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目的研制一种壳聚糖衍生物并探讨其应用于生物医学工程的可行性。方法将高相对分子质量的壳聚糖通过纤维素酶降解,产生平均相对分子质量在100 kD~250 kD左右的低相对分子质量壳聚糖。将甲基丙烯酸酐与壳聚糖溶液混合反应,利用红外光谱1、H核磁共振研究产物结构。向反应产物的水溶液中加入过硫酸钠和抗坏血酸以形成凝胶,通过扫描电镜观察凝胶的超显微结构。结果甲基丙烯酸连接在壳聚糖分子上,生成壳聚糖甲基丙烯酸酯。利用不同相对分子质量的壳聚糖,通过改变反应时间和反应物浓度,能够生成不同取代度的壳聚糖甲基丙烯酸酯,产物能够溶解的溶液pH值也随着取代度的不同而相应发生改变。扫描电镜的研究结果表明,壳聚糖甲基丙烯酸酯凝胶的颗粒和微孔直径都小于100 nm。此凝胶经过-20和-80℃冷冻处理后能够形成疏松多孔的结构,颗粒和微孔直径在200~500 nm。结论壳聚糖甲基丙烯酸酯可以用作纳米级生物医学材料。
Objective To develop a chitosan derivative and explore the feasibility of its application in biomedical engineering. Methods High molecular weight chitosan was degraded by cellulase to produce low molecular weight chitosan with an average relative molecular mass of 100 kD ~ 250 kD. The methacrylic anhydride and chitosan solution were mixed reaction, the use of infrared spectroscopy 1, H NMR study of product structure. Sodium persulfate and ascorbic acid were added to the aqueous solution of the reaction product to form a gel, and the ultrastructure of the gel was observed by a scanning electron microscope. As a result, methacrylic acid is attached to the chitosan molecule to form chitosan methacrylate. Using different relative molecular mass of chitosan, by changing the reaction time and the concentration of reactants, can generate different degrees of substitution of chitosan methacrylate, the product can dissolve the solution pH value with the degree of substitution corresponding to occur change. Scanning electron microscopy results show that the chitosan methacrylate gel particles and micropores diameter of less than 100 nm. After gelation at-20 and -80 ℃, the gel can form loose porous structure with diameter of 200 ~ 500 nm. Conclusion Chitosan methacrylate can be used as nano-scale biomedical materials.