纳米纤维仿生支架可诱导iPSC向心肌细胞分化

目的 利用诱导多能干细胞（induced pluripotent stem cell,iPSC）与纳米纤维仿生支架构建人工心肌，探讨纳米纤维支架用于诱导多能干细胞心肌特异性分化的可行性及潜在作用，为构建组织工程心肌提供参考。方法 采用静电纺丝技术制作聚己内酯/明胶复合纳米纤维仿生支架，接种鼠源Oct4-GFP+ iPSCs培养分化15 d。鼠源Oct4-GFP+ iPSCs同样接种于组织培养皿，培养分化15 d作为对照组。免疫荧光染色检测心肌细胞特异性标志物，流式细胞计数统计心肌细胞分化效率。结果 Oct4-GFP+ iPSCs能够在聚己内酯/明胶复合纳米纤维仿生支架上正常增殖、分化；培养15 d后，Oct4-GFP+ iPSCs在支架上分化出心肌细胞特异性标志物cTnT/MLC2a双染阳性的心肌细胞；而且支架组心肌细胞分化效率显著高于对照组（P<0.05）。结论 聚己内酯/明胶纳米纤维仿生支架支持iPSCs增殖，且能够促进其向心肌细胞分化，适用于组织工程心肌构建。

Nanofibrous bionic scaffolds promote cardiomyocyte differentiation of induced pluripotent stem cells

AIM To explore the viability and the potential role of bionic scaffolds on cardiomyocyte (CM) differentiation of induced pluripotent stem cells (iPSCs). METHODS Oct4-GFP+mouse iPSCs (iPSCs) were cultured on poly-(ε-caprolactone)/Gelatin (PCL/Gelatin) composite nanofibrous bionic scaffolds, which were fabricated by an electrospinning technique and were differentiated spontaneously for 15 days. Oct4-GFP+ mouse iPSCs (iPSCs) cultured on tissue culture plates (TCPs) were used as control. The development of CMs was verified by immunofluorescence staining of cardiac specific markers, such as cardiac Troponin T (cTnT) and myosin light chain 2a (MLC2a). The efficiency of iPSC-derived-CMs was calculated by flowcytometric analysis. RESULTS The results demonstrated that Oct4-GFP+iPSCs proliferated on the PCL/Gelatin composite nanofibrous scaffold and grew in colonies during the spontaneous differentiation period. Immunofluorescence staining after differentiation for 15 days revealed that some of the iPSCs-derived cells were co-labeled with cTnT and MLC2a. Moreover, flowcytometric analysis demonstrated that the ratio of cTnT+-cells derived from iPSCs was significantly higher in PCL/Gelatin scaffolds than in controls (P<0.05). CONCLUSION These results suggest that the PCL/Gelatin composite nanofibrous bionic scaffold could support the proliferation and cardiomyocyte differentiation of Oct4-GFP+ iPSC and could be potentially used as a platform for myocardium tissue engineering.