Science Advances
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2016
·Vol. 2
·期 8
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IF 0
Bo Wu,Xiaowen Wang,Jun Yang,Zan Hua,Kangzhen Tian,Ran Kou,Jian Zhang,Shuji Ye,Yi Luo,Vincent S. J. Craig,Guangzhao Zhang,Guangming Liu
Weak polyelectrolytes have found extensive practical applications owing to their rich pH-responsive properties. In contrast, strong polyelectrolytes have long been regarded as pH-insensitive based on the well-established fact that the average degree of charging of strong polyelectrolyte chains is independent of pH. The possible applications of strong polyelectrolytes in smart materials have, thus, been severely limited. However, we demonstrate that almost all important properties of strong polyelectrolyte brushes (SPBs), such as chain conformation, hydration, stiffness, surface wettability, lubricity, adhesion, and protein adsorption are sensitive to pH. The pH response originates from the reorganization of the interchain hydrogen bond network between the grafted chains, triggered by the pH-mediated adsorption-desorption equilibrium of hydronium or hydroxide with the brushes. The reorganization process is firmly identified by advanced sum-frequency generation vibrational spectroscopy. Our findings not only provide a new understanding of the fundamental properties of SPBs but also uncover an extensive family of building blocks for constructing pH-responsive materials.
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INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2017
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IF 3.671
Ziqie Rao,Hongyu Ge,Liangling Liu,Chen Zhu,Lian Min,Meng Liu,Lihong Fan,Dan Li
Nanotechnology has been studied to improve drug delivery and cancer treatment. The aim of this study is to introduce amino groups into graphene oxide (GO) to form aminated fumed graphene (GO-ADH) and combine GO-ADH with carboxymethyl cellulose (CMC) to produce GO-CMC complex as a drug carrier matrix. The anti-cancer drug small molecule doxorubicin hydrochloride (DOX) was bond to GO-CMC by π-π bond interaction and hydrogen bonding to form GO-CMC/DOX drug loading system. Via the FT-IR, transmission electron microscopy (TEM) and Zeta potential analyzer analysis showed that GO-CMC complex was successfully synthesized. Studies have shown that when pH = 5.0, the cumulative release rate of drugs can reach 65.2%, which means it has pH-sensitive ability. The cells were treated with MTT method and human cervical cancer cells (Hela cells) and mouse fibroblasts (NIH-3T3 cells). The results showed that GO-CMC had no obvious cytotoxicity and good biocompatibility.
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COLLOIDS AND SURFACES B-BIOINTERFACES
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2013
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IF 3.554
Xin Gu,Jingjing Wang,Yanming Wang,Yinong Wang,Hui Gao,Guolin Wu
Biodegradable shell cross-linked nanocapsules were prepared via layer-by-layer assembly of PADH (tertiary amine and hydrazide grafted polyaspartamide) and PACA (carboxyl and aldehyde grafted polyaspartamide) on silica spheres. Both of the polyaspartamide derivatives are water-soluble and biodegradable polymers with a protein-like structure, and obtained by aminolysis reaction of polysuccinimide. The latter is prepared by thermal polycondensation of aspartic acid. Dynamic light scattering and zeta potential measurements were used to analyze the layer-by-layer assembly process. Bovine serum albumin (BSA), as a model protein, was entrapped in the nanocapsules via electrostatic adsorption. Nanocapsules encapsulating BSA were prepared via layer-by-layer assembly on protein-entrapping amino-functionalized silica spheres, hydrazone cross-linking and silica core removal. The BSA release profiles exhibited a pH-dependent behavior. BSA release rate increased significantly as the ambient pH dropped from the physiological pH to acidic. Cell viability study suggests that the obtained polymeric nanocapsules have good biocompatibility. These kinds of novel composite nanocapsules may offer a promising delivery system for proteins.
