中文摘要：

目的 制备叶酸偶联的壳聚糖纳米粒. 方法 根据叶酸与壳聚糖的偶联比选择最佳工艺条件,通过叶酸活性酯与壳聚糖上的氨基反应,制得叶酸偶联的壳聚糖,再通过离子交联法制得叶酸偶联壳聚糖纳米粒,并测定纳米粒的粒径和表面电位.结果 正交实验结果显示叶酸活性酯用量和反应温度是影响偶联比的主要因素,在叶酸活性酯与壳聚糖用量比为2：1,反应温度50 ℃,反应时间2 h的条件下可得到偶联比大致为每个壳聚糖分子上偶联3个叶酸分子的叶酸偶联壳聚糖.所制得的纳米粒粒径316 nm,表面电位为（24.85±1.14） mV,透射电镜下观察其形态圆整.结论 该方法可成功制备叶酸偶联壳聚糖纳米粒.

英文摘要：

Objective To prepare and characterize＇ folate-coupled chitosan nanoparticles. Methods Optimal technological conditions were selected according to the coupling ratio of folate and chitosan. Folate-coupled chitosan was prepared by the reaction of the activated folate ester with the amine group on the chitosan. Folate-coupled chitosan nanoparticles were then prepared with the ionic cross-linking method and the average diameter, Zeta potential of the nanoparticles were determined. Results It was shown by the results of an orthogonal test that the amount of the activated folate ester used and the reaction temparature were the main factors influencing the coupling ratio. Folate-coupled chitosan with a ratio of about three folate molecules coupled to one chitosan molecule could be prepared when the ratio of the amounts of the active folate ester to chitosan used was 2 ： 1, the reaction temperature was 50℃ and the reaction time was 2 h. The average diameter and Zeta potential of the nanoparticles were 316 nm and （24.85 ± 1.14） my, respectively. The folate-coupled chitosan nanoparticles were spherical in shape as shown under the transmission election microscope. Conclusion Folate-coupled chitosan nanoparticles could be prepared successfully with the method.