【作者】 宋鹏飞；

【导师】 王荣民； 王云普；

【作者基本信息】 西北师范大学 ， 高分子化学与物理， 2004， 硕士

【摘要】 智能水凝胶是一类对外界刺激能产生敏感响应性的水凝胶，属于智能材料，已经在很多领域取得了广泛应用。另一方面，壳聚糖是一种天然高分子，来源丰富，应用广泛，特别是其良好的生物活性，引起了人们的广泛关注。本文首先对智能水凝胶的性质、合成方法及应用和壳聚糖的物理性质、化学性质、生物活性以及分子量对其性质影响的研究进展进行了综述。 第二，制备了pH敏感性壳聚糖基水凝胶并研究了其对药物的智能释放性能。以壳聚糖作为原料，运用互穿网络技术，合成了pH敏感的壳聚糖／聚乙烯基吡咯烷酮、壳聚糖／聚乙烯醇、壳聚糖／聚乙二醇三种水凝胶。并通过元素分析、红外光谱、扫描电镜和热分析确定了水凝胶的半互穿网络结构。 研究了三种水凝胶的溶胀性能、刺激响应性能和体外药物释放性能。结果表明：1)水凝胶在酸性介质中溶胀，在碱性介质中收缩；2)水凝胶刺激响应性能好。随着介质的pH值变化，其体积出现溶胀收缩，且该过程可逆；3)三种水凝胶都对药物氟哌酸具有一定缓释效果。 第三，制备了纳米壳聚糖、甘氨酸金属混配物，研究其生物活性。利用H₂O₂法氧化降解壳聚糖，制备得到纳米壳聚糖。并通过元素分析、红外光谱、凝胶渗透色谱法、透射电镜和原子力显微镜等测试手段对其表征，确定降解所得壳聚糖已达到纳米级别。以制备的纳米壳聚糖为原料，合成了5种纳米壳聚糖、甘氨酸金属配合物（CS-M-Gly，M：Zn、Ni、Cu、Fe、Co），并通过元素分析、ICP、XPS和红外光谱等测试手段表征配合物的结构。 通过紫外光谱法、荧光光谱法研究了CS-M-Gly系列金属配合物与DNA的作用，结果表明，该系列金属配合物不仅能对小牛胸腺DNA产生减色、增色效应，而且能使EB／DNA体系发生荧光猝灭，即CS-M-Gly系列金属配合物对DNA作用并使其结构发生损伤。通过SRB法（Sulforhodamine B）测试了其抗肿瘤活性，结果表明，CS-M-Gly系列金属配合物对肝癌H7402细胞具有一定的杀伤作用，其中CS-Cu-Gly配合物对肿瘤细胞的杀死率可达86.46％。 第四，首次合成了5种纳米壳聚糖水杨醛希夫碱、甘氨酸金属配合物（CS-Sal-M-Gly，M：Zn、Ni、Cu、Fe、Co），并通过元素分析、ICP、XPS和红外光谱等测试手段表征配合物的结构。采用紫外光谱法、荧光光谱法和SRB法研究了cs一sal一M一Gly系列金属配合物的生物活性。结果发现，该系列金属配合物不仅能对DNA作用并使其结构发生损伤，而且具有抗肿瘤活性。其对肝癌H7402细胞最大杀死率可达90，28%，对肿瘤细胞的毒性已达到最高的4级。更多还原

【Abstract】 Smart hydrogels can response to the change of environment, as a kind of intelligent materials, which will be applied in many fields. On the other hand, chitosan, a naturally abundant polymer, has a wide range of application, especially in bioactivity. There are two parts in review. One focus on properties, preparation and applications of smart hydrogels. Another is properties and bioactivity of chitosan including the effect of molecular size on its properties.pH sensitive hydrogels based on chitosan (chitosan-polyvinyl pyrrolidone, chitosan-polyvinyl alcohol, chitosan-polyethylene glycol) were synthesized by using the means of interpenetrating network(IPN). The IPN structure of them were characterized by element analysis, IR spectra, SEM and DTA. The hydrogels showed excellent pH sensitivity, which can swell in acid medium and contractile in base medium. Furthermore, the hydrogels have good swelling-contracting reversibility in the solution which pH value was alternately changed, and can be used as delivery system of norfloxacin.Nano-chitosan were prepared from oxidation degrade with hydrogen peroxide and characterized by element analysis, IR spectra, GPC, TEM and AFM. Nano-chitosan and glycine metal complexes(CS-M-Gly, M: Zn, Ni, Cu, Co, Fe) were prepared from nano-chitosan, and characterized by element analysis, IR spectra, ICP and XPS.The interaction between CS-M-Gly with DNA was investigated by UV/Vis and fluorescent probe technique. The results showed that CS-M-Gly can destroy the structure of DNA. The antitumor activity of CS-M-Gly were also studied by SRB. The results indicated that CS-M-Gly can inhibit the growth of liver cancer H7402 cell and the death percent of CS-Cu-Gly to tumor cell is 88.46%.Nano-chitosan salicylaldehyde Schiff base and glycine metal complexes (CS-Sal-M-Gly, M: Zn, Ni, Cu, Co, Fe) were synthesized, and characterized by element analysis, IR spectra, ICP and XPS. The bioactivity of CS-Sal-M-Gly were investigated by UV/Vis, fluorescent probe and SRB, the results showed thatCS-Sal-M-Gly can make interaction with DNA and destroy its structure. Moreover, CS-Sal-M-Gly have better antitumor activity. The death percent of tumor cell can reach 90.28% in the presence of CS-Sal-M-Gly. That means the cell toxicity of CS-Sal-M-Gly to tumor cell is the highest four grade.更多还原