Biomed Research International
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2016
·
IF 2.134
Yan Li,Song Liu,Yukun Qin,Ronge Xing,Xiaolin Chen,Kecheng Li,Pengcheng Li
In this study, three pyrimethanil grafted chitosan (PML-g-CS) derivatives were obtained. The structures of the conjugates were confirmed by FT-IR, 1H NMR, and EA. The grafting ratios were measured by HPLC. Antifungal properties of pyrimethanil grafted chitosan (PML-g-CS) derivatives against the plant pathogenic fungi Rhizoctonia solani and Gibberella zeae were investigated at concentrations of 100, 200, and 400 mg/L. The PML-g-CS derivatives showed enhanced antifungal activity in comparison with chitosan. The PML-g-CS-1 showed the best antifungal activity against R. solani, whose antifungal index was 58.32%. The PML-g-CS-2 showed the best antifungal activity against G. zeae, whose antifungal index was 53.48%. The conjugation of chitosan and pyrimethanil showed synergistic effect. The PML-g-CS derivatives we developed showed potential for further study and application in crop protection.
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高影响因子
POLYMER ENGINEERING AND SCIENCE
·
2016
·Vol. 56
·期 12
·1432-1436
·
IF 1.719
Shiping Zhan,Nan Liu,Weijing Wang,Shuhua Chen,Jingchang Wang
To improve the properties of chitosan (CS) and poly(L-lactic acid) (PLLA) and obtain fully biodegradable materials, CS- g -PLLA copolymers were prepared using 1-(3-Dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC)/N-hydroxyl succinimide (NHS) as a coupling agent. The copolymers were characterized by Fourier transform infrared analysis (FTIR), 1 H nuclear magnetic resonance ( 1 H NMR), elemental analysis, differential scanning calorimetry (DSC), X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results obtained by FTIR and 1 H NMR showed that CS and PLLA were grafted successfully via an amide bond. DSC and XRD results showed that the thermal stability of CS had been significantly improved by grafting PLLA to the molecular chains of CS and the crystallinity of the CS- g -PLLA copolymers decreased significantly. Elemental analysis showed that the achieved the maximum degree of substitution of PLLA was 60.88%, while the concentration of CS was 2 mg/mL, the PLLA molecular weight was 10,000, and the EDC/NHS ratio was 2:1. Images from SEM demonstrated that the copolymers had a spherical shape and smooth surface. Moreover, the products were well dispersed without any aggregation. POLYM. ENG. SCI., 56:1432–1436, 2016. © 2016 Society of Plastics Engineers
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JOURNAL OF MEMBRANE SCIENCE
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2016
·
IF 5.557
Xiao-Hua Ma,Zhe Yang,Zhi-Kan Yao,Zhen-Liang Xu,Chuyang Y. Tang
A novel positively charged nanofiltration (NF) membrane was fabricated by incorporating metal-organic frameworks (MOFs) into chitosan polymeric matrix for enhanced removal of multivalent cations. The synthesized MOFs, NH 2 -MIL-101(Al) and NH 2 -MIL-101(Cr), could be homogeneously dispersed in the chitosan polymeric matrix. The morphologies of MOFs had a significant influence on the permeability of NF membranes. NF membrane filled with NH 2 -MIL-101(Al) with rod-like structure attained two times higher flux but similar rejection compared with that filled with NH 2 -MIL-101(Cr) with grainy structure. The effect of MOF loadings (NH 2 -MIL-101(Al)) on the membrane performance were evaluated by XRD , FTIR and SEM. These positively charged MOF/chitosan NF membranes were able to reject up to 93.0% of MgCl 2 , and the salt rejection followed the order of MgCl 2 >CaCl 2 >NaCl>Na 2 SO 4 .
