CARBOHYDRATE POLYMERS
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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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CARBOHYDRATE POLYMERS
·
2021
·
IF 9.381
Yahao Dong,Jiajun Bi,Shujun Ming,Shoute Zhang,Dajian Zhu,Di Meng,Tao Li
Chitosan is a versatile polysaccharide in different domains due to facile modification and good biodegradability. In this paper, taking advantage of such functional properties, we have developed a stabilizer agent [OCMCS-SB] produced from chitosan, and palladium was successfully immobilized on this designed stabilizer [OCMCS-SB-Pd(II)]. The obtained complex was illuminated by 13 C CP-MAS NMR, FT-IR, TGA, XRD, XPS, SEM, TEM and ICP-OES analyses. Due to the interactions of primary hydroxyl groups on chitosan, Schiff base and carboxy groups, the Pd complex showed excellent reactivity (up to 99 %) and stability towards Suzuki reactions in eco-friendly medium. Subsequently, the reusability experiments for OCMCS-SB-Pd(II) formed from chitosan were examined in five consecutive cycles, which showed no appreciable decrease in activity. Furthermore, a reasonably trifunctional complex structure was proposed. The present bio-based system offers a promising approach in utilizing such biopolymers in organic transformations.
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APPLIED CLAY SCIENCE
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2020
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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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Nanomaterials
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2020
·Vol. 10
·期 3
·559
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IF 4.324
Lei Li
Bionanocomposite has promising biomemristic behaviors for data storage inspired by a natural biomaterial matrix. Carboxylated chitosan (CCS), a water-soluble derivative of chitosan avoiding the acidic salt removal, has better biodegradability and bioactivity, and is able to absorb graphene quantum dots (GQDs) employed as charge-trapping centers. In this investigation, biomemristic devices based on water-soluble CCS:GQDs nanocomposites were successfully achieved with the aid of the spin-casting method. The promotion of binary biomemristic behaviors for Ni/CCS:GQDs/indium-tin-oxide (ITO) was evaluated for distinct weight ratios of the chemical components. Fourier transform infrared spectroscopy, Raman spectroscopy (temperature dependence), thermogravimetric analyses and scanning electron microscopy were performed to assess the nature of the CCS:GQDs nanocomposites. The fitting curves on the experimental data further confirmed that the conduction mechanism might be attributed to charge trapping–detrapping in the CCS:GQDs nanocomposite film. Advances in water-soluble CCS-based electronic devices would open new avenues in the biocompatibility and integration of high-performance biointegrated electronics.Keywords:biomemristic behavior;water-soluble CCS:GQDs nanocomposites;CCS-based binary biomemory
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CARBOHYDRATE POLYMERS
·
2020
·
IF 7.182
Hangyue Zhao,Lei Wang,Tarun Belwal,Yunhong Jiang,Dong Li,Yanqun Xu,Zisheng Luo,Li Li
This work was designed to develop the chitosan-based melatonin layer-by-layer assembly (CMLLA) via the inclusion method. The structural characterizations and interaction present in CMLLA were investigated by the scanning electron microscope (SEM), X-ray diffraction (XRD) and Fourier Transform-Infrared spectroscopy (FTIR). The ratio of chitosan (CH) to carboxymethylcellulose (CMC) greatly influenced the mechanical properties, including the tensile strength, moisture content and color performance. Results showed that both antioxidant and antimicrobial properties of CMLLA were enhanced with the addition of melatonin (MLT). Furthermore, it was demonstrated that the CMLLA with 1.2 % (w/v) CH, 0.8 % (w/v) CMC and 50 mg/L MLT better contributed to the delay of chlorophyll degradation and the maintenance of shelf-life quality. Results from this study might open up new insights into the approaches of quality improvement of postharvest fresh products by incorporating the natural antioxidant compounds into natural polymers.
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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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CARBOHYDRATE POLYMERS
·
2020
·
IF 7.182
C.Q. Zhao,W.G. Liu,Z.Y. Xu,J.G. Li,T.T. Huang,Y.J. Lu,H.G. Huang,J.X. Lin
Three kinds of methods based on extrusion and 3D printing and different acidic solutions (formic acid (FA), acetic acid (AA), glycolic acid (GA) and lactic acid (LA)) were applied for manufacturing the CS ducts. The tensile properties and preliminary cytotoxicity were measured for selecting the optimal ratio of CS slurry. The 3D printability of CS slurry was also studied. The tensile strength, Young’s modulus, and fracture strain were tested for evaluating the degree of mechanical matching to soft-tissue. The optimal solvent to CS was 30 wt.% GA solution. The CS slurry possessing shear-thinning properties was suitable for 3D printing. The tensile strength, Young’s modulus, and fracture strain of the CS rods were 10.98 ± 0.61 MPa, 12.38 ± 1.19 MPa, and 146.03 ± 15.05 %, correspondingly. The CS ducts manufactured by 3D printing had an excellent mechanical matching to soft-tissue, outstanding biocompatibility and have great potential for soft-tissue restorations.
