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Zhanyong Guo - One of the best experts on this subject based on the ideXlab platform.
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enhanced antifungal activity of novel Cationic Chitosan derivative bearing triphenylphosphonium salt via azide alkyne click reaction
International Journal of Biological Macromolecules, 2020Co-Authors: Wenqiang Tan, Jingjing Zhang, Fang Dong, Zhanyong GuoAbstract:Abstract As one of the most promising biopolymers for a variety of potential applications, Chitosan has attracted much attention because of its unique biological, chemical, and physical properties. The functionalization of Chitosan has been adopted to synthesize novel Chitosan derivatives with improved water-solubility and excellent biological activities. In this paper, Chitosan was functionalized with a triphenylphosphonium group by means of the copper (I) catalyzed azide-alkyne “click” reaction and has been investigated as potential polymer for agricultural antifungal biomaterial. The influence of chemical modification on the structural characteristics and water-solubility of Chitosan was investigated by FTIR spectroscopy, 1H NMR spectroscopy, elemental analysis, and UV–vis spectrum. Furthermore, the antifungal property of target Chitosan derivative against four plant threatening fungal pathogens was evaluated and in vitro investigation demonstrated that triphenylphosphonium salt incorporated Chitosan backbone had excellent antifungal property compared with Chitosan and intermediate Chitosan derivative. Notably, target Chitosan derivative displayed relatively strongest antifungal effect with over 80% inhibitory index against Botrytis cinerea at 1.0 mg/mL. The results of a detailed antifungal study indicated that Cationic Chitosan derivative bearing 1,2,3-triazole and triphenylphosphonium moieties provided a promising platform for preparation of novel Cationic antifungal biomaterials in the field of agriculture.
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synthesis characterization and evaluation of antifungal and antioxidant properties of Cationic Chitosan derivative via azide alkyne click reaction
International Journal of Biological Macromolecules, 2018Co-Authors: Wenqiang Tan, Jingjing Zhang, Fang Dong, Zhanyong GuoAbstract:Abstract In this work, quaternary ammonium group was introduced into Chitosan backbone by cuprous-catalyzed azide-alkyne cycloaddition (CuAAC) to synthesize the Cationic Chitosan derivative bearing 1,2,3-triazole. The products were identified structurally by FTIR, 1H NMR spectroscopy, XRD, and elemental analysis. The water solubility of Chitosan derivatives at different pH values was determined by a turbidity measurement. The antifungal properties of Cationic Chitosan derivatives against Botryis cinerea, Phomopsis asparagi, Fusarium oxysporum f. sp. niveum, and Fusarium oxysporum f. sp. cucumerium were evaluated using the radial growth assay. Besides, the antioxidant activities of them were also tested by superoxide-radical scavenging and reducing power assays. Compared to Chitosan, Cationic Chitosan derivative bearing 1,2,3-triazole showed the good water solubility especially at alkaline condition, excellent antifungal action with over 70% inhibitory indices against tested fungi at 1.0 mg/mL, and enhanced antioxidant activity with complete scavenging efficiency against superoxide-radical at 1.6 mg/mL because of the introduction of 1,2,3-triazole and quaternary ammonium moieties. These excellent biological properties present a promising prospect for this Chitosan derivative in antifungal and antioxidant biomaterials.
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novel Cationic Chitosan derivative bearing 1 2 3 triazolium and pyridinium synthesis characterization and antifungal property
Carbohydrate Polymers, 2018Co-Authors: Wenqiang Tan, Jingjing Zhang, Fang Dong, Fang Luan, Lijie Wei, Yuan Chen, Zhanyong GuoAbstract:Abstract In this paper, novel Cationic Chitosan derivative possessing 1,2,3-triazolium and pyridinium groups was synthesized conveniently via cuprous-catalyzed azide-alkyne cycloaddition (CuAAC) and methylation. FTIR, 1H NMR, and elemental analysis examined the structural characteristics of the synthesized derivatives. The antifungal efficiencies of Chitosan derivatives against three plant-threatening fungi were assayed by hypha measurement in vitro. The determination showed that Chitosan derivative bearing 1,2,3-triazolium and pyridinium displayed tremendously enhanced antifungal activity as compared with Chitosan and Chitosan derivative bearing 1,2,3-triazole and pyridine. Notably, the inhibitory indices of it against Colletotrichum lagenarium attained 98% above at 1.0 mg/mL. The results showed that N-methylation of 1,2,3-triazole and pyridine could effectively enhance antifungal activity of the synthesized Chitosan derivatives. Besides, the prepared Chitosan derivatives showed non-toxic effect on cucumber seedlings. This synthetic strategy might provide an effective way and notion to prepare novel Cationic Chitosan antifungal biomaterials.
