MOLECULAR PHARMACEUTICS
·
2014
·
IF 4.787
Huan Huang,Duanwen Cao,Linghao Qin,Shouqin Tian,Yang Liang,Shirong Pan,Min Feng
Numerous preclinical studies have demonstrated that polycation mediated gene delivery systems successfully achieved efficient gene transfer into cells and animal models. However, results of their clinical trials to date have been disappointing. That self-assembled gene and polycation systems should be stable undergoing dilution in the body is one of the prerequisites to ensuring efficiency of gene transfer in clinical trials, but it was neglected in most preclinical studies. In this account, we developed the dilution-stable PAMAM G1-grafted polyrotaxane (PPG1) supermolecules in which PAMAM G1-grafted α-cyclodextrins are threaded onto a PEG chain capped with hydrophobic adamantanamine. The PPG1/pDNA polyplex (approximate 100 nm in diameter) was very stable and kept its initial particle size and a uniform size distribution at ultrahigh dilution, whereas DNA/PEI 25K polyplex was above three times bigger at a 16-fold dilution than the initial size and their particle size distribution indicated multiple peaks mainly due to forming loose and noncompacted aggregates. PPG1 supermolecules showed significantly superior transfection efficiencies compared to either PEI 25K or Lipofectamine 2000 in most cell lines tested including normal cells (HEK293A) and cancer cells (Bel7402, HepG2, and HeLa). Furthermore, we found that the PPG1 supermolecules delivered DNA into HEK293A through a caveolae-dependent pathway but not a clathrin-dependent pathway as PEI 25K did. These findings raised the intriguing possibility that the caveolae-dependent pathway of PPG1 supermolecule/pDNA polyplex avoiding lysosomal degradation was attributed to their high transfection efficiency. The dilution-stable PPG1 supermolecule polyplex facilitating caveolae-dependent internalization has potential applications to surmount the challenges of high dilutions in the body and lysosomal degradation faced by most gene therapy clinical trials.
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JOURNAL OF CHROMATOGRAPHY A
·
2017
·
IF 3.981
Xingru Hu,Chao Liu,Jiansheng Li,Rui Luo,Hui Jiang,Xiuyun Sun,Jinyou Shen,Weiqing Han,Lianjun Wang
In this study, a novel hollow mesoporous carbon spheres-based fiber (HMCSs-F) was fabricated to immobilize HMCSs onto a stainless steel wire for solid-phase microextraction (SPME). Characterization results showed that the HMCSs-F possessed a large specific surface area, high porosity and uniform pore size. To demonstrate the extraction performance, a series of polycyclic aromatic hydrocarbons (PAHs) was chosen as target analytes. The experimental parameters including extraction and desorption conditions were optimized. Compared to commercial fibers, the HMCSs-F exhibited better extraction efficiency for PAHs. More interestingly, a good extraction selectivity for PAHs from the complex matrix was observed in these HMCSs-F. The enhanced SPME performance was attributed to the unique pore structure and special surface properties of the HMCSs. Furthermore, under the optimum conditions, the limits of detection (LODs) for the HMCSs-F were in the range of 0.20–1.15 ng L −1 with a corresponding relative standard deviation that was below 8.6%. The method was successfully applied for the analysis of PAHs in actual environmental water samples with recoveries ranging from 85.9% to 112.2%. These results imply that the novel HMCSs-F have potential application in environmental water analysis.
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JOURNAL OF CHROMATOGRAPHY A
·
2017
·
IF 3.981
Juanjuan Wu,Ruiyang Ma,Lin Hao,Chun Wang,Qiuhua Wu,Zhi Wang
A hypercrosslinked organic polymer material (named as PPTPA) was prepared by a simple one-step self-polycondensation of triphenylamine. A series of characterization experiments, including N 2 adsorption, scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectra, and thermogravimetric analysis, were carried out to evaluate the morphology, structure and other intrinsic properties of the PPTPA. To investigate its adsorption performance, the PPTPA was used as the solid-phase extraction adsorbent for the extraction of phenylurea herbicides from water, milk and tomato juice samples followed by high-performance liquid chromatographic analysis. Under optimum conditions, good linearity for the analytes was observed in the range of 0.05–40.0 ng mL −1 , 0.1-40.0 ng mL −1 and 0.5–40.0 ng mL −1 for water, milk and tomato juice samples, respectively. The established method also showed low limits of detection (S/N = 3) in the range of 0.008–0.01 ng mL −1 , 0.01–0.03 ng mL −1 and 0.05–0.1 ng mL −1 for water, milk and tomato juice samples, respectively. The possible adsorption mechanism of the PPTPA towards the analytes was investigated, and the results demonstrated that the hydrogen bonding was the main interaction force between the PPTPA and the analytes. It suggests that the PPTPA can serve as a promisingadsorbent for the efficient pre-enrichment of organic compounds with more hydrogen-bonding donor sites.
