Nanoscale
·
2017
·Vol. 9
·期 15
·4928-4933
·
IF 7.367
Zetan Fan,Shixin Zhou,Cesar Garcia,Louzhen Fan,Jiangbing Zhou
Cancer remains a major cause of morbidity and mortality around the world. Improved cancer treatment requires enhancement of cancer diagnosis and detection. To achieve this goal, here we report a novel imaging probe, pH-responsive fluorescent graphene quantum dots (pRF-GQDs). pRF-GQDs were prepared by electrolysis of graphite rods in sodium p-toluenesulfonate acetonitrile solution. The resulting pRF-GQDs, which have minimal toxicity, display a sharp fluorescence transition between green and blue at pH 6.8, a pH matching the acidic extracellular microenvironment in solid tumors. We found that this unique fluorescence switch property allows tumors to be distinguished from normal tissues. In addition to fluorescence, pRF-GQDs also exhibit upconversion photoluminescence (UCPL). We demonstrate that the combination of UCPL and fluorescence switch enables detection of solid tumors of different origin at an early developmental stage. Therefore, pRF-GQDs have great potential to be used as a universal probe for fluorescence-guided cancer surgery and cancer diagnosis.
研究领域:
生物医学工程
·
肿瘤学
·
材料科学
✓ 已验证
DOI
PubMed
高影响因子
Food Bioscience
·
2019
·
IF 3.22
Li Wei,Liwei Cao,Shanbai Xiong,Juan You,Yang Hu,Ru Liu
The effects of pH on myosin self-assembly at low temperature to improve the structural attributes by controlling the solution conditions were studied. Myosin from silver carp was dissolved in solutions at various pH (5.0, 5.5, 6.0, 6.5, 7.0, 8.0 and 9.0). Effects of pH on the particle size, intermolecular forces, and micro-morphology of myosin at low temperature were investigated. The structures of myosin assemblies were observed to be influenced by varying pH using the variations in the degree of protonation and surface charge state of myosin molecules. The low electrostatic repulsion in acidic conditions resulted in the assembly before unfolding of myosin, leading to a relatively high turbidity and UV absorption as well as a decreased solubility. Confocal laser scanning microscopy analysis showed that myosin assemblies with coarse filamentous structure were formed in acid conditions. In alkaline conditions, the increased electrostatic repulsion led to a higher rate of unfolding than assembly and exposure of more hydrophobic residues, as showed by increased S 0 -ANS values and free SH contents. This relatively high rate of unfolding contributed to the formation of assemblies with a fine and ordered structure. At pH 7.0, the most active structure of myosin molecules was maintained as shown by the highest Ca 2+ -ATPase activity. Myosin assemblies with an ordered and uniform structure were obtained at pH 7.0.
研究领域:
食品科学
·
生物化学
✓ 已验证
DOI
高影响因子
Nanomaterials
·
2022
·Vol. 12
·期 15
·2587
·
IF 5.719
Gaihuan Ren,Zhanzhao Li,Dongxu Lu,Bo Li,Lulu Ren,Wenwen Di,Hongqin Yu,Jianxin He,Dejun Sun
Herein, we describe pH and magnetism dual-responsive liquid paraffin-in-water Pickering emulsion stabilized by dynamic covalent Fe3O4(DC-Fe3O4) nanoparticles. On one hand, the Pickerinfigureg emulsions are sensitive to pH variations, and efficient demulsification can be achieved by regulating the pH between 10 and 2 within 30 min. The dynamic imine bond in DC-Fe3O4can be reversibly formed and decomposed, resulting in a pH-controlled amphiphilicity. The Pickering emulsion can be reversibly switched between stable and unstable states by pH at least three times. On the other hand, the magnetic Fe3O4core of DC-Fe3O4allowed rapid separation of the oil droplets from Pickering emulsions under an external magnetic field within 40 s, which was a good extraction system for purifying the aqueous solution contaminated by rhodamine B. The dual responsiveness enables Pickering emulsions to have better control of their stability and to be applied more broadly.
