INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2018
·
IF 3.909
Weixiang Liu,Yukun Qin,Song Liu,Ronge Xing,Huahua Yu,Xiaolin Chen,Kecheng Li,Pengcheng Li
A novel type of water soluble chitosan derivatives (TQCSPX) were synthesized including 3-aminopyridine (TQCSP1) and 3-Amino-4-methylpyridine (TQCSP2). The theoretical structures of TQCSPX were calculated by Gaussian 09 and confirmed by FT-IR, 1 H NMR, 13 C NMR, elemental analysis and XRD. The antifungal properties of TQCSPX against Phytophthora capsici ( P. capsici ), Rhizoctonia solani ( R. solani ), Fusarium oxysporum ( F. oxysporum ) and Fusarium solani ( F. solani ) were evaluated at concentrations ranging from 0.2 mg/mL to 0.8 mg/mL. Antifungal results indicated that the derivatives have significantly enhanced antifungal activity after quaternized compared with the original chitosan (CS). Moreover, TQCSP1 inhibited the growth of P. capsici with inhibitory indices of 91.94% at 0.8 mg/mL. The experimental results demonstrated that the increasing number of the positive charge would improve the antifungal efficiency of chitosan, which may provide a novel direction for the development of fungicides.
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Journal of Cleaner Production
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2018
·
IF 5.651
Lingxiao Liu,Haiyan Liang,Jing Zhang,Pengfei Zhang,Quan Xu,Qiming Lu,Chaoqun Zhang
The development of sustainable and transient materials is not only significant importance for environmental concern and human health, but also meets the highly demand for specific application in biomedical, military and intelligence fields. In this study, polymer blends of poly(vinyl alcohol) and chitosan were used to prepare sustainable and degradable polymer films which are promising to be applied as substrates for transient bioelectronics. The effect of the material composition and chemical structures on the mechanical, thermo-physical and thermal stability was studied and characterized by tensile testing , dynamic mechanical analysis , thermogravimetric analysis , and Fourier-transform infrared spectroscopy, respectively. In addition, the transiency rate of the composites as a function of temperature and composition was investigated and discussed. It is found that the transience rate of the composites can be tailored by controlling the composition and chemical structures. Addition of chitosan tends to decrease the time constant. In addition, the temperature also strongly affects the transience behavior of the polymer blends . The tailored performance and programmable degradation of these novel polymer composites provide a sustainable platform for widely application in transient biomedical and electronic devices.
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Nanomaterials
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2018
·Vol. 8
·期 5
·326
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IF 3.504
Wu Wen,Biao Han,Feng Yan,Liang Ding,Bojie Li,Liansheng Wang,Lei Zhu
We describe here the preparation of copper nanoparticles stabilized on a chitosan/poly (vinyl alcohol) composite film. This material could catalyze the borylation of α,β-unsaturated acceptors in aqueous media under mild conditions. The corresponding organoboron compounds as well as their converted β-hydroxyl products were all obtained in good to excellent yields. It is noteworthy that this catalyst of copper nanoparticles can be easily recycled eight times and remained catalytically reactive. This newly developed methodology provides an efficient and sustainable pathway for the synthesis of organoboron compounds and application of copper nanoparticles.Keywords:chitosan composite film;copper nanoparticles;organoboron compounds;easily recyclable
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Materials
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2018
·Vol. 11
·期 8
·1403
·
IF 2.467
Jie Li,Bing Xie,Kai Xia,Yingchun Li,Jing Han,Chunmao Zhao
