口腔粘膜上皮构建上皮化带血供组织工程气管用于建立气管功能重建大动物模型

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.

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。

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。在课题的前期研究过程中发现，修复术后移植段管状软骨腔内大量肉芽增生，这导致气管管腔狭窄，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。本项目将口腔粘膜上皮作为上皮化的种子细胞来源，通过动物体内实验证实了口腔粘膜上皮作为上皮化种子细胞来源的可行性，同时确定最优且临床易行的上皮化方案，并用于大动物气管旁构建带血供上皮化气管移植物。同时进一步证实管状软骨血供丰富且明确对于预上皮化成功以及预防气管内肉芽组织增生的重要性，故项目进一步改进预血管化方案，构建出血供明确的上皮化管状软骨移植物。项目利用此移植物修复气管节段性缺损，目前已有大型哺乳动物存活，通过对不同时间点呼吸功能以及移植物的检测，进一步确定口腔粘膜上皮对于抑制气道内肉芽组织增生的重要性。该项目为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奠定了理论及技术基础，将组织工程气管最终实现临床应用的目标又向前推进了一步。