ANALYTICA CHIMICA ACTA
·
2014
·
IF 4.517
Qing Wang,Jie Chen,Kun Huang,Xin Zhang,Li Xu,Zhi-guo Shi
A hydrophilic stationary phase (SP) was prepared through grafting N -methylene phosphonic acid chitosan on magnesia–zirconia particles (P-CTS-MgO–ZrO 2 ) via Lewis acid–base interaction. The resulting material was characterized by thermogravimetric analysis, Fourier transform infrared spectroscopy, scanning electron microscope and nitrogen adsorption analysis. The chromatographic performance of P-CTS-MgO–ZrO 2 was systemically evaluated by studying effect of acetonitrile content, pH and buffer concentration in the mobile phase. The results demonstrated that the novel SP provided hydrophilic, electrostatic-repulsion and ion-exchange interactions. Compared to the bare MgO–ZrO 2 , P-CTS-MgO–ZrO 2 exhibited superior peak shape, reasonable resolution and reduced analysis time in separation of basic analytes. Besides, remarkable resolving power of acids, i.e. six non-steroidal anti-inflammatory drugs which failed to be eluted from the bare MgO–ZrO 2 , was obtained with the theoretical plate number (N/m) of 4653–31313, asymmetry factor <1.21 and the resolution of 1.6–3.4. Finally, P-CTS-MgO–ZrO 2 SP was applied to separate monosaccharides, phospholipids and peptides. P-CTS-MgO–ZrO 2 was a promising hydrophilic SP for wide applications.
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产品关联
DOI
PubMed
高影响因子
CELLULOSE
·
2022
·Vol. 29
·期 10
·5803-5816
·
IF 6.123
Zhang Qi,Luo Yangyang,Wang Dengke,Yang Zheming,Zheng Jinxia,Xie Mali,Shao Linjun,Du Yijun,Qi Chenze
In this paper, chitosan composite nanofibers with mean diameters of 300–500 nm have been prepared by electrospinning with poly(methacrylic acid) as the crosslinking agent and poly(ethylene oxide) as the cospinning polymer. Afterwards, these composite nanofibers were annealed at temperatures ranging from 110 to 190 °C to improve their solvent resistance. Their morphologies and structures were characterized by scanning electron microscopy, infrared spectroscopy (IR) and positron annihilation life spectroscopy. These composite nanofibers were used to adsorb the Pd 2+ cations in aqueous solutions. The effects of chitosan content, annealing temperature, adsorption temperature, solution pH and initial Pd 2+ concentration were carefully studied. The adsorption result shows that these composite nanofibers had better adsorption performance than the pristine chitosan and commercial activated carbon. Under the optimized adsorption conditions, the maximum adsorption capacity was found to be 366 mg/g. The adsorption kinetic, FT-IR and XPS confirmed the chemical adsorption behavior of Pd 2+ cations on the composite nanofibers. The thermodynamic parameters (ΔG 0 , ΔH 0 and ΔS 0 ) acquired by Van’t Hoff equation indicated that the adsorption process was spontaneous and exothermic in nature. Moreover, selective adsorption study revealed that these composite nanofibers exhibited good adsorption selectivity for Pd 2+ cations from the mixture of metal ions in aqueous solution. At last, the reusability of these novel composite nanofibers was tested for four runs. Overall, this study indicated that the as-prepared nanofiber mat was an efficient adsorbent for the recovery of precious palladium cations from aqueous solutions.
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DOI
高影响因子
AAPS PHARMSCITECH
·
2022
·Vol. 23
·期 5
·1-10
·
IF 4.026
Guo Chen,Zhu Xichun,Yuan Haoyang,Liu Haoyu,Zhang Yu,Yin Tian,He Haibing,Gou Jingxin,Tang Xing
In recent years, the oral administration of vinorelbine has gradually replaced intravenous administration in the treatment of several types of tumors. Even though the risk of phlebitis is avoided with oral administration, oral vinorelbine is still not a highly patient-compliant route due to the severe gastrointestinal toxicity. Vinorelbine-loaded liposomes with high encapsulation efficiency and suitable particle size were prepared using the ammonium sulfate gradient method. Chitosan-coated liposomes showed the slowest in vitro release compared to uncoated liposomes and vinorelbine solution. No damage was observed in the intestinal epithelial cells of mice orally administered with coated vinorelbine liposomes due to the low presence of the free drug in the gastrointestinal tract and the LD 50 was increased from 129.83 to 182.25 mg/kg compared to oral vinorelbine solution. In addition, the positive surface potential of chitosan-coating endowed liposomes with mucosal adhesive function, delaying the time to reach the peak plasma concentration of vinorelbine from 1 to 4 h after administration. And bioavailability was increased to 2.1-fold compared to vinorelbine solution. In short, a new strategy to address the severe gastrointestinal side effects of oral vinorelbine has been developed.
