JOURNAL OF BIOMATERIALS SCIENCE-POLYMER EDITION
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2020
·
IF 2.69
Penghui Wang,Wei Liu,Shuai Liu,Rong Yang,Yajie Pu,Wenjie Zhang,Xiaoxue Wang,Xin Liu,Yanhan Ren,Bo Chi
Here, a novel pH-responsive block copolymer, poly (ethylene glycol)-poly(ε-caprolactone)-poly(L-histidine) (PEG-PCL-PHis), was synthesized and designed for anti-cancer drug delivery with excellent biocompatible, biodegradable, and strong drug loading efficiency. 1H-NMR, IF-IR, and GPC were used to characterize the structure of the PEG-PCL-PHis copolymer. In addition, the morphology, particle size, Zeta potential, and critical micelle concentration (CMC) of different degree of polymerization were determined by transmission electron microscopy (TEM), dynamic light scattering granulometer (DLS), and fluorescence spectrometer, respectively. The strong affinity between the core of micelles and hydrophobic drug was manifested with 15.09% drug loading content and 84.65% entrapment efficiency. In vitro release of DOX from the block copolymer micelle demonstrated, the PEG-PCL-PHis copolymer micelle has stable and durable drug releasing ability accompanied with pH-sensitivity. From the mechanism of cellular uptake the micelles, the pathway of drug release was captured by confocal laser scanning microscope. These experiments demonstrated the safe delivery for anticancer medicine through this novel copolymer. In conclusion, the PEG-PCL-PHis copolymer micelle has great potential to become a safe drug carrier for cancer chemotherapy.
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CERAMICS INTERNATIONAL
·
2020
·
IF 3.83
Xuejun Ruan,Xin Ren,Wenting Zhou,Qi Cheng,Zheng Yao,Wenqi Yu,Lujiang Jin,Liyi Shi
This article systematically studies the relationship between the dispersity of the mixed suspension, the microstructures and the electrical properties of the ZnO varistors by adjusting the dispersant content and the pH value. The suspension dispersity was measured by viscosity, zeta potential , particle size distribution and TEM observation. The structure of the as-prepared ZnO varistors was characterized by XRD and SEM. The electrical properties were investigated by testing E-J characteristics, breakdown voltage, leakage current, nonlinear coefficient, 8/20 μs waveform current impulse and accelerated aging performance. When the suspension reached the best dispersion condition of 0.3 wt% dispersant and the original pH value, the ZnO varistors had optimum electrical properties: breakdown voltage gradient of 299.95 V mm −1 , leakage current I L of 0.33 μA, voltage ratio U 5kA /U 1mA of 1.686, nonlinear coefficient of 46.71, and a downward trend of power consumption in the accelerated aging test.
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JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
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2020
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IF 4.192
Hui He,Meixiao Cheng,Yuting Liang,Hongxiang Zhu,Yupei Sun,Die Dong,Shuangfei Wang
Novel nanosized biomass-based pH-responsive cellulose nanofibers (CNF-PEI) with excellent biocompatibility were tailored by grafting polyethylenimine (PEI) onto carboxylated cellulose nanofibers (CNF-COOH); the active site (−COOH, 0.96 mmol/g) was anchored on cellulose nanofibers (CNFs) to introduce PEI with a high density (10.57 mmol/g) of amino groups. The as-prepared CNF-PEI not only maintained the good properties of CNFs but also possessed excellent biocompatibility and pH-responsive properties, offering interesting possibilities for pH-induced sustained drug release and medical dressing. The CNF-PEI showed rapid wettability conversion from hydrophilic, underwater superoleophobic (WCA = 20.7°, OCA = 159.3°) to hydrophobic, superoleophilic (WCA = 129.6°, OCA = 29.7°) in response to pH change from acidic conditions to alkaline conditions. The antibacterial activity of CNF-PEI toward Escherichia coli and Listeria monocytogenes was 100% and 94.6% under acidic conditions, respectively. Furthermore, the pH-responsive mechanism of CNF-PEI was revealed by XPS, 13C NMR, 1H NMR, and AFM analyses.