研究领域:
材料科学
·
化学工程
·
环境科学
✓ 已验证
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2015
·
IF 6.723
Liang-Liang Feng,Guo-Dong Li,Yipu Liu,Yuanyuan Wu,Hui Chen,Yun Wang,Yong-Cun Zou,Dejun Wang,Xiaoxin Zou
Splitting water to produce hydrogen requires the development of non-noble-metal catalysts that are able to make this reaction feasible and energy efficient. Herein, we show that cobalt pentlandite (Co9S8) nanoparticles can serve as an electrochemically active, noble-metal-free material toward hydrogen evolution reaction, and they work stably in neutral solution (pH 7) but not in acidic (pH 0) and basic (pH 14) media. We, therefore, further present a carbon-armoring strategy to increase the durability and activity of Co9S8 over a wider pH range. In particular, carbon-armored Co9S8 nanoparticles (Co9S8@C) are prepared by direct thermal treatment of a mixture of cobalt nitrate and trithiocyanuric acid at 700 °C in N2 atmosphere. Trithiocyanuric acid functions as both sulfur and carbon sources in the reaction system. The resulting Co9S8@C material operates well with high activity over a broad pH range, from pH 0 to 14, and gives nearly 100% Faradaic yield during hydrogen evolution reaction under acidic (pH 0), neutral (pH 7), and basic (pH 14) media. To the best of our knowledge, this is the first time that a transition-metal chalcogenide material is shown to have all-pH efficient and durable electrocatalytic activity. Identifying Co9S8 as the catalytically active phase and developing carbon-armoring as the improvement strategy are anticipated to give a fresh impetus to rational design of high-performance noble-metal-free water splitting catalysts.
研究领域:
材料科学
·
化学
✓ 已验证
DOI
高影响因子
FOOD HYDROCOLLOIDS
·
2020
·
IF 7.053
Zhili Ji,Hongsheng Liu,Long Yu,Qingfei Duan,Ying Chen,Ling Chen
Studies on unique blends of cool and thermal gels have attracted increasing attention since they both have scientific and commercial importance, such as functional food design and edible packaging materials etc. In this work, the pH dependent gelation behaviors and morphologiesof blends of a cool gel, gelatin (GA), and a thermal gel,hydroxypropylmethylcellulose (HPMC), in aqueous solution were investigated by rheometer, UV spectrophotometer, fluorescence microscope (FM) and environmental scanning electron microscopy (ESEM). It was found that when pH < 4.75, HPMC was the continuous phase, while GA was the separated phase distributed in HPMC matrix as small spherical domains. Phase transition occurred at pH 5.00, in which GA became the continuous phase, while HPMC appeared as separated droplets dispersed in GA matrix. At lower pH values, GA and HPMC were compatible based on UV detection, ESEM observation, as well as phase separation kinetics. Near the isoelectric point (pI) of gelatin (pH 7.0–9.0), a maximum viscoelastic module (G') was detected. It was noticed that there were many interphasic regions in the blend systems. Each phase was not pure: GA phase contained some HPMC and vice versa at all pH values, which means that GA and HPMC are partly miscible or compatible to a certain degree.
研究领域:
食品科学
·
材料科学
✓ 已验证
DOI
高影响因子
EUROPEAN POLYMER JOURNAL
·
2024
·
IF 5.8
Dan Ji,Yaping Wang,Mengqing Luo,Zihao Zhang,Xiaohua Chang,Yutian Zhu
Dual-responsive shape-transformable block copolymer (BCP) particles have arisen great attentions because of their tunable physical and chemical characteristics triggered by external stimuli. Herein, we developed a simple yet effective strategy to realize pH and light dual-triggered shape-switchable BCP particles through the co-assembly of BCPs with photo-responsive additive 4-hydroxyazobenzene (Azo-OH) within the evaporation emulsion droplets. The formation of hydrogen bonding interactions between the Azo-OH and 4-vinylpyridine (4VP) unit increases the volume fraction of P4VP domain, in turn leading to a morphological transition of the particles from onions to pupas by tuning the Azo-OH content. Subsequent light-induced trans – cis transition of the Azo unit induces the enhancement of the hydrophilicity of the P4VP domains, giving rise to internal shape transitions of the BCP particles from pupas to onions with P4VP at the outmost-layer. Furtherly, since the hydrogen bonds between Azo-OH and 4VP group are sensitive to pH, the interfacial properties of the emulsion droplets and the assembled structures are tuned through adjusting the environment pH of the aqueous solution, causing the formation of various particle shape, including pupas, raspberries, and onions. This work offers a promising method to engineer the microstructures of polymeric assemblies, which may attract more attention on the applications of the stimuli-responsive particles.