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Frontiers in Bioengineering and Biotechnology
·
2024
·
IF 4.3
Chen Xiaohua,Liu Hengyu,Zhang Qianqian,Chen Xuehua,Wang Lihui,Yu Yanling,Hao Yuanping
Acidic bacterial biofilms-associated enamel white spot lesions (WSLs) are one of the hallmarks of early caries, causing demineralization and decomposition of dental hard tissues. Therefore, to effectively prevent and treat WSLs, it is important to inhibit the activity of cariogenic bacteria while promoting the remineralization of demineralized enamel. Amorphous calcium phosphate (ACP) favors hard tissue remineralization due to its biological activity and ability to release large amounts of Ca2+ and PO43-. However, ACP-based biomineralization technology is not effective due to its lack of antimicrobial properties. Here, carboxymethyl chitosan (CMCS) was employed as a reducing agent and stabilizer, and dual-functional nanohybrids CMCS/AuNPs/ACP with biofilm resistance and mineralization properties were successfully synthesized. The addition of AuNPs enhances the antimicrobial activity and participates in regulating the formation of hydroxyapatite (HAp). The nanohybrids exhibited significant destructive effects against cariogenic bacteria and their biofilms and showed bactericidal activity under bacteria-induced acidic conditions. More importantly, this nanohybrids showed superior results in promoting the remineralization of demineralized enamel, compared to fluoride and CMCS/ACP in vitro. The CMCS/AuNPs/ACP nanohybrids not only reverse the cariogenic microenvironment at the microbial level, but also promote self-repairing of enamel WSLs regarding the microstructure. The present work offers a theoretical and experimental basis for using the CMCS/AuNPs/ACP nanohybrids as a potential dual-functional agent for the clinical treatment of enamel WSLs.
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INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2024
·
IF 7.7
Ding Wang,Yaoqing Chu,Shuiping Liu,Lianjiang Tan
Vessel normalization has proved imperative in tumor growth inhibition. In this work, biopolymer-based hybrid nanospheres capable of normalizing blood vessels were designed to improve the therapeutic effect of chemotherapeutic drugs. Zn 0.4 Fe 2.6 O 4 nanoparticles (ZFO NPs) were synthesized, and were encapsulated in cross-inked chitosan (CS) along with a nitric oxide (NO) precursor, DETA NONOate, forming hybrid ZFO/NO@CS nanospheres highly stable in physiological environment. The structure, morphology and size of the nanospheres were characterized. The ZFO/NO@CS nanospheres could release NO under acidic conditions typical of intratumoral and intracellular environment. The results of related factors expression, wound healing and tube formation assays demonstrated that both the encapsulated ZFO NPs and the released NO were able to inhibit angiogenesis in tumors. The ZFO/NO@CS nanospheres enhanced the antitumor efficacy of the chemotherapeutic drug DOX by normalizing tumor vessels, as evidenced by in vivo experiments for CT26 tumor-bearing mice. By analyzing the contents of Fe in the tumor and different organs, the nanospheres were found to accumulate primarily at the tumor site. The blood analysis showed little side effect of the nanospheres. The ZFO/NO@CS nanospheres have great potential in improving tumor therapeutic effect when used in combination with chemotherapeutic drugs.
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INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
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2024
·Vol. 25
·期 15
·8125
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IF 4.9
Taoyang Cai,Shangjie Ge-Zhang,Chang Zhang,Pingxuan Mu,Jingang Cui
Transparent films with excellent antibacterial properties and strong mechanical properties are highly sought after in packaging applications. In this study, Ag/SiO2nanoparticles were introduced into a mixed solution of chitosan (CS) and polyvinyl alcohol (PVA) and a Ag/SiO2-CS-PVA transparent film was developed. The excellent properties of the film were confirmed by light transmittance, water contact angle tests and tensile tests. In addition, for the antibacterial test, the antibacterial properties of the sample against Gram-negative bacteria (Escherichia coli) and Gram-positive bacteria (Staphylococcus aureus) were explored, and the average size of the bacteriostatic circle was measured by the cross method. The final results show that Ag/SiO2-CS-PVA transparent film has the advantages of good antibacterial properties, high transparency and high mechanical strength.