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preparation and characterization of novel Cationic Chitosan derivatives bearing quaternary ammonium and phosphonium salts and assessment of their antifungal properties
Molecules, 2017Co-Authors: Wenqiang Tan, Fang Dong, Qiuhong Chen, Zhanyong GuoAbstract:Chitosan is an abundant and renewable polysaccharide, its derivatives exhibit attractive bioactivities and the wide applications in various biomedical fields. In this paper, two novel Cationic Chitosan derivatives modified with quaternary phosphonium salts were successfully synthesized via trimethylation, chloride acetylation, and quaternization with tricyclohexylphosphine and triphenylphosphine. The structures and properties of synthesized products in the reactions were characterized by FTIR spectroscopy, 1H-NMR, 31P-NMR, elemental and thermogravimetric analysis. The antifungal activities of Chitosan derivatives against four kinds of phytopathogens, including Phomopsis asparagi, Watermelon fusarium, Colletotrichum lagenarium, and Fusarium oxysporum were tested using the radial growth assay in vitro. The results revealed that the synthesized Cationic Chitosan derivatives showed significantly improved antifungal efficiency compared to Chitosan. It was reasonably suggested that quaternary phosphonium groups enabled the obviously stronger antifungal activity of the synthesized Chitosans. Especially, the triphenylphosphonium-functionalized Chitosan derivative inhibited the growth of Phomopsis asparagi most effectively, with inhibitory indices of about 80% at 0.5 mg/mL. Moreover, the data demonstrated that the substituted groups with stronger electron-withdrawing ability relatively possessed greater antifungal activity. The results suggest the possibility that Cationic Chitosan derivatives bearing quaternary phosphonium salts could be effectively employed as novel antifungal biomaterials for application in the field of agriculture.
Christine Allen - One of the best experts on this subject based on the ideXlab platform.
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Intermolecular Interactions and Morphology of Aqueous Polymer/Surfactant Mixtures Containing Cationic Chitosan and Nonionic Sorbitan Esters
Biomacromolecules, 2008Co-Authors: Justin Grant, Christine AllenAbstract:In this study, the impact of surfactant molecular composition (saturated sorbitan monolaurate or unsaturated sorbitan monooleate) on polymer/surfactant assemblies was examined. Specifically, the associations between the Cationic Chitosan and the uncharged surfactants were monitored by surface tension, turbidity, and conductivity measurements. Bright field, confocal laser scanning, and transmission electron microscopy revealed that nanometer-sized Chitosan/surfactant aggregates comprised of a Chitosan-rich shell and a Chitosan-poor core agglomerate at high surfactant concentrations to yield micrometer-scaled supramolecular structures with highly ordered internal structure. The size and architecture of these Chitosan/surfactant assemblies were dependent on the structure and concentration of the surfactant employed. The association mechanism among Chitosan, surfactant, and the Chitosan/surfactant aggregates was discussed in terms of the semirigid polyelectrolyte character of Chitosan and the hydrophobic char...