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DOI
高影响因子
CARBOHYDRATE POLYMERS
·
2015
·
IF 4.074
Zhengyang Li,Tingting Li,Libao An,Pengfei Fu,Cangjian Gao,Zhiming Zhang
Chitosan/polymethylmethacrylate (PMMA) composite nanofibrous membrane was prepared by electrospinning technique with a single solvent system. Characterization with Fourier transformation infrared spectroscopy (FT-IR) indicated that there was weak interaction (such as hydrogen bonds) between PMMA and chitosan. Scanning electron microscopy (SEM) measurements illustrated that the average diameter of the composite nanofibers decreased as the chitosan content was increased, while the number of nano/micrometer sized beads increased in the membrane. The composite nanofibrous membrane with chitosan:PMMA ratio of 0.3:1.0 exhibited a maximum adsorption capacity (67.0 mg g −1 ) of Cr(VI) in static adsorption, which was nearly three times higher than that of chitosan powder (22.9 mg g −1 ). The adsorption capacity of Cr(VI) via filtration became even higher, where the maximum value was 92.5 mg g −1 at pH 3.0. Notably, most of Cr(VI) has been removed after the first filtration at all pH values (2.0–6.0) investigated in this report. The adsorption capacity of the composite nanofibrous membrane decreased slightly (17.1%) after three filtration cycles even with the solution of pH 2.0, which shall be attributed to the enhanced mechanical strength and acid fastness of the composite membrane. X-ray photoelectron spectroscopy (XPS) analysis indicated that amino groups played an important role in the adsorption of Cr(VI).
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DOI
高影响因子
Journal of the Taiwan Institute of Chemical Engineers
·
2016
·
IF 2.848
Wenyu Wang,Qinyan Yue,Baoyu Gao,Ruihua Li
In this study, the tendency of coagulation performances, floc characteristics and membrane resistances under different pH conditions in coagulation–ultrafiltration hybrid process was investigated by different Al species and chitosan (CS). Results indicated that CS as coagulation aid was independent of aluminum species. Coagulation efficiencies of three Al species (Al a , Al b and Al c ) combined with CS were enhanced comparing with Al species used alone and shown similar variation tendencies during the pH range. The values of floc size and strength/recovery factor were relatively high at pH 6, and the maximum fractal dimension was achieved under alkaline conditions generally due to adsorption sweeping. Al a /Al b /Al c combined with CS contributed to larger flocs, higher recovery factors and smaller fractal dimension values than those without CS. The results of ultrafiltration experiments shown that membrane resistances during alkaline ranges were higher than those of acidic conditions, which indicated membrane fouling was more serious in alkaline range. In addition, the total membrane resistance was decreased significantly by CS addition.
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DOI
高影响因子
Environmental Technology & Innovation
·
2021
·
IF 5.263
Xiaohui Tang,Yaoyao Huang,Qiang He,Yongjuan Wang,Huaili Zheng,Yadan Hu
With the abuse of tetracycline antibiotics and their high detection rate in the water environment, causing non-negligible environmental hazards and health risks, the treatment of tetracycline wastewater has been paid much attention. Herein, a noval magnetic adsorbent, nitrilotriacetic acid-modified magnetic chitosan microspheres (NDMCMs) was successfully prepared and applied to remove tetracycline antibiotics (TC) from wastewater. The results found that the solution pH and ion strength greatly affected the adsorption capacity of TC by NDMCMs. Additionally, the adsorption capacity of NDMCMs (373.5 mg g −1 ) was four times higher than that of MCMs (92 mg g −1 ) at pH 8.0, attributed to the various amino and carboxyl groups in the grafted chain. The experiment data were better correlated with the Freundlich isotherm model and the pseudo-second-order kinetic model, indicating that the adsorption between TC and adsorbent surfaces occurred as multilayer adsorption, and the chemical interaction played as a rate-limiting step in the adsorption process. The thermodynamic parameter calculation results demonstrated that the adsorption of TC by NDMCMs followed a spontaneous, endothermic, and orderly process. Besides, the regeneration performance of NDMCMs showed that it is fully qualified for practical application of TC adsorption. The adsorption mechanism proposed by the FT-IR spectroscopic analysis of the adsorbent before and after the adsorption of TC was mainly through π - π interaction, cation- π bond, hydrogen bond , and amidation reaction. Based on all experimental results, NDMCMs is an efficient and sustainable magnetic adsorbent, which can be used to remove TC from wastewater.
