Bioengineered grafts for laryngotracheal reconstruction

项目摘要/摘要 严重的声门下狭窄，声带正下方的呼吸道变窄，是对 在美国，每年有近10%的早产儿接受插管治疗。严重情况下需要 喉-气管重建术，外科医生将环状软骨切开，并添加一块自体患者- 衍生的软骨可以扩张呼吸道，恢复正常的气流。然而，在儿童中，成功率是 低至50%，再狭窄发生率高，需要翻修手术。移植物的失败直接与缺乏 儿童足够大小的自体软骨，组织工程学已经被提出要发展 可供选择的儿童LTR移植选择。一些方法，包括我们以前的一些工作，已经 在生产功能性软骨方面是有效的，但构建匹配所需的总体时间框架 天然软骨的力学性能(24周)与临床移植(8周)不相容。 此外，目前的细胞来源，如扩增的自体软骨细胞和间充质干细胞 通常会导致组织肥大和钙化。我们的目标是设计一种新型的软骨 植入物由患者细胞填充，机械上可行，适合临床上的LTR 相关的时间框架。我们的方法是利用血管和弹性蛋白纤维，这些纤维独特地存在于 酶促半月板纤维弹性软骨形成有效再细胞化的微通道 去细胞。我们正在申请专利的半月板脱细胞支架