纯化海藻酸钠在间充质干细胞微囊化中的应用

Application of purified sodium alginate in mesenchymal stem cells microencapsulation

目的应用纯化海藻酸钠(PSA)制备间充质干细胞(MSCs)的微胶囊。方法制备MSCs细胞悬液,MTT法分别测定PSA或海藻酸钠(SA)处理对MSCs增殖的影响。分别以PSA和SA为囊材,制备MSCs的海藻酸钠-聚赖氨酸微囊。倒置显微镜下观察微囊形态;以微胶囊破损率为指标考察其机械强度;EB/Calcein-AM染色并于荧光显微镜下分析微囊化细胞存活率。SD大鼠体内移植试验对比不同回收时间点两种微囊的完整性和囊周纤维化程度。结果MTT法测定结果显示,PSA处理组MSCs的吸光度值明显高于SA处理组。与SA制备的微囊比较,PSA制备的微囊粒径均匀,微囊膜破损率较低,不同时间点的细胞存活率回升明显。SD大鼠体内移植试验显示,SA组回收微囊约25%破损,而PSA组回收微囊的破损率<10%。同时,PSA组囊周纤维化程度低于SA组。结论PSA可应用于MSCs的微囊化中,其具有机械强度高及生物相容性好的优点。

Objective To prepare mesenchymal stem cells （MSCs） loaded microcapsules using purified sodium alginate （PSA）. Methods MSCs cell suspension was prepared and the effects of purified and non-purified sodium alginate （SA） on MSCs＇s proliferation were measured using MTT assay. MSCs loaded alginate-polylysine microcapsules were prepared using PSA and SA, respectively. Micro- capsule morphologies were observed under inverted microscope, the broken rate of microcapsules was adopted as an index to investigate their mechanical strength, and viabilities of microencapsulated MSCs were measured through EB/Calcein-AM staining. Moreover, two kinds of microcapsules were retrieved to compare their morphologies and pericapsular fibrosis after transplantation in SD rats for different times. Results MTT assay results indicated that OD values of PSA group were much higher than those of SA group. Microcapsules of PSA group had uniform particle diameter, low broken rate, and significant rally of cell viabilities of microencapsulated MSCs. In vivo experiments revealed that microcapsules obtained of SA group had a broken rate of about 25% , while less than 10% of PSA group. And the fibrosis rate of PSA group was lower. Conclusion PSA, which bears the advantages of high membrane mechanical strength and improved biocompatibility, could be applied in the microencapsulation of MSCs.