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DOI
高影响因子
CERAMICS INTERNATIONAL
·
2018
·
IF 3.057
Jingwei Wang,Yong Kong,Feng Liu,Dan Shou,Yongxin Tao,Yong Qin
Construction of simple and convenient platforms for controlled delivery of anti-cancer drugs is of great importance for medical science and pharmaceutics. Here, chitosan (CS) gels were used to induce the growth of calcium carbonate (CaCO 3 ) microspheres , and the resulting CaCO 3 microspheres were well dispersed within the three-dimensional (3D) network framework of the CS gels. The synthesized CaCO 3 /CS composites were then examined by field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), Fourier transform infrared spectrometry (FT-IR) and X-ray diffractometry (XRD). Finally, the designed CaCO 3 /CS composites were used for loading and controlled delivery of methotrexate (MTX), an anti-cancer drug. The encapsulation ratio of MTX calculated by UV–vis spectroscopy was approximately 78.8%. In addition, pH-responsive delivery of MTX from the CaCO 3 /CS composites was successfully achieved due to the pH-sensitive property of CS, and the cumulative release of MTX could reach 93.3%, 86.6% and 77.6% at pH 8.5, 7.4 and 5.8, respectively.
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DOI
高影响因子
FOOD HYDROCOLLOIDS
·
2022
·
IF 11.504
Jiahao Yu,Shanlin Xu,Gulden Goksen,Caifu Yi,Ping Shao
Deep eutectic solvents (DES) as plasticizers of chitosan film show great potential for food packaging. This paper introduced some novel antioxidant and antibacterial films based on chitosan and DES consisting of choline chloride (ChCl) and organic acids. The effects of the composition and contents of choline-based DES on structures, mechanical properties, thermal stability, contact angle, optical, antioxidant and antibacterial properties of chitosan films were studied. FTIR analysis showed that choline-based DES did exist in the chitosan film with good polymer matrix compatibility. Most of the films exhibited uniform, flat surfaces and cross sections. The Young's modulus of the films decreased inversely to the level of choline-based DES, and maximal mechanical characteristics were achieved for films plasticized with ChCl and acetylsalicylic acid. The addition of choline-based DES apparently reduced water contact angles, decreased the decomposition temperature and the thermal stability of chitosan films. In terms of antioxidant capacities and ultraviolet (UV) shielding, chitosan films plasticized with choline-based DES containing acetylsalicylic acid and vitamin C had strong UV shielding and antioxidant properties. Chitosan films plasticized with choline-based DES containing acetylsalicylic acid, malonic acid and lactic acid showed excellent antibacterial properties against Escherichia coli and Staphylococcus aureus . In conclusion, the chitosan film with the choline-based DES, especially for ChCl and acetylsalicylic acid showed a good application prospect in food active packaging.
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DOI
高影响因子
CARBOHYDRATE POLYMERS
·
2020
·
IF 7.182
Juanjuan Fu,Yinglian Zhu,Fansheng Cheng,Shuangling Zhang,Tiantian Xiu,Yue Hu,Shuo Yang
For preparing stable water-in-oil-in-water emulsion, the role of nanoparticles in stabilizing the interface is very important. In this study, chitosan hydrochloride-carboxymethyl chitosan (CHC-CMC) nanoparticles were prepared considering electrostatic interactions; then the emulsion was prepared and the stability characteristics in presence of NaCl (0–200 mmol/L) and 30 d storage were studied. CHC-CMC nanoparticles (261 nm) were obtained when the CHC: CMC ratio was 1:2. CHC-CMC formation was verified by FT-IR when a new peak appeared at 1580 cm −1 ; W 2 contained 2 wt % CHC-CMC and W 1 contained 1 wt % sodium alginate , the creaming index (81.6 %) was higher for the emulsions than Tween 80 (67.4 %) after 30 d. Confocal laser scanning microscopy confirmed the double microstructures, in contrast to the collapse with Tween 80, because the CHC-CMC nanoparticles were densely adsorbing on the oil-water interface. This indicates that CHC-CMC has a stronger ability to stabilize W 1 /O/W 2 emulsion than Tween 80.
