BIOMACROMOLECULES
·
2016
·
IF 5.583
Wenliang Wang,Bo Wang,Xiaojing Ma,Sanrong Liu,Xudong Shang,Xifei Yu
Rapid cellular uptake and efficient drug release in tumor cells are two of the major challenges for cancer therapy. Herein, we designed and synthesized a novel pH-responsive polymer–drug conjugate system poly(2-(methacryloyloxy)ethyl choline phosphate)-b-poly(2-methoxy-2-oxoethyl methacrylate-hydrazide-doxorubicin) (PCP-Dox) to overcome these two challenges simultaneously. It has been proved that PCP-Dox can be easily and rapidly internalized by various cancer cells due to the strong interaction between multivalent choline phosphate (CP) groups and cell membranes. Furthermore, Dox, linked to the polymer carrier via acid-labile hydrazone bond, can be released from carriers due to the increased acidity in lysosome/endosome (pH 5.0–5.5) after the polymer prodrug was internalized into the cancer cells. The cell viability assay demonstrated that this novel polymer prodrug has shown enhanced cytotoxicity in various cancer cells, indicating its great potential as a new drug delivery system for cancer therapy.
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高影响因子
Nanoscale
·
2016
·Vol. 8
·期 21
·11052-11059
·
IF 7.76
Aiping Wu,Chungui Tian,Haijing Yan,Yanqing Jiao,Qing Yan,Guoyu Yang,Honggang Fu
A low-cost catalyst for the hydrogen evolution reaction (HER) over a broad pH range is highly desired to meet the practical needs in different areas. In this study, hierarchical flower-like MoS2@MoP core–shell heterojunctions (HF-MoSP) are designed as a promising catalyst for HER over a broad pH range. The materials are obtained by the controllable phosphidation of the hierarchical MoS2 flower (HF-MoS2) composed of thin silk belt-like sheets. The phosphidation degree, P/S ratio and work function (WF) of HF-MoSP can be tuned easily over broad range by changing the phosphidation temperature. Under optimized condition, HF-MoSP exhibits excellent electrocatalytic activity for HER with a low onset overpotential of 29 mV and η of 108 mV at 10 mA cm−2 in 0.5 M H2SO4 and retains its good activity for 30 h. In addition, the catalyst shows excellent activity in 1 M KOH with an onset overpotential of 42 mV and η of 119 mV at 10 mA cm−2. The catalysts also exhibit obvious activity in neutral, weak acid and weak alkaline conditions. The good performance is relative to the synergy of the MoP shell and MoS2 core and the high WF of HF-MoSP close to Pt, and the large SBET of HF-MoSP benefited from the hierarchical structure. This study represents the construction of the core–shell heterojunction and provides a new way to provide the low-cost and high-performance catalyst for HER.
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高影响因子
RSC Advances
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2016
·Vol. 6
·期 100
·97684-97693
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IF 3.289
Yongchao Yao,Deqiu Xu,Chang Liu,Yayuan Guan,Jiya Zhang,Yuling Su,Lili Zhao,Fancui Meng,Jianbin Luo
Biodegradable multi-blocked polyurethane (PU) based micelles with a hydrophilic PEG corona were extensively studied for anti-cancer drug delivery systems. The hydrophilic PEG segment usually incorporated as a soft segment or as an end capping reagent, which has difficulty forming a dense PEG coating with a brush like conformation due to the low mobility of the PEG domains at the soft segment and the low amount of the PEG at the end of PU chains. In the present study, biodegradable pH sensitive polyurethane micelles with a dense brush like coating of PEG were prepared by a new kind of PEG grafted polyurethanes (PEG-g-PU) which were synthesized using PEGylated diethanolamine (MPEG-DEAM) as a chain extender. The high mobility of pendant MPEG in PEG-g-PU results in the formation of a dense and brush like PEG corona on the PEG-g-PU micelles. Meanwhile the MPEG attached on the hard segment will transfer the diethanolamine (DEAM) to the surface of nanoparticles during the self-assembly process and the DEAM render the particles with positive charges which potentially enhances cellular uptake and endosomal escape. DLS, TEM and AFM showed that a dense PEG domain was formed on the surface of PEG-g-PU micelles while no obvious PEG microdomain was observed for the other two kinds of micelles. FTIR and DSC results demonstrated the enhanced microphase separation of PEG-g-PU micelles compared with PEG-g-PU bulk materials and the other two contrast PU micelles, i.e. PEG-b-PU and PEG-c-PU. Paclitaxel (PTX) was chosen as a model hydrophobic drug to evaluate the loading and pH-triggered release of the PU micelles. The enhanced cytotoxicity of PTX-loaded PEG-g-PU-3 micelles against H460 cancer cells reveals that they are more potent for intracellular delivery of PTX as compared to PEG-b-PU-3 and PEG-c-PU-3 micelles.
