ACS Applied Materials & Interfaces
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2014
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IF 5.9
Jiyang Liu,Xiaohui Wang,Tianshu Wang,Dan Li,Fengna Xi,Jin Wang,Erkang Wang
Biological modification of monolithic and porous 3D graphene is of great significance for extending its application in fabricating highly sensitive biosensors. The present work reports on the first biofunctionalization of monolithic and freestanding 3D graphene foam for one-step preparation of reagentless enzymatic biosensors by controllable chitosan (CS) electrodeposition technology. Using a homogeneous three-component electrodeposition solution containing a ferrocene (Fc) grafted CS hybrid (Fc-CS), glucose oxidase (GOD), and single-walled carbon nanotubes (SWNTs), a homogeneous biocomposite film of Fc-CS/SWNTs/GOD was immobilized on the surface of 3D graphene foam by one-step electrodeposition. The Fc groups grafted on chitosan can be stably immobilized on the 3D graphene surface and keep their original electrochemical activity. The SWNTs doped into the Fc-CS matrix act as a nanowire to facilitate electron transfer and improve the conductivity of the biocomposite film. Combined with the extraordinary properties of 3D graphene foam including large active surface area, high conductivity, and fast mass transport dynamics, the 3D graphene based enzymatic biosensor achieved a large linear range (5.0 μM to 19.8 mM), a low detection limit (1.2 μM), and rapid response (reaching the 95% steady-state response within 8 s) for reagentless detection of glucose in the phosphate buffer solution.
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INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2015
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IF 2.858
Bitao Lu,Tianyou Wang,Zhiquan Li,Fangying Dai,Lingmei Lv,Fengling Tang,Kun Yu,Jiawei Liu,Guangqian Lan
A chitosan–gelatin sponge (CSGT) was prepared using a chitosan/ascorbic acid solution blend containing gelatin, followed by crosslinking with tannin acid and freeze-drying, thereby combining the chitosan sponge and gelatin sponge. The structure of the CSGT was observed by scanning electron microscopy and was shown to have uniform and abundant pores measuring about 145–240 μm in size. We also characterized the sponges by infrared spectroscopy, thermogravimetric analysis, mechanical property tests, swelling behavior analysis, water retention capacity tests, antibacterial property analysis, and cytotoxicity tests. Our data showed that the CSGT had good thermostability and mechanical properties as well as efficient water absorption and retention capacities. Moreover, the CSGT could effectively inhibit the growth of Escherichia coli and Staphylococcus aureus with low toxicity. In animal experiments, macroscopic observations and histological examinations showed that the wound covered by the CSGT healed quickly. Additionally, loading of the CSGT with platelet-rich plasma resulted in further acceleration of wound healing. Therefore, the CSGT and the CSGT with platelet-rich plasma were suitable for application as a wound dressing and may have potential for use in various biomedical applications.
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JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
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2014
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IF 3.107
Minhao Xie,Bing Hu,Yan Wang,Xiaoxiong Zeng
A new, simple, and effective method to graft gallic acid (GA) onto chitosan (CS) in aqueous solution in the presence of carbodiimide and hydroxybenzotriazole was developed. The grafting amount of GA reached as much as 209.9 mg/g of copolymer, which appears as the highest one among the reported literature, and the grafting degree of GA to CS was adjustable with modulation of the mass ratio of GA to CS. The covalent insertion of GA onto the polymeric backbones was confirmed by UV–vis and 1H NMR analyses. Grafting endowed the resulting copolymer GA-grafted-CS (GA-g-CS) with both the advantages of CS and GA. The antioxidant capacity of GA-g-CS was much higher than that of the plain CS examined by assays of DPPH, superoxide, and ABTS radicals scavenging activities, reducing power, chelating power, inhibition of lipid peroxidation, ferric reducing antioxidant potential, and β-carotene-linoleic acid assays. Particularly, GA-g-CS showed significantly higher antioxidant activity than GA in β-carotene-linoleic acid assay. Furthermore, the viscosity of GA-g-CS was significantly higher than that of CS. The present study developed a novel approach to synthesize GA-g-CS that could be a potential biomaterial in food industries.