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intermolecular interactions and morphology of aqueous polymer surfactant mixtures containing Cationic Chitosan and nonionic sorbitan esters
Biomacromolecules, 2008Co-Authors: Justin Grant, Helen Lee, Roger C W Liu, Christine AllenAbstract:In this study, the impact of surfactant molecular composition (saturated sorbitan monolaurate or unsaturated sorbitan monooleate) on polymer/surfactant assemblies was examined. Specifically, the associations between the Cationic Chitosan and the uncharged surfactants were monitored by surface tension, turbidity, and conductivity measurements. Bright field, confocal laser scanning, and transmission electron microscopy revealed that nanometer-sized Chitosan/surfactant aggregates comprised of a Chitosan-rich shell and a Chitosan-poor core agglomerate at high surfactant concentrations to yield micrometer-scaled supramolecular structures with highly ordered internal structure. The size and architecture of these Chitosan/surfactant assemblies were dependent on the structure and concentration of the surfactant employed. The association mechanism among Chitosan, surfactant, and the Chitosan/surfactant aggregates was discussed in terms of the semirigid polyelectrolyte character of Chitosan and the hydrophobic char...
Wenqiang Tan - One of the best experts on this subject based on the ideXlab platform.
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enhanced antifungal activity of novel Cationic Chitosan derivative bearing triphenylphosphonium salt via azide alkyne click reaction
International Journal of Biological Macromolecules, 2020Co-Authors: Wenqiang Tan, Jingjing Zhang, Fang Dong, Zhanyong GuoAbstract:Abstract As one of the most promising biopolymers for a variety of potential applications, Chitosan has attracted much attention because of its unique biological, chemical, and physical properties. The functionalization of Chitosan has been adopted to synthesize novel Chitosan derivatives with improved water-solubility and excellent biological activities. In this paper, Chitosan was functionalized with a triphenylphosphonium group by means of the copper (I) catalyzed azide-alkyne “click” reaction and has been investigated as potential polymer for agricultural antifungal biomaterial. The influence of chemical modification on the structural characteristics and water-solubility of Chitosan was investigated by FTIR spectroscopy, 1H NMR spectroscopy, elemental analysis, and UV–vis spectrum. Furthermore, the antifungal property of target Chitosan derivative against four plant threatening fungal pathogens was evaluated and in vitro investigation demonstrated that triphenylphosphonium salt incorporated Chitosan backbone had excellent antifungal property compared with Chitosan and intermediate Chitosan derivative. Notably, target Chitosan derivative displayed relatively strongest antifungal effect with over 80% inhibitory index against Botrytis cinerea at 1.0 mg/mL. The results of a detailed antifungal study indicated that Cationic Chitosan derivative bearing 1,2,3-triazole and triphenylphosphonium moieties provided a promising platform for preparation of novel Cationic antifungal biomaterials in the field of agriculture.
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synthesis characterization and evaluation of antifungal and antioxidant properties of Cationic Chitosan derivative via azide alkyne click reaction
International Journal of Biological Macromolecules, 2018Co-Authors: Wenqiang Tan, Jingjing Zhang, Fang Dong, Zhanyong GuoAbstract:Abstract In this work, quaternary ammonium group was introduced into Chitosan backbone by cuprous-catalyzed azide-alkyne cycloaddition (CuAAC) to synthesize the Cationic Chitosan derivative bearing 1,2,3-triazole. The products were identified structurally by FTIR, 1H NMR spectroscopy, XRD, and elemental analysis. The water solubility of Chitosan derivatives at different pH values was determined by a turbidity measurement. The antifungal properties of Cationic Chitosan derivatives against Botryis cinerea, Phomopsis asparagi, Fusarium oxysporum f. sp. niveum, and Fusarium oxysporum f. sp. cucumerium were evaluated using the radial growth assay. Besides, the antioxidant activities of them were also tested by superoxide-radical scavenging and reducing power assays. Compared to Chitosan, Cationic Chitosan derivative bearing 1,2,3-triazole showed the good water solubility especially at alkaline condition, excellent antifungal action with over 70% inhibitory indices against tested fungi at 1.0 mg/mL, and enhanced antioxidant activity with complete scavenging efficiency against superoxide-radical at 1.6 mg/mL because of the introduction of 1,2,3-triazole and quaternary ammonium moieties. These excellent biological properties present a promising prospect for this Chitosan derivative in antifungal and antioxidant biomaterials.
