Polymers
·
2017
·Vol. 9
·期 12
·698
·
IF 3.364
Yinglei Zhai,Xing Zhou,Lina Jia,Chao Ma,Ronghua Song,Yanhao Deng,Xueyao Hu,Wei Sun
The differences in micro-environment between cancer cells and the normal ones offer the possibility to develop stimuli-responsive drug-delivery systems for overcoming the drawbacks in the clinical use of anticancer drugs, such as paclitaxel, doxorubicin, and etc. Hence, we developed a novel endosomal pH-sensitive paclitaxel (PTX) prodrug micelles based on functionalized poly(ethylene glycol)-poly(ε-caprolactone) (mPEG-PCL) diblock polymer with an acid-cleavable acetal (Ace) linkage (mPEG-PCL-Ace-PTX). The mPEG-PCL-Ace-PTX5with a high drug content of 23.5 wt % was self-assembled in phosphate buffer (pH 7.4, 10 mM) into nanosized micelles with an average diameter of 68.5 nm. The in vitro release studies demonstrated that mPEG-PCL-Ace-PTX5micelles was highly pH-sensitive, in which 16.8%, 32.8%, and 48.2% of parent free PTX was released from mPEG-PCL-Ace-PTX5micelles in 48 h at pH 7.4, 6.0, and 5.0, respectively. Thiazolyl Blue Tetrazolium Bromide (MTT) assays suggested that the pH-sensitive PTX prodrug micelles displayed higher therapeutic efficacy against MCF-7 cells compared with free PTX. Therefore, the PTX prodrug micelles with acetal bond may offer a promising strategy for cancer therapy.Keywords:prodrug;polymer micelles;pH-sensitive;acetal;paclitaxel
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高影响因子
POLYMER BULLETIN
·
2012
·Vol. 69
·期 5
·597-620
·
IF 1.532
Luo Yan-Ling,Yu Wei,Xu Feng
pH-sensitive hydrophilic poly(methacrylic acid)- b -poly(ethylene glycol)- b -poly(methacrylic acid) (PMAA- b -PEG- b -PMAA) triblock copolymers were synthesized through atom transfer radical polymerization, and were characterized by FT-IR, 1 H NMR, and GPC. The as-synthesized polymers can self-assemble into stable and almost spherical nanomicelles in aqueous solution with an average size range from 18 to 89 nm, depending on the micellar concentrations, while they assumed well-defined spherical morphologies in PBS solutions. The micellization behavior in different media was investigated by a fluorescence spectroscopy technique, UV–Vis transmittance, and dynamic light scattering measurements. The critical micelle concentration and size of the micelles decrease with the increasing the length or molecular weights of PEG and PMAA chains. A pH-dependent phase transition behavior produces at a pH value of about 5.2, and the stable pH micellization behavior varied within a narrow pH range from ca. 4.8 to 7.4. These triblock copolymers are generally low cytotoxicity at a micellar concentration below 400 mg L −1 , as revealed by the MTT assay. The prednisone release and release kinetics studies disclosed that these pH-sensitive polymeric micelles are good carriers for the drug delivery.
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RSC Advances
·
2015
·Vol. 5
·期 106
·87512-87520
·
IF 3.84
Ruiqing Liu,Shuang Liang,Cun Jiang,Xin Wang,Ying Gong,Penghui Li,Zushun Xu,Haibo Xu,Paul K. Chu
Smart polymer-based theranostic agents often have the problem of a low drug release rate and it is difficult for them to reach the site of brain tumors for magnetic resonance imaging (MRI). To synthesize a theranostic agent for brain tumor MRI with a high drug release rate, paramagnetic, pH and temperature-sensitive polymeric particles (PPPs) are synthesized using a simplified processes in this work. These dually sensitive polymeric particles show negligible cytotoxicity against HeLa and glioma (C6) cells. The obtained polymeric particles can effectively be loaded with the anticancer drug doxorubicin (DOX). In vitro drug release measurements exhibit retarded release profiles when subjected to varying pH or temperature. Moreover, DOX-loaded PPPs exhibit obvious antitumor properties for C6 cells. The percentage of cumulative DOX release is higher than 95% when both pH and temperature are changed. The T1-weighted relaxivity values at 3 T are 12.41 mM−1 s−1 (pH = 6.3) and 10.75 mM−1 s−1 (pH = 7.4). In vivo MRI reveals that the PPPs can be effectively imaged in brain tumors (gliomas). These results indicate that the PPPs have great potential in diagnosing and treating glioma.