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DOI
高影响因子
Frontiers in Chemistry
·
2024
·
IF 3.8
Sun Jingxuan,He Lina,An Qi,Ye Xu,Ma Jinjie,Yan Jing,Xie Xiaoqi,Sun Xiangyu,Niu Yumei,Cao Wenxin
Introduction: Facial nerve injury significantly impacts both the physical and psychological] wellbeing of patients. Despite advancements, there are still limitations associated with autografts transplantation. Consequently, there is an urgent need for effective artificial grafts to address these limitations and repair injuries. Recent years have witnessed the recognition of the beneficial effects of chitosan (CS) and graphene in the realm of nerve repair. Dental pulp stem cells (DPSCs) hold great promise due to their high proliferative and multi-directional differentiation capabilities.Methods: In this study, Graphene/CS (G/CST) composite tubes were synthesized and their physical, chemical and biological properties were evaluated, then DPSCs were employed as seed cells and G/CST as a scaffold to investigate their combined effect on promoting facial nerve injury repair.Results and Disscussion: The experimental results indicate that G/CST possesses favorable physical and chemical properties, along with good cyto-compatibility. making it suitable for repairing facial nerve transection injuries. Furthermore, the synergistic application of G/CST and DPSCs significantly enhanced the repair process for a 10 mm facial nerve defect in rabbits, highlighting the efficacy of graphene as a reinforcement material and DPSCs as a functional material in facial nerve injury repair. This approach offers an effective treatment strategy and introduces a novel concept for clinically managing facial nerve injuries.
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DOI
PubMed
高影响因子
CARBOHYDRATE RESEARCH
·
2018
·
IF 2.074
Zhiqiang Jiang,Xiaoyan Dong,Yan Sun
Amyloid β-protein (Aβ) aggregation is crucial for the pathogenesis of Alzheimer's disease, and surface charge of nanoparticles (NPs) has been recognized as an important factor influencing Aβ aggregation. Herein, we report a systematic study on the issue with a series of self-assembled chitosan-hyaluronic acid composite (CH) NPs of different surface charges (CH1 to CH7, zeta potentials from +38 to −35 mV). Both the positive and negative CH NPs inhibited Aβ aggregation and the inhibitory effect increased with increasing the surface charges density. Circular dichroism spectroscopy and atomic force microscopy revealed the difference in their working mechanisms. Studies at different pH values further confirmed the importance of electrostatic interactions in Aβ aggregation and presented that the effects of CH NPs changed due to the change of Aβ charge property with pH. This work has thus provided new insight into the surface charge effects on Aβ aggregation.
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高影响因子
Polymers
·
2021
·Vol. 13
·期 11
·1891
·
IF 4.329
Zongkun Lin,Yuru Yang,Zizhan Liang,Lei Zeng,Aiping Zhang
In order to avoid the secondary pollution of the toxic residue of chemical crosslinking agent accompanied by chemical hydrogel adsorbent and enhance the adsorption performance of physical hydrogel, chitosan/calcium alginate/bentonite (CTS/CA/BT) composite physical hydrogel was constructed. The formation mechanism and structure of the composite hydrogel were determined by FTIR, XRD and SEM. Adsorption performances of the hydrogel toward Pb2+, Cu2+and Cd2+in water under different condition as well as multi-ion competitive sorption were investigated. The adsorption processes were described with the canonical adsorption kinetics and isotherms models. With the utilization of XPS analysis and adsorption thermodynamics analysis, it was found that the adsorptions were spontaneous physico-chemical adsorptions. The results showed that the maximum adsorption capacity of the hydrogel for Pb2+, Cu2+and Cd2+reached up to 434.89, 115.30 and 102.38 mg·g−1, respectively, better than those of other physical hydrogels or chitosan/bentonite composite. Moreover, the composite hydrogel improved the collectability of bentonite and showed a good reusability. The modification of bentonite and the formation of hydrogel were completed simultaneously, which greatly simplifies the operation process compared with the prior similar works. These suggest that the CTS/CA/BT composite hydrogel has promising application prospects for removal of heavy metal ions from water.
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DOI
高影响因子
危险品化学品经营许可证（带存储）