei Ge,Qidong Wang,Lixin Chen
Mg(AlH 4 ) 2 nanoparticles with a particle size less than 10 nm have been successfully synthesized by mechanochemical method using LiAlH 4 and MgCl 2 as raw materials together with LiCl buffering additive. In comparison to Mg(AlH 4 ) 2 microparticles, Mg(AlH 4 ) 2 nanoparticles exhibit a faster hydrogen desorption kinetics and lower desorption temperature. The hydrogen desorption temperatures of the first and second dehydrogenation steps are 80 and 220 °C for the Mg(AlH 4 ) 2 nanoparticles, which are about 65 and 60 °C, respectively, lower than those of Mg(AlH 4 ) 2 microparticles. The decomposition activation energy is reduced from 135 kJ/mol for Mg(AlH 4 ) 2 microparticles to 105.3 kJ/mol for Mg(AlH 4 ) 2 nanoparticles. It is proposed that the shortened diffusion distance and enhanced diffusivity of Mg(AlH 4 ) 2 /MgH 2 nanoparticles provide an energy destabilization for lowering the dehydrogenation temperature, and thus being the key factor for promoting the hydrogen desorption kinetics. More importantly, it is demonstrated that the dehydrided nano MgH 2 hydride with a particle size below 10 nm can be formed after rehydrogenation process, resulting in the good cycling hydrogen desorption performance of nano MgH 2 .
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