SEPARATION AND PURIFICATION TECHNOLOGY
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2016
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IF 3.299
Qinqin Liu,Yan Zhao,Jiefeng Pan,Bart Van der Bruggen,Jiangnan Shen
Using molecularly imprinted technology and the phase inversion method, a chlorogenic acid molecularly imprinted chitosan membrane was prepared. Chlorogenic acid was used as the template molecule and chitosan as the film-forming material. Sulfuric acid was chosen as the cross-linking agent, in order to inhibit the swelling of chitosan membranes. The selectivity of these imprinted membranes in terms of permeability and adsorption capacity was studied. Furthermore, the chemical composition and surface structure of the membranes as well as their thermo-stability were characterized. Scatchard results show that there are two kinds of adsorption sites present on the molecularly imprinted membranes, one with high affinity sites and one with low affinity sites. For the high affinity sites, the maximum adsorption capacity was 139.57 μmol g −1 and that for the low affinity sites was 287.86 μmol g −1 . In contrast, for the non-imprinted membranes, only one kind of sites was found, with a maximum adsorption capacity of 83.84 μmol g −1 . The adsorption isotherms indicate that the adsorption isotherm curve of chlorogenic acid binding onto the imprinted membrane agrees with the Freundlich model while that of the non-imprinted membrane conforms to the Langmuir model. The permeation experiments proved that the imprinted membrane has a selective adsorption capacity for chlorogenic acid.
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JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
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2017
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IF 3.154
Dongliang Zhang,Yanfei Cao,Chengye Ma,Shanfeng Chen,Hongjun Li
There is a paradox when incorporating enzyme into an edible chitosan film that chitosan is dissolved in acid solution and enzyme activity is maintained under mild conditions. A method for maintaining the pH of the chitosan solution at 4–6 to prepare a chitosan film containing β-cyclodextrin, resveratrol−β-cyclodextrin inclusion (RCI), was developed, using glucamylase and acetic acid. A considerable amount of resveratrol was released by the glucamylase-incorporated film within 15 days, and the maximum amount released was 46% of the total resveratrol content. The highest resveratrol release ratio (released resveratrol/total resveratrol) was obtained in the film with 6 mL of RCI. Scratches and spores were generated on the surface of the glucamylase-added film immersed in water (GAFW) for 7 days because of β-cyclodextrin hydrolysis during film drying and water immersion. RCI and β-cyclodextrin were extruded from the film surface and formed teardrops, which were erased by water on the GAFW surface but appeared on the glucamylase-added film without water immersion (GAF). The bubbles generated by the reaction of acetic acid and residual sodium bicarbonate were observed in both glucamylase-free films immersed in water (GFFW) for 7 days and without water immersion (GFF). The FT-IR spectra illustrated that the covalent bond was not generated during water immersion and β-cyclodextrin hydrolysis. The crystal structure of chitosan was destroyed by water immersion and β-cyclodextrin hydrolysis, resulting in the lowest chitosan crystallization peak at 22°. The increasing of water holding capacity determined by EDX presented the following order: GAF, GFFW, GFF, and GAFW.
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INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2016
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IF 3.138
Chao Chen,Yong Yu,Xiaoli Wang,Ping Shi,Yibing Wang,Ping Wang
Podophyllotoxin (PPT) offers a broad-spectrum of anticancer activities, but little has been reported for its controlled release. This work shows that by manipulating molecular interactions between PPT and Chitosan, efficient nanoscale capsulation of PPT can be realized. The drug encapsulation efficiency is as high as 52%, with a final particle drug loading in the order of 10% (wt/wt). It further demonstrates that changes in pH can also significantly affect the rate of drug release from the Chitosan nanoparticles. Upon contact with cancer cells, chitosan nanoparticles enable efficient internalization and drug release. In vitro evaluations with HepG-2 and MCF-7 cells indicate that the chitosan nanoparticle carriers can improve drug efficacy in comparison to free PPT, most likely by regulating the intrinsic apoptotic signaling pathway to induce apoptosis. Overall, PPT chitosan nanoparticles promise a safe and efficient drug delivery system for PPT.
