CELLULOSE
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2021
·Vol. 28
·期 7
·4397-4409
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IF 5.044
Ni Shuzhen,Liu Na,Fu Yingjuan,Gao Hailong,Qin Menghua
Abstract Herein, a great potential approach initiated by laccase is applied to graft the biopolymers (chitosan and phenols) onto the unbleached Kraft pulp fibers to enhance the hydrophobicity and strength. The results showed that the chitosan and laccase/phenols exhibited a synergistic action on the significant improvement of the hydrophobicity of the KP pulp fibers. Compared with the base paper, a high sizing degree value (227.08 s) was achieved when the fibers were treated by the laccase/4-hexyloxyphenol/chitosan (Lac/HP/CTS) system. The water retention value of the corresponding KP fibers reduced from 176.8 to 171.3%, and the Kappa number of treated fibers increased from 26.8 to 29.3, confirming the successful graft of HP onto the fibers. The effect of the reaction parameters, including the temperature, pH, HP and chitosan dosage, reaction time and pulp suspension consistency on the strength and hydrophobicity was investigated. pH value was found as the most remarkable factor influencing the sizing degree and gave a highest sizing value (506.2 s) at pH 5.5. The strength performance presented an opposite trend against the hydrophobicity, since the number of formed hydrogen bonds is the least when the hydrophobicity is the best. This work is extremely significant for providing valuable reference on improving the hydrophobicity and strength performance of papers through a green and biological way. Graphic abstract
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BIOTECHNOLOGY AND APPLIED BIOCHEMISTRY
·
2021
·Vol. 69
·期 2
·567-575
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IF 2.431
Jianhua Zhang,Huaying Hu,Pengchang Wang,Chi Zhang,Majiaqi Wu,Lianqiao Yang
An acetylcholinesterase (AChE) biosensor was successfully fabricated with a stable structure and high detection accuracy. Graphene (Gra) nanofragments modified with chitosan (CS) and AChE were successively drip coated on the surface of a glassy carbon electrode via a layer-by-layer assembly method. The concentration range of the sensor to detect dichlorvos was 0.1–100,000 nM, and the limit of detection was 54 pM. CS was used to modify Gra for the first time, which enhanced the mechanical flexibility of these Gra nanostructures, significantly improving the stability and detection accuracy of this sensor.
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CARBOHYDRATE RESEARCH
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2021
·
IF 2.104
Jun Wang,Zongyong Zhang,Yilong Ai,Fang Liu,Min-Min Chen,Dahai Liu
In order to achieve efficient delivery of methotrexate (MTX), thymine-chitosan nanoparticles (Thy-Cs NPs) were prepared, and further decorated with lactobionic acid (LA) to obtain tumor-targeting nanoparticles (LA-Thy-Cs NPs). These nanoparticles possessed a regular spherical structure with the average size about 190–250 nm and narrow size distribution, which were kinetically stable in the physiological environment. Due to electrostatic interactions and multiple hydrogen-bonding interactions between MTX and carriers, MTX was loaded into Thy-Cs NPs with high drug loading content (~20%). MTX release from Thy-Cs NPs was significantly accelerated in the mildly acidic environment due to the destruction of two types of non-covalent interactions. In vitro cell experiments demonstrated that LA-Thy-Cs NPs could be efficiently internalized into hepatoma carcinoma cells, leading to higher cytotoxicity. Moreover, MTX-loaded LA-Thy-Cs NPs performed an enhanced growth inhibition in three-dimensional multicellular tumor spheroids . Thus, the LA decorated thymine-chitosan nanocarriers can be a promising candidate for efficient delivery of MTX.
