【摘要】 背景:大量研究表明经过半乳糖修饰的材料可以显著改善肝细胞的黏附能力,进而影响肝细胞的形态和功能。静电复合制备的微胶囊被广泛应用于细胞包裹、酶固定和药物包埋等诸多领域,但国内外未见以壳低聚糖和海藻酸钠制备微胶囊用于肝细胞包裹的研究。目的:制备一种新型用于肝细胞包裹的半乳糖化海藻酸钠-壳低聚糖微胶囊。方法:对海藻酸钠进行半乳糖化修饰,红外光谱、核磁共振谱和元素分析表征半乳糖化海藻酸钠的合成。浊度法研究壳低聚糖的水溶性。采用一步法制备半乳糖化海藻酸钠-壳低聚糖微胶囊,研究制备过程中半乳糖化海藻酸钠含量(半乳糖化海藻酸钠与海藻酸钠的质量比分别为100%,50%,30%,0)和静电反应成膜时间(5,10,20min)对微胶囊的影响。结果与结论:对于半乳糖化海藻酸钠的合成,红外光谱表明了羧基峰的消失和C-N键的形成;核磁共振谱表明产物中不但出现了乳糖酸中对应的峰,而且还偶合了一部分碳二亚胺的分子链;元素分析计算出半乳糖接枝含量为20%,偶合到海藻酸钠分子链中的碳二亚胺含量为8%。半乳糖修饰对微胶囊制备的影响为:半乳糖的引入在一定程度上削弱了海藻酸钠分子链上负电荷的密度,影响了静电复合成膜的过程。结果表明只有当半乳糖化海藻酸钠与海藻酸钠以小于1∶1的质量比混合时,才能得到力学稳定的微胶囊。更多还原

【Abstract】 BACKGROUND: Numerous studies showed that material surface modified with galactose can improve adhesion of hepatocytes, and then affect morphology and functional expression of hepatocytes. Microcapsule prepared by electrostatic complex has been widely used in cell encapsulation, enzyme immobilization, drug controlled release and etc. However, there is no report on hepatocytes encapsulated into the microcapsule prepared with chitosan oligomer and alginate sodium. OBJECTIVE: To prepare a novel galactosylated alginate-chitosan oligomer microcapsule for hepatocytes encapsulation. METHODS: The synthesized galactosylated alginate was characterized with Fourier transform infrared spectra, nuclear magnetic resonance spectroscopy, and elemental analysis. The solubility of chitosan oligomer was studied by turbidimetric method. The effect of preparation conditions on the microcapsule was finally studied, including content of galactosylated alginate (100%, 50%, 30%, 0) and membrane formation time (5, 10, 20 minutes). RESULTS AND CONCLUSION: For the synthesis of galactosylated alginate, Fourier transform infrared spectra indicated the disappearance of carboxylic groups and the formation of C-N bonds. Nuclear magnetic resonance spectroscopy suggested that not only the peak corresponding to lactobionic acid appeared in the product, but also some ethyl (dimethylaminopropyl) carbodiimide chains were coupled. According to elemental analysis, the calculated galactose grafting content was 20%, and the coupling ethyl (dimethylaminopropyl) carbodiimide C was 8%. Due to decrease of the negative charge of the alginate molecular chains after coupling, the electrostatic complex membrane formation was affected. The microcapsules possessing mechanical stability can be obtained when the content of galactosylated alginate sodium is lower than 50% in the mixture of galactosylated alginate sodium and alginate sodium.更多还原