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NANOTECHNOLOGY
·
2020
·Vol. 31
·期 19
·195103
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IF 3.551
Junlong Liang,Xiaokang Jin,Biling Chen,Jinhua Hu,Qianwei Huang,Junmin Wan,Zhiwen Hu,Bing Wang
The integration of chemotherapy drugs and photosensitizers to form versatile nanoplatforms for achieving chemo-photodynamic synergetic therapy has shown great superiority in tumor theranostic applications. We constructed pH-responsive nanoparticles (DOX/PB NPs) encapsulating the chemotherapeutic drug doxorubicin (DOX) into the cores of PLGA NPs coated with bovine serum albumin (BSA) via a water-in-oil (W/O/W) emulsion method. A simple and efficient chemo-photodynamic synergetic nanoplatform (DOX/PB@Ce6 NPs) was obtained by the adsorption of photosensitizer chlorin e6 (Ce6) onto the surface of the DOX/PB NPs. With optimal size, pH-responsive drug release behavior and excellent singlet oxygen production, the DOX/PB@Ce6 NPs have the potential to enhance anti-tumor efficiency. The cellular uptake, cytotoxicity, chemo-photodynamic synergetic effect and biocompatibility of the NPs were evaluated based on HeLa cells via in vitro experiments. The in vitro chemo-photodynamic synergetic experiments indicated that the DOX/PB@Ce6 NPs had remarkable cancer cell killing efficiency under laser irradiation. Notably, by hemolysis assay, all the NPs displayed excellent blood compatibility and were expected to be applicable for intravenous injection. In summary, the designed DOX/PB@Ce6 NPs multifunctional theranostic nanoplatform had excellent reactive oxygen species generation and would be a potential therapeutic platform for chemo-photodynamic synergetic therapy.
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JOURNAL OF ELECTROANALYTICAL CHEMISTRY
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2020
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IF 3.807
Gengxin Hu,Nanxi Li,Yuwei Zhang,Hong Li
The electrochemical oxidative quinone-functionalization of tryptophan (Trp) residues, and the proton-coupled electron transfer properties between quinonized Trp (Trp=O) and its re-reduced species (Trp-OH) are investigated for potentiometric pH sensors. The Trp=O/Trp-OH couples are assembled on a graphite electrode using multiple cyclic voltammetry, and exhibit a pair of well-defined redox peaks at redox potential of 0.090 V (vs. SCE) at pH 7.0 and 298 K. The proton-coupled electron transfer properties of Trp=O/Trp-OH couples are dependent on electrode substrate material, incubation temperature and pH values, and Trp residue sources including amino acid, peptide and protein. The Trp=O/Trp-OH-based surface-confined exothermic electrode reaction rates show a decrease with increasing incubation temperature from 283 to 323 K at pH 5.0. Both of redox peak potential and open-circuit potential under optimum conditions have a good linear pH dependence between 1.0 and 12.0 with sensitivity of more than 52 mV pH −1 and relative standard derivation of 1.5%. The proposed potentiometric pH sensor has significant advantages of low cost, good stability and reproducibility, and strong anti-interference ability. The present study shows a new approach to endow Trp, Trp-containing peptides and non-conjugated proteins with analogous proton-coupled electron transfer performance to prosthetic groups of quinoproteins for monitoring pH changes in milk samples.
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CHEMICAL ENGINEERING JOURNAL
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2021
·
IF 13.273
Zhiwei Wang,Yue Zhang,Fengmin Li,Haixiang Han,Chunhua Xu
Sulfidation of zero-valent iron (SZVI) is an important means to greatly inhibit the formation of inert hydr/oxide and improve the overall reactivity in pollutant removal reactions, which is mainly benefiting from the formation of FeS x layer on surface of the zero-valent iron (ZVI). However, FeS x phase can act as reducing reagent in the treatment of pollutants, resulting in inevitable consumption. Considering that, copper cation was introduced to the FeS x phases to prepare copper-doped sulfides with improved durability. In this study, we successfully prepared copper-doped SZVI (Cu-SZVI). The composition and structure have been clearly confirmed by a combination of several techniques, including Raman spectroscopy and X-ray powder diffraction. Cu-SZVI exhibits a superior sequestration reaction to remove Cr(VI) with higher removal capacity of 82.93 mg/g, with the comparison of SZVI (57.54 mg/g) and ZVI (8.23 mg/g). Moreover, Cu-SZVI possesses better operational pH tolerance and longer lifetime of usage, which makes it particularly attractive to large-scale environmental applications. This work proposes a new way to modify SZVI by doping a secondary cation, which can be used to further explore new SZVI materials based on specific needs.