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高影响因子
RSC Advances
·
2016
·Vol. 6
·期 44
·37385-37390
·
IF 3.289
Zhichao Zeng,Jia Wen,Hui Yan,Zonglun Liu,Yongqian Xu,Hongjuan Li,Chongmin Zhong,Fengyu Liu,Shiguo Sun
In this work, we report the development of easy-prepared, low cost and portable photoluminescent films for pH and amine vapors detection based on Eu(III)-complex functionalized materials: Eu(DBM)3Phen (LMOF-1), Eu(DBM)3BPY (LMOF-2), which were loaded on portable matrices (e.g. neutral silica plate and normal filter paper). The films not only displayed response over a pH range of 4–13 but also can be employed to sense volatile amines or acids vapors like ammonia, ethylenediamine, acetic acid and hydrochloric acid etc., which is significant for portable pH or acid–base vapors detection.
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高影响因子
Acta Biomaterialia
·
2016
·
IF 6.008
Wen Hu,Lipeng Qiu,Liang Cheng,Qing Hu,Yang Liu,Ziyang Hu,Dawei Chen,Lifang Cheng
To solve the contradiction between long circulation time and effective intracellular drug release, redox and pH-responsive drug delivery system was developed by incorporated redox-sensitive disulfide linkage between poly(amidoamine) dendrimers (PAMAM) and poly(ethylene glycol) (PEG). Doxorubicin (DOX) was loaded into the hydrophobic core of the conjugates to prepare PAMAM-SS-PEG/DOX complexes (PSSP/DOX). In vitro release studies suggested that DOX release from PSSP/DOX complexes followed an redox and acid-triggered manner and increased with increasing PEGylation degree. In vitro cytotoxicity of PSSP/DOX complexes against B16 tumor cells increased with, while cellular uptake decreased with increasing PEGylation degree. Further, intracellular DOX release observation and measurement indicate that the intracellular DOX release played a critical role for the cytotoxicity of DOX-loaded PSSP conjugates. In addition, cellular entry mechanism of the PSSP/DOX study demonstrated that both clathrin- and caveolae-mediated endocytosis were the primary pathways for cellular entry of PSSP/DOX. Finally, in vivo study of PSSP/DOX complexes in B16 tumor-bearing mice indicate that PSSP/DOX could significantly improve antitumor efficiency and present a good safety. The redox and pH-responsive drug delivery system has been demonstrated to be a promising candidate for solid tumor therapy. Statement of Significance In previous research, pH-sensitive diblock polymer of poly(ethylene glycol)-poly(2,4,6-trimethoxybenzylidene-pentaerythritol carbonate) (PEG-PTMBPEC) was synthesized to facilitate the intracellular anticancer drug release. However, the nanoparticles based on PEG-PTMBPEC get into the tumor cells just relying on the EPR-mediated passive targeting resulting in the low drug accumulation. Therefore, cRGD peptide modified PEG-PTMBPEC polymeric micelles were developed for specific targeted delivery of doxorubicin (DOX) to neovascular cells and tumor cells simultaneously. The precise intracellular target site and effective drug concentration will contribute to enhancing the antitumor toxicity and reducing the systematic toxicity of DOX. The cRGD modified pH-sensitive micellar system is a promising vehicle for intracellular drug delivery to αvβ3 integrin receptor overexpressed tumor cells and neovascular cells.
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高影响因子
DALTON TRANSACTIONS
·
2016
·Vol. 45
·期 16
·7078-7084
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IF 4.177
Xiao-Yu Xu,Bing Yan
A pH sensor is fabricated via a reaction between an AlIII salt and 2-aminoterephthalic acid in DMF which leads to a MOF (Al-MIL-101-NH2) with free amino groups. The Al-MIL-101-NH2 samples show good luminescence and an intact structure in aqueous solutions with pH ranging from 4.0 to 7.7. Given its exceptional stability and pH-dependent fluorescence intensity, Al-MIL-101-NH2 has been applied to fluorescent pH sensing. Significantly, in the whole experimental pH range (4.0–7.7), the fluorescence intensity almost increases with increasing pH (R2 = 0.99688) which can be rationalized using a linear equation: I = 2.33 pH + 26.04. In addition, error analysis and cycling experiments have demonstrated the accuracy and utilizability of the sensor. In practical applications (PBS and lake water), Al-MIL-101-NH2 also manifests its analytical efficiency in pH sensing. And the samples can be easily isolated from an aqueous solution by incorporating Fe3O4 nanoparticles. Moreover, the possible sensing mechanism based on amino protonation is discussed in detail. This work is on of the few cases for integrated pH sensing systems in aqueous solution based on luminescent MOFs.