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Polymers
·
2021
·Vol. 13
·期 17
·2929
·
IF 4.329
Jing Miao,Liwen Zhang,Peng Gao,Huawei Zhao,Xianji Xie,Junyan Wang
Glucose Transporter-1 (GLUT-1) is considered to be a possible intrinsic marker of hypoxia in malignant tumors, which is an important factor in radioresistance of laryngocarcinoma. We speculated that the inhibition of GLUT-1 expression might improve the radiosensitivity of laryngocarcinoma. GLUT-1 siRNA was designed to inhibit the GLUT-1 expression, but the high molecular weight and difficult drug delivery limited the application. Herein, we constructed a glycolipid polymer chitosan oligosaccharide grafted stearic acid (CSSA) to conjugate siRNA via electrostatic interaction. The characteristics of CSSA and CSSA/siRNA were studied, as well as the radiosensitization effect of siRNA on human laryngocarcinoma epithelial (Hep-2) cells. Compared with the traditional commercial vector LipofectamineTM2000 (Lipo), CSSA exhibited lower cytotoxicity, more efficiently cellular uptake. Incubating with CSSA/siRNA, the survival rates of Hep-2 cells were significantly decreased comparing with either the group before transfection or Lipo/siRNA. CSSA is a promising carrier for efficient siRNA delivery and radiosensitization of laryngocarcinoma.Keywords:GLUT-1;siRNA;chitosan oligosaccharide grafted stearic acid;laryngocarcinoma;radiosensitization
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STARCH-STARKE
·
2021
·
IF 2.741
Dan Qin,Jun Wu,Yuxiang Zhang,Mian Bao,Xiaoyue Du,Hongqing Sang,Zhengyou Wei
This study experimentally investigates the effect of changes in amylose-to-amylopectin ratio on the multi-scale structures, hydrophilicity, and thermal properties of starch–chitosan essential oil (EO) films incorporated with vanillin. The results indicate that aggregates and uneven structures tend to form in the EO films with a higher proportion of amylose. In Fourier transform infrared spectroscopy, as the chitosan content increases, the wavenumber of stretching vibration of hydroxyl and the bending vibration of amino groups decrease, while the wavenumber of stretching vibration of C-O increases. Furthermore, with an increase in the chitosan content, the changes in the starch–chitosan EO film structure impacts the hydrophilic trend, and the hydrophilic changes in the EO films with common starch and G80 starch are significant changes with the proportions of starch to chitosan from 7:3 to 5:5. When their mass ratio is 3:7, the starch–chitosan EO films investigated exhibit the lowest decomposition peak temperature.
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CARBOHYDRATE POLYMERS
·
2021
·
IF 9.381
Chen Zhou,Hai-Yong Ao,Xiao Han,Wen-Wen Jiang,Zhi-Fei Yang,Le Ma,Xiao-Yan Deng,Yi-Zao Wan
As a mild cationic antibacterial agent, hydroxypropyltrimethyl ammonium chloride chitosan (HACC) could kill gram-positive bacteria and gram-positive drug-resistant bacteria without cytotoxicity. Nevertheless, it was not effective against gram-negative bacteria. Herein, protocatechuic acid (PA) with broad-spectrum antibacterial properties and pharmacological activities was grafted on HACC. PA-g-HACC showed favourable antioxidant capacity and anti-inflammatory properties. Most importantly, the results of antibacterial assay indicated that the antibacterial rates of all PA-g-HACC groups against Staphylococcus aureus ( S. aureus ) and methicillin-resistant Staphylococcus aureus ( MRSA ) were above 92 %, and the antibacterial rate of PA-g-HACC against E. coli was increased with the amount of grafted PA. Furthermore, the cytocompatibility of PA-g-HACC was improved by appropriate grafting ratio of PA, while excessive grafted PA can lead to toxicity. We believe that PA-g-HACC in optimum grafting ratio of PA with favorable antibacterial properties, pharmacological activities and cytocompatibility will be potential antibacterial agent for treating infections.
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ACS Sustainable Chemistry & Engineering
·
2020
·
IF 7.632
Jiaqi Shan,Dagang Liu,Fan Su,Minyu Li,Huafeng Tian,Mengna Guo,Wenhao Qiao,Jie He,Qin Li,Jun Qian
Highly surface-charged rigid bionanofibrils are difficult to be processed into integrated foams or aerogels owing to lack of good interfibrillar adhesion. An alternative solution is to involve flexible hydrophilic polymers for gluing fibril bundles, allowing a perfect alignment under ice induction in the lyophilized foams. In this work, we incorporated the defibrillated chitin/chitosan nanofibrils (CTF/CSF) into gelatinized starch foams and investigated the effects of surface charge, solid content, nanofibril loading, and directional orientation on the dimensional stability, morphology, crystallinity, compressive stress, and flame-retardant properties of lyophilized composite foams. Results show that CTF with low positive surface charges presents stable electroattractions to negatively charged starch and also exhibits sustainable reinforcement effects on the composite foam. What is more, compact, small porous, and lamellar CTF-supported foams exhibit relatively high resistance to flammable combustion. In the case of high loading of polycationic CSF, directional freeze-drying successfully induced the channel orientation along the vertical, horizontal, spiral, or bi/triphase junctional direction in the anisotropic foams, which revealed variable compression properties according to the fibril alignment.