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novel Cationic Chitosan derivative bearing 1 2 3 triazolium and pyridinium synthesis characterization and antifungal property
Carbohydrate Polymers, 2018Co-Authors: Wenqiang Tan, Jingjing Zhang, Fang Dong, Fang Luan, Lijie Wei, Yuan Chen, Zhanyong GuoAbstract:Abstract In this paper, novel Cationic Chitosan derivative possessing 1,2,3-triazolium and pyridinium groups was synthesized conveniently via cuprous-catalyzed azide-alkyne cycloaddition (CuAAC) and methylation. FTIR, 1H NMR, and elemental analysis examined the structural characteristics of the synthesized derivatives. The antifungal efficiencies of Chitosan derivatives against three plant-threatening fungi were assayed by hypha measurement in vitro. The determination showed that Chitosan derivative bearing 1,2,3-triazolium and pyridinium displayed tremendously enhanced antifungal activity as compared with Chitosan and Chitosan derivative bearing 1,2,3-triazole and pyridine. Notably, the inhibitory indices of it against Colletotrichum lagenarium attained 98% above at 1.0 mg/mL. The results showed that N-methylation of 1,2,3-triazole and pyridine could effectively enhance antifungal activity of the synthesized Chitosan derivatives. Besides, the prepared Chitosan derivatives showed non-toxic effect on cucumber seedlings. This synthetic strategy might provide an effective way and notion to prepare novel Cationic Chitosan antifungal biomaterials.
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preparation and characterization of novel Cationic Chitosan derivatives bearing quaternary ammonium and phosphonium salts and assessment of their antifungal properties
Molecules, 2017Co-Authors: Wenqiang Tan, Fang Dong, Qiuhong Chen, Zhanyong GuoAbstract:Chitosan is an abundant and renewable polysaccharide, its derivatives exhibit attractive bioactivities and the wide applications in various biomedical fields. In this paper, two novel Cationic Chitosan derivatives modified with quaternary phosphonium salts were successfully synthesized via trimethylation, chloride acetylation, and quaternization with tricyclohexylphosphine and triphenylphosphine. The structures and properties of synthesized products in the reactions were characterized by FTIR spectroscopy, 1H-NMR, 31P-NMR, elemental and thermogravimetric analysis. The antifungal activities of Chitosan derivatives against four kinds of phytopathogens, including Phomopsis asparagi, Watermelon fusarium, Colletotrichum lagenarium, and Fusarium oxysporum were tested using the radial growth assay in vitro. The results revealed that the synthesized Cationic Chitosan derivatives showed significantly improved antifungal efficiency compared to Chitosan. It was reasonably suggested that quaternary phosphonium groups enabled the obviously stronger antifungal activity of the synthesized Chitosans. Especially, the triphenylphosphonium-functionalized Chitosan derivative inhibited the growth of Phomopsis asparagi most effectively, with inhibitory indices of about 80% at 0.5 mg/mL. Moreover, the data demonstrated that the substituted groups with stronger electron-withdrawing ability relatively possessed greater antifungal activity. The results suggest the possibility that Cationic Chitosan derivatives bearing quaternary phosphonium salts could be effectively employed as novel antifungal biomaterials for application in the field of agriculture.
Lars Wågberg - One of the best experts on this subject based on the ideXlab platform.
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Superior Flame-Resistant Cellulose Nanofibril Aerogels Modified with Hybrid Layer-by-Layer Coatings
ACS Applied Materials & Interfaces, 2017Co-Authors: Oruç Köklükaya, Federico Carosio, Lars WågbergAbstract:Nanometer thin films consisting of Cationic Chitosan (Ch), anionic poly(vinylphosphonic acid) (PVPA), and anionic montmorillonite clay (MMT) are deposited on highly porous, wet-stabilized cellulose nanofibril (CNF) aerogels via the layer-by-layer (LbL) technique. Model experiments with silicon oxide surfaces are used to study the details of LbL formation and the multilayer structure. Formation of layers on the aerogels is also investigated as a function of solution concentration by use of polyelectrolyte titration. Thermogravimetric analysis indicates that the LbL coating significantly improves thermal stability of the CNF aerogel. Horizontal flame test shows that aerogels coated with five quadlayers of Ch/PVPA/Ch/MMT, using solutions/dispersion of high concentration, are able to self-extinguish immediately after removal of flame, and LbL-coated aerogels do not ignite under heat flux (35 kW/m2) in cone calorimetry. The LbL-coated aerogel can prevent flame penetration from a torch focused on the surface, a...