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高影响因子
JOURNAL OF POLYMER RESEARCH
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2017
·Vol. 24
·期 6
·1-11
·
IF 1.615
Xia Shan,Gao Yang,Yu Zhe,Duan Lijie,Gao Guang Hui
A novel pH-sensitive charge reversal and self-fluorescent polymeric micelle is designed and synthesized successfully. The smart micelle is prepared based on MPEG-polyurethane multi-block copolymer, which is synthesized by polycondensation, with 1, 4-bis (hydroxyethyl) piperazine (HEP) and hydroxyl-sulfamethazine (Hydroxyl-SM) as pH-sensitive molecules and fluorescein isothiocyanate (FITC) as fluorescent segment. The resulting MPEG-polyurethane multi-block copolymer is examined by 1 H–NMR, UV-vis spectra, fluorescence spectra and an acid-base titration. Moreover, the diameter, morphology and cytotoxicity of obtained polymer micelle are measured by dynamic light scattering (DLS), transmission electron microscopy (TEM) and MTT assay. The results indicate that the micelle has a small diameter of less than 200 nm and can remain unchanged within two weeks. Zeta-potential measurement shows that the negative charge of micelle can switch into positive charge as the pH value decreasing from 9.0 to 3.0. Subsequently, the fluorescence intensity decreases significantly with the reducing of pH values. The MTT assay shows the low cytotoxicity and good biocompatibility of the MPEG-polyurethane polymeric micelles. Finally, doxorubicin (DOX) is loaded into micelles to detect in vitro release behavior. The drug loaded micelles show a faster release behavior at pH 5.0 than that at pH 7.4. Therefore, the pH-sensitive charge reversal and self-fluorescent micelle can be a potential smart carrier for delivery and controlled release of protein drug.
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高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
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2016
·Vol. 23
·期 19
·19266-19280
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IF 2.76
Yang Hui,Hu Yuanan,Cheng Hefa
Sorption of 2-chlorophenol (2-CP), 2,4-dichlorophenol (2,4-DCP), and 2,4,6-trichlorophenol (2,4,6-TCP) on a range of dealuminated zeolites were investigated to understand the mechanism of their sorption on microporous minerals, while the influence of common metal cations, solution pH, and humic acid was also studied. Sorption of chlorophenols was found to increase with the hydrophobicity of the sorbates and that of the microporous minerals, indicating the important role of hydrophobic interactions, while sorption was also stronger in the micropores of narrower sizes because of greater enhancement of the dispersion interactions. The presence of metal cations could enhance chlorophenol sorption due to the additional electrostatic attraction between metal cations exchanged into the mineral micropores and the chlorophenolates, and this effect was apparent on the mineral sorbent with a high density of surface cations (2.62 sites/nm 2 ) in its micropores. Under circum-neutral or acidic conditions, neutral chlorophenol molecules adsorbed into the hydrophobic micropores through displacing the “loosely bound” water molecules, while their sorption was negligible under moderately alkaline conditions due to electrostatic repulsion between the negatively charged zeolite framework and anionic chlorophenolates. The influence of humic acid on sorption of chlorophenols on dealuminated Y zeolites suggests that its molecules did not block the micropores but created a secondary sorption sites by forming a “coating layer” on the external surface of the zeolites. These mechanistic insights could help better understand the interactions of ionizable chlorophenols and metal cations in mineral micropores and guide the selection and design of reusable microporous mineral sorbents for sorptive removal of chlorophenols from aqueous stream.
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高影响因子
APPLIED SURFACE SCIENCE
·
2017
·
IF 3.387
Huanhuan Xu,Lihe Yan,Vanthan Nguyen,Yang Yu,Yanmin Xu
Nitrogen-doped carbon nanodots (CDs) are synthesized by one-step femtosecond laser ablation of graphite powder in aminotoluene at room temperature. The as-prepared CDs have the average diameter of 2.87 nm and possess an excitation-independent emission covering nearly the whole visible light region at a single excitation wavelength. The X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR) analysis indicate that there are a huge number of multiple oxygen groups and amine groups on the surface of the CDs. As their different fluorescence peaks originated from different emission surface groups on the nanodots show different pH dependence, these CDs can be used for ratiometric pH sensing.