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NANO
·
2014
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IF 1.26
HUI LI,CHUANXI WANG,YINGNAN JIANG,ZHANCHEN CUI,QUAN LIN
Lanthanide-doped luminescent nanoscale materials have great potential applications in biological researches. Herein, we reported a novel and mild method for one-step synthesis of chitosan/ NaGdF 4 : Eu 3+ nanocomposites. The luminescent Eu 3+ ions and magnetic resonance imaging (MRI) contrast agent Gd 3+ ions were incorporated to these biocompatible nanocomposites. The resultant nanocomposites exhibited strong fluorescence and attractive magnetic features. The nanocomposites also have pure hexagonal phase with uniform size of about 65 nm. FT-IR spectra revealed that these nanocomposites were successfully coated by hydrophilic chitosan, whose amine groups conferred the nanocomposites excellent dispensability in aqueous solution. Besides, the MTT assay and laser confocal microscopy images have confirmed the good biocompatibility of the nanocomposites. These results indicated that the as-prepared nanocomposites could be used as an excellent targeted imaging agent in biological fields.
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RSC Advances
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2015
·Vol. 5
·期 128
·106197-106205
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IF 3.84
Cenjin Zhang,Yuzhi Wang,Junxia Guo,Yanjin Liu,Yigang Zhou
This paper discusses the construction of surface molecularly imprinted polymers (MIPs) based on the modified chitosan (CS) nanoparticle carrier to recognize and separate bovine serum albumin (BSA, pI 4.9, MW 69.0 kDa) in aqueous solution. Functional biopolymer CS was selected as the supporting material. The CC group was introduced to CS by glycidyl methacrylate (GMA) to form ethylene-modified chitosan (GMA-CS), so that the imprinting polymerization could be initiated onto GMA-CS. Both bi-functional monomers MIP1 composed of acrylamide (AAm) and acrylic acid (AA) and single functional monomer MIP2 polymerized only by AA were prepared. Transmission electron microscopy (TEM) and field emission scanning electron microscopy (FESEM) were used to characterize the micro-morphology of MIP1 and MIP2, respectively. Static adsorption experiments showed that the adsorption capacity of MIP2 for BSA was much higher than MIP1, so we chose MIP2 for further research. The results showed that the MIP2 could accomplish adsorption equilibrium within only 2 h under an initial BSA concentration of 1.0 mg mL−1 and gave an imprint factor of 2.35. The theoretical maximum adsorption capacity (Qmax) was determined by the Langmuir model, which turned out to be 373.13 mg g−1. The selectivity of the MIP2 was evaluated by direct adsorption of a single reference protein and mixed proteins. The UV measurement and sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analysis results indicated that the MIP2 had a relatively higher adsorption capacity with good recognition and binding selectivity for BSA, which made it possible to remove the template protein from different sample solutions. After three adsorption–desorption cycles, MIP2 could still maintain 66.5% of absorption capacity. It was also found that the buffer pH had a great influence on the adsorption capacity of MIP2, indicating electrostatic interactions played an important role in the absorption and recognition process.
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RSC Advances
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2015
·Vol. 5
·期 120
·99418-99424
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IF 3.84
Jinda Fang,Ke Zhang,Jingwei Jia,Zhengke Wang,Qiaoling Hu
To improve the drug-loading capacity and control the initial release of amphiphilic drug carriers, a series of N-phthaloyl-chitosan-g-(PEO–PLA–PEO) compounds were synthesized with well-defined structures. The self-assembly behavior of copolymers in aqueous solutions was confirmed by various techniques such as fluorescence spectrometry, dynamic light scattering, and transmission electron microscopy. The results demonstrated that the micellization behavior of graft copolymers was different from that of their linear counterparts. The micelle sizes of the graft copolymers could be tuned with chemical composition as well as temperature. Furthermore, when hydrophobic indomethacin was loaded into the micelles, the graft copolymer micelles trapped more indomethacin than PEO–PLA–PEO micelles, facilitating the in vitro control of the initial burst release of the drug. Drug release could be controlled in vitro by simply altering the EO/LA ratio of the grafting chains. The graft copolymer showed low cytotoxicity to 293T cells, indicating its great potential application for drug delivery.