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ENERGY & FUELS
·
2017
·
IF 3.091
Weipeng Yang,Tengfei Wang,Zexia Fan
Foam stabilized by particles has been applied in enhanced oil recovery (EOR). However, many difficulties in establishing a foam system with high stability, foamability, and resistance to harsh conditions still exist. In this study, foam stabilized by hydrophobic modified alumina nanoparticles was systematically studied. Sodium cumenesulfonate (SC) was used to modify nanoparticles and generate foam. A competitive effect between nanoparticles and SC was found. Specifically, foam stability increased with SC concentration at lower SC concentration range. Foam with high stability and relatively high foamability was obtained at an SC concentration of 20 mM, and then, foam stability sharply decreased because of the competitive effect. The presence of an electrolyte slowed down the adsorption of SC at the air–water interface by forming an ion pair between the headgroup of SC and the cation, which influences foamability and stability. Meanwhile, the electrolyte also caused detachment of particles from foam due to the decrease of hydrophobicity as a result of the decreased SC adsorption. Despite these effects, the particle-stabilized foam maintained high stability in a wide range of electrolyte concentrations. Sandpack flooding experiments showed that the oil recovery rate increased with SC concentration because of the enhanced foamability and stability, leading to a higher displacement efficiency and water flush resistance.
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JOURNAL OF CHROMATOGRAPHY A
·
2017
·
IF 3.981
Chengjiang Zhang,Xialin Luo,Tianfu Wei,Yufei Hu,Gongke Li,Zhuomin Zhang
A new dynamic covalent polymer (DCP) gel was well designed and constructed based on imine chemistry. Polycondensation of 4,4′-biphenyldicarboxaldehyde and 1,3,5-benzenetricarbohydrazide via Schiff-base reaction resulted in an acylhydrazone bond gel (AB-gel) DCP. AB-gel DCP had three-dimensional network of interconnected nanoparticles with hierarchically porous structure. AB-gel DCP was successfully fabricated as a monolithic column by an in-situ chemical bonding method for online enrichment and separation purpose with excellent permeability. AB-gel DCP based monolithic column showed remarkable adsorption affinity towards target analytes including sulfonamides (SAs) and fluorescent whitening agents (FWAs) due to its strong π-π affinity, hydrophobic effect and hydrogen bonding interaction. Then, AB-gel DCP based monolithic column was applied for online separation and analysis of trace SAs and FWAs in food samples coupled with high-performance liquid chromatography (HPLC). Sulfathiazole (ST) and sulfadimidine (SM2) in one positive weever sample were actually found and determined with concentrations of 273.8 and 286.3 μg/kg, respectively. 2,5-Bis(5- tert -butyl-2-benzoxazolyl) thiophene (FWA184) was actually quantified in one tea infusion sample with the concentration of 268.5 ng/L. The spiked experiments suggested the good recoveries in range of 74.5–110% for SAs in weever and shrimp samples with relative standard deviations (RSDs) less than 9.7% and in range of 74.0-113% for FWAs in milk and tea infusion samples with RSDs less than 9.0%. AB-gel DCP monolithic column was proved to be a promising sample preparation medium for online separation and analysis of trace analytes in food samples with complex matrices.
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INTERNATIONAL BIODETERIORATION & BIODEGRADATION
·
2017
·
IF 2.962
Guang Guo,Fang Tian,Keqiang Ding,Lihong Wang,Tingfeng Liu,Feng Yang
The metabolism of polycyclic aromatic hydrocarbons (PAHs) in polluted soil is limited by low contaminant bioaccessibility and low degradation by bacteria. A bacterial consortium that degraded 76 per cent of pyrene within 10 days was enriched from a contaminated soil. Hydroxypropyl-β-cyclodextrin (HPCD) enhanced the rate of degradation by the consortium. The bacterial consortium was used to bioremediate PAH-contaminated soil (pyrene and benzo[α]pyrene) in the presence or absence of HPCD. Enhanced PAH mineralization was observed after 10 weeks, particularly in the presence of HPCD, which increased the bioavailability of PAHs. Illumina sequencing was performed to analyze the changes in the bacterial communities. The dominant genus was Burkholderia in all treated soils. Importantly, the inoculated bacteria cannot compete with native bacteria and will therefore not invade the community. The significantly stimulated genera were Burkholderia , Nitratireductor , Nevskia and Sulfuritalea . These results suggest that the combination of bacteria with HPCD can enhance the bioremediation of PAH-contaminated soil.
