壳聚糖/海藻酸盐微胶囊膜的物质扩散性能研究

Study on membrane diffusivity of chitosan/alginate microcapsules

针对微囊化细胞三维培养研究背景,以壳聚糖、海藻酸钠为微载体制备材料,采用脉冲电场液滴工艺制备海藻酸钙微球,使之与壳聚糖溶液通过聚电解质络合反应生成选择透过性微囊膜.以传统细胞培养的重要碳源葡萄糖与柠檬酸、氮源L-谷氨酸为小分子模型,以聚乙二醇为测定微囊膜截留相对分子质量的模型分子,开展微胶囊传递性能研究.结果表明,葡萄糖、柠檬酸和L-谷氨酸可以自由透过微囊膜扩散,并且柠檬酸和L-谷氨酸能通过竞争螯合Ca2+引起微囊凝胶结构解聚;采用20mg/mL海藻酸钠溶液与5万相对分子质量、2mg/mL壳聚糖溶液制备微胶囊,囊膜的截留相对分子质量为1500.

Based on three-dimensional culture system of cell microencapsulation, using chitosan and sodium alginate as the microcarrier preparation materials, the alginate-Ca gel beads are prepared by the impulsive electrostatic preparation process, then the alginate -Ca gel beads react with the solution of chitosan by polyelectrolyte interconnection, so the selective permeability membrane of microcapsule is made. Glucose and citric acid are the necessary carbon source for the cell culture, and L -glutarnic acid is the nitrogen source. In this work, using these subjects as the low molecule models, and a series of poly（ethylene glycol）s （PEG） of different molecular mass as the high molecule models to study the molecular mass cut-off（MMCO） the diffusivity of chitosan/alginate microcapsules were investigated. Experimental results show that glucose, citric acid and L - glutamic acid can diffuse through the membrane freely, and the gel structure in the microcapsules is depolymerizated by competitively chelating Ca^2＋ with the ingress of citric acid and L - glutamic acid. The molecular mass cut-off（MMCO） of microcapsules prepared with 20 mg/mL sodium alginate and fifty thousand molecular mass,2 mg/mL chitosan is 1 500.