壳聚糖纳米纤维的制备及其在生物医学领域的应用

本文主要讨论了壳聚糖纳米纤维的制备及在生物医学领域的应用。壳聚糖纳米纤维主要采用静电纺丝的方法制备,为改善壳聚糖的可纺性将其与其他高分子进行混合纺丝;壳聚糖纳米纤维的应用主要集中在医用敷料、组织支架、仿生细胞质基质等方面。通过对壳聚糖纳米材料的制备及应用的文献综述,对壳聚糖纳米材料进行了展望。     

壳聚糖及其衍生物在食品工农业中的应用研究进展

壳聚糖作为一种天然碱性多糖,具有高附加值、可再生资源、抑菌、无毒、易成膜、可生物降解、螯合重金属等优点。文章综述了壳聚糖在食品工农业方面的应用研究进展情况,详细介绍了壳聚糖、改性壳聚糖和复合壳聚糖在果蔬保鲜、植物诱导、防止微生物生长、果汁澄清、添加剂和食品工业废水方面的应用性能,并对壳聚糖在食品中应用的未来发展进行展望。     

壳聚糖衍生物抗菌研究进展

壳聚糖具有抗菌活性,有广泛的应用前景。为了扩大壳聚糖抗菌活性在不同领域的应用,在壳聚糖分子链上接入不同基团,或螯合金属纳米粒子可得到更强抗菌特性的壳聚糖衍生物。壳聚糖衍生物主要有季铵化壳聚糖、羧甲基化壳聚糖、杂环化合物壳聚糖、壳聚糖衍生物与金属纳米粒子螯合等。本文就不同种类壳聚糖衍生物的抗菌特性进行简要综述。     

壳聚糖在纳滤膜中的应用研究

壳聚糖是一种含氮的多糖类,无毒、具有优异的生物相容性和可降解性、成膜性好,且易于进行化学改性。这使壳聚糖在纳滤膜方面得到广泛的应用。近年来通过复合、改性、共混等制备壳聚糖纳滤膜得到了较大的发展。文章对壳聚糖及其衍生物在纳滤膜中的应用进行了综述,并对其存在问题及发展方向进行了展望。为进一步开发利用壳聚糖提供参考。     

壳聚糖的改性研究进展

壳聚糖是自然界含量仅次于纤维素的低毒、生物降解性好的天然高分子化合物,在工业领域有重要的应用价值。但由于其溶解性差,应用受到了一定限制。通过各种改性能提高壳聚糖的理化性质,使其应用范围进一步扩展。本文简单概述了改性壳聚糖的应用,重点综述了壳聚糖的改性方法,最后就壳聚糖改性中存在的问题进行探讨。     

壳聚糖季铵盐及其衍生物的应用研究进展

壳聚糖是一种天然无毒多糖,可生物降解,具有生物相容性。在实际应用中壳聚糖水溶性差,只能在酸性介质中溶解。为了提高壳聚糖的溶解度并改善其理化及生物特性以扩大其应用范围,有必要对壳聚糖进行化学修饰。壳聚糖季铵盐是一种常见的壳聚糖修饰产物,属于水溶性壳聚糖衍生物,由于骨架上有强正电荷,因此其pH值溶解范围较宽。综述了壳聚糖季铵盐及其衍生物在抗菌活性、基因运载、给药系统、抗凝血材料、传感器等方面的应用进展,提出改进壳聚糖季铵盐及其衍生物的合成路线,可合成一系列生物学性能改良的壳聚糖季铵盐及其衍生物,有望将其应用于特殊领域。     

壳聚糖及低聚壳聚糖在日用化妆品中的应用

随着壳聚糖及其衍生物、低聚壳聚糖研究的迅速发展，其研究内容和应用范围越来越广泛，从壳聚糖及低聚壳聚糖在护发、护肤、美容等方面对其在日用化妆品中的应用进行了综述，并对其发展前景进行了简要评述。     

壳聚糖及其衍生物应用研究进展

介绍了壳聚糖的性质及研究历史,综述了壳聚糖及其衍生物在水处理、膜分离、分析化学、纺织工业、冷却水循环系统的阻垢、液晶及生物医用材料等方面的应用研究,并对壳聚糖的应用研究进行了展望。     