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flame retardant paper from wood fibers functionalized via layer by layer assembly
ACS Applied Materials & Interfaces, 2015Co-Authors: Oruç Köklükaya, Federico Carosio, Jaime C Grunlan, Lars WågbergAbstract:The highly flammable character of cellulose-rich fibers from wood limits their use in some advanced materials. To suppress the flammability and introduce flame-retardant properties to individual pulp fibers, we deposited nanometer thin films consisting of Cationic Chitosan (CH) and anionic poly(vinylphosphonic acid) (PVPA) on fibers using the layer-by-layer (LbL) technique. The buildup of the multilayer film was investigated in the presence and absence of salt (NaCl) using model cellulose surfaces and a quartz crystal microbalance technique. Fibers were then treated with the same strategy, and the treated fibers were used to prepare paper sheets. A horizontal flame test (HFT) and cone calorimetry were conducted to evaluate the combustion behavior of paper sheets as a function of the number of bilayers deposited on fibers. In HFT, paper made of fibers coated with 20 CH/PVPA bilayers (BL), self-extinguished the flame, while uncoated fibers were completely consumed. Scanning electron microscopy of charred pa...
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flame retardant paper from wood fibers functionalized via layer by layer assembly
ACS Applied Materials & Interfaces, 2015Co-Authors: Oruç Köklükaya, Federico Carosio, Jaime C Grunlan, Lars WågbergAbstract:The highly flammable character of cellulose-rich fibers from wood limits their use in some advanced materials. To suppress the flammability and introduce flame-retardant properties to individual pulp fibers, we deposited nanometer thin films consisting of Cationic Chitosan (CH) and anionic poly(vinylphosphonic acid) (PVPA) on fibers using the layer-by-layer (LbL) technique. The buildup of the multilayer film was investigated in the presence and absence of salt (NaCl) using model cellulose surfaces and a quartz crystal microbalance technique. Fibers were then treated with the same strategy, and the treated fibers were used to prepare paper sheets. A horizontal flame test (HFT) and cone calorimetry were conducted to evaluate the combustion behavior of paper sheets as a function of the number of bilayers deposited on fibers. In HFT, paper made of fibers coated with 20 CH/PVPA bilayers (BL), self-extinguished the flame, while uncoated fibers were completely consumed. Scanning electron microscopy of charred paper after HFT revealed that a thin shell of the charred polymeric multilayer remained after the cellulose fibers had been completely oxidized. Cone calorimetry demonstrated that the phosphorus-containing thin films (20 BL is ∼25 nm) reduced the peak heat release rate by 49%. This study identifies a unique and highly effective way to impart flame-retardant characteristic to pulp fibers and the papers made from these fibers.
Xiaowen Zhao - One of the best experts on this subject based on the ideXlab platform.
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controlled ph and glucose responsive drug release behavior of Cationic Chitosan based nano composite hydrogels by using graphene oxide as drug nanocarrier
Journal of Industrial and Engineering Chemistry, 2017Co-Authors: Xiaowen Zhao, Xue ZouAbstract:Abstract To realize tight control of hyperglycemia for diabetic patients, Cationic Chitosan (HTCC) based nano-composite hydrogels were prepared by using graphene oxide (GO) as nano-carrier for the model drug (bovine serum albumin, BSA). BSA intercalated into the layers of GO and the intercalation process was mainly driven by the mutual electrostatic interaction. By introducing GO-BSA, a more compact GO-centered network structure formed for the hydrogel. Compared with HTCC/BSA, HTCC/2.0wt%GO-BSA hydrogels exhibited a more distinct pH-/glucose-sensitivity and a much lower initial burst release, which was attributed to the compact structure and strong interactions among HTCC, GO and BSA in the hydrogel system.