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ACS Applied Materials & Interfaces
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2016
·
IF 7.145
Donghui Liang,Zhong Lu,Hao Yang,Jingting Gao,Rong Chen
A novel silver nanoparticles (AgNPs)/chitosan composite dressing with asymmetric wettability surfaces was successfully prepared via a simple two-step method for biomedical applications as wound healing materials. First, AgNPs were assembled into the chitosan sponge which was prepared by lyophilization process. Then one side of the sponge was modified by a thin layer of stearic acid. The incorporation of AgNPs into chitosan dressing could enhance the antibacterial activity against drug-sensitive and drug-resistant pathogenic bacteria. The asymmetric surface modification endows the dressing with both highly hydrophobic property and inherent hydrophilic nature of chitosan. The hydrophobic surface of the dressing shows waterproof and antiadhesion for contaminant properties, whereas the hydrophilic surface preserves its water-absorbing capability and efficiently inhibits the growth of bacteria. Furthermore, the AgNPs/chitosan composite dressing displays improved moisture retention and blood clotting ability compared to the unmodified dressings. Cytocompatibility test evaluated in vitro and in a wound infection model illustrates the nontoxic nature of the composite dressing. More importantly, the in vivo wound healing model evaluation in mice reveals that the asymmetric AgNPs/chitosan dressing promotes the wound healing and accelerates the reepithelialization and collagen deposition. The silver accumulation in mice body treated by the composite dressing is far lower than that of the clinically used Acasin nanosilver dressing treated mice. This work indicates the huge potential of the novel AgNPs/chitosan wound dressing with asymmetrical wettability for clinical use.
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INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2016
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IF 3.138
Ying Ren,Hongguo Xie,Xiaocen Liu,Fan Yang,Weiting Yu,Xiaojun Ma
The goal of this work is to tune the formation and stability of the alginate-chitosan (AC) polyelectrolyte complexes (PECs) and microcapsules. Particularly, we explore the role of the conformation of chitosan on its interaction with alginate to understand the mechanism underpinning their interactions at the molecular level. Reducing the charge density by increasing pH will increase the compactness of chitosan, the values of the enthalpy (H) and stoichiometry (N) of binding between chitosan and alginate. Consequently, chitosan has advantage in being adsorbed on alginate beads to form microcapsules, including the binding rate and binding amount. Though the total heat release remain similar in the range of ionic strength , chitosan diffuses much easier into alginate hydrogels when in higher ionic strength. Increasing pH and ionic strength both help AC microcapsules to have higher stability. The results indicate that the formation and stability of AC microcapsules are related to the rigidity and conformations of chitosan molecules. After increasing acetylation degree (DA) of chitosan, the binding rate of chitosan and mechanical strength of AC microcapsules are both reduced. This work demonstrates the versatility and feasibility of tuning the formation and stability of polysaccharide microcapsules by physical factors and chitosan chemical structures.
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EUROPEAN JOURNAL OF PHARMACEUTICAL SCIENCES
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2016
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IF 3.773
Yashu Yao,Mengxin Xia,Huizhen Wang,Guowen Li,Hongyi Shen,Guang Ji,Qianchao Meng,Yan Xie
A novel nanogel/gel based on chitosan (CS) for the oral delivery of myricetin (Myr) was developed and evaluated comprehensively. The particle size of the obtained Myr-loaded CS/β-glycerol phosphate (β-GP) nanogels was in the range of 100–300 nm. The rheological tests showed that the sol-gel transition happened when the nanogels were exposed to physiological temperatures, and 3D network structures of the gelatinized nanogels (gels) were confirmed by Scanning Electron Microscopy. Myr was released from CS/β-GP nanogel/gel in acidic buffers via a Fickian mechanism, and this release was simultaneously accompanied by swelling and erosion. Moreover, the nanogel/gel exhibited no cytotoxicity by MTT assay, and the oral bioavailability of Myr in rats was improved with an accelerated absorption rate after Myr was loaded into CS/β-GP nanogel/gel. In summary, all of the above showed that CS/β-GP nanogel/gel was an excellent system for orally delivering Myr.