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Nanoscale
·
2024
·
IF 5.8
Xiaodong Yu,Jihao Fan,Shengquan Zheng,Linlin Ma,Xiaojing Liu,Yue Wu,Chuangqi Zhao,Lei Jiang
High strength/toughness nanocomposites are increasingly in demand due to the development needs of high-end applications. However, the aggregation and random orientation of nanofillers and the weak crosslinking of the polymer matrix lead to the degradation of the mechanical properties of nanocomposites. Here, we present a strategy to prepare chitosan-based nanocomposites with aligned nanosheets via the in situ photo-crosslinking of modified chitosan. The well-dispersed and highly aligned nanosheets, as well as the dense covalently crosslinked network between the modified chitosan chains, effectively improve the mechanical properties of the prepared nanocomposites. For example, the chitosan-based nanocomposite films exhibit a tensile strength of up to 340.6 ± 13.4 MPa, a Young's modulus of 8.2 ± 0.2 GPa and a toughness of 22.0 ± 2.5 MJ m−3, which are 4.2, 4.8 and 1.8 times higher, respectively, than those of pure chitosan films. Moreover, the thermal decomposition temperature of the chitosan-based nanocomposite films reaches 286.8 °C, which is 48.5 °C higher than that of pure chitosan films. We consider that our strategy, which constructs a crosslinked chitosan structure with aligned nanofillers, could lead to the development and application of the bio-based composites with excellent mechanical properties.
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BIOMACROMOLECULES
·
2025
·
IF 5.4
Hongyan Wang,Lin Shi,Zhongxu Zhang,Long Chen,Xinli Xu,Weiwei Ding,Chuntao Chen,Dongping Sun
Managing uncontrolled and noncompressible bleeding presents a major challenge in emergency trauma care. Methods to halt bleeding quickly and efficiently, without applying direct pressure on the wound, have become a key focus of research. Herein, a novel fructose-modified chitosan/gelatin composite sponge has been developed, exhibiting high elasticity, low rebound pressure, and excellent cell compatibility. This material can rapidly return to its original form in around 1.5 s after being compressed by 80% upon contact with water. Additionally, experimental results from a rat liver wound model demonstrated that it exhibited a clear hemostatic effect. The hemostatic time was shortened from 204 ± 15.35 s to 53.3 ± 6.54 s, and the blood loss was reduced from 867 ± 153.15 mg to 187 ± 61.06 mg. Moreover, it can promote tissue healing by inhibiting the production of inflammatory factors including TNF-α, MCP-1, and IL-6. This material offers an effective solution for noncompressible tissue injuries.
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CARBOHYDRATE POLYMERS
·
2024
·
IF 10.7
Fang Liu,Yinchun Liu,Youli Guo,Jianrui Liu,Jingwen Dong,Tengbin Wang,Di Hao,Yongqin Zhang
We developed and validated a novel Fourier transform infrared (FTIR) method to determine the degree of molar substitution (MS) for hydroxypropyl chitosan (HPCS) using nuclear magnetic resonance ( 1 H NMR) as a reference, and investigated the factors influencing the MS assay. Through extensive screening of integration methods for candidate bands in the FTIR spectrum of HPCS using 20 HPCS samples with degrees of acetylation (DA) ranging from 0.003 to 0.139, we found that when using band area at 2970 cm −1 as a probe integral, the MS values obtained via the 1 H NMR method exhibited linear correlations (R 2 > 0.98) with at least 16 integral ratios derived from their FTIR spectra. The optimal reference bands with high reliability are located at 3440 cm −1 and 1415 cm −1 , with R 2 exceeding 0.99 and a MS range of 0.17–1.92. The band at 2875 cm −1 is less affected by the trace moisture present in HPCS samples than the others. The results of the method validation demonstrated a mean recovery of 98.9 ± 2.8 % and an RSD below 10 %, suggesting a simple, robust, and highly accurate and precise method. This method could be extendable for the determination of the MS of insoluble HPCS derivatives and other hydroxypropylated polysaccharides .