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Polymers
·
2020
·Vol. 12
·期 8
·1780
·
IF 3.426
Shunli Chen,Min Wu,Caixia Wang,Shun Yan,Peng Lu,Shuangfei Wang
The use of advanced and eco-friendly materials has become a trend in the field of food packaging. Cellulose nanofibrils (CNFs) were prepared from bleached bagasse pulp board by a mechanical grinding method and were used to enhance the properties of a chitosan/oregano essential oil (OEO) biocomposite packaging film. The growth inhibition rate of the developed films with 2% (w/w) OEO againstE. coliandL. monocytogenesreached 99%. With the increased levels of added CNFs, the fibrous network structure of the films became more obvious, as was determined by SEM and the formation of strong hydrogen bonds between CNFs and chitosan was observed in FTIR spectra, while the XRD pattern suggested that the strength of diffraction peaks and crystallinity of the films slightly increased. The addition of 20% CNFs contributed to an oxygen-transmission rate reduction of 5.96 cc/m2·day and water vapor transmission rate reduction of 741.49 g/m2·day. However, the increase in CNFs contents did not significantly improve the barrier properties of the film. The addition of 60% CNFs significantly improved the barrier properties of the film to light and exhibited the lowest light transmittance (28.53%) at 600 nm. Addition of CNFs to the chitosan/OEO film significantly improved tensile strength and the addition of 60% CNFs contributed to an increase of 16.80 MPa in tensile strength. The developed chitosan/oregano essential oil/CNFs biocomposite film with favorable properties and antibacterial activity can be used as a green, functional material in the food-packaging field. It has the potential to improve food quality and extend food shelf life.Keywords:cellulose nanofibrils;chitosan;oregano essential oil;antimicrobial;oxygen barrier properties
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Journal of the Taiwan Institute of Chemical Engineers
·
2020
·
IF 4.794
Yefeng Liu,Peng Zuo,Fei Wang,Ying Lv,Ruixin Wang,Weizhou Jiao
In this study, Keggin- and Dawson-type polyoxometalates (POMs) were immobilized on chitosan (CS)-modified Fe 3 O 4 @CS by electrostatic interaction for the preparation of heterogeneous catalysts Fe 3 O 4 @CS@POM (POM=PMo 12 , PW 12 , SiW 12 , P 2 W 17 , or P 2 W 18 ). The oxidative desulfurization (ODS) of dibenzothiophene (DBT) by Fe 3 O 4 @CS@POMs was evaluated. It is found that Fe 3 O 4 @CS@POM shows the good ODS performance due to the good dispersion of POM on Fe 3 O 4 surface and the good accessibility of substrate to it leaded by the full swelling of the cross-linked CS in acetonitrile . The catalytic activity follows the order of Fe 3 O 4 @CS@PMo 12 > Fe 3 O 4 @CS@PW 12 > Fe 3 O 4 @CS@P 2 W 17 > Fe 3 O 4 @CS@P 2 W 18 > Fe 3 O 4 @CS@SiW 12 . At 333 K, the desulfurization rate of DBT (500 ppm) reaches 99.7% at 60 min and 100% at 90 min in the presence of 0.1 g of Fe 3 O 4 @CS@PMo 12 and 100 µL of H 2 O 2 . The ODS process can be well described by the pseudo-first-order kinetic model (R 2 > 0.99) with a high kinetic constant (0.0761 min −1 ) and a low apparent activation energy (60.57 kJ / mol). In addition, the as-prepared catalyst can be easily separated and recycled in the external magnetic field, and it still has the good reusability for several times, stemming from the stable encapsulation of POM clusters by cross-linked chitosan on Fe 3 O 4 surface.