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CHEMICAL ENGINEERING JOURNAL
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2016
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IF 5.31
Shaopeng Zhang,Yayi Dong,Zhen Yang,Weiben Yang,Jiaqing Wu,Chang Dong
A series of magnetic composite adsorbents with core-brush topology were prepared through grafting co-polymerization on the surface of chitosan/Fe 3 O 4 composite particles (CS-MCP), and then applied for the removal of two pharmaceuticals (diclofenac sodium (DCF) and tetracycline hydrochloride) from water. Adsorption performance evaluation, including adsorption capacities from single- and binary-solute solutions at different pHs, influences of coexisting salts, desorption and reusability, demonstrated CD-MCP with polycationic brushes was a cost-effective adsorbent for DCF removal: Compared to CS-MCP, all the modified MCPs exhibited higher removal efficiencies, due to the enhanced surface areas resulting from core-brush topology; Among the modified MCPs with different surface charges, CD-MCP displayed the highest adsorption capacities, attributed to the electrostatic attraction between the positively charged brushes and the anionic contaminant’s species. Adsorption mechanism was investigated from both the macroscopic (thermodynamics and kinetics) and microscopic (changes of solution pH and spectral analyses of the adsorbent after adsorption) viewpoints: Charge attraction was the intrinsic driving force; A monolayer coverage of pharmaceuticals were adsorbed onto the brushes of CD-MCP; OH − exerted competitive adsorption effect; After adsorption, the originally extended polycationic brushes turned collapsed. The current study provided a strategy for the design of adsorbents from both topological and chemical structures.
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FOOD CHEMISTRY
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2017
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IF 4.529
Jie Long,Bao Zhang,Xingfei Li,Xiaobei Zhan,Xueming Xu,Zhengjun Xie,Zhengyu Jin
In this study, pullulanase was firstly immobilized by covalent bonding onto chitosan/Fe 3 O 4 nanoparticles or encapsulation in sol-gel after bonding onto chitosan/Fe 3 O 4 nanoparticles, and then the immobilized pullulanase was used for the effective production of resistant starch (RS). The highest RS content (35.1%) was obtained under the optimized condition of pH 4.4, enzyme concentration of 10 ASPU/g and hydrolysis time of 12 h when debranched by free pullulsanase, indicating that RS content was significantly (p < 0.05) increased when compared to native starch (4.3%) and autoclaved starch (12.5%). Under these conditions, the immobilized pullulanase (10 ASPU/g dry starch) yielded higher RS content compared to free enzyme (10 ASPU/g dry starch), especially, the pullulanse immobilized by sol-gel encapsulation yielded the highest RS content (43.4%). Moreover, compared to starches hydrolyzed by free pullulanase, starches hydrolyzed by immobilized pullulanase showed a different saccharide profile of starch hydrolysate, including a stronger peak C (MW = 5.0 × 10 3 ), as well as exhibited an additional absorption peak around 140 °C. Reusability results demonstrated that pullulanase immobilized by sol-gel encapsulation had the advantages of producing higher RS content as well as better operational stability compared to pullulanase immobilized by cross-linking. The resulting enhanced RS content generated by the process described in this work could be used as an adjunct in food processing industries.