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BIOSENSORS & BIOELECTRONICS
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2014
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IF 6.451
Wei Fang,Zhuyuan Wang,Shenfei Zong,Hui Chen,Dan Zhu,Yuan Zhong,Yiping Cui
A type of pH-controllable drug carrier is demonstrated based on mesoporous silica nanoparticles and chitosan/poly (methacrylic acid), which can simultaneously serve as the surface enhanced Raman scattering (SERS) traceable drug carriers for targeting cancer cells. The pH-sensitive releasing characteristics can be achieved by coating the nanoparticles with a layer of chitosan/poly (methacrylic acid) (CS-PMAA), while strong SERS signals can be obtained from the SERS reporter tagged Ag nanoparticles in the core. Our experimental results show that doxorubicin (DOX) was effectively encapsulated into the nanocarriers and can be released in response to the ambient pH value. Specifically, an increased amount of DOX release was observed at lower pH value. In addition, the composite nanoparticles were conjugated with transferrin (Tf) to target transferrin receptor (TfR)-overexpressed cancer cells. The targeting ability as well as the intracellular location of the drug carrier was investigated through SERS mapping while the distribution of DOX was monitored by fluorescence images. The results show that the demonstrated drug carrier can simultaneously fulfill the functionalities of pH-responsive drug release, SERS-traceable characteristics and cancer cells targeting, which has a unique potential for the pH-controllable drug delivery nanosystems .
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JOURNAL OF COLLOID AND INTERFACE SCIENCE
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2013
·
IF 3.172
Xiaoxue Song,Huanbin Li,Weijun Tong,Changyou Gao
Encapsulation of pH sensitive fluorophores as reporting molecules provides a powerful approach to visualize the transportation of multilayer capsules. In this study, two pH sensitive dyes (fluorescein and oregon green) and one pH insensitive dye (rhodamine B) were simultaneously labeled on the microcapsules to fabricate ratiometric pH sensors. The fluorescence of the triple-labeled microcapsule sensors was robust and nearly independent of other intracellular species. With a dynamic pH measurement range of 3.3–6.5, the microcapsules can report their localized pH at a real time. Cell culture experiments showed that the microcapsules could be internalized by RAW 246.7 cells naturally and finally accumulated in acidic organelles with a pH value of 5.08 ± 0.59 (mean ± s.d.; n = 162).
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COLLOIDS AND SURFACES B-BIOINTERFACES
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2014
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IF 4.287
Jingjing Wang,Chu Gong,Yinong Wang,Guolin Wu
A dually responsive nanocarrier with a multilayer core–shell architecture was prepared based on Fe 3 O 4 @SiO 2 nanoparticles successively coated with poly(benzyl L-aspartate) (PBLA) and poly(ethylene glycol) (PEG) for the purpose of tumor specific drug delivery applications. In this system, PEG chains are connected to the surface via pH-sensitive benzoic-imine bonds and serve as a pH-sheddable hydrophilic corona. Meanwhile, the PBLA segments serve as a hydrophobic middle layer used to load the drugs via hydrophobic interactions. The Fe 3 O 4 @SiO 2 nanoparticle functions as a superparamagnetic core used to direct the drug loaded nanocarrier to the target pathological site. The obtained materials were characterized with FT-IR, 1 H NMR, dynamic light scattering , zeta-potential, TEM , TGA, and hysteresis loop analysis. An anticancer drug doxorubicin (DOX) was selected as the model drug loaded into the nanocarrier, which was relatively stable under physiological conditions due to its neutral hydrophilic shell, and could quickly release the drug in response to increased acidity via shedding of the PEG shells through cleavage of the intermediate benzoic-imine bonds. Meanwhile, the neutral shell shedding would reveal a positively charged nanoparticle surface that is readily taken up by tumor cells. These pH- and magnetic-responsive nanoparticles showed significant potential for use in the targeted intracellular delivery of hydrophobic chemotherapeutics in cancer therapy.