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ACS Sustainable Chemistry & Engineering
·
2021
·
IF 8.198
Yun Tong,Dongmei Feng,Pengzuo Chen
Developing highly efficient electrocatalysts for large-scale implementation of the hydrogen evolution reaction (HER) at a large current density is critical for renewable H2 fuel. The designed electrocatalysts by non-noble metals are expected to operate well at wide pH conditions, but it remains a major challenge. In this work, a novel dual modification strategy is applied to develop a series of P/Mo modified Ni3S2 on nickel foam (denoted as P-MNS/NF) as pH-universal electrocatalysts for HER. Benefiting from the plentiful catalytic active sites, optimized electronic structure, and improved reaction kinetics, the P-MNS/NF electrode realizes remarkable catalytic activity and stability at a large current density. The optimal P3-MNS3/NF catalyst exhibits the low overpotential of 245 and 243 mV at a high current density of 1 A cm–2 for both alkaline/acidic media. Those are promising performance results compared to those of the other nickel sulfide-based materials. Importantly, this P3-MNS3/NF can also achieve good performance in a neutral electrolyte. This needs a small overpotential of 360 mV to reach the current density of 0.5 A cm–2. Our strategy provides a new method to guide rational design of highly active HER electrocatalysts over a wide pH window.
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DYES AND PIGMENTS
·
2021
·
IF 4.889
Lu Yang,Hao Lu,Ting Zhang,Shengyu Zhou,Xiaoyan Yang,Zhiwen Luo,Wei Huang,Yijun Shen,Guangbo Wang,Yingshuai Liu,Jing Liu
Levofloxacin (LVFX) is a fluoroquinolone antibacterial agent and widely used in the treatment of bacterial infections. However, the abuse of LVFX will do great harm to human being, and alkaline urine (pH > 7.0) with decreased solubility of LVFX will further cause adverse side effects. There is an urgent demand and great challenge to construct a mutlifunctional nano-system for the detection of LVFX and pH. We report a novel water-dispersible europium (Eu)-grafted covalent organic framework nanoplates (Eu@CON) with luminescent characteristics of Eu 3+ . Eu@CON shows high selective and sensitive luminescence sensing for LVFX with a limit of detection (LOD) at 0.51 μM. A visual test strip has been further designed and fabricated for on-site and rapid pH measurement with a detection range from 1 to 4 and 11 to 14. This proof-of-concept study not only reports a new type of luminescent LVFX and pH sensor, but also provides a promising strategy for the design of water-dispersible lanthanide-grafted luminescent CONs to further extends its application in chemo-biosensing.
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ANALYST
·
2021
·Vol. 146
·期 20
·6262-6269
·
IF 4.616
Fangbin Fan,Licheng Wang,Xiaofeng Lu,Xiaojing Liang,Yong Guo
Inspired by porous smart gel materials, we designed pH-responsive polymer-modified silica microspheres as liquid chromatography stationary phase materials by a one-step strategy. The free radicals generated by the oxidation of dopamine are used to initiate the cross-linking polymerization of functional monomers. At the same time, the good adhesion of dopamine enables the polymer to be modified on silica. The hydrophilicity of this new stationary phase can change in response to the pH of the mobile phase and the stationary phase has weaker hydrophilicity under acidic (pH = 3.78) mobile phase conditions and stronger hydrophilicity under neutral mobile phase conditions. The hydrophilicity difference of the stationary phase leads to the selectivity difference in separation. To evaluate the chromatographic performance of this new stationary phase, 10 oligosaccharides and 9 nucleosides/bases were separated on this stationary phase. This paper will provide good guidance for us to achieve more pH-responsive hydrophilic/hydrophobic stationary phases in the future.