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JOURNAL OF APPLIED POLYMER SCIENCE
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2015
·Vol. 132
·期 22
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IF 1.768
Jiaxuan Feng,Hongjun Zang,Qing Yan,Mingguang Li,Xinqiang Jiang,Bowen Cheng
1-Carboxymethyl-3-methylimidazolium hydrochloride ([IMIM–COOH]Cl), a new ionic salt, is proposed as a green, promising solvent for dissolving chitosan. However, because of the optimal dosage of chitosan dissolved in [IMIM–COOH]Cl, a 12 wt % [IMIM–COOH]Cl aqueous solution was selected as an optimum solvent system for dissolving chitosan. The structures of the original and regenerated chitosan were characterized by Fourier transform infrared spectroscopy and X-ray diffraction analysis. Scanning electron microscopy was used to visualize the morphological features of the reconstituted chitosan membranes. Meanwhile, the absorbance, tensile strength, and breaking elongation of the chitosan membranes were measured. The results reveal that 10–11 wt % was an optimal chitosan concentration for preparing membranes. Furthermore, the adsorption capacity for Cu(II) ion of the chitosan membranes was increased with the chitosan concentration decreased from 12 to 8 wt %. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132 , 41965.
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ADVANCES IN POLYMER TECHNOLOGY
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2015
·Vol. 34
·期 3
·
IF 1.045
Ting Lü,Hongting Zhao,Dongming Qi,Ying Chen
This study reported the successful synthesis of a new amphiphilic and cationic flocculant (denoted as CS- g -PDBC) by grafting a cationic monomer, dimethyl acryloyloxyethyl benzyl ammonium chloride (DBC), onto chitosan (CS) initiated by ceric ammonium nitrate. The molecular structure and surface morphology of the newly synthesized graft copolymer CS- g -PDBC were characterized in detail by using Fourier transform infrared spectroscopy, X-ray powder diffraction, field emission scanning electron microscope, thermogravimetric analysis , and elemental analysis. Moreover, its flocculation efficiency for treating simulated emulsified oil wastewaters was evaluated and the results indicated that CS- g -PDBC was more efficient than those of CS and two other commonly used flocculants, i.e., cationic polyacrylamide and polyaluminum chloride. It was found that, as compared with CS, the successful introduction of cationic and hydrophobic groups into the CS backbone resulted in a significantly broadened flocculation window and a greatly enhanced flocculation efficiency for the prepared CS- g -PDBC in the treatment of oily wastewater, suggesting that this newly synthesized CS- g -PDBC would be a promising green agent for oily wastewater treatment.
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TALANTA
·
2015
·
IF 3.545
Zhiguang Liu,Yujing Guo,Chuan Dong
In this report, a new nanocomposite was successfully synthesized by chemical deposition of nickel nanoparticles (NiNPs) on polyvinylpyrrolidone (PVP) stabilized graphene nanosheets (GNs) with chitosan (CS) as the protective coating. The as obtained nanocomposite (PVP–GNs–NiNPs–CS) was characterized by X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). Benefiting from the synergistic effect of GNs (large surface area and high conductivity), NiNPs (high electrocatalytic activity towards the glucose oxidation) and CS (good film-forming and antifouling ability), a nonenzymatic electrochemical glucose sensor was established. The nanocomposite displays greatly enhanced electrocatalytic activity towards the glucose oxidation in NaOH solution. The PVP–GNs–NiNPs–CS based electrochemical glucose sensor demonstrates good sensitivity, wide linear range (0.1 μM–0.5 mM), outstanding detection limit (30 nM), attractive selectivity , good reproducibility, high stability as well as prominent feasibility for the real sample analysis. The proposed experiment might open up a new possibility for widespread use of non-enzymatic sensors for monitoring blood glucose owing to its advantages of low cost, simple preparation and excellent properties for glucose detection.
