壳低聚糖-海藻酸钠微胶囊的制备与表征

Preparation and performance of alginate-oligochitosan microcapsules

目的:探索了壳低聚糖-海藻酸钠微胶囊的制备方法和工艺条件,分析了微胶囊膜的厚度、机械强度、通透性等性能,对比得出性能最佳的壳低聚糖-海藻酸钠微胶囊。方法:改变壳低聚糖溶液pH值和成膜反应时间来制备微胶囊,用倒置相差显微镜观察并计算膜厚,用回旋式振荡器、AG-10TA万能测试仪对微胶囊膜力学强度进行检测,用牛血清白蛋白做蛋白释放对膜通透性等性能进行检测。结果:壳低聚糖溶液pH值为7时制备的微胶囊膜厚随反应时间的增加而增加。该条件下制备的微胶囊的压缩模量在成膜反应10min时已达到5.12kPa,通过回旋式振荡器振荡6h无一破损。微胶囊的蛋白释放随成膜时间的增加而减小。当成膜反应10min时,微胶囊的蛋白释放率随盐离子浓度增加而减小。当成膜时间延长后,微胶囊的蛋白释放率随盐离子浓度的增加而增加。结论:用壳低聚糖在溶液pH值为7时制备出的微胶囊力学性能较好。此种微胶囊膜的通透性在较短成膜时间下主要受到膜厚的影响;当成膜时间延长,膜的致密度则成为其主要影响因素。

OBJECTIVE： To investigate the preparation conditions of the oligochitosan-alginate microcapsules and analyze the membrane thickness, mechanical strength and permeability so as to make a rnicrocapsule with the best performance. METHODS： The rnicrocapsule was prepared by changing the pH value of the oligochitosan solution and reaction time. Inverted phase contrast microscope was used to observe and calculate the membrane thickness. Mechanical strength of microcapsule was determined with a shaker and a pressure testing machine. Membrane permeability was estimated with bovine serum albumin （BSA） release profiles. RESULTS： Membrane thickness of the rnicrocapsule was increased with the increase of the reaction time when the pH value of the oligochitosan solution reached 7. Under this condition, the compress modulus of the rnicrocapsule had reached 5.12 Kpa after 10 minutes and none of them damaged after shaking for 6 hours. Protein release rate of the rnicrocapsule decreased with the increase of reaction time. When reaction for 10 minutes, protein release rate decreased with the increase of the concentration of salt ions; however, protein release rate increased with the increase of the concentration of salt ions after 20 minutes. CONCLUSION： The microcapsules prepared under the pH value 7 exhibited good mechanical properties. The membrane permeability, under short reaction time, was mainly affected by membrane thickness. However, the membrane permeability was mainly affected by membrane density when reaction time was prolonged.