基于定向光控细胞片技术的血管化组织工程骨膜的构建及相关机制研究

骨膜既是骨皮质的血供来源，也是骨生发的细胞来源，在骨稳态和再生中起着关键作用。但天然骨膜来源有限无法广泛应用于临床，而现有的骨膜组织工程研究尚不完善。申请人前期研究证实，定向成纤维细胞片可分泌有序的细胞外基质并能促进ECs血管化；定向MSCs细胞片保留多向分化潜能且成骨能力得到强化。在此基础上，本研究拟基于定向光控细胞片培养技术探讨构建具有仿生细胞外基质的双层血管化组织工程骨膜的可行性，与3D打印PCL支架复合后在体内外评价其成骨及成血管效果。同时，重点研究定向细胞及方向性细胞外基质在仿生骨膜三维血管网形成中的作用，探讨转录调节子YAP/TAZ如何整合机械力信号与可溶性分子以控制ECs行为，阐明定向成纤维细胞片促进ECs血管化的分子机制。本研究有助于加深对天然骨膜的结构和功能的认识，深化材料拓扑结构调控细胞行为的分子机制，为新型组织工程骨膜的临床应用提供实验基础和理论支持。

The periosteum provides vital blood supply to the cortical bone and acts as the source of bone-forming cells. It plays a critical role in bone homeostasis and regeneration. However, the natural periosteum can’t be widely used in clinical practice because of the limited availability, and previous studies on tissue-engineered periosteum constructs have failed to accurately reproduce the structure and function of the natural periosteum. Our previous studies confirmed that light-induced anisotropic fibroblasts sheets could secrete aligned extracellular matrix and had better pro-angiogenic effects; anisotropic mesenchymal stem cell sheets retained multidirectional differentiation capacity with enhanced osteogenic potential. On this basis, the aim of this study is to explore the feasibility of constructing a double-layer vascularized tissue-engineered periosteum with aligned extracellular matrix by light-induced anisotropic cell sheet technology and photosensitive gel system. The osteogenesis and angiogenesis effects of biomimetic periosteum combined with 3-D printed PCL scaffold will be evaluated in vitro and in vivo. Meanwhile, the role of anisotropic cell sheets and aligned extracellular matrix in the formation of 3-D microvascular network of biomimetic periosteum was studied. The role of YAP/TAZ-based mechanotransduction pathway in cell alignment and differentiation was deeply studied. The molecular mechanism of aligned extracellular matrix promoting ECs vascularization was elaborated. We believe these work will elicit a deeper understanding of the structure and function of the natural periosteum, and provide experimental basis and theoretical support for the clinical application of the new tissue engineered periosteum.