BIOSENSORS & BIOELECTRONICS
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2014
·
IF 6.451
Changqin Ding,Yang Tian
The dysregulated pH is working as a mark of cancer. It is a challenge for developing a biosensor for targeted imaging in cancer cells and monitoring of intracellular pH . Here, a ratiometric fluorescence biosensor for pH determination was developed with targeted imaging into folate acceptor (FR)-rich cancer cells at the same time. AuNCs protected by bovine serum albumin (BSA) worked as reference fluorophore and fluorescein-isothiocyanate (FITC) acted as the response signal for pH. For targeted imaging of cancer cells, the AuNCs were simultaneously conjugated with folic acid (FA). The developed ratiometric biosensor can monitor pH with a wide linear range from 6.0–7.8 with a pKa at 6.84. Under every different pH condition , the probe showed high selectivity over various metal ions and amino acids with its fluorescence ratio stayed almost constant (<5%). It also showed good cyclic accuracy when pH switched between 6.0 and 8.0, as well as low cytotoxicity. The AuNC-based inorganic–organic nanohybrid biosensor showed good cell-permeability, low cytotoxicity, and long-term photostability. Accordingly, the pH biosensor was employed to gain targeted imaging in FR +ve Hela cells with FR −ve lung carcinoma cells A549 as comparison, and achieved to monitor the pH changes in Hela cells.
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SENSORS AND ACTUATORS B-CHEMICAL
·
2023
·
IF 8.4
Ning Xu,Qinglong Qiao,Yi Tao,Pengjun Bao,Yinchan Zhang,Wei Zhou,Jin Li,Zhifeng Li,Zhaochao Xu
Subcellular pH plays a key role to modulate protein structures or specific active sites to impact diverse biological processes. The heterogeneity and high dynamics of intracellular pH require probes that can detect pH in the vicinity of the protein and have a wide pH response range. Here, we reported a protein proximity ligation fluorescent probe for super-resolution imaging of subcellular pH dynamics. Relying on SNAP-tag protein labeling technology, the pH-sensitive fluorophore BG-NDM based on photo-induced electron transfer mechanism was localized to the adjacent positions of the target protein in different subcellular organelles. The equilibrium between the non-fluorescent aggregate and the fluorogenic monomer enabled BG-NDM to have the ability of wash-free super-resolution imaging in live cells. And the wide pH response ranges from pH 6 to pH 12 made the probe have the ability of recognizing pH dynamics. The pH changes around functional proteins during mitophagy, cellular alkalosis and acidosis were revealed. Through long-term super-resolution imaging, we could further record the pH dynamics around mitochondrial proteins COX8A during mitochondrial contacts, fusion and fission at the resolution of a single mitochondria.
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NEW JOURNAL OF CHEMISTRY
·
2022
·Vol. 46
·期 19
·9075-9084
·
IF 3.925
Yanping Li,Ya Liu,Li Wang,Hongsheng Lu
Polyacrylamide and its derivatives are widely used in oilfields due to their efficient viscosity building and drag-reducing properties. At present, the commonly used products of polyacrylamide include two types: polymer powder and polymer emulsions. However, the low dissolution rate of powdered products and the instability of polymer emulsions limit their application. Here, we constructed a pH-sensitive inverse polymer emulsion of poly(acrylamide-co-acrylic acid-co-2-acrylamide-2-methylpropyl sulfonic acid), showing a phase separation and phase inversion from W/O to O/W at pH < 6 and pH > 8 due to a pH-switchable surfactant N,N-dimethylcyclohexylamine/Oleic acid complex (DM–OA). The demulsification or phase inversion of the W/O polymer emulsion can release the polymer that was originally in the aqueous phase, and the released polymer can quickly dissolve in water to perform its function of viscosity building and friction reduction. Therefore, this pH-sensitive modified-polyacrylamide polymer emulsion shows a fast dissolution rate with a dissolution time of about 1 min and a long storage stability. The utilization of stimuli-responsive surfactants to construct pH-responsive water-soluble polymer W/O emulsions provides a new approach to the preparation of water-soluble polymer emulsion additives that can be quickly dissolved and stored for long periods of time in water-treatment, papermaking and oil recovery fields.
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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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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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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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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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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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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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COLLOIDS AND SURFACES B-BIOINTERFACES
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2022
·
IF 5.999
Weinan Li,HeXin Gong,Yuhan Fu,Jialin Sun,Yanhong Wang
Developing chemotherapy with nanoparticle-based prodrugs provides promising strategies for improving the safety and delivery of anti-cancer drugs therapeutics and effective cancer treatment. Herein, we developed a pH-sensitive prodrug delivery system (All-Trans-Retinoic Acid (ATRA) grafted poly (β-amino esters) (PBAE) copolymers , ATRA-g-PBAE) for delivery of ATRA with some physicochemical and biological properties. The in vitro release of ATRA-g-PBAE prodrug nanoparticles (PNPs) was sustained-release and pH-sensitive. The cytotoxicity and uptake of different preparations in vitro were evaluated on MCF-7 cells at pH 7.4 and 5.5. The carrier PBAE had no cytotoxicity, and ATRA-g-PBAE PNPs could significantly inhibit cell growth at pH 5.5. MCF-7 cells treated with Cy5.5 grafted PBAE (Cy5.5-PBAE) showed stronger fluorescence signals at pH 5.5. Meanwhile, ATRA-g-PBAE PNPs entered the cell via a clathrin-mediated endocytic pathway. Subsequently, PBAE protonation facilitated the escape of PNPs from the lysosome and released the drug. ATRA-g-PBAE seems promising as a novel pH-sensitive prodrug to overcome the limitations of ATRA for breast cancer therapy.
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Biomaterials Science
·
2018
·Vol. 6
·期 5
·1227-1237
·
IF 5.831
Qianwen Li,Donghui Wang,Jiajun Qiu,Feng Peng,Xuanyong Liu
Hard tissue implant materials which can cause a suitable alkaline microenvironment are thought to be beneficial for stimulating osteoblast differentiation while suppressing osteoclast generation. To make the local pH around the interface between materials and cells controllable, we prepared a series of Mg–Fe layered double hydroxide (LDH) films on acid-etched pure titanium surfaces via hydrothermal treatment. By adjusting the Mg/Fe proportion ratio, the interlayer spacing of Mg–Fe LDHs was regulated, making their OH− exchange abilities adjustable, and this ultimately resulted in a microenvironment with a controllable pH value. In vitro experiments demonstrated that the Mg–Fe LDH film-modified titanium surface possessed good biocompatibility and osteogenic activity, especially the Mg–Fe LDH film with Mg/Fe proportion ratio of 4, which could form a suitable alkaline microenvironment for the growth and osteogenetic differentiation of stem cells. These results demonstrate the potential application of the prepared Mg–Fe LDH films in enhancing the osteogenesis of implant materials while providing a new way into the design of controllable alkaline environment.
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