Tissue engineering of the head and neck organs

本研究的目的是将头颈癌手术后的功能障碍降至最低。应用原位组织工程技术修复头颈部器官的外科缺损。作为呼吸道再生的组织支架，胶原蛋白海绵覆盖的螺纹增强聚丙烯网管用于自然组织再生。在Beagle犬的实验研究中，切除颈、胸段气管，并将支架植入缺损处。切除环状软骨的前半部分，部分支架用补片缝合。所有犬术后3~60个月内窥镜检查均未见呼吸道阻塞。有些狗虽然都没有症状，但有肉芽组织和轻微的网眼裸露。光镜和电子显微镜显示喉腔和气管内腔被纤毛上皮覆盖。基于力学测试的应变-力测量，支架由再生组织以及正常的环状软骨和气管牢固地支撑。为了实现声带再生，用聚丙烯网片制作了喉内表面可复制的声带支架。对一只比格犬进行半喉切除，植入含有骨髓基质细胞的支架以修复缺损。术后一年，支架上的组织再生获得。在成功的实验动物研究基础上，将目前的再生技术应用于一例甲状腺癌患者的气管修复。27个月来，气管管腔表面上皮化良好，无任何并发症。这项技术避免了气管切开、第二次手术和畸形。组织工程技术用于头颈部器官的再生是可行的。

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.