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APPLIED CLAY SCIENCE
·
2020
·
IF 4.605
Chao Wang,Zuyu He,Yunhao Liu,Chuang Zhou,Jing Jiao,Puwang Li,Dequan Sun,Liyun Lin,Ziming Yang
Halloysite nanotubes (Hal) are naturally occurring tubular clay nanomaterials that have a unique tubular structure and surface modifiability. In order to increase the stability and to achieve controlled release of fertilizers, chitosan (CS) was assembled on the surface of Hal as a valve for preparing Hal@CS and to control the mesoporous surface and lumen ports. Transmission electron microscopy (TEM), X-ray diffraction, Fourier transform infrared, thermogravimetric analysis and nitrogen adsorption isotherm analysis were conducted to confirm the successful grafting of CS onto the surface of the Hal. The cumulative release ratio of urea from the Hal@CS in vitro after 96 h was 34.37% without glutathione (GSH). After introducing GSH the rate of release of urea from the Hal@CS increased. The uptake, translocation, and distribution of the Hal@CS in the epidermal layer and endodermis of root tissue were detected by fluorescence labeling and TEM. We conclude that Hal@CS are a potential controlled-release carrier and delivery system for agricultural fertilizers.
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PROGRESS IN ORGANIC COATINGS
·
2020
·
IF 4.469
Qian Gao,Min Lei,Kemeng Zhou,Xinliang Liu,Shuangfei Wang,Huimin Li
The objective of this research was to develop an effective and complete green approach for the production of composite films with enhanced antioxidant and antibacterial properties and oxygen barrier properties. This was accomplished by incorporating chitosan (CS) and polypyrrole (PPy) to microfibrillated by coasting method prepare MFC/CS/PPy film. The contact angle was used to evaluate poor water resistance, which increased from 94.1° to 122°. The contact angle of the composite film was further increased to 122° due to the chemical polymerization of pyrrole produces a layer of PPy nanoparticles on the surface of the MFC/CS composite film. The CS and PPy improved the uniformity of the surface and filled the pores, indicating that the channel has been blocked, resulting in significant reduction in oxygen transmission (32.38 cm 3 (m −2 ·day −1 ). The MFC/CS/PPy film showed bactericidal activity against Escherichia coli (5.43 log CFU mL −1 reduction) The synergistic effect of proton amino (in acidic medium) in CS with the positively charged PPy chain improves the antimicrobial performance of MFC/CS/PPy. The positive charges Ions may attach to the negatively charged bacterial cell wall, thus destroying the cell wall and eventually killing the bacteria. The composite films have good thermal stability. The ability of MFC/CS/PPy composite membrane to inhibit 2,2-diphenyl-1-picrylhydrazyl assay (DPPH) activity increases to 54 %. This property depends on the increased activity of the hydrogen atoms. Considering a series of current properties, MFC/CS/PPy composite film was successfully used in the active packing of fresh cherry tomatoes (10 days), effectively extending shelf life. Therefore, MFC/CS/PPy composite film has the potential to be used as biodegradable packaging materials for fresh fruits.
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INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2020
·
IF 5.162
Shuifang Mao,Xiaoli Liu,Wenshui Xia
In this study, chitosan oligosaccharide (COS) was modified by grafting Linalool (Lin) on its backbone to improve its anti-inflammatory activity. By changing the molar ratios of COS to Lin, three different degrees of substitution COS-g-Lin1-3 were prepared. The degrees of substitution of derivatives were 0.65, 0.80 and 1.14 respectively. The structure of COS-g-Lin1-3 were characterized by UV–vis, FT-IR, 1 H NMR and elemental analysis in order to show the COS-g-Lin1-3 successfully synthesized. Besides, the thermal stability , solubility, pH stability as well as crystallinity were also investigated. The results revealed that the derivatives exhibited higher thermal stability and more remarkable anti-inflammatory property against hyaluronidase and collagenase than that of COS. The good biocompatibility made this novel material a promising and effective compound for anti-inflammatory applications.
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