研究领域:
材料科学
·
化学
✓ 已验证
DOI
高影响因子
ACS Applied Polymer Materials
·
2025
·
IF 4.7
Kehui Xiang,Hanxin Jian,Zexin Liu,Yunpeng Yang,Hao Huang,Shuguang Yang
Actuating fibers are characterized by their flexibility and capacity for further knitting and weaving. They exhibit rapid stimuli response, satisfying diverse practical applications. The pH-actuating fibers are typically prepared from weak negative polyelectrolytes, contracting in acid and extending in alkali, while weak positive polyelectrolytes can be used to construct fibers with inverse pH-actuating behaviors. Herein, we fabricate an “alkaline contraction and acid extension” actuating fiber, utilizing the biobased weak positive polyelectrolyte chitosan (CHI). To address the issues of CHI fiber dissolution at low pH values and its inherent brittleness, covalent cross-linking and toughening are introduced to produce the actuating fiber. The fiber performs work in response to pH variations with a maximum output strain of 62%, work density of 20 kJ/m3, and modulus of 215 MPa, which are all higher than those of human skeletal muscle, and can be assembled into devices with other kinds of fiber actuators to perform complex motions, holding a promising role in soft robots and biomedicines.
研究领域:
材料科学
·
生物医学工程
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
FOOD CHEMISTRY
·
2024
·
IF 8.5
Yexuan Yao,Li Ma,Chengwei Yu,Ce Cheng,Hongxia Gao,Teng Wei,Litong Li,Zhiyue Wang,Wei Liu,Zeyuan Deng,Liqiang Zou,Ting Luo
To improve the poor water solubility and oral bioavailability of tyrosol, novel tyrosol liposomes (Tyr-LPs) were prepared by pH-driven method. Fourier transform infrared (FTIR) absorption spectra and X-ray diffraction (XRD) analysis indicated that Tyr-LPs were successfully encapsulated and tyrosol was in an amorphous state in liposomes. When tyrosol content in Tyr-LP was 1.33 mg/ml and the Tyr:LP (mass ratio) = 1:2, favorable dispersibility of Tyr-LP was exhibited, with an instability index of 0.049 ± 0.004, PDI of 0.274 ± 0.003, and the EE of 94.8 ± 2.5 %. In vivo pharmacokinetic studies showed that after oral administration of tyrosol or Tyr-LP (Tyr:LP = 1:2), concentration-versus-time curve (AUC 0–720mins ) and maximum concentration (C max ) values of Tyr-LP was respectively 1.5-fold ( P < 0.01) and 2.25-fold ( P < 0.01) higher than tyrosol, which indicated that the oral bioavailability of tyrosol was effectively improved in Tyr-LPs. Our study thereby provides theoretical support for the application of Tyr-LP for optimal delivery of tryosol.
研究领域:
药剂学
·
药理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2025
·
IF 8.5
Yuantong Cao,Yuhe Dong,Tong Wu,Linyan Chen,Wanying Zhu,Tao Jiang,Nan He,Yao Liu,Ran Huang,Xi Yu,Ying Xiao,Tian Zhong
Fruit spoilage caused by microorganisms results in huge economic losses and health risks worldwide every year. To develop an intelligent antimicrobial material capable of responding to the physiological activity of postharvest fruits and releasing antibacterial agents on demand, we fabricated a pH-responsive film for the release of chlorine dioxide (ClO 2 ) using carboxymethyl cellulose (CMC) and sodium chlorite (NaClO 2 ) via the solution casting method, with a CMC:NaClO 2 ratio of 1:2 w /w. An acid environment simulated by 4 % acetic acid activated 43 % of ClO 2 released by the film within 7 days. A 1 × 2 cm 2 film in acid environment effectively inhibited the growth of Staphylococcus aureus (10 6 CFU/mL), Escherichia coli (10 5 CFU/mL), and Aspergillus niger on agar media (with colony diameters reduced from 60.00 mm to 19.07 mm). A 3 × 3 cm 2 film reduced the decay incidence caused by A. niger in strawberry from 100 % (control) to only 20 % on day 6. Compared with the control group, no significant differences in color, total soluble solids (TSSs) or triable acidity (TA) were observed in the film-treated groups. The development of pH-responsive NaClO 2 -CMC films offers a practical and effective solution for extending the shelf-life and maintaining the quality of fruit.