Nano titanium dioxide (TiO2) with photocatalytic activity was firstly modified by diethanolamine, and it was then doped with broad spectrum antibacterial silver (Ag) by in situ method. Further, both Ag doped TiO2-chitosan (STC) and TiO2-chitosan (TC) composites were prepared by the inverse emulsion cross-linking reaction. The antibacterial activities of STC composites were studied and their antibacterial mechanisms under visible light were investigated. The results show that in situ doping and inverse emulsion method led to good dispersion of Ag and TiO2nanoparticles on the cross-linked chitosan microsphere. The STC with regular particle size of 1–10 μm exhibited excellent antibacterial activity againstE. coli,P. aeruginosaandS. aureusunder visible light. It is believed that STC with particle size of 1–10 μm has large specific surface area to contact with bacterial cell wall. The increased antibacterial activity was attributed to the enhancement of both electron-hole separations at the surface of nano-TiO2by the silver ions under the visible light, and the synergetic and sustained release of strong oxidizing hydroxyl radicals of nano-TiO2, together with silver ions against bacteria. Thus, STC composites have great potential applications as antibacterial agents in the water treatment field.Keywords:cross-linked chitosan;silver;titanium dioxide;photocatalytic antibacterial
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INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2018
·
IF 3.909
Qian Wang,Jiayi Wang,Wu Ding,Dequan Zhang,Kevin Reed,Boce Zhang
Preservatives in processed meat raise significant concerns associated with bowel cancer and diabetes, and implicate various public health issues. This introduces the need for safer preservatives to uphold public health standards. However, developing safer alternatives to these preservatives poses a significant challenge to food industry. A potential solution to this issue is the use of loaded nanoparticles as preservative agents. This study investigated antimicrobial and antioxidant effects of sorbic acid-loaded chitosan/tripolyphosphate nanoparticles (SAN) in Chinese Sausage. SAN were prepared through ionic gelation, followed by natural air-drying for 20 days. After preparation, the antimicrobial and antioxidant activities of various treatment groups were analyzed intermittently during storage at room temperature. SAN-treated samples had significantly lower levels of surviving bacteria, molds, and yeasts than the blank control ( p < 0.05) over the entire 72 days of storage. Additionally the SAN-treated samples also had lower levels of surviving bacteria than the chitosan/tripolyphosphate samples after 31–56 days of storage ( p < 0.05). The thiobarbituric acid value and pH of the SAN-treated samples were also significantly lower than the blank control ( p < 0.05). These results indicated that SAN could be a good intervention strategy to retard lipid oxidation and inhibit microbial growth in Chinese Sausage.
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CARBOHYDRATE POLYMERS
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2018
·
IF 5.158
Pan Zhang,Nan Zhang,Qiang Wang,Ping Wang,Jiugang Yuan,Jinsong Shen,Xuerong Fan
Chitosan, a natural biopolymer, is used as a multifunctional agent for modification of wool either through chemical crosslinking or physical coating. For the first time, wool fabric has been modified with chitosan through disulfide bond breaking and reforming reactions. The chitosan was thiolated and then grafted onto the reduced wool fibers through disulfide bonds. In order to understand the mechanism of the grafting of thiolated chitosan onto wool, glutathione was used as a model compound for wool in the research. The structures of thiolated chitosan reacted with glutathione and wool fabrics grafted with thiolated chitosan were investigated by FTIR, 13 CNMR, XPS, XRD, SEM. The dyeability, shrink-resistance and biocompatibility were also tested. The results suggested that glutathione reacted with thiolated chitosan and formed disulfide bond. The thiolated chitosan-grafted wool fabric had good shrink-resistance and dyeability. Hydrophilicity and antibacterial properties were also improved compared with untreated wool fabric. The results provide a novel approach for modification of wool through fiber-intrinsic groups like disulfide bonds.