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高影响因子
APPLIED SURFACE SCIENCE
·
2016
·
IF 3.15
Ting Lü,Shuang Zhang,Dongming Qi,Dong Zhang,George F. Vance,Hongting Zhao
Emulsified oil wastewaters, arisen from oil industry and oil spill accidents, cause severe environmental and ecological problems. In this study, a series of pH-sensitive magnetic nanomaterials (MNPs) were synthesized and characterized for their evaluation in separation of emulsified oil from aqueous environments. A coprecipitation method was used to produce Fe 3 O 4 magnetic nanoparticles that were coated in a 2-step process with first silica to form a surface for anchoring an (3-aminopropyl)triethoxysilane (APTES) molecular layer. Detailed studies were conducted on effects of MNPs dosage, APTES anchoring density ( D A ) and pH on oil-water separation performance of the synthetic MNPs. Results showed that, under both acidic and neutral conditions, MNPs with high D A exhibited enhanced oil-water separation performance, while under alkaline condition, the oil-water separation process was minimal. Alkaline conditions allowed the MNPs to be recycled up to 9 cycles without showing any significant decrease in oil-water separation efficiency. An examination of the oil-water separation mechanism found that electrostatic interaction and interfacial activity both played important roles in oil-water separation. In conclusion, pH-sensitive MNPs can be easily synthesized and recycled, providing a promising, cost-effective and environmentally-friendly process for the efficient treatment of emulsified oil wastewater.
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高影响因子
Journal of Materials Chemistry B
·
2016
·Vol. 4
·期 14
·2498-2511
·
IF 4.872
Zhaojun Jia,Pan Xiong,Yuying Shi,Wenhao Zhou,Yan Cheng,Yufeng Zheng,Tingfei Xi,Shicheng Wei
The design of functional biomaterials that respond intelligently to external stimuli has become a rapidly growing area with widespread interest. This work contributes to the development of a feedback-active anticorrosion system with intriguing self-healing ability to protect magnesium (Mg) from biocorrosion. The system was constituted by an inner micro/nano-porous, ceramic-like pre-coating developed readily from the substrate, and an outermost inhibitor (nanosized cerium (Ce) oxides) containing chitosan (CS) multilayers. Here, the pre-coating acted as both an “anchoring” and a “barrier” layer to acquire structural integrity and improved impedance, respectively. Green CS served as cargo for Ce to be entrapped, harnessing Ce–NH2 complexation chemistry. The coating barrier properties were evaluated by electrochemical impedance spectroscopy. The active corrosion inhibition was assessed by immersion degradation tests with respect to Mg2+ release, pH alteration, crack development, and scanning Kelvin potential. To our delight, the coatings effectively protected the substrate from biocorrosion in vitro compared with bare alloys. Putatively, the pH-triggered formation of Ce oxide precipitation, along with the pH-buffering activity and movable swelling capacity of CS macromolecules, should have contributed to restraining the anodic activity and healing the cracks/defects dynamically. Furthermore, the coated substrate had the biocompatibility to elicit better attachment and growth of osteoblasts.
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高影响因子
Analytical Methods
·
2016
·Vol. 8
·期 12
·2561-2567
·
IF 1.915
Shaping Huang,Liping Song,Zhidong Xiao,Yue Hu,Meiwen Peng,Jinquan Li,Xinsheng Zheng,Bin Wu,Chao Yuan
In this paper, fluorescent graphene quantum dots (GQDs) grafted onto the surface of mesoporous silica nanoparticle (MSN) vehicles were prepared and characterized. The as-prepared graphene quantum dot-decorated mesoporous silica nanoparticles (GQD-MSNs) exhibited excellent luminescence properties in vitro. Interestingly, compared to pure MSNs, the specific surface area and pore volume of GQD-MSNs increased by 59.1% and 48.9%, respectively. These optimized features granted GQD-MSNs a high aspirin loading capacity, which was twice as much as that of pure MSN. Moreover, most of the aspirin encapsulated (95.15%) could be released from the surface of GQD-MSNs under acidic conditions (pH 2.5) within 33 h.
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高影响因子
危险品化学品经营许可证（带存储）