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CHEMICAL ENGINEERING JOURNAL
·
2020
·
IF 10.652
Yuyang Wu,Huaili Zheng,Hong Li,Yongjun Sun,Chun Zhao,Rui Zhao,Chen Zhang
In this study, a novel magnetic nickel cobalt sulfide/sodium dodecyl benzene sulfonate (FSNCS/SDBS) adsorbent was synthesized successfully by a facile protocol and was developed to remove ciprofloxacin (CIP) for water purification. The FSNCS/SDBS adsorbent is featured with excellent CIP adsorption capacity of 625 mg·g −1 (much higher than reported most adsorbents), wide pH adaptability (little changed CIP adsorption capacity in pH 6–11), and good magnetic property. The effects of pH and ionic strength on CIP adsorption were investigated. The calculative thermodynamic parameters indicated that CIP adsorption by FSNCS/SDBS was spontaneous and exothermic. CIP adsorption followed pseudo-second-order kinetics and an isotherm best fit with the Langmuir adsorption mode. The adsorption mechanism of CIP onto FSNCS/SDBS was proposed and demonstrated, which included the electrostatic interaction, π–π interaction, coordination with metal and hydrogen bonding.
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ACS Catalysis
·
2022
·
IF 13.7
Shuchao Jiang,Junxia Yang,Shengliang Zhai,Ling Zhang,Rui Tu,Tie Yu,Dong Zhai,Lei Sun,Weiqiao Deng,Guoqing Ren
Formic acid (FA)/formate as a promising liquid organic hydrogen carrier exhibits great potential for future energy supplies. However, FA/formate-based hydrogen storage and release, which can be operated under ambient conditions, is challenging but attractive. Here, we report an ambient hydrogen storage and release process that uses the acidity and alkalinity of the reaction solution to control hydrogen production or consumption via an l-arginine-functionalized active carbon-supported PdAu alloy catalyst (PdAu/AC-LA). By regulating the LA loading and Pd/Au ratio, we obtain the optimal catalytic activity with turnover frequency (TOF) of 1760 h–1 for FA dehydrogenation under acidic conditions and 138 h–1 for CO2 hydrogenation under alkaline conditions. Comprehensive characterizations, including X-ray photoelectron spectroscopy (XPS), CO2 temperature-programmed desorption (CO2-TPD), and HCOO– adsorption experiments, reveal that the synergistic effect between PdAu alloy and strongly basic l-arginine enhances catalytic activity by regulating the adsorption of reactants. Our work, as a successful example of FA/formate-based hydrogen storage and release under ambient conditions, may aid putting the safe and energy-saving use of hydrogen into practice.
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ACS Applied Materials & Interfaces
·
2017
·
IF 7.504
Ji-Chun Yang,Yang Chen,Yu-Hao Li,Xue-Bo Yin
The combination of multidrug chemotherapy and photothermal therapy (PTT) enhances cancer therapeutic efficacy. Herein, we develop a simple and smart pH/NIR dual-stimulus-responsive degradable mesoporous CoFe2O4@PDA@ZIF-8 sandwich nanocomposite. The mesoporous CoFe2O4 core acts as T2-weighted magnetic resonance (MR) imaging probe, PTT agent, and loading platform of hydrophilic doxorubicin (DOX). A polydopamine (PDA) layer is used to avoid the premature leakage of DOX before arriving at tumor site, enhance PTT efficiency, and facilitate the integration of ZIF-8 (a kind of metal–organic framework). The ZIF-8 shell serves to encapsulate hydrophobic camptothecin (CPT) and as the switch for the pH and NIR stimulation-responsive release of the two drugs. Therefore, T2-weighted MR imaging-guided multidrug chemotherapy and PTT synergistic treatment is achieved. Two kinds of anticancer drugs, hydrophilic DOX and hydrophobic CPT, are successfully loaded in CoFe2O4 and ZIF-8, respectively, so no mutual interference between the two drugs exists. A unique two-stage stepwise release process is exhibited for CPT and DOX with an interval of 12 h to improve the anticancer efficacy under the acidic microenvironment of tumor tissue. NIR irradiation achieves the burst drug-release and PTT after laser stimulation, simultaneously. With this smart design, high drug concentration is achieved at the tumor site by quick release, especially for the therapeutic drugs that show nonlinear pharmacokinetics, and PTT is integrated efficiently. Furthermore, negligible biotoxicity and a remarkable synergic antitumor effect of the hybrid nanocomposites are validated by HepG2 cells and tumor-bearing mice as models. Our multidrug delivery-releasing composite improves tumor therapeutic efficiency significantly compared with a single-drug chemotherapy system. The simple multifunctional composite system can be applied as an effective platform for personal nanomedicine with diagnosis, smart drug delivery, and cancer treatment through its remarkable photothermal property and controllable multidrug release.