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RSC Advances
·
2021
·Vol. 11
·期 49
·30971-30979
·
IF 3.361
Huadong Zhang,Zhongyi Yan,Zhizhou Yang,Jinshui Yao,Qiuhong Mu,Dan Peng,Hui Zhao
A novel silicone resin (SR-OH) containing phenolic hydroxyl (Ph–OH) groups was designed and synthesized via co-hydrolysis/condensation and catalytic hydrogenation. During the curing process, the cross-linking degree of the resin was further increased by the Si–O–Ph bonds formed by the reaction of the Ph–OH and terminal Si–OH groups. Thermogravimetric analysis (TGA) showed that the cured resin product exhibited excellent thermal and thermo-oxidative stability, which was much higher than that of a typical methyl phenyl silicone resin (SR-Ph). The temperature at which 5% weight loss occurs (Td5) was up to 606 °C (nitrogen) and 542 °C (air), and its char yield at 800 °C was 91.1% and 85.3% in nitrogen and air, respectively. The significant improvement in thermal stability was mainly attributed to the formation of Si–O–Ph bonds which not only increases the cross-linking degree of the resin but also significantly prevents degradation by the ‘back-biting’ and oxidative cleavage.
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ENERGY & FUELS
·
2019
·
IF 3.021
Kaiyu Zhang,Guodong Zhang,Zhuojing Li,Jirui Hou
Low pH fracturing fluids, such as the transition metal cross-linked guar derivative, can reduce the formation damage caused by clay swelling and fines migration in hydraulic fracturing treatments. However, a major disadvantage of the fluids is the uncontrollable rapid viscosity development, especially cross-linking under a pH below 3.0. In this paper, a novel delayed organic zirconium cross-linker with lactate and ethylene glycol as ligands was designed to overcome the shortcoming. Carboxymethyl hydroxypropyl guar (CMHPG), which results in a low gel residue after breaking, was used as the polymer at low concentration. The impact of gelation parameters on the properties of zirconium-CMHPG gel system was systematically investigated using a Sydansk bottle-testing method combined with a controlled stress rheometer. Desirable gelation time delay with agreeable rheological performance could be obtained by optimizing the polymer and cross-linker concentrations even at a pH as low as 2.0. Uniformly and compactly generated 3D network microstructures could firmly lock the free water within the gel, which further improved the thermostability and acid-resistance of the system. Meanwhile, the structures could also maintain the viscoelasticity of the fluid at a high level to ensure the efficient transportation of the proppants. Proppant settling and gel breaking tests demonstrated that the low pH and low polymer concentration gel system generated fewer insoluble residues with an uncompromised suspension performance. Moreover, the formation damage evaluation revealed that the low pH fracturing fluid system produced a better return permeability than the high pH system.
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Small
·
2019
·Vol. 15
·期 44
·1902823
·
IF 10.856
Pei Yang,Ziqi Zhu,Tao Zhang,Wei Zhang,Weimin Chen,Yizhong Cao,Minzhi Chen,Xiaoyan Zhou
Monitoring of wound pH is critical for interpreting wound status, because early identification of wound infection or nonhealing wounds is conducive to administion of therapies at the right time. Here, novel orange-emissive carbon quantum dots (O-CDs) are synthesized via microwave-assisted heating of 1,2,4-triaminobenzene and urea aqueous solution. The as-prepared O-CDs exhibit distinctive colorimetric response to pH changing, and also display pH-sensitive fluorescence. Benefiting from the response of O-CDs over a wound-relevant pH range (5–9), medical cotton cloth is selected to immobilize O-CDs through hydrogen bond interactions, the resultant O-CDs-coated cloth with emission at 560 nm shows a high response to pH variation in the range of 5–9 via both fluorescence and visible colorimetric changes. Moreover, the sensitivity of fluorescence to pH is capable of establishing an analytical mode for determining pH value. Further, the O-CDs-based pH indicator possesses not only superior biocompatibility and drug compatibility but also excellent resistance leachability and high reversibility. Importantly, the usage of O-CDs-coated cloth to detect pH is free from the interference of blood contamination and long-term storage, thus providing a valuable strategy for wound pH monitoring through visual response and quantitative determination.
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