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MICROCHIMICA ACTA
·
2017
·Vol. 184
·期 10
·3773-3779
·
IF 4.58
Wu Juanjuan,Liang Xinyu,Hao Lin,Wang Chun,Wu Qiuhua,Wang Zhi
A nanocomposite (designated as PAG) possessing amphiphilic properties was prepared by a single-step method from graphene oxide and phytic acid, in which phytic acid acts as both an inducer and cross-linking agent. The morphology and microstructure of PAG were characterized by nitrogen adsorption, scanning electron microscopy and transmission electron microscopy. The PAG possess a 3 dimensional network structure with interpenetrated nano- and micropores and represent a viable adsorbent for solid-phase extraction of carbamate pesticides prior to their quantitation by high performance liquid chromatography. Under optimum conditions, the calibration plot is linear in the 0.5 to 80 ng g −1 concentration range in case of apple samples, and in the 1.0 to 80 ng mL −1 range for juice samples. The respective limits of detection (for S / N = 3) are between 0.05 and 0.1 ng g −1 , and between 0.2 and 0.3 ng mL −1 . The PAG has a high adsorption capability, and in our preception it may become a useful adsorbent for the preconcentration of other organic pollutants.
A amphiphilic nanocomposite (prepared from phytic acid and graphene oxide; denoted as PAG) was prepared by a single-step method. Phytic acid acts as both an inducer and cross-linking agent. The PAG was used as an adsorbent to extract carbamates from apple and juice samples.
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ChemCatChem
·
2016
·Vol. 9
·期 17
·3349-3357
·
IF 4.724
Shiyue Bian,Chenjuan Zhou,Peiran Li,Jiyang Liu,Xiaoping Dong,Fengna Xi
Graphical Joining the dots : Oxygen-functionalized graphene quantum dots (GQDs) are encapsulated into flocculated flexible titania nanosheets (TNSs) to form GQDs/TNSs composite photocatalyst through a facile electrostatic flocculation route. GQDs/TNSs exhibit high photocatalytic activity for the degradation of Rhodamine B under visible light irradiation owing to promoted charge separation. Titania nanosheets (TNSs) are of importance for photocatalytic application owing to the unique two-dimensional (2D) morphology, high crystallinity and plentiful surface charge. However, the large band gap prohibited the efficient utilization of sun light. Herein, we employed graphene quantum dots (GQDs) as green photocatalytic promoter to decorate TNSs during the electrostatic flocculation. The obtained GQDs/TNSs heterojunction was systematically characterized, and the results demonstrated that the composite exhibited an intimate coupling of GQDs and TNSs, a markedly visible light absorption and therefore the enhanced separation efficiency of photogenerated charges. This composite photocatalyst shows enhanced photocatalytic performance for the photodegradation of Rhodamine B (RhB) under visible light irradiation in comparison with pure restacked TNSs (rs-TNSs) and GQDs. Furthermore, this composite exhibited a superior reusability, and a high degradation ratio about 90 % was still achieved in the 5 th cycle. Moreover, a possible mechanism was proposed and superoxide radicals, holes and hydroxyl radicals were determined as the active species.
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Petroleum Science
·
2016
·Vol. 14
·期 1
·195-202
·
IF 0.901
Chen Shi-Jia,Chen Bin,Zhu Hong-Qing,Wang Cheng-Sheng,Wu Xiao-Yan,Lv Peng
The influence of emulsified oil, suspended solids, Fe 3+ , Fe 2+ , cationic water clarifier and sulfate-reducing (SR) bacteria on the aggregation behavior of residual hydrophobic modified polyacrylamide in treated oily wastewater from polymer flooding was studied by fluorescence spectroscopy and dynamic light scattering. The result of I
1
/I
3 showed that the polarity of hydrophobic microdomains increased, whereas the size of the hydrophobic microdomains may be decreased, where the value of I
1
/I
3 represents the ratio of the intensity of peak I
1 (374.0 nm) to that of peak I
3 (385.0 nm) of the vibration fine structure of pyrene monomer emission in residual polymer solution. The results of the ratio of I
1 at 48 h to I
1 at 0 h ( I
1,48h
/I
1,0h ) indicated that oil and cationic water clarifier could inhibit the aggregation to some extent, while Fe 2+ and suspended solids were helpful for aggregation, and Fe 3+ and SR bacteria had no significant influence on the aggregation of polymer.