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Water
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2018
·Vol. 10
·期 11
·1659
·
IF 2.069
Rong Cheng,Liang-Jie Shen,Ying-Ying Zhang,Dan-Yang Dai,Xiang Zheng,Long-Wen Liao,Lei Wang,Lei Shi
The removal of phosphate in water is crucial and effective for control of eutrophication, and adsorption is one of the most effective treatment processes. In this study, microporous lanthanum-chitosan magnetic spheres were successfully synthetized and used for the removal of phosphate in water. The characterization results show that the dispersion of lanthanum oxide is improved because of the porous properties of the magnetic spheres. Moreover, the contact area and active sites between lanthanum oxide and phosphate were increased due to the presence of many honeycomb channels inside the magnetic spheres. In addition, the maximum adsorption capacity of the Langmuir model was 27.78 mg P·g−1; and the adsorption kinetics were in good agreement with the pseudo-second-order kinetic equation and intra-particle diffusion model. From the results of thermodynamic analysis, the phosphate adsorption process of lanthanum-chitosan magnetic spheres was spontaneous and exothermic in nature. In conditional tests, the optimal ratio of lanthanum/chitosan was 1.0 mmol/g. The adsorption capacity of as-prepared materials increased with the augmentation of the dosage of the adsorbent and the decline of pH value. The co-existing anions, Cl−and NO3−had little effect on adsorption capacity to phosphate, while CO32−exhibited an obviously negative influence on the adsorption capacity of this adsorbent. In general, owing to their unique hierarchical porous structures, high-adsorption capacity and low cost, lanthanum-chitosan magnetic spheres are potentially applicable in eutrophic water treatment.Keywords:porous structure;lanthanum;La-chitosan magnetic spheres;adsorption capacity;phosphate;adsorption isotherm
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Materials
·
2018
·Vol. 11
·期 10
·2009
·
IF 2.467
Moxi Wang,Li Feng,Xiaowei Fan,Dongmei Li,Wenqi Qu,Shuxian Jiang,Shaoxiu Li
In this study, a series of chitosan-based quaternary ammonium graft flocculants, namely chitosan-graft-poly(acrylamide and methacryloyl ethyl trimethyl ammonium chloride) [CTS-g-P(AM-DMC)], was successfully synthesized by plasma initiation, and the as-prepared [CTS-g-P(AM-DMC)] had both flocculation and sterilization functions. Various characterization techniques were used to study the structure and physicochemical properties of the chitosan-based flocculants.1H nuclear magnetic resonance spectroscopy (1H NMR), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction spectroscopy (XRD), and thermogravimetric analysis/differential scanning calorimetry (TG/DSC) confirmed the successful synthesis of CTS-g-P(AM-DMC). Scanning electron microscopy (SEM) analysis exhibited that CTS-g-P(AM-DMC) contained a smooth convex and porous structure with an enormous surface area. CTS-g-P(AM-DMC) was then used to flocculate the simulated wastewater of the kaolin suspension and theSalmonellasuspension. Besides external factors, such as the dosage of flocculant and pH, the effect of the internal factor graft ratio was also evaluated. The experimental results showed that CTS-g-P(AM-DMC) also revealed a strong sterilization effect, aside from the excellent flocculation effect. Moreover, the sterilization mechanism was investigated through a series of conductivity measurements and the analysis of fluorescence-based cell live/dead tests. The results indicated that CTS-g-P(AM-DMC) destroyed the cell membrane ofSalmonellathrough its grafted quaternary ammonium salt, thereby exhibiting sterilization property.Keywords:chitosan-based flocculant;bifunctional;turbidity removal;sterilization;plasma initiation
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Soft Matter
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2018
·Vol. 14
·期 32
·6667-6677
·
IF 3.709
Yonggang Shangguan,Mingguo Liu,Lei Jin,Mengjie Wang,Zhengke Wang,Qiang Wu,Qiang Zheng
A novel thermo-thickening behavior of a chitosan-g-polyacrylamide (CS-g-PAM, GPAM) aqueous solution is reported for the first time in this work. The viscosity of GPAM aqueous solutions significantly increases above a critical temperature upon heating, as observed in dynamic and steady rheological experiments. Differing from the widely reported hydrophobic modified CS, GPAM was prepared by grafting hydrophilic polyacrylamide side chains onto the CS backbone, therefore the thermo-thickening behavior of the GPAM aqueous solution could not be explained by the usual thermo-thickening mechanism induced by the additional hydrophobic moiety or LCST segment. The origin of the thermo-thickening in GPAM solutions was explored using transmission electron microscopy (TEM), dynamic light scattering (DLS), and nuclear magnetic resonance (NMR) tests of the GPAM solution. A transformation from a hydrogen bonding (H-bonding) aggregate to a hydrophobic aggregate upon heating was confirmed to be responsible for the thermo-thickening. The heating initiates a transformation of large loose H-bonding aggregates into abundant small compact ones formed by self-assembled hydrophobic chitosan backbones, resulting in aggregate associations and thus flocculated aggregate networks. Some factors of the thermo-thickening were investigated and discussed in detail, including the heating history, concentration, grafting ratio, and length of the PAM side chain. Besides the influence caused by the heating history, this thermo-thickening process is influenced by kinetic factors, including the mobility of the macromolecule chains and the formation of new aggregate networks that are dependent on the number of hydrophobic clusters.