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高影响因子
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
2019
·
IF 3.571
Yongkang Xi,Yuxiao Zou,Zhigang Luo,Liang Qi,Xuanxuan Lu
Lipid-based delivery systems (LBDSs) are widely applied in pharmaceuticals and health care because of the increased bioavailability of lipophilic components when they are coadministered with high-fat meals. However, how to accurately control their in vivo release and stability is still challenging. Here, after introducing the simple esterification and coprecipitation, we created the dual-functional composite ODS-β-CD-VE by the coassembly of β-cyclodextrin (β-CD), octadecenyl succinic anhydride (ODSA), and vitamin E (VE). The resulting dual-functional particle presented a uniform sheetlike shape and nanometer size. In addition, its chemical structure was clarified in detail via nuclear magnetic resonance (NMR), Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). Benefiting from the antioxygenation of VE, lipid oxidation in the ODS-β-CD-VE-stabilized Pickering emulsion was effectively inhibited. Meanwhile, pH-induced protonation/deprotonation of carboxyl groups guaranteed that the emulsions kept steady at pH ≤4 but were unsteady under neutral conditions. In this way, the lipids contained in the emulsion were protected from gastric juice and then digested and accurately released as n-3 polyunsaturated fatty acids (PUFA) in the simulated intestine environment. This strategy sheds some light on the rational and efficient construction of LBDSs for nutrient supplements and even pharmaceuticals in a living digestive tract.
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高影响因子
FEBS Open Bio
·
2020
·Vol. 10
·期 12
·2733-2739
·
IF 2.231
Sai-sai Ding,Jin-peng Zhu,Yang Wang,Bin Wu,Zongpei Zhao
In the paper industry, chlorine is often used to treat the pulp for bleaching. After pulping, a large amount of xylan is present in the fiber. Xylanase can be used to degrade xylan in an eco-friendly process called biobleaching, which can help minimize the usage of chlorine in the delignification process. However, a bottleneck in the adoption of biobleaching is the cost of xylanase and the requirement that xylanase be active and stable at extreme conditions. Here, we investigated whether using sodium alginate beads to immobilize an extracellular xylanase from Bacillus subtilis (Lucky9) can reduce the potential cost of enzyme usage. The optimal pH and the activity of the immobilized enzyme were increased at optimal temperature compared with the free enzyme. In addition, immobilized xylanase was shown to be more stable than free xylanase. The results of this study suggest that the immobilized xylanase has potential applications in the biobleaching industry.