壳聚糖类水凝胶的制备及其作为吸附材料的应用研究进展

壳聚糖是一种天然生物材料,其来源广泛,但是由于壳聚糖吸水溶胀所导致的在湿环境下机械性能差、容易降解等问题极大地限制了壳聚糖材料的应用。通过物理交联和化学交联等方式将壳聚糖制备成水凝胶可以有效提高壳聚糖的利用率,同时能扩大水凝胶的应用范围。该文对壳聚糖复合水凝胶的制备方法及其在吸附方面的应用进行了总结,并对目前国内外的研究进展进行了分析和讨论,最后展望了壳聚糖复合水凝胶后期的研究重点和方向。     

12壳聚糖酶的研究进展

壳聚糖酶是最近发现催化壳聚寡糖降解的专一性酶,壳聚糖经其降解后生成低分子量壳聚寡糖,并且在医药领域中有着广泛的应用前景。本文概述了壳聚糖酶的研究概况,主要是壳聚糖酶的发现、分类、分布、理化性质及其应用进行了综述。     

壳聚糖及其衍生物去除金属离子的研究进展

壳聚糖具有来源广泛、无毒无害、功能基团丰富、化学活性强等特点,广泛应用于化工、环保、医药、食品等领域.围绕壳聚糖分子链上活性基团对金属离子的吸附能力,综述了壳聚糖及其衍生物在去除溶液中金属离子方面的研究工作及进展.介绍了对壳聚糖单体进行官能团置换或重组的化学改性法和改变壳聚糖物理形态的物理改性法,详细阐述了交联改性法、接枝改性法、磁化改性法、分子印迹法的基本原理、应用效果和优缺点,并对壳聚糖微球、壳聚糖膜的制备方法和材料性能进行了归纳.结合壳聚糖及其衍生物在制备和应用过程中存在的问题,提出了将化学改性和物理改性相结合制备新型印迹壳聚糖基聚合物,从而实现高效和选择性去除金属离子的研究方向.     

不同虾壳部位中的甲壳素和壳聚糖

用EDTA的方法分别从虾壳的不同部位:虾头、虾身、虾足和虾头内容物三部分制备甲壳素和壳聚糖,对三组试样的性能参数如脱乙酰度和相对分子量等进行分析研究。得出结论:由虾壳不同部位所制得的甲壳素和壳聚糖结构基本一致,但其脱乙酰度和相对分子量有较大差别,其物化性质也有所不同。在三组试样中,以从虾头壳制备的甲壳素和壳聚糖的相对分子质量为最大;而脱乙酰度则以从虾足和虾头内容物中制得试样较高。     

虾壳制备甲壳素和壳聚糖的研究

用EDTA的方法分别从虾壳的不同部位:虾头、虾身、虾足和虾头内容物三部分制备甲壳素和壳聚糖,对三组试样的性能参数如脱乙酰度和相对分子量等进行分析研究。得出结论:由虾壳不同部位所制得的甲壳素和壳聚糖结构基本一致,但其脱乙酰度和相对分子量有较大差别,所以其物化性质也有所不同。特别值得一提的是,在三组试样中,以从虾头壳制备的甲壳素和壳聚糖的相对分子质量为最大;而脱乙酰度则以从虾足和虾头内容物中制得试样较高。     

Guanidinylation: A simple way to fabricate cell penetrating peptide analogue‐modified chitosan vector for enhanced gene delivery

In view of the analogous transmembrane function to cell penetrating peptides, guanidine group was incorporated into chitosan by chemical modification to enhance the transfection performance of chitosan vectors. Guanidinylated chitosan (GCS) was shown to be well soluble in neutral aqueous solution. The interaction between GCS with plasmid DNA was characterized by agarose retardation experiment and ethidium bromide displacement assay. GCS formed more stable complexes with DNA under physiological pH than chitosan. The transfection efficiency of GCS was evaluated employing COS‐7 cell line—GCS polyplexes demonstrated higher transfection efficiency and lower cytotoxicity relative to chitosan. The optimum efficiency of GCS was achieved in the vicinity of the critical complexing ratio. The results of flow cytometry indicated that guanidinylation promoted an eightfold increase in the cell uptake. The study revealed that guanidinylated chitosan is a promising candidate as an effective nonviral vector for in vivo gene delivery. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Synthesis,characterization, and microsphere formation of galactosylated chitosan

