组织工程技术可以再生大体积管状软骨，有望解决长段气管修复的临床难题，但大动物节段性气管缺损的长期功能重建一直未获突破。申请人前期研究发现，修复术后移植段管状软骨腔内肉芽增生导致的管腔狭窄，是动物早期死亡的主要原因，而气管移植物内壁早期缺乏上皮化是肉芽增生的主要原因。本项目提出将口腔粘膜上皮作为上皮化的种子细胞来源，通过裸鼠体内实验证实口腔粘膜上皮作为上皮化种子细胞来源的可行性，确定最优的上皮化方案及技术参数，并用于大动物气管旁构建带血供上皮化气管移植物。利用此移植物修复气管节段性缺损，探讨口腔上皮在气道微环境内向气道上皮转化的可能性与相关机制，以及预上皮化对减轻术后肉芽增生的有效性。同时改进手术吻合技术，优化支撑管的放置方式，加强术后护理，实现全面预防及治疗肉芽增生，提高气管修复术后早期存活率，最终建立气管缺损长期功能重建的大动物模型。

Tissue engineering technique, which can regenerate cartilage with certain volume, made a new promising strategy for solving the problem of reconstructing segmental tracheal defect. However, no breakthrough has been achieved so far for the treatment of the segmental tracheal defect in large animals, which impeded the clinical translation of the tissue engineering tracheal (TET) technique. According to our previous study, the important reason for susceptible death post-operation was the acute hyperplasia of granulation in the lumen of TET graft. The hyperplasia of granulation related to the lack of epithelium in the lumen of TET graft post-operation. In order to address the problem, this project proposes to use oral epithelial cells as seed cells for epithelization of TET. Firstly, regenerating epithelialized and vascularized tubular cartilage in nude mice by three different strategies and expressing the optimal epithelization strategy. Secondly, constructing epithelialized and vascularized cartilage graft in goat model by the optimal strategy. Finally, we would reconstruct segmental tracheal defect by the graft in goat model. Through combining the optimal epithelization strategies with improved stenting strategy and nursing care post-operation, it is possible to prevent and treat the granulation hyperplasia, and establish a large animal model of segmental tracheal defect reconstruction in this project. Furthermore, the project would also demonstrate the possibility mechanisms of transformation from oral epithelia cells to airway epithelium in airway environment.