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Journal of Materials Chemistry B
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2017
·Vol. 5
·期 19
·3521-3530
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IF 4.543
Yixian Zhang,Yiran Xu,Xiangyi Xi,Surakshya Shrestha,Pengfei Jiang,Wenjing Zhang,Changyou Gao
The extensive development and application of engineered nanoparticles (NPs) in various fields worldwide have been subjected to increasing concern due to their potential hazards to human health and the environment. Therefore, a simple, economical, and effective method for suppressing the toxicity of metal-based nanomaterials is needed. In this study, glutaraldehyde-crosslinked chitosan nanoparticles (CS NPs) were prepared and further modified with lysine (Ly-CS), glutamic acid (Glu-CS), or sodium borohydride reduction (R-CS), and used to suppress cytotoxicity induced by copper oxide NPs (CuO NPs) through chelation with intracellularly released copper ions. All three kinds of CS NPs had similar sizes of ∼100 nm in a dry state and ∼200 nm in cell culture medium, as determined by scanning electron microscopy, transmission electron microscopy, and dynamic light scattering. The chelating efficiency of different CS NPs followed the order Ly-CS > Glu-CS > R-CS. The CS NPs showed minimal or no toxicity to three different cell lines (HepG2, A549, and RAW264.7 cells) at 100 μg mL−1 with similar cell internalization and exocytosis processes. Comparatively, RAW264.7 cells exhibited higher endocytosis and exocytosis rates, as revealed by flow cytometry and confocal laser scanning microscopy. CS NPs were found as agglomerates inside A549 cells and RAW264.7 cells, with the amount of agglomerates inside RAW264.7 cells decreasing significantly with prolonged incubation. All three CS NPs, especially Ly-CS and Glu-CS NPs, efficiently suppressed the cytotoxicity induced by CuO NPs, and reduced the intracellular level of reactive oxygen species.
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JOURNAL OF BIOMATERIALS APPLICATIONS
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2017
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IF 2.31
Jianzhou Cai,Wu Zhang,Jiake Xu,Wei Xue,Zonghua Liu
Chitosan, as a potential vaccine delivery material, has obtained much attention for immunization prevention and therapy. However, its poor water solubility brings inconvenience for the practical applications. To address this issue, researchers have carried out many chemical modifications to prepare water-soluble chitosan derivatives for vaccine delivery. In this work, we prepared a chitosan derivative N-phosphonium chitosan with excellent water solubility and explored its potential as an intramuscular vaccine delivery system by using ovalbumin as a model antigen. Different vaccine formulations were intramuscularly injected into test mice. Through an immunohistochemistry assay, N-phosphonium chitosan-based antigen formulation could promote antigen arrival from injection site to the secondary lymph organ spleen. Further immunization results showed that 1 mg/ml N-phosphonium chitosan-based vaccine formulation could contribute to significantly higher level of antigen-specific immune responses, including higher antigen-specific IgG antibody titer, splenocyte proliferation, and cytokines secretion (interferon-γ, interleukin-10, and interleukin-4) by the splenocytes of the immunized mice. From the results, the water-soluble chitosan derivative N-phosphonium chitosan could be developed as a potential antigen carrier for immunization prevention and therapy.
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RSC Advances
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2017
·Vol. 7
·期 80
·50920-50927
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IF 3.108
Kuerbanjiang Rouzi,Abuderixiti Abulikemu,Jie Zhao,Biao Wu
A new chitosan based colorimetric anion receptor bearing nitrophenyl as a chromogenic signal group, and urea moiety as recognition site was designed and synthesized. The receptor structure was characterized by FTIR and 1H NMR. The sensing abilities of the receptor for anions were investigated with UV-vis methods. During the addition of PO43− and F− anions, the sensor responded with a dramatic color change, and no change was observed in the presence of other anions. The UV-vis absorption titration data showed that the receptor shows selective recognition and sensing in DMSO-H2O (1%) for PO43− and F− anions. The Job's curve showed that 3 : 2 stoichiometry complexes were formed between the receptor and the anion.
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CHEMICAL PAPERS
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2012
·Vol. 67
·期 4
·423-428
·
IF 1.096
Zhu Guo-Quan,Wang Fa-Gang,Liu Yu-Ying,Gao Qiao-Chun
A series of water-soluble carboxymethyl chitosan (CMCS)/poly(propylene glycol) (PPG) blend films with various CMCS/PPG mole ratios were prepared by the solution casting method. Morphology of the CMCS/PPG blend films was investigated by scanning electron microscopy (SEM). Thermal, mechanical, and chemical properties of the CMCS/PPG blend films were studied by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), tensile tests, and contact angle tests. It was found that the introduction of PPG can markedly affect the morphology and the properties of CMCS films.
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