Chitosan derivative with galactose groups, which was recognized specifically by the asialoglycoprotein receptor (ASGR), was synthesized by introduction of the galactose group into the amino group of chitosan. The chemical structure of galactosylated chitosan was characterized by FT‐IR, ¹H‐NMR, ¹³C‐NMR, WAXD, and DSC techniques. The results indicated that although acyl reaction on the part of amino groups of chitosan took place, the degree of galactosylated substitution was 20%, and the crystallization, solubility, stability, and other physical properties were different from chitosan. Microspheres of chitosan and galactosylated chitosan were prepared by the physical precipitation and coacervation method with sodium sulfate, respectively. The characterizations of microspheres were determined by means of scanning electron microscopy (SEM), particle size/ζ potential analysis, and DSC methods. Spherical, positively charged chitosan and galactosylated chitosan microspheres were formed, with an average diameter of 0.54 and 1.05 μm, and average ζ potential of +17 mV and +15 mV, respectively. The novel galactosylated chitosan microspheres may be used as a potential drug delivery system with passive and active hepatic targeting properties. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 659–665, 2004     

壳聚糖的化学改性(Ⅰ)

壳聚糖是一种带阳离子的天然活性多糖,在一定条件下可以发生降解反应,其降解产物具有比壳聚糖更优良的功能特性,广泛应用于医药、食品、农业及环保等领域。壳聚糖与醛、酮可发生Schiff反应生成相应的醛亚胺或酮亚胺化合物,后者在氢硼化物作用下加氢进一步转化为各种N-烷基类衍生物。文章概述了近年来壳聚糖化学改性方面取得的某些研究进展,主要包括糖类改性,三甲基化、N-琥珀酰化、硫醇化和叠氮化改性,环状糊精改性,冠醚改性,化学接枝改性等。     

Application of chitosan solutions gelled by melB tyrosinase to water‐resistant adhesives

An investigation was undertaken on the application of dilute chitosan solutions gelled by melB tyrosinase‐catalyzed reaction with 3,4‐dihydroxyphenethylamine (dopamine). The tyrosinase‐catalyzed reaction with dopamine conferred water‐resistant adhesive properties to the semi‐dilute chitosan solutions. The viscosity of the chitosan solutions highly increased by the tyrosinase‐catalyzed quinone conversion and the subsequent nonenzymatic reactions of o‐quinones with amino groups of the chitosan chains. The viscosity of chitosan solutions highly increased in shorter reaction times by addition of melB tyrosinase. Therefore, in this study, the gelation of a chitosan solution was carried out without poly(ethylene glycol) (PEG), which was added for the gelation of chitosan solutions using mushroom tyrosinase. The highly viscous, gel‐like modified chitosan materials were allowed to spread onto the surfaces of the glass slides, which were tightly lapped together and were held under water. Tensile shear adhesive strength of over 400 kPa was observed for the modified chitosan samples. An increase in either amino group concentration of the chitosan solutions or molecular mass of the chitosan samples used effectively led to an increase in adhesive strength of the glass slides. Adhesive strength obtained by chitosan materials gelled enzymatically was higher than that obtained by a chitosan gel prepared with glutaraldehyde as a chemical crosslinking agent. In addition, the use of melB tyrosinase led to a sharp increase in adhesive strength in shorter reaction times without other additives such as PEG. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

甲壳素与甲壳胺纤维 3.纤维的化学改性

作为天然高分子材料,甲壳素和甲壳胺有许多优良的物化和生物活性。通过化学改性,甲壳素和甲壳胺可以获得更多的性能。总结了甲壳素和甲壳胺的化学衍生物和各种复合材料。     

Some Structural Properties of Spray-Dried Chitosan Microgranules

The characteristics of concurrent spray dried chitosan microgranules are presented in this article. The investigated parameters were four chemical compositions of solutions subjected to drying to produce chitosan microgranules with different structures and chemical compositions. The analysis of dried product included shape, size, density, porosity, moisture content, and solubility in water. The results show the possibilities of applying spray-drying in the formation of chitosan microgranules with required physicochemical properties.     

Hemocompatibility of 2-N-3,6-O-sulfated chitosan films

Sulfated chitosan (SC) can be used for such coating because of its similarity with heparin. The position of sulfate group incorporation in the chitosan chain is important for the improvement of its biological mechanism. The substitution of each reactive group of chitosan is required to increase the electrostatic repulsion between the sulfated films and blood proteins or platelets, and, thereby, reduce the thrombus formation. Moreover, the polymeric hydroxyl groups can activate the complement system through the alternative pathway. In this study, we developed SC films, with larger distribution of sulfate groups by substitution of three reactive groups in the chitosan chain to improve its hemocompatibility. Successful chemical modification confirmed the partially 2-N-3,6-O-SC. The hemocompatibility results showed decrease in bovine serum albumin and fibrinogen adsorption, platelet adhesion and an increase in the intrinsic pathway anticoagulant activity. Based on these results, partially tri-SC can be considered suitable candidate for coating blood-contacting medical devices. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47128.