【作者】 李若慧； 谢飞；

【Author】 Li ruo-hui1, Xie Fei 1Biochemical Engineering College, Beijing Union University,Beijing,100023

【机构】 北京联合大学生物化学工程学院；

【摘要】 把聚乙二醇接枝到壳聚糖的大分子链上,同时对其分子链的氨基进行保护,可以改善壳聚糖的亲水性,更好地满足在生物医药方面的应用要求。使用铜离子对壳聚糖(CS)大分子上的氨基进行保护,将甲氧基聚乙二醇(mPEG)的端羟基与六亚甲基二异氰酸酯缩合成端基为异氰酸酯的聚乙二醇大分子单体,进而与保护后的壳聚糖链节上的羟基进行选择性地缩合接枝共聚反应,合成聚乙二醇接枝壳聚糖(mPEG-g-CS)共聚物。研究mPEG的用量对接枝率、接枝效率及其在水中的溶胀性质的影响。结果表明:铜离子对氨基的保护作用很有效;mPEG的用量越多,接枝率越高;当mPEG的用量为20g,此时mPEG/CS质量比为5,接枝效率达到最大,为24%;当mPEG/CS质量比为8.75时,平衡溶胀度最高可以达到120%;在水中浸泡同样的时间,mPEG的用量越多,聚乙二醇接枝壳聚糖(mPEG-g-CS)共聚物的溶胀能力越强。更多还原

【Abstract】 Chitosan was selectively grafted by monomethoxy poly(ethylene glycol)(mPEG-OH) in the form of a mPEG-NCO prepared by combining hydroxyl of mPEG-OH with hexamethylene diisocyanate(HDI). The hydrophilic copolymers of chitosan having grafting ratio of methoxy group poly(ethylene glycol) of the maximum about 250% were prepared by condensation reaction of isocyanate group on mPEG-NCO with hydroxy groups on chitosan chains; in the meantime amino groups on chitosan chains were protected by copper ion. The results showed that copper ions was very effective to be used for protection of the amino groups. The graft ratio increased with increasing amount of mPEG. Grafting efficiency increased reaching to the maximum about 24% when mass ratio of mPEG to CS was about 5. Equilibrium swelling degree was up to above 120% when mass ratio of mPEG to CS was about 8.75. The extent of swelling ability of the grafting copolymer increased with increasing the amount of mPEG when mPEG-g-CS was soaked for the same time in water.更多还原