【作者】 程德书；

【导师】 李明春；

【作者基本信息】 华侨大学 ， 材料学， 2008， 硕士

【摘要】 壳聚糖和环糊精是两种性能优良的天然多糖,在生物医药和环境工程领域得到广泛的研究和应用。壳聚糖有良好的生物活性和吸附性,环糊精有着亲水的外壁和疏水的空腔,可与疏水分子形成包结物。如何将环糊精固载到壳聚糖上把两者的优点结合起来,并用于水处理和药物控释等领域有着重要的现实意义。本文首次用环氧氯丙烷在碱性条件下,交联β-环糊精(β-CD)和N-丁二酸单酯壳聚糖(SCS)制得N-丁二酸单酯壳聚糖固载环糊精(CDS)。合成CDS的实验结果表明,该反应条件温和,产率较高,NaOH的浓度、环氧氯丙烷的用量、反应温度和SCS/β-CD投料比对产物有较大的影响。将元素分析和化学方法结合起来,对CDS中β-CD和SCS的含量进行了确定。该合成方法可制得β-CD取代度较高并含量可控的CDS。论文研究了CDS对2,4-二硝基酚的吸附性能,考察了吸附时间、吸附温度、溶液pH值、酚的浓度和吸附剂的用量对吸附性能的影响,实验结果表明,最佳吸附温度为30℃,吸附时间为60min,pH值为3.6。而吸附容量随着酚的浓度增大而增加,当吸附剂用量达到0.1g时,对10mL浓度为1.5×10-2mg/mL的2,4-二硝基酚溶液的吸附率达到100%。CDS与单纯环糊精的交联物(ECD)、单纯SCS的交联物(ECS)和单纯壳聚糖的对比吸附实验表明:ECD,ECS和CS的吸附容量分别为6.84 mg/g、11.19 mg/g和9.23 mg/g。CDS的吸附效果明显比ECD、ECS和CS高。这可能是因为β-环糊精疏水性空腔对2,4-二硝基酚的包结作用和壳聚糖基材料与2,4-二硝基酚形成氢键、静电吸引等协同作用的结果。用乙醇对吸附后的CDS进行了洗脱,洗3次后,其洗脱率达到99.5%。用洗脱后的CDS对酚进行了再次吸附,重复4次仍然有较好的吸附效果。为了研究和掌握环糊精与药物包结作用的规律和机理,本文研究了环糊精母体分子与酮洛芬的包结作用。通过紫外-可见光谱证明了β-CD与酮洛芬在水溶液中形成了包结物。并制备了β-CD与酮洛芬的固体包结物,用FTIR、X射线、DSC和TG证实了固体包结物的形成。以酮洛芬为模型药物,研究了载药CDS在模拟胃液和模拟肠液中的药物释放行为。实验发现载药CDS在模拟胃液和模拟肠液中有不同的释放行为,在模拟肠液中释放速率很快,10h的药物释放率就接近100%,而在模拟胃液中,有一个缓慢的释放过程,要40h才能达到平衡,药物平衡释放率接近100%。通过对比载药ECD和ECS在上述两种溶液中的药物释放行为,初步认为载药CDS在模拟胃液和模拟肠液中的药物释放行为与以下两个原因有关:1) CDS在碱性条件下能很好的溶胀,有利于药物的扩散;2)是酮洛芬是弱酸性,其在碱性条件下更容易溶出。载药CDS的这种pH值响应具有实际应用的价值。更多还原

【Abstract】 Chitosan and cyclodextrin are well-known naturally occurring polysaccharides which are widely used in biomedical and environmental engineering areas. Chitosan and its derivatives possess excellent bioactivity and adsorption ability. Cyclodextin are cyclic oligosaccharides with a lipophilic central cavity and a hydrophilic outer surface, able to form inclusion complexes with lipophilic molecules. Therefore, grafting CD molecules into chitosan may lead to a molecular carrier exhibiting promising properties because of the cumulative effects of both.In this paper, a novel approach to prepare N-succinyl chitosan immobilized withβ-cyclodextrin(CDS)had been set up. The experimental results of synthesis indicated that CDS can be obtained using epichlorohydrin as crosslinking agent with a higher yield under mild conditions, and the reaction was affected by the concentration of NaOH, the amount of crosslinking agent, the reactive temperature and the weight ration ofβ-CD/SCS. The CDS was characterized by FTIR and element analysis. The apparent amounts ofβ-CD content in CDS were determined by ultraviolet spectroscopy and element analysis respectively. According to this novel approach, apparent amounts ofβ-CD and SCS content in CDS could be controlled and higher.The adsorption experiments of CDS for 2, 4-dinitrophenol had been carried out. The experimental results showed the optimal adsorption conditions as follows: 30℃, 60min, pH3.6. The adsorption capacity of CDS to 2, 4-dinitrophenol was increased with enlarging the concentration of 2, 4-dinitrophenol. The adsorption rate of 2, 4-dinitrophenol would reach to 100%, while 0.1g CDS and 10 mL of 1.5×10-2mg/mL 2, 4-dinitrophenol solution was used. The experimental results showed that the adsorption capacity of CDS to 2, 4-dinitrophenol was much higher than that of ECS, ECD and CS. This may be owing to the cumulative effects of cyclodextrins’s complexes ability and chitosan’s adsorption ability.To understand the molecular interaction mechanism of inclusion complex betweenβ-CD and the medicine, the supramolecular interaction between parent ?β-CD and ketoprofen in aqueous solutions was studied by UV spectrophotometer. The solid inclusion complexes ofβ-CD/ ketoprofen were also prepared, and the results of IR, DSC, TG and the power X-ray diffraction data indicated that novel crystalline structure for inclusion complex exists. Using ketoprofen (KP) as model drug, the release behavior of ketoprofen from CDS in simulated gastric juice and intestinal liquid had been carried out. The results indicated that the drug release equilibrium was reached and the equilibrium rates of KP release were closed to 100% after 40h in simulated gastric juice and 10h in intestinal liquid. To get the mechanisms of drug release of CDS, the drug release behavior in different polymer matrixes (ECD and ECS) was studied as well. It seemed that the release of KP obeyed a swelling-controlled release mechanism, especially at the initial period of release, and the release was most probably followed by a diffusion-controlled mechanism after the initial period, in which the swelling equilibrium was achieved. The pH-response property of the drug-loaded CDS was valuable for application.更多还原