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BIOMACROMOLECULES
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2015
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IF 5.75
Xu Jia,Xubo Zhao,Kun Tian,Tingting Zhou,Jiagen Li,Ruinian Zhang,Peng Liu
A novel water-soluble pH stimuli-responsive fluorescent copolymer of P(PEGMA-b-(MAH-co-Rh6GEAm)) was synthesized by two-step sequential RAFT polymerization. The prodrug with drug content of 0.1560 mg/mg was prepared by coupling doxorubicin (DOX) onto the copolymer via acid-cleavable hydrazone bond, formed between the carbonyl group of DOX and abundant hydrazide functional groups in the copolymer. The amphiphilic DOX-conjugated prodrug (P(PEGMA-b-(MAH-DOX-co-Rh6GEAm))) could easily form a micelle in water with Dh of less than 100 nm. It could be transported into HepG2 cells and release DOX without burst release, while the leakage of DOX can be avoided in the simulated normal physiological media. Furthermore, its fluorescence intensity experienced a reversible change with the transformation of the media pH. The better biocompatibility, pH stimuli-responsiveness, and the strong fluorescence at low pH media make the nanoparticles a potential platform for the controlled release of anticarcinogens and real-time fluorescent imaging of tumor tissues.
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COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2015
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IF 2.752
Jiao Wang,Xiao Chen,Wanling Cui,Sijing Yi
pH-responsive vesicles have been prepared from the mixture of 1-(10-(4-formyl-phenoxy) decyl)-pyridinium (FDP) or 1-methyl-3-(10-(4-formyl-phenoxy) decyl) imidazolium (FDI) with 1-octyl amine at a molar ratio of 1:1 in alkaline aqueous solutions. Their structures and morphologies were characterized by transmission electron microscopy with sample preparations by negative staining or freeze-fracture. Basically, the spherical unilamellar vesicles were formed with the mean diameters respectively of about 71 and 107 nm for two supra-amphiphile systems, which were based on the formation of dynamic imine bonds between amine and FDP (i-FDP) or FDI (i-FDI). The loading and release studies of a fluorophore, Nile red (NR), demonstrated the capabilities of these vesicles to encapsulate NR and a rapid release at low pH environment. The vesicles from i-FDP behaved relatively more sensitive to acidic environment than those from i-FDI. The dynamic transitions of supra-amphiphiles were characterized by nuclear magnetic resonance or fluorescence emission spectroscopy measurements. A lower critical micelle concentration and a higher aldehyde conversion efficiency of i-FDI than those of i-FDP were observed. The characteristics of facile formation, fast dissociation, and switchable morphologies of studied systems should be referable for designing novel smart supra-amphiphile systems with potential applications as controlled drug delivery systems.
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COLLOIDS AND SURFACES B-BIOINTERFACES
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2015
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IF 4.152
Liufeng Lin,Wei Xu,Hongshan Liang,Lei He,Shilin Liu,Yan Li,Bin Li,Yijie Chen
Novel nano-particles were developed from lysozyme-pectin through self-assembly, and the nanogels could be used as a carrier for the antitumor agent, methotrexate (MTX). The nanogels exhibited spherical with diameters about 109 ± 2 nm and narrow particle size distribution, as well as negative surface charge. Furthermore, the particle size and morphology of the nanogels hardly changed with the incorporation of MTX. The loading capacity of MTX in nanogels could reach 17.58 ± 0.85%. MTX-loaded nanogels were pH-dependent, accelerated release of MTX at a decreasing pH from 7.4 to 5.3. The MTT assay indicated that encapsulated MTX exhibited higher anticancer activity than free MTX. Meanwhile, MTX-loaded nanogels could be effectively endocytosed by HepG2 cells, resulting in enhanced cancer-cell apoptosis comparing to free MTX. It indicated that the nanogels had good biocompatibility and low toxicity. The obtained nanogels had great potential in the development of a new nanocarrier for anti-cancer drug delivery.
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JOURNAL OF MOLECULAR LIQUIDS
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2024
·
IF 5.3
Bin Zhou,Xiaoqian Cao,Yujuan Rong,Can Wu,Yuying Hu,Bin Li,Bing Cui
Modifying and improving protein functionality is crucial for expanding the application of proteins in the food industry. The aim of this study was to investigate the effect of pH-shift treatments on the emulsifying and interfacial properties of glutenin (Glu). Glu was exposed to acidic (pH 1–3) and basic (pH 10–13) pH values for 4 h and subsequently neutralized for refolding. The pH-shifting treatments significantly improved Glu surface wettability with three-phase contact angle from 66.21 ± 2.31° to 91.4 ± 0.88°. The alkali shift treatment resulted in samples with larger K diff values. The treated samples also showed amplitude and frequency dependence in their E, E v , and E d values, with higher E and E d values indicating an elastic membrane at the interface. Emulsions prepared from Glu treated with alkali shift treatment exhibited smaller particle size, larger ζ-potential, and more stable storage properties. The rheological results indicated higher viscosity, thixotropy and creep of emulsions prepared from alkali shift treated Glu. In conclusion, treatment of Glu with alkali shift resulted in significant improvements in emulsifying and interfacial properties, suggesting that Glu may be a more promising ingredient for use in food.
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BIOPROCESS AND BIOSYSTEMS ENGINEERING
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2024
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IF 3.5
Wang Lingqin,Jia Mengya,Gao Dandan,Li Haixing
The probiotic fermentation of the bioactive substance gamma-aminobutyric acid (GABA) is an attractive research topic. There is still room for further improvement in reported GABA fermentation methods based on a single substrate ( l -glutamic acid or l -monosodium glutamate). Here, we devised a pH auto-buffering strategy to facilitate the fermentation of GABA by Levilactobacillus brevis CD0817. This strategy features a mixture of neutral monosodium l -glutamate plus acidic l -glutamic acid as the substrate. This mixture provides a mild initial pH; moreover, the newly dissolved l -glutamic acid automatically offsets the pH increase caused by substrate decarboxylation, maintaining the acidity essential for GABA fermentation. In this study, a flask trial was first performed to optimize the GABA fermentation parameters of Levilactobacillus brevis CD0817. The optimized parameters were further validated in a 10 L fermenter. The flask trial results revealed that the appropriate fermentation medium was composed of powdery l -glutamic acid (750 g/L), monosodium l -glutamate (34 g/L [0.2 mol/L]), glucose (5 g/L), yeast extract (35 g/L), MnSO 4 ·H 2 O (50 mg/L [0.3 mmol/L]), and Tween 80 (1.0 g/L). The appropriate fermentation temperature was 30 °C. The fermenter trial results revealed that GABA was slowly synthesized from 0–4 h, rapidly synthesized until 32 h, and finally reached 353.1 ± 8.3 g/L at 48 h, with the pH increasing from the initial value of 4.56 to the ultimate value of 6.10. The proposed pH auto-buffering strategy may be popular for other GABA fermentations.
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INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2024
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IF 7.7
Zhen Lin,Fan Nie,Ruyu Cao,Wenrui He,Jing Xu,Yuanqiang Guo
Cancer poses a significant threat to human health, and there is an urgent need for more effective treatments. Combining chemotherapy and immunotherapy is an effective strategy to enhance curative outcomes and holds great potential for widespread application. The natural phytochemical genistein (GEN) exhibits cytotoxicity against tumors and is a potential chemotherapeutic agent. Lentinan (LTN) is a natural polysaccharide with immune-enhancing properties that has been utilized in tumor treatment. This study constructed a pH-responsive nanoparticle GEN@LTN-BDBA with chemotherapy and immunotherapy functions using GEN and LTN. After characterizing the nanoparticles, the molecular mechanism of GEN@LTN-BDBA formation was explored using in-silico simulation. GEN@LTN-BDBA can significantly inhibit the proliferation of A549 and HepG2 cells in vitro . The in vivo experiment results demonstrated that treatment with GEN@LTN-BDBA can significantly reduce tumor cell mass and prevent metastasis. In this nanoparticle, GEN induced oxidative stress and apoptosis of tumor cells. Meanwhile, the released LTN initiated an anti-tumor immune response by promoting dendritic cell maturation and upregulating the expression of costimulatory molecules and major histocompatibility complex. The construction method of GEN@LTN-BDBA can be extended to the preparation of other polysaccharides and hydrophobic chemotherapy molecules, offering a novel strategy to enhance the low efficacy of monotherapy.
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