Tissue engineering of the head and neck organs

本研究的目的是尽量减少头颈部肿瘤手术切除后的功能障碍。应用原位组织工程技术修复头颈部器官缺损。作为气道再生的组织支架材料，我们研制了一种表面包覆胶原蛋白海绵的聚丙烯网状管，用于组织的自然再生。在比格犬的实验研究中，切除颈胸段气管，将支架植入缺损处。切除环状软骨的前半部分，用补片缝合植入部分支架。内窥镜检查显示所有犬术后3至60个月均无气道阻塞。一些犬中存在肉芽组织和轻微补片暴露，但均无症状。光镜和电镜下可见纤毛上皮覆盖的喉内腔和气管内腔。根据应变力测量和力学测试，支架被再生组织以及正常环状软骨和气管牢固地支撑。为了声带再生，使用聚丙烯网片开发具有复制的喉内表面的支架。在Beagle犬半喉切除术后，植入含骨髓基质细胞的支架重建缺损。手术后一年，支架上的组织再生得以实现。基于成功的实验动物研究，当前的再生技术应用于甲状腺癌患者的气管修复。术后27个月，气管腔表面上皮化良好，无并发症发生。该技术避免了气管切开术、二次手术和畸形。组织工程技术为头颈部器官的再生提供了可能。

The purpose of the current study is to minimize the functional disability after the surgical resection of the head and neck cancer. In situ tissue engineering technique was applied for the reconstruction of the surgical defect in the head and neck organs. As the tissue scaffold for airway regeneration, polypropylene mesh tube reinforced with threads covered by collagen sponge was developed for natural tissue re-growth. In the experimental study with beagle dogs, the cervical and thoracic trachea was resected and the scaffold was implanted into the defect. The anterior half of the cricoid cartilage was resected and a part of the scaffold was implanted with patch suture. Endoscopic examination showed no airway obstruction postoperatively for the period from 3 to 60 months in all dogs. There was granulation tissue and slight mesh exposure in some dogs although they were all asymptomatic. Light microscopy and electron microscopy showed the endolaryngeal and endotracheal lumen covered by the ciliated epithelium. Based on strain-force measurement with mechanical test, framework was firmly supported by regenerated tissue as well as the normal cricoid and trachea. For vocal fold regeneration, the scaffold with replicated inner laryngeal surface was developed using polypropylene mesh sheet. With hemilaryngectomy in a beagle dog, the scaffold with bone marrow derived stromal cells was implanted for reconstruction of the defect. Tissue regeneration over the scaffold was obtained one year after the surgery. Based on the successful experimental animal studies, the current regenerative technique was applied for repair of the trachea of a patient with thyroid cancer. Good epithelization has been observed on the tracheal luminal surface without any complication for twenty seven months. This technique avoided tracheotomy, a second operation, and deformity. Tissue engineering technique will be feasible for regeneration of head and neck organs.