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高影响因子
MOLECULES
·
2015
·Vol. 20
·期 9
·16709-16722
·
IF 2.416
Hai-Min Shen,Wen-Jie Zhou,Xin Ma,Hong-Ke Wu,Wu-Bin Yu,Ning Ai,Hong-Bing Ji,Hong-Xin Shi,Yuan-Bin She
A pH-dependence of the Brønsted acid-catalyzed oxidation of sulfides to the corresponding sulfoxides with H2O2is reported for the first time based on our systematic investigation of the catalytic performance of a series of Brønsted acids. For all of the Brønsted acids investigated, the catalytic performances do not depend on the catalyst loading (mol ratio of Brønsted acid to substrate), but rather depend on the pH value of the aqueous reaction solution. All of them can give more than 98% conversion and selectivity in their aqueous solution at pH 1.30, no matter how much the catalyst loading is and what the Brønsted acid is. This pH-dependence principle is a very novel perspective to understand the Brønsted-acid catalysis system compared with our common understanding of the subject.Keywords:sulfide;oxidation;sulfoxide;pH-dependence;Brønsted acid
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高影响因子
ACS Sustainable Chemistry & Engineering
·
2015
·
IF 4.642
Chen Feng,Shaoyu Lü,Chunmei Gao,Xinggang Wang,Xiubin Xu,Xiao Bai,Nannan Gao,Mingzhu Liu,Lan Wu
With the fast development of sustainable modern agriculture, there has been a shift toward the development of controlled/slow release fertilizers (CSRFs) that can overcome current limitations of conventional fertilizers. Ideally, CSRFs would release nutrient matching plants demands, even when environmental conditions fluctuate. However, no current CSRFs meet this ideal, especially as nutrient release is affected by temperature and pH. In this study, a “smart” fertilizer with polymer brushes of poly(N,N-dimethylaminoethyl methacrylate) grafting from polydopamine-coated ammonium zinc phosphate via surface-initiated atom-transfer radical polymerization is reported. The structure and morphology of the fertilizer were measured by transmission electron microscopy (TEM); the composition of the product was determined with Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), and inductively coupled plasma (ICP) emission spectrometer. Dual-responsive controlled-release behaviors were characterized in water by spectrophotometry and ICP, and results demonstrate the “smart” fertilizer shows excellent temperature- and pH-responsive behavior to release nutrients according to the ambient environment. The nutrients release rate can be obviously accelerated in an acidic pH (below pKa) medium at a definite temperature. In addition, low temperature (below LCST) can accelerate the nutrients release rate in a basic medium (above pKa), which is contrasting to the reduction of nutrients release rate at high temperature (above LCST) in the same medium. The pH- and temperature-responsive “smart” fertilizer will improve nutrients availability and avoid excessive release of nutrients causing damage to plant roots at high temperature, which indicating that the stimuli-responsive system has potential application in sustainable modern agriculture.
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CHEMISTRY OF MATERIALS
·
2022
·
IF 10.508
Han Lin,Hideyuki Mitomo,Yusuke Yonamine,Zhiyong Guo,Kuniharu Ijiro
The emerging concept of tunable plasmonic chirality is mostly observed as a reconfigurable behavior or a feature of complex chiral plasmonic assemblies. For discrete colloidal particles, it is challenging to achieve reversible tunability or a transient response with regard to chiroptical activities, particularly in the visible or near-infrared region. Herein, we demonstrate a stimulus-responsive system based on chiral molecule–achiral plasmonic nanoparticles coated with polyaniline (PANI) as a variable dielectric layer, in which l-/d-cysteine molecules are introduced between the gold core and the shell as a static chiral source, allowing the chiral transfer effect to be greatly amplified by the hotspot gap of sub-monomolecular thickness. By taking advantage of the responsive properties to either pH or the electric potential dual stimuli of PANI, which also provides a stable and real-time switchable dielectric environment for the whole system, dynamic tuning of the plasmon and its induced chiroptical activities of core–gap–shell nanoparticles@PANI were precisely obtained. This well-defined design provides an open platform for flexible and rational tailoring of plasmonic cores, chiral molecules, and variable dielectrics to chiroptical needs, which is important for realizing applications in chemical sensing, chiral nanocatalysis, enantioselective separations, and novel optical devices.
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Journal of Materials Chemistry C
·
2019
·Vol. 7
·期 9
·2563-2569
·
IF 6.641
Chao Xia,Mengmeng Cao,Jinfeng Xia,Guohong Zhou,Danyu Jiang,Dafeng Zhang,Jing Wang,Huili Li
Carbon dots (CDs), as a new kind of fluorescent pH nanoprobe, have attracted significant attention due to their favorable optical properties and excellent environmental friendliness. However, a real ratiometric and self-calibrating fluorescent pH nanoprobe based on intrinsic dual-emission CDs (DECDs) still remains scarce. In this study, we reported a kind of intrinsic DECDs for ratiometric fluorescence pH sensing. Interestingly, the two emission bands at 393 and 580 nm from the DECDs simultaneously display strong pH-dependence but with an adverse variation trend. The ratio of the intensity of 393 and 580 nm matches well with an empirical function against pH in the range from 2.2 to 8.0, and further, an excellent linear relationship is presented in an acidic environment with a responsive pH range of 2.2–4.0. Moreover, the rapid response time (<1 min), high sensitivity, good reversibility and pinpoint accuracy (±1.0%) for pH sensing reveals that the as-prepared DECDs can act as excellent ratiometric luminescent nanoprobes for pH detection. We hope that this study will offer new possibilities for expanding the applications of luminescent CDs in chemical sensing, biomedicine and food safety.
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