酶法制备壳寡糖及其抗肿瘤活性评价

为进一步分析壳寡糖抗肿瘤活性及其机制,采用酶法制备工艺获取组分清晰的壳寡糖,优化酶解条件为酶解时间4 h、加酶量120 U/g,结合乙醇沉淀、超滤和纳滤联用的工艺获得聚合度2～4的壳寡糖。比较评价壳寡糖及其与阿霉素联用对3种肿瘤细胞的抑制效果,其中作用最为明显的人乳腺癌MDA-MB-231的细胞生存率降低20%。利用细胞迁移实验和激光共聚焦分析机制,得出壳寡糖可抑制MDA-MB-231细胞迁移并促进阿霉素入核。由此说明,壳寡糖可增强MDA-MB-231细胞对阿霉素的敏感性。

Preparation of Chitosan Oligosaccharides by Enzymatic Hydrolysis and Evaluation of Antitumor Activities

To further analyze the antitumor activities and mechanism of chitosan oligosaccharides,enzymatic hydrolysis method was applied to obtain chitosan oligosaccharides with clear composition. The optimized enzymatic hydrolysis conditions were 4 h of reaction time and 120 U/g for the ratio of enzyme and substrate dosage. Chitosan oligosaccharides with degree of polymerization 2 to 4 were obtained by ethanol precipitation, ultrafiltration and nanofiltration. Comparative evaluation of inhibitory effect on three tumor cell lines was conducted with chitosan oligosaccharides and its combination with doxorubicin. The most significant effect was observed on the cell viability of human breast cancer MDA-MB-231 with 20% reduction. Cell migration assay and confocal laser scanning microscopy (CLSM) were used for mechanism analysis, which showed that chitosan oligosaccharides could inhibit cell migration and facilitate doxorubicin to enter the nucleusin MDA-MB-231 cells. The results implied chitosan oligosaccharides could enhance the sensitivity of MDA-MB-231 cells to doxorubicin.