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Nano Energy
·
2015
·
IF 10.325
Pin Hao,Zhenhuan Zhao,Yanhua Leng,Jian Tian,Yuanhua Sang,Robert I. Boughton,C.P. Wong,Hong Liu,Bin Yang
Graphene-based nitrogen self-doped hierarchical porous carbon aerogels were synthesized for supercapacitor electrode application by using chitosan as a raw material through a carefully controlled aerogel formation–carbonization–activation process. The as-synthesized N-doped graphene-based carbon aerogels contained both macropores and mesopores from the aerogel preparation and carbonization process, and micropores from the chemical activation, confirmed by TEM, SEM, BET, etc. Because chitosan is a nitrogen-containing renewable biopolymer , the carbon aerogel derived from chitosan in this work was N-self-doped. The carbonized carbon aerogel was composed of a graphene framework and amorphous carbon , and the ratio between these two components was controlled by the activation temperature. With an increase in activation temperature, the amorphous carbon was etched away gradually, and a stable graphene portion remained to form a framework. Accordingly, the performance of the graphene-based carbon aerogel as a supercapacitor varied with increasing activation temperature. Electrochemical investigation measurements showed that the N-doped graphene-based hierarchical porous carbon aerogel represents a good electrode candidate for construction of a solid symmetric supercapacitor, which displays a high specific capacitance of about 197 F g −1 at a current density of 0.2 A g −1 . In addition, the solid state supercapacitor displayed excellent cyclability with a capacitance retention of about 92.1% over 10,000 cycles. The excellent energy storage ability of the chitosan-derived hierarchical graphene-based carbon aerogels is ascribed to the high conductivity of the graphene framework with nitrogen doping and the high storage ability of amorphous carbon with variable pore size and distribution.
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Materials Science & Engineering C-Materials for Biological Applications
·
2015
·
IF 3.088
Qingqing Yao,Wei Li,Shanshan Yu,Liwei Ma,Dayong Jin,Aldo R. Boccaccini,Yong Liu
Novel chitosan–polyvinyl pyrrolidone/45S5 Bioglass® (CS-PVP/BG) scaffolds were prepared via foam replication and chemical cross-linking techniques. The pristine BG, CS-PVP coated BG and genipin cross-linked CS-PVP/BG (G-CS-PVP/BG) scaffolds were synthesized and characterized in terms of chemical composition, physical structure and morphology respectively. Resistance to enzymatic degradation of the scaffold is improved significantly with the use of genipin cross-linked CS-PVP. The bio-effects of scaffolds on MC3T3-E1 osteoblast-like cells were evaluated by studying cell viability, adhesion and proliferation. The CCK-8 assay shows that cell viability on the resulting G-CS-PVP/BG scaffold is improved obviously after cross-linking of genipin. Cell skeleton images exhibit that well-stretched F-actin bundles are obtained on the G-CS-PVP/BG scaffold. SEM results present significant improvement on the cell adhesion and proliferation for cells cultured on the G-CS-PVP/BG scaffold. The drug release performance on the as-synthesized scaffold was studied in a phosphate buffered saline (PBS) solution. Vancomycin is found to be released in burst fashion within 24 h from the pristine BG scaffold, however, the release period from the G-CS-PVP/BG scaffold is enhanced to 7 days, indicating improved drug release properties of the G-CS-PVP/BG scaffold. Our results suggest that the G-CS-PVP/BG scaffolds possess promising physicochemical properties, sustained drug release capability and good biocompatibility for MC3T3-E1 cells' proliferation and adhesion, suggesting their potential applications in areas such as MC3T3-E1 cell stimulation and bone tissue engineering.
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JOURNAL OF MOLECULAR LIQUIDS
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2014
·
IF 2.083
Lei Zhang,Zhengjun Cheng,Xiao Guo,Xiaohui Jiang,Rong Liu
We report an investigation of the title process. The corresponding process variables such as the concentration of surfactant, temperature, initial concentration of dye have been optimized by the response surface methodology (RSM). A 2 3 full factorial design was employed to analyze the individual and interaction effects of the process variables. The experimental data have been well-fitted to second order polynomial equations and the models were also examined using the analysis of variance and t test statistics. The obtained optimal conditions are as following: C s = 30.92 μM, T = 20 °C and C OG = 320 mg/L for the orange G , and C s = 34.10 μM, T = 50 °C and C OA = 500 mg/L for the acid orange 7. The measured experimental maximum adsorption capacities for the orange G and acid orange 7 systems under above optimization conditions were 1452.07 and 2352.99 mg/g, which were in good agreement with their corresponding predicted values (1427.13 and 2357.31 mg/g), with small relative errors of 1.72% and − 0.18%, respectively. Moreover, many aspects of the adsorption kinetics and isotherms for the two dyes are presented. The results indicated that the two adsorption equilibriums were achieved within 210 and 240 min for the acid orange 7 and orange G, the pseudo-second-order model was followed, and Langmuir isotherm model could be well described their adsorption data. In addition, the adsorption mechanism of two dyes onto chitosan/surfactant was discussed further by FTIR and X-ray diffraction (XRD) methods.
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