研究领域:
食品科学
·
材料科学
·
微生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MATERIALS LETTERS
·
2014
·
IF 2.269
Caidan Zhang,Shaohua Wu,Xiaohong Qin
Stable pH-sensitive poly(aspartic acid) (PASP) hydrogel in nanofibrous structure was successfully manufactured. Firstly, polysuccinimide (PSI), the intermediate of PASP, was synthesized by thermal polymerization of aspartic acid and electrospun into nanofibrous mat. Secondly, imide rings on the main chains of PSI were partly opened to form crosslinking points by amino groups of ethylenediamine. Eventually, the residual imide rings of PSI were opened to obtain PASP hydrogel nanofibers by hydrolysis. The PASP hydrogel nanofibers exhibited significant hydrogel characteristics with fast swelling, high water absorption and pH-sensitivity. Durability test showed the morphological robustness and stability of PASP hydrogel nanofibers. The swelling ratio of pH-sensitive PASP hydrogel nanofibers ranged from 14.8 g/g to 128.1 g/g with the pH values increasing from 1.0 to 10.0.
研究领域:
材料科学
·
生物医学工程
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2014
·Vol. 4
·期 31
·15856-15862
·
IF 3.708
Jingjing Wang,Chu Gong,Yinong Wang,Guolin Wu
For the purpose of tumor-specific drug delivery applications, a magnetic and pH dually responsive nano-carrier with a multilayer core–shell architecture was prepared from amine-functionalized Fe3O4@SiO2 through the surface-initiated ring opening polymerization of benzyl-L-aspartate N-carboxyanhydride, and then coated with α-methoxy poly(ethylene glycol) (mPEG) via a pH-sensitive benzoic–imine bond. In order to control the layer thickness of poly(benzyl-L-aspartate) (PBLA), a surface passivation agent was applied to modulate the amino density of the functionalized Fe3O4@SiO2 initiator. In this system, the Fe3O4@SiO2 nanoparticles function as a superparamagnetic core used to target the drug loaded nanocarriers to the pathological site. Meanwhile, the mPEG and PBLA segments serve as a pH-sheddable hydrophilic corona and a hydrophobic middle layer used to load the drug via hydrophobic interactions. The obtained materials were characterized by FT-IR, 1H NMR, DLS, zeta-potential, TEM, TGA and hysteresis loop analysis. Furthermore, the loading and release behavior of doxorubicin on the nanocarrier was investigated and it was shown that the drug loaded nanoparticle was relatively stable under physiological conditions and quickly released in response to acidity due to the shedding of mPEG shells through the pH-cleavage of intermediate benzoic–imine bonds. This pH and magnetic responsive nanoparticle has appeared highly promising for the targeted intracellular delivery of hydrophobic chemotherapeutics in cancer therapy.
研究领域:
生物材料学
·
药剂学
·
癌症治疗
✓ 已验证
产品关联
DOI
高影响因子
LANGMUIR
·
2014
·
IF 4.384
Chunyu Yang,Wei Guo,Liru Cui,Na An,Ting Zhang,Huiming Lin,Fengyu Qu
Polymer-modified nanoparticles, which can load anticancer drugs such as doxorubicin (DOX), showing the release in response to a specific trigger, have been paid much attention in cancer therapy. In our study, a pH-sensitive drug-delivery system consisting of Fe3O4@mSiO2 core–shell nanocomposite (about 65 nm) and a β-thiopropionate-poly(ethylene glycol) “gatekeeper” (P2) has been successfully synthesized as a drug carrier (Fe3O4@mSiO2@P2). Because of the hydrolysis of the β-thiopropionate linker under mildly acidic conditions, Fe3O4@mSiO2@P2 shows a pH-sensitive release performance based on the slight difference between a tumor (weakly acid) and normal tissue (weakly alkaline). And before reaching the tumor site, the drug-delivery system shows good drug retention. Notably, the nanocomposites are quickly taken up by HeLa cells due to their small particle size and the poly(ethylene glycol) modification, which is significant for increasing the drug efficiency as well as the cancer therapy of the drug vehicles. The excellent biocompatibility and selective release performance of the nanocomposites combined with the magnetic targeted ability are expected to be promising in the potential application of cancer treatment.
研究领域:
生物医学工程
·
纳米医学
·
药物递送系统
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）