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JOURNAL OF CHEMICAL THERMODYNAMICS
·
2016
·
IF 2.196
Guangyue Bai,Jianhui Sheng,Yujie Wang,Hui Wu,Yang Zhao,Kelei Zhuo,Margarida Bastos
The thermodynamics of molecular self-assembling of an anionic biosurfactant, sodium cholate (NaCA) and its mixtures with sodium dodecyl sulfate (SDS) in aqueous solution have been investigated by isothermal titration calorimetry (ITC), along with fluorescence and conductivity measurements. Different critical concentrations were obtained by these three techniques – critical pre-micelle concentration (cmc pre ) and critical micelle concentration (cmc) for pure NaCA, and critical micelle concentrations (cmc mix ) for the mixed systems with differently initial SDS concentrations. Importantly, ITC allowed us to directly measure the enthalpy changes of pre-micelle formation (Δ H premic = (−0.28 ± 0.02) kJ·mol −1 ) and of micelle formation (Δ H mic = (−1.76 ± 0.05) kJ·mol −1 ) for pure NaCA as well as the enthalpies for micellization for the mixed systems NaCA/SDS. The non-ideality of the mixed surfactant solution was evaluated in terms of interaction parameters and excess enthalpies that were calculated in the light of Clint’s and Rubingh’s models. It was found that there is an obvious synergistic effect in the NaCA/SDS mixed system. From all these results we can ascribe the strong interaction between the same charge surfactants NaCA and SDS to the structural difference in their hydrophobic moieties. In fact, the flexible alkyl chains of SDS and the non-planar hydrophobic β -faces of NaCA tend to have a more compact packing than pure NaCA.
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CHEMOSPHERE
·
2016
·
IF 3.698
Tingru Chen,Xiaoyan Liu,Xinying Zhang,Xiao Chen,Kaiyun Tao,Xiaoxin Hu
At present, few research focus on the phytoremediation for organic pollutants and heavy metals enhanced by surfactants and chelate agents in the combined contaminated soils or sediments. In this study, the effect of a novel combined addition of alkyl polyglucoside (APG) and nitrilotriacetic acid (NTA) into pyrene and lead (Pb) co-contaminated soils on bioaccessiblity of pyrene/Pb and dehydrogenase activities (DHA) was studied. Through the comparison of the results with the alone and combined application, synergistic effect on bioaccessiblity of pyrene and Pb was found while APG and NTA was applied together. Results also indicated a significant promotion on the DHA in mixed addition of APG and NTA. In addition, correlation and principal component analysis were performed to better understand the relationship among APG/NTA, bioaccessiblity of pyrene/Pb and the DHA. Results showed that APG and NTA can affect DHA directly by themselves but also can affect DHA indirectly by changing bioaccessible pyrene and exchangeable Pb.
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JOURNAL OF BIOMATERIALS SCIENCE-POLYMER EDITION
·
2016
·
IF 1.733
Liyan Shi,Kaikai Ding,Xin Sun,Ling Zhang,Tian Zeng,Yihua Yin,Hua Zheng
In this paper, a kind of glutathione-sensitive polymeric micelles was prepared through assembling in aqueous solution of an amphiphilic polymeric prodrug which was synthesized by linkage of 6-mercaptopurine (6-MP) and polyethylene glycol monomethyl ether using propiolic acid as a connecting arm. The glutathione (GSH)-sensitive strategy is based on a Michael addition–elimination reaction, that is the amphiphilic polymeric prodrug which contains α, β-unsaturated carbonyl group acts as a Michael acceptor to receive the attack of nucleophile – glutathione, and undergoes elimination reaction to release the original drug. Transmission electron microscope observation showed that the polymeric micelles (PMs) had a spherical-like morphology with a mean diameter of 28 ± 3.2 nm. The dynamic light scattering investigation data exhibited that the size and distribution changes of PMs are negligible after being placed for 15 days. In vitro drug release study indicated that only less than 13% of 6-MP was released from the micelles under GSH stimulation at micromolar level, while 34.5, 53.7, and 77.8% accumulative release rates were achieved under GSH stimulation at millimolar level (1, 2 and 10 mM), respectively. The cell inhibition rate of PM solution against HL-60 cells carried out by MTT method reached 85%. The cellular uptake and the intracellular drug release of PMs in HL-60 cells were observed through determining the intracellular 6-MP content by UV–vis spectrophotometer. In vitro macrophage uptake study showed a low phagocytosis rate, indicating the long-circulation ability of the PMs.
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