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MICROCHIMICA ACTA
·
2019
·Vol. 186
·期 6
·1-12
·
IF 5.479
Yang Xing,Niu Xiaohui,Mo Zunli,Guo Ruibin,Liu Nijuan,Zhao Pan,Liu Zhenyu
A composite was prepared from graphene functionalized with 3,4,9,10-perylene tetracarboxylic acid and chitosan (rGO-PTCA-chitosan) by a chemical method. It involves non-covalent functionalization of rGO with PTCA followed by amidation reaction with chitosan. Scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and electrochemical methods were used to characterize the composites. By combining the chiral features of chitosan and the excellent electrochemical behaviors of rGO-PTCA, a graphene-based material with enantioselectivity was constructed for electrochemical chiral recognition of tryptophan (Trp) enantiomers. A glassy carbon electrode (GCE) modified with rGO-PTCA-chitosan had a higher recognition capability for L-Trp than for D-Trp. Best operated at a working voltage near 0.78 V (vs. SCE), the enantioselectivity coefficient is 3.0. The sensor has a linear response in the 1 mM to 10 mM Trp concentration range and a 1.2 μM detection limit (at S/ N = 3) for L-Trp, and of 3.0 μM to D-Trp. The sensor was successfully used to detect Trp enantiomers in real samples, and a recognition mechanism is presented.
Schematic presentation of a composoie prepared by graphene functionalized with 3,4,9,10-perylene tetracarboxylic acid and chitosan (rGO-PTCA-chitosan) via a chemical method. It involves non-covalent functionalization of rGO with PTCA followed by amidation reaction with chitosan and voltammetric determination of tryptophan enantiomers.
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INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2019
·
IF 4.784
Menglu Xu,Sajid Asghar,Shuang Dai,Yajing Wang,Shanshan Feng,Liang Jin,Feng Shao,Yanyu Xiao
The combination of controlled release technology and targeted drug delivery has become a promising strategy for cancer therapy. In this study, cell-nanoparticle hybrid vector was constructed using mesenchymal stem cells as the targeting cellular carrier and biotinylated chitosan polymer nanoparticles as the drug depot. Drug-loaded nanoparticles (hydrodynamic size =377.0 ± 14.6 nm and zeta potential = 9.6 ± 1.9 mV) were prepared by encapsulating hydrophobic model drug curcumin into biotinylated chitosan polymer. The biotin-modified nanoparticles were anchored on biotinylated mesenchymal stem cells surface by biotin-avidin binding, achieving an upload of 54.73 ± 3.95 pg/cell. The anchorage of nanoparticles on mesenchymal stem cells had no effect on their viability and homing property. Biotin-avidin binding lasted over 48 h, which could be sufficient for cell-directed tumor-tropic delivery. The in vitro and in vivo anti-tumor results advocate that cell-nanoparticle hybrid vector could prove beneficial in pulmonary melanoma metastasis therapy.
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FOOD HYDROCOLLOIDS
·
2018
·
IF 5.089
Mingyu Ji,Xinyu Sun,Xiaoban Guo,Wenjin Zhu,Jiulin Wu,Li Chen,Jianhua Wang,Mingmao Chen,Cui Cheng,Qiqing Zhang
As a natural preservative, cinnamaldehyde (CA) has a bright application prospect. However, CA is sensitive to light and can be easily oxidized. What's more, its water solubility is poor. These properties greatly limit its application. In this study, CA/sodium alginate (SA)/chitosan (CS) nanoparticles (CA/SA/CS NPs) were prepared by using SA and CS as wall materials, and CA as core material. The single factor experiment showed that the optimal CA/SA/CS NPs can be obtained when the mass ratio of SA to CS was 5.5/1, SA to CaCl 2 was 5/1, SA to CA was 1/2, and the pH of CS solution was 5.0. Under this condition, the average size of the prepared nanoparticles was 455.2 nm, polymer dispersity index (PDI) value was 0.189, zeta potential was −40.8 mV, and the encapsulation efficiency was 72.92%. The scanning electron microscopy (SEM) and atomic force microscopy (AFM) images confirmed the formation of nanoparticles, which were spherical or ellipsoidal in shape. The fourier transform infrared spectroscopy (FTIR) and multifunctional polycrystalline X-ray diffraction (XRD) spectra indicated that CA was encapsulated in the nanoparticles. Furthermore, in vitro release experiments showed that CA/SA/CS NPs had the function of sustained release. In summary, SA/CS NPs can be used as a promising carrier for CA.
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