肩袖撕裂后腱骨不愈合是临床上常见的问题，但有效的修复方法和具体分子机制尚未阐明。申请人前期发现取向/无规双相支架能诱导干细胞双向分化，但单纯在支架内接种细胞，接种效力低且细胞分布不均匀，致使细胞分化具有不确定性。申请人前期利用SPIO标记干细胞，发现其能在外磁场作用下产生定向牵引力，能提高细胞在支架上的接种效力。预实验结果表明双相支架内磁性接种磁标记干细胞后，CDR1as/miR-7和FGF2表达激活，双向分化能力形成。据此提出科学假说：外磁场作用下构建的载磁标记干细胞双相支架能促进细胞聚集和粘附，通过调节CDR1as/miR-7/FGF2轴，诱导干细胞向软骨/腱双向分化，促进腱骨一体化修复。本项目拟进一步在细胞学及动物模型中研究载磁标记干细胞双相支架在腱骨一体化修复中诱导干细胞粘附及分化的能力，并阐明CDR1as/miR-7/FGF2轴的分子调控机制，可望为临床修复肩袖撕裂提供新的思路。

The failure of tendon-bone healing after rotator cuff tear still remains a major challenge. We have indicated that the biphasic scaffold (aligned/randomized scaffold) have the ability to induce stem cells differentiation. However, current tissue engineering with low efficiency of seeding cells and inhomogeneous cell distribution results in the uncertainty of cell differentiation, as the fact that cell condensation and adhesion are the critical parameters for cell differentiation. Previously, we used superparamagnetic iron oxide (SPIO) to label bone marrow stromal cells (BMSCs), and found that magnetic field could induce SPIO-labeled BMSCs targeted migration, and further improve the efficiency of seeding cells and promote cell condensation. SPIO-BMSCs magnetic-seeded into a biphasic scaffold would activate the signal of CDR1as/miR-7/FGF2, and promote biphasic differentiation. The hypothesis is that magnetically seeding SPIO-BMSCs in a biphasic scaffold could enhance cell gather and interaction, induce stem cells differentiate into chondrocyte/tendon cells, and further promote tendon-bone healing. In this project, we plan to magnetic seeding SPIO-BMSCs in a biphasic scaffold to further study the mechanism of the signal of CDR1as/miR-7/FGF2 in promoting tendon-bone healing. The development of this project will provide a new theoretical support for clinical practice in the treatment rotator cuff tears.