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Materials Science & Engineering C-Materials for Biological Applications
·
2017
·
IF 4.164
Meng Pan,Zonghao Tang,Jianbing Tu,Zhengchao Wang,Qinhui Chen,Rongdong Xiao,Haiqing Liu
Quick hemostats for non-lethal massive traumatic bleeding in battlefield and civilian accidents are important for reducing mortality and medical costs. Chitosan (CS) has been widely used as a clinic hemostat. To enhance its hemostatic efficiency, Zn 2 + in the form of zinc alginate (ZnAlg) was introduced to CS to make porous CS@ZnAlg microspheres with ZnAlg component on the surface. Such microspheres were prepared by successive steps of micro-emulsion, polyelectrolyte adhesion, and thermally induced phase separation. Their structure and hemostatic performance were analyzed by SEM, FT-IR, XPS and a series of in vitro hemostatic experiments including thromboelastography analysis. The composite microspheres had an outer and internal interconnected porous structure. Their size, surface area, and water absorption ratio were ca. 70 μm, 48 m 2 /g, and 1850%, respectively. Compared to the neat chitosan microspheres, the CS@ZnAlg microspheres showed shorter onset of clot formation, much faster in vitro and in vivo whole blood clotting, bigger clot, less blood loss, and shorter hemostatic time in the rat liver laceration and tail amputation models. The synergetic hemostatic effects from (1) the electrostatic attraction between chitosan component and red blood cells, (2) the activation of coagulation factor XII by Zn 2 + of zinc alginate component, and (3) physical blocking by microsphere matrix, contributed to the enhanced hemostatic performance of CS@ZnAlg microspheres.
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CARBOHYDRATE POLYMERS
·
2017
·
IF 4.811
Yongli Zhang,Xingrui Wang,Chen Xu,Weiwei Yan,Qiang Tian,Zhiming Sun,Hongduo Yao,Jianping Gao
Hydrophobic and dispersible functionalized reduced graphene oxide (FrGO) was employed to prepare chitosan gel droplets by crosslinking an inverse Pickering emulsion. The emulsion was prepared using toluene as the continuous phase and a chitosan aqueous solution as the dispersed phase. The effects of the FrGO concentration and the water/oil ratio on the chitosan droplet morphology were studied. At appropriate concentrations, the FrGO acted as a stabilizer and chitosan gel droplets were formed. Decreasing the FrGO concentration or increasing the water/oil ratio was unfavorable to the formation of chitosan droplets. Using this method, drug loaded chitosan gel droplets (microgels) were prepared and their release profiles as well as the factors that influence the drug release were investigated.
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SCIENCE OF THE TOTAL ENVIRONMENT
·
2018
·
IF 4.61
Chunzhen Fan,Kan Li,Yi He,Yalin Wang,Xufang Qian,Jinping Jia
Although many magnetic chitosan materials have been prepared for adsorption of metal ions , there is no standard method for comprehensive evaluation of material performance. The common practice simply compares either adsorption capacity (Q) or saturation magnetization (M s ) of interested materials; however, these two important parameters often work in opposite way. This study aims to establish two methods for evaluation of the overall performance of magnetic materials. The proposed methods consider both heavy metal ion adsorption capacity and magnetic recovery of the material after use. The first method introduces adsorption recovery index (ARI, ARI = Q t ), which is calculated using Q and recovery time (t) needed for achieving 98% material recovery. Higher ARI value shows better performance of a magnetic material. The second method uses effort-vector data visualization, in which the position of a magnetic material is shown on a coordinate depicted using normalized Q and M s value. The distance of the data point to the target (ideal Q and M s value) indicates the performance of the material. The shorter the distance, the better the overall performance is. Two series of MCBs with different Fe 3 O 4 chitosan mass ratios were prepared by using embedding method and chemical co-precipitation method respectively. They were used as model compounds for investigation of the feasibility of the proposed evaluation methods through adsorption of various metal ions (Ag + , Cu 2+ , Hg 2+ , Cr 3+ and Cr 6+ ) and MCBs recovery test. The best performers were able to be identified by using both methods and the results agreed with each other. Compared with ARI, the effort-vector data visualization was more straightforward and easier to use. This method was successfully applied to evaluate a wide selection of magnetic materials, including those prepared in this work and reported from literatures, for their overall performance.
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