细胞膜片技术是现代再生医学的一个研究热点，骨髓间充质干细胞（BMSC）膜片已广泛用于骨缺损的修复与再生。血管化一直是制约骨组织再生效果的瓶颈，如何实现膜片的快速血管化以达到理想的基于BMSC膜片的骨再生是非常有意义的一个科学问题。本课题组前期在国际上首次采用非病毒转染技术将antimiR-138转入BMSC膜片后发现其可显著提高BMSC膜片的成骨能力，同时考虑到miR-126对血管内皮细胞在血管发生中的重要促进作用，我们提出将antimiR-138修饰的BMSC膜片与miR-126修饰的血管内皮细胞连续共培养来构建预血管化BMSC膜片，体内外实验对其骨再生和血管生成作用进行系统评估，并探讨其快速血管化的分子机制。本研究有望成功构建血管化BMSC膜片，为骨组织工程血管化提供新的思路，亦为miRNA在再生医学中的应用提供更多的证据，为miR-126促血管化的分子机制提供更深入的理解。

Currently, the cell sheet engineering has attracted increasing attention in the field of regenerative medicine. In particular, the bone marrow mesenchymal stem cell (BMSC) based cell sheet engineering has already been applied for the repair and regeneration of bone tissue defects. However, the main hurdle of current bone tissue engineering is how to obtain sufficient blood supply to the bone tissue graft. One good strategy for overcoming this obstacle could be the development of prevascularized BMSC sheet based tissue constructs before transplantation. Based on our previous study, we have successfully delivered antimiR-138 to the BMSC sheets by using the non-viral way. To our knowledge, this is the first attempt to use the non-viral approach to deliver oligonucleotides to the cell sheets. We also find that that the antimiR-138 delivery significantly enhances the osteogenesis of BMSC sheets. Moreover, considering the interactions of miR-126 with the vascular endothelial cells (EC) play a crucial role in the development of angiogenesis and the maintenance of vascular integrity, we plan to co-culture the antimiR-138 delivered BMSC sheets with the miR-126 overexpressed endothelial cells to fabricate the prevascularized cell sheets containing the capillary-like networks in vitro. A systemic study will be conducted on the osteogenesis and angiogenesis effects of the miRNA-MSC/EC sheets. Then, we will try to uncover the underlying molecular mechanism for the fast vascularization of the miRNA-MSC/EC sheets. Our present study aims to successfully construct the prevascularized miRNA-MSC/EC sheets, which may provide new idea for the development of vascularized tissue engineered bone. Meanwhile, the results also provide more evidences to support the application of miRNA delivery technology in the regenerative medicine.