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INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2020
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IF 5.162
A.A. Menazea,M.M. Eid,M.K. Ahmed
With the increase of antibiotic resistance currently available at an alarming rate, new improved films of Chitosan (CS) have been achieved with different levels of Tigecycline (TIGE) using traditional casting technology. The structural, optical, and morphological characterizations of the prepared (CS/TIGE) composites were investigated using XRD, FT-IR, UV–visible, and FE-SEM. Also, the antibacterial characterization was investigated. XRD pattern shows a semi-crystalline peak at 2θ = 21° begins to appear at Cs/TIGE2 concentration and its intensity increase with increasing TIGE concentration which indicate the interaction between TIGE and Cs. FT-IR reveals conservation of the distinctive bands with change in both intensity and position that attributed to increase the ratios of TIGE in Chitosan. UV–vis spectra confirmed the interaction of the CS and the drug TIGE. FE-SEM photos confirm the increasing of TIGE particles on the surface of CS/TIGE films by increasing the ratios of TIGE. The antimicrobial effect of Chitosan and five different ratios of Chitosan with TIGE have been identified against four different bacterial species, two gram-negative ( Escherichia coli , Bacillus subtilis) and two gram-positive bacteria ( Staphylococcus aureus , Pseudomonas aeruginosa ). The obtained results indicated that the composite Cs/TIGE can be used in many antimicrobial applications because of its greatly antimicrobial activity .
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POLYMER BULLETIN
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2020
·Vol. 78
·期 7
·3785-3801
·
IF 2.014
Ma Yu,Wang Lulu,Feng Ruijiang,Wang Jilin,Cai Tianzhou
In this study, we prepared a novel composite membrane (QCS-IRMOF-3) by attaching IRMOF-3 (metal–organic framework materials, formed by coordination of metallic zinc and 2-aminoterephthalic acid) with a free amino group to a quaternized chitosan (QCS) by chemical cross-linking. The successful synthesis of IRMOF-3 was verified by SEM, XRD, and FT-IR. Then, the mechanical properties, swelling properties, ion exchange capacity, hydroxide conductivity and chemical stability of the composite membrane (QCS-IRMOF-3) were also investigated. It was found that the performance of the aforementioned composite membrane was affected obviously by the amount of IRMOF-3 crystals. The composite membrane doped with 15 wt% IRMOF-3 crystals exhibits better overall performance, which included that the tensile strength is 22.4 MPa, water uptake is 78.4%, hydroxide conductivity is 29.9 mS cm −1 at 80 °C, and after immersion in 6.0 mol L −1 KOH solutions at 60 °C for about 240 h, only the conductivity decreased by less than 10%. This result implies that the composite membrane synthesized in this research is promising for application in alkaline polymer electrolyte fuel cells.
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INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2020
·
IF 5.162
Tarig Elshaarani,Haojie Yu,Li Wang,Jingyi Feng,Chengjiang Li,Weibin Zhou,Amin Khan,Muhammad Usman,Bilal Ul Amin,Rizwan Khan
Different hydrogels of poly(acrylamide- co -3-acrylamido phenylboronic acid- co -chitosan grafted maleic acid) (P(AM- co -AAPBA- co -CSMA)s) were synthesized using poly(ethylene glycol) diacrylate (PEGDA) as a crosslinker to serve for glucose sensing and insulin delivery. The structure and morphology of the hydrogels, named as CSPBA were studied by FTIR and SEM, while the mechanical properties were tested using dynamic mechanical analysis (DMA) and universal testing machine. The prepared hydrogels shrinked at low glucose concentration due to the 2:1 boronate-glucose binding, and swelled at high glucose concentration because of 1:1 boronate-glucose complexation. Both binding mechanisms are useful for glucose sensing and insulin delivery. The integration of CSMA into hydrogels network not only enhanced the response to glucose at physiological pH, but also improved the mechanical properties and increased the encapsulation efficiency of the prepared hydrogels. These CSPBA may find potential as implantable hydrogels in applications were continuous glucose monitoring and controlled release is beneficial.
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PROGRESS IN ORGANIC COATINGS
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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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Scientific Reports
·
2020
·Vol. 10
·期 1
·1-9
·
IF 3.998
Mei Lin,Xu Zhenlong,Shi Yanmei,Lin Chunlei,Jiao Shuyan,Zhang Lijun,Li Pengxu
Chitosan oligosaccharide functionalized silver nanoparticles with synergistic bacterial activity were constructed as a multivalent inhibitor of bacteria. Placing the chitosan oligosaccharide on silver nanoparticles can dramatically enhance the adsorption to the bacterial membrane via multivalent binding. The multicomponent nanostructures can cooperate synergistically against gram-positive and gram-negative bacteria. The antibacterial activity was increased via orthogonal array design to optimize the synthesis condition. The synergistic bacterial activity was confirmed by fractional inhibitory concentration and zone of inhibition test. Through studies of antimicrobial action mechanism, it was found that the nanocomposites interacted with the bacteria by binding to Mg 2+ ions of the bacterial surface. Then, the nanocomposites disrupted bacterial membrane by increasing the permeability of the outer membrane, resulting in leakage of cytoplasm. This strategy of chitosan oligosaccharide modification can increase the antibacterial activity of silver nanoparticles and accelerate wound healing at the same time. The nanomaterial without cytotoxicity has promising applications in bacteria-infected wound healing therapy.
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