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synthesis of hydrophobic Cationic Chitosan flocculant and its sludge dewatering property
Journal of Macromolecular Science Part B, 2016Co-Authors: Peng Huang, Xiaowen ZhaoAbstract:ABSTRACTThe hydrophobic Cationic Chitosan (HTCC) flocculant was synthesized by reacting Chitosan with epoxy propyl trimethyl ammonium chloride (EPTAC) and (2,3-epoxy propyl) dodecyl dimethyl ammonium chloride (EDC), to improve its waste sludge dewaterability. By FTIR and 1H NMR analysis, EPTAC and EDC were confirmed to be grafted onto the molecular chains of Chitosan (CTS) successfully. With the increase of EDC content, G′ of HTCC aqueous solution with 1:1.5:1.5 mole ratio of CTS:EPTAC:EDC consistently showed higher values than G″ over the entire frequency range explored, indicating the formation of a physically cross-linked network. The crystallization ability of HTCC decreased compared with pristine CTS. The long alkyl chains on the EDC molecules enhanced the hydrophobicity of HTCC, and better dewaterability of the waste sludge was achieved through the promoted bridging action of HTCC.
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synthesis of Cationic Chitosan hydrogel with long chain alkyl and its controlled glucose responsive drug delivery behavior
RSC Advances, 2015Co-Authors: Xue Zou, Xiaowen ZhaoAbstract:A novel glucose-responsive controlled drug release system based on Cationic Chitosan derivative (HDCC) with long chain alkyl was synthesized by etherification with glycidyl trimethylammonium chloride (GTMAC) and (2,3-epoxypropoxy) dodecyldimethylammonium chloride (EDC). The composition of HDCC was characterized by FTIR and 1H NMR analysis. An improved water solubility and a relatively wide pH buffering path can be achieved for HDCC. With increasing substitution degree of long chain alkyl groups (DSA) of HDCC hydrogels, the modulus and crosslinking density increased, while the swelling ratios decreased, suggesting the formation of a more compact structure due to the physical entanglement of the long alkyl chains. The encapsulation efficiency (EE) and drug loading capacity (LC) of HDCC hydrogels increased with increasing DSA, suggesting the enhancement of interactions between the long alkyl chains and bovine serum albumin (BSA). By increasing the pH value from 6.8 to 7.4, a considerable decrease in cumulative release was observed for all hydrogels because the acidic environment could promote the hydrolysis of their Cationic groups. Introduction of long alkyl chains slowed down the initial burst release rate of the hydrogels and better pH and glucose sensitive release behavior of BSA and insulin can be observed. Drug release kinetic data under different pH values and glucose concentrations for BSA-loaded hydrogels presented an almost Fickian release behavior, and the kinetic constant k decreased with increasing DSA, indicating that HDCC hydrogels may achieve a better slow-release effect.
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synthesis of Cationic Chitosan hydrogel and its controlled glucose responsive drug release behavior
Chemical Engineering Journal, 2015Co-Authors: Xue Zou, Xiaowen ZhaoAbstract:A novel glucose-responsive controlled drug release system based on pH sensitive Cationic Chitosan hydrogel (HTCC) with different degree of substitution (DS) was successfully prepared. The composition and structure of HTCC were analyzed by FTIR, 1H NMR and rheological evaluation. With increasing DS of HTCC hydrogels, the network mesh size (Lc) increased and the crosslinking density decreased, and in the meantime the swelling ratio and pH-sensitivity of the hydrogel increased. In a narrow pH variation range (pH-6.8 to 7.4), a considerable difference in the cumulative release of BSA was observed with distinct sensitivity, while the resulting electrostatic repulsion between the protonated Cationic groups of the hydrogel with high zeta potentials weakened the inter- and intra-molecular hydrogen bonding of HTCC molecules, and much loose network structure formed at subacid environment. HTCC hydrogels presented an obvious glucose concentration-dependent response release behavior, and the steplike release behavior for incremental doses of glucose clearly showed the versatility of the system to respond to the sequential addition of glucose. Korsmeyer–Peppas model was used for describing BSA release kinetics of HTCC hydrogels under different pH values and glucose concentrations, which corresponded to a Fickian release behavior.