RSC Advances
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2017
·Vol. 7
·期 66
·41838-41846
·
IF 3.108
Yanqing Du,Yujiang Li,Tao Wu
Oil/water separation has become a worldwide challenge due to large volumes of industrial oily wastewater and frequent oil spill accidents, which constitute an enormous threat to human and biological safety. Herein, a superhydrophilic and underwater superoleophobic composite membrane was fabricated using the vacuum-assisted filtration technique of assembly of chitosan (CS) and titanium dioxide (TiO2) on a cellulose acetate membrane for emulsified oil separation. The hydrophilic chitosan–TiO2 (CST) composite and nanoscale hierarchical structure are beneficial for forming a water layer that can repel the infiltration of oil droplets into the membrane. The modified membrane demonstrated an excellent flux up to 6002.5 L m−2 h−1 for hexadecane-in-water emulsion, which is one order of magnitude higher than traditional filtration membranes. Furthermore, the separation efficiency for all of the emulsified oils is above 97%, indicating superior oil/water separation performance. Most importantly, the modified membrane can maintain underwater superoleophobicity even in corrosive aqueous media, including strongly acidic, strongly alkaline, and highly saline solutions. It is expected that the chitosan–TiO2 composite membrane can be potentially useful in treating oily wastewater from industry and daily life.
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FOOD CHEMISTRY
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2017
·
IF 4.529
Tiantian Wu,Jiaqi Huang,Yangyang Jiang,Yaqin Hu,Xingqian Ye,Donghong Liu,Jianchu Chen
Novel hydrogels based on chitosan/sodium alginate (CS-ALG) were prepared to deliver and protect lysozyme while eliminating food-borne microorganisms. These hydrogels were characterized according to the zeta potential, optical microscopy, scanning electron microscopy (SEM), UV–visible spectroscopy (UV–vis), fourier transform infrared (FT-IR), and small-angle X-ray scattering (SAXS). The results demonstrated that the resultant hydrogels were negatively charged and spherical in shape. In addition, the maximum swelling ratio was 45.66 ± 7.62 for CS-ALG hydrogels loaded with lysozyme. The relative activity of the released lysozyme was 87.72 ± 3.96%, indicating that CS-ALG hydrogels are promising matrices for enzyme loading and adsorption. Furthermore, a 100% bacterial clearance rate of CS/ALG loaded with lysozyme was observed to correspond to the superposition effect stimulated by CS and lysozyme, which improved the antibacterial activity against E. coli and S. aureus compared to CS/ALG, suggesting its potential use in the food industry as well as other applications.
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Science Bulletin
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2016
·
IF 0
Miao He,Liying Lu,Jinchi Zhang,Danzhen Li
Highly stable dispersions of nanosized copper (Cu) particles with an average size of (2.6 ± 0.5) nm were synthesized by in situ reduction of Cu(II) to immobilize Cu nanoparticles on the amino-enriched surface of chitosan (CTS). The synthetic process and stability of the l -ascorbic acid-stabilized Cu-CTS nanocomposites were investigated by X-ray photoelectron spectroscopy and Fourier transform Infrared spectroscopy. The antimicrobial efficiency and potency of the Cu-CTS nanocomposites were studied. The Cu-CTS nanocomposites were found to exhibit a broad antimicrobial spectrum and high antimicrobial activity against Gram-positive bacterial pathogen Staphylococcus aureus and fungal pathogen Monilia albican . The minimum inhibitory concentration of the Cu-CTS nanocomposites toward S. aureus was found to be 6.4 μg mL −1 , much lower than those reported in the literature. Furthermore, the Cu-CTS nanocomposites were stable and maintained good disinfection potential even after 90-day shelf-time under ambient conditions.
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Materials Science & Engineering C-Materials for Biological Applications
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2016
·
IF 3.42
Jian Jiao,Xian Li,Sha Zhang,Jie Liu,Donghua Di,Ying Zhang,Qinfu Zhao,Siling Wang
In this paper, a hollow mesoporous silica nanoparticles (HMSN) was used as the drug vehicle to develop the redox and pH dual stimuli-responsive delivery system, in which the chitosan (CS), a biodegradable cationic polymer, was grafted on the surface of HMSN via the cleavable disulfide bonds. CS was chosen as the gatekeeper mainly due to its appropriate molecular weight as well as possessing abundant amino groups which could be protonated in the acidic condition to achieve pH-responsive drug release. In addition, the PEG was further grafted on the surface of CS to increase the stability and biocompatibility under physiological conditions. The DOX loaded DOX/HMSN-SS-CS@PEG had a relatively high drug loading efficiency up to 32.8%. In vitro release results indicated that DOX was dramatically blocked within the mesopores of HMSN-SS-CS@PEG in pH 7.4 PBS without addition of GSH. However, the release rate of DOX was markedly increased after the addition of 10 mM GSH or in pH 5.0 release medium. Moreover, the release of DOX was further improved in pH 5.0 PBS with 10 mM GSH. The HMSN-SS-CS@PEG could markedly decrease the hemolysis percent and protein adsorption, and increase the biocompatibility and stability of HMSN compared with the HMSN-SS-CS and bare HMSN. This work suggested an exploration about HMSN based stimuli-responsive drug delivery and these results demonstrated that HMSN-SS-CS@PEG exhibited dual-responsive drug release property and could be used as a promising carrier for cancer therapy.
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RSC Advances
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2016
·Vol. 6
·期 47
·41404-41409
·
IF 3.289
Wei-Hong Zhang,Shan-Shan Liu,Ping Liu,Jie Xu,Bing Xue,Xian-Yong Wei,Yong-Xin Li
Chitosan immobilized with an acidic ionic liquid (CS–VImPS–PW) was fabricated via a radical addition reaction of N-vinylimidazoliumpropane sulfonate and chitosan, followed by acidification with a heteropolyacid. It was characterized by a Fourier transform infrared spectrometer, solid-state 13C nuclear magnetic resonance spectrometer, thermogravimetric analyzer, elemental analyzer, and Hammett indicator. Some acetalization reactions were investigated to evaluate the catalytic activity of CS–VImPS–PW. The results show that CS–VImPS–PW is highly active for the acetalization reactions in high acetal yields ranging from 83.2 to 96.2% and can be reused 8 times without noticeable loss of activity.
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CARBOHYDRATE POLYMERS
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2016
·
IF 4.219
Ang Li,Runjun Lin,Chong Lin,Bianyang He,Tingting Zheng,Lingbin Lu,Yang Cao
Developing environment-friendly green absorbents for disposal of wastewater remains to be studied. In this paper, the cross-linked chitosan aerogel (CsA) as an environment-friendly absorbent was obtained by a simple method involving cross-linked process and freeze drying technique. Compared with conventional absorbents, the porous chitosan aerogel was provided with unique properties such as low density (0.0283 g/cm 3 ), high porosity (97.98%) and outstanding adsorption performance. The chitosan aerogel also displayed good reusability and excellent elasticity with a maximal thickness recovery up to 96.8% of the original thickness. The as-prepared absorbent exhibited preferable adsorption capacities for crude oil, diesel and copper ion (41.07 g/g, 31.07 g/g and 21.38 mg/g, respectively). The aerogel can collect a wide range of organic solvents and oils with absorption capacities up to 40 times their own weight, depending on the density and viscosity of the liquids. The adsorption capacity for heavy metal ion was also considerable and the maximum adsorption capacity ( q m ) of the aerogel for copper ion was 35.08 mg/g according to Langmuir isotherm model. Consequently, the chitosan aerogel with versatile adsorption properties has a good potential for wastewater treatment in environmental application.
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APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
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2016
·Vol. 122
·期 5
·1-7
·
IF 1.444
Peng Huili,Wu Jianning,Wang Yixi,Wang Hao,Liu Zhiyong,Shi Yulin,Guo Xuhong
We fabricate cellulose/chitosan (CE/CS) aerogel with stable superhydrophilic ( θ ≈ 0°) and underwater superoleophobic ( θ
oil > 150°) through a simple way. During the process of preparation of CE/CS aerogel, chitosan will self-assemble into number micron diameter particles on the surface of aerogel. Furthermore, the hydrogen bonding network structure of cellulose was destroyed and more hydrophilic groups (–OH) were exposed. Rough surface and hydrophilicity make CE/CS aerogel have a property of underwater superoleophobicity. CE/CS aerogel shows underwater superoleophobicity to different oils, and it still have stable superoleophobicity in corrosive solution. The important thing is that CE/CS aerogel can separate free oil/water mixture and surfactant-stabilized emulsions under gravity effectively. The sample is green, low cost, and environmental friendly, which is a promising candidate to be used in oil/water separation.
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MACROMOLECULES
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2016
·
IF 5.554
Jun You,Shuyi Xie,Jinfeng Cao,Hao Ge,Min Xu,Lina Zhang,Jinping Zhou
Quaternized chitosan (QCh) was homogeneously synthesized by reacting chitosan with 3-chloro-2-hydroxypropyltrimethylammonium chloride (CHPTAC) in alkali/urea aqueous solution for the first time. The structure and solution properties of QCh were characterized by using element analysis, FT-IR, 13C NMR, SEC-LLS, rheology, viscometer, and ξ-potential measurements. Subsequently, polyelectrolyte complex (PEC) hydrogels were constructed by in situ polymerization of acrylic acid (AA) monomers in the concentrated QCh solution. The structure and mechanical behavior of the prepared hydrogels were systematic studied. Because of the high charge density and solubility of QCh, strong electrostatic interactions were formed in the hydrogels and endowed them tough with self-recovery properties. The mechanical behavior of the hydrogels was accurately tuned from stiff and viscoelastic to soft and elastic by changing the poly(acrylic acid) (PAA) content. The regulation mechanism relied on the remarkable difference in the chain segmental mobility between QCh and PAA. Moreover, the QCh/PAA PEC hydrogels displayed excellent solvent-induced shape-memory behavior due to the reversible properties of the ionic bonds. In summary, we offered a novel modification method for chitosan and opened up a new avenue to construct chitosan-based hydrogels with outstanding mechanical properties.
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BIOMATERIALS
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2016
·
IF 8.387
Zi-Wei Jing,Yi-Yang Jia,Ning Wan,Min Luo,Meng-Lei Huan,Tai-Bin Kang,Si-Yuan Zhou,Bang-Le Zhang
The covalently modified ureido-conjugated chitosan/TPP multifunctional nanoparticles have been developed as targeted nanomedicine delivery system for eradication of Helicobacter pylori . H. pylori can specifically express the urea transport protein on its membrane to transport urea into cytoplasm for urease to produce ammonia, which protects the bacterium in the acid milieu of stomach. The clinical applicability of topical antimicrobial agent is needed to eradicate H. pylori in the infected fundal area. In this study, we designed and synthesized two ureido-conjugated chitosan derivatives UCCs-1 and UCCs-2 for preparation of multifunctional nanoparticles. The process was optimized in order to prepare UCCs/TPP nanoparticles for encapsulation of amoxicillin. The results showed that the amoxicillin-UCCs/TPP nanoparticles exhibited favorable pH-sensitive characteristics, which could procrastinate the release of amoxicillin at gastric acids and enable the drug to deliver and target to H. pylori at its survival region effectively. Compared with unmodified amoxicillin-chitosan/TPP nanoparticles, a more specific and effective H. pylori growth inhibition was observed for amoxicillin-UCCs/TPP nanoparticles. Drug uptake analysis tested by flow cytometry and confocal laser scanning microscopy verified that the uptake of FITC-UCCs-2/TPP nanoparticles was associated with urea transport protein on the membrane of H. pylori and reduced with the addition of urea as competitive transport substrate. These findings suggest that the multifunctional amoxicillin-loaded nanoparticles have great potential for effective therapy of H. pylori infection. They may also serve as pharmacologically effective nanocarriers for oral targeted delivery of other therapeutic drugs to treat H. pylori .
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Materials Science & Engineering C-Materials for Biological Applications
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2016
·
IF 3.42
Xuan Liu,Yunfei Mo,Xiaoyu Liu,Rui Guo,Yi Zhang,Wei Xue,Yuanming Zhang,Changyong Wang,Seeram Ramakrishna
The development of safe and efficient gene carriers is the key to the clinical success of gene therapy. In the present study, carboxymethyl chitosan (CMCS) was prepared by chitosan (CS) alkalisation and carboxymethylation reactions. Then polyethyleneimine (PEI) was grafted to the backbone of CMCS by an amidation reaction. The CMCS–PEI copolymer showed strong complexation capability with DNA to form nanoparticles, and achieved lower cytotoxicity and higher transfection efficiency compared with PEI (25 kDa) towards 293T and 3T3 cells. Moreover, the haemocompatibility of the CMCS–PEI copolymer was investigated through the aggregation, morphology and lysis of human red blood cells (RBCs), along with the impact on the clotting function with activated partial thromboplastin time (APTT), prothrombin time (PT) and thromboelastographic (TEG) assays. The results demonstrated that the CMCS–PEI copolymer with a concentration lower than 0.05 mg/mL had little impact on the aggregation, morphology or lysis of RBCs, or on blood coagulation. Therefore, the copolymer may be a strong alternative candidate as an effective and safe non-viral vector.
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SCIENCE OF THE TOTAL ENVIRONMENT
·
2017
·
IF 4.9
Xi Lu,Yanhua Xu,Wenquan Sun,Yongjun Sun,Huaili Zheng
In this study, maleyl chitosan- graft -polyacrylamide (MHCS-g-PAM), a novel chitosan-based flocculant , was prepared through UV irradiation, and maleyl chitosan (MHCS) was designed and prepared with maleic anhydride and acrylamide (AM) through maleyl acylation reaction. The effects of monomer concentration, MHCS-to-AM ratio, illumination time, initiator concentration, pH on viscosity, and grafting efficiency were investigated to optimize the synthesis of these substances. MHCS-g-PAM was characterized through Fourier transform infrared spectroscopy , nuclear magnetic resonance hydrogen spectroscopy, scanning electron microscopy, and thermal gravimetric analysis . Flocculation mechanisms in alga-containing wastewater at various pH levels and dosages were examined in detail on the basis of zeta potential measurements. Zeta potential experiments indicated that the adsorption-bridging and charge neutralization mechanisms played an important role in algal removal. Flocculation tests on algal removal demonstrated that the flocculation performance of MHCS-g-PAM was more effective than that of cationic polyacrylamide, polyferric sulfate, and polymeric aluminium. The optimal Chl- a and COD removal rate obtained by MHCS-g-PAM was 98.6% and 94.9% at pH 7 and 4 mg·L − 1 , respectively.
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RSC Advances
·
2016
·Vol. 6
·期 41
·34081-34089
·
IF 3.289
Liang Zhao,Kai Zhang,Wenhuan Bu,Xiaowei Xu,Han Jin,Bei Chang,Banchao Wang,Yingjian Sun,Bai Yang,Changyu Zheng,Hongchen Sun
Treating bone defects is still a challenge in clinical practice. Recently, researchers used human bone morphogenetic protein 2 gene (hBMP-2) to induce osteoblast differentiation and promote new bone formation. However, an efficient way to deliver hBMP-2 still needs to be created. In this study, we evaluated whether chitosan–polyethylenimine (CS–PEI) nanoparticle could effectively deliver hBMP-2 locally with lower or no toxicity and promote osteoblast differentiation and new bone formation in vitro and in vivo. Data demonstrated that the synthesized CS–PEI/hBMP-2 nanoparticle at a W/W ratio of 20 to 1, which was the smallest size (162 nm) and highest zeta potential (24 mV), effectively transfected MC3T3-E1 cells without cytotoxicity in vitro, and had the ability to promote cell proliferation. Interestingly, the CS–PEI/hBMP-2 nanoparticle eliminated disadvantages of lower transfection efficiency from chitosan and cytotoxicity from PEI. RT-QPCR data showed that MC3T3-E1 cells treated with CS–PEI/hBMP-2 nanoparticle dramatically expressed higher levels of BMP-2 and significantly increased gene expressions of Col1 on days 3 and 14, Sp7 on days 3, 7, and 14, and ALP on day 14. Alizarin red staining demonstrated that CS–PEI/hBMP-2 nanoparticle-treated MC3T3-E1 cells significantly increased cell mineralization. These in vitro data suggest that the CS–PEI/hBMP-2 nanoparticle can effectively induce osteogenic differentiation of MC3T3-E1 cells in vitro. Western blot analysis further demonstrated that transgene BMP-2 indeed phosphorylated Smad1/5/8, which indicates that CS–PEI/hBMP-2 nanoparticle affects cell differentiation through a BMP-2 signal pathway. Importantly, in vivo data showed that CS–PEI/hBMP-2 nanoparticle clearly promoted new bone formation at the bone defect area 12 weeks post-implantation. This indicates that synthesized CS–PEI/hBMP-2 nanoparticle has the potential to become a useful therapeutic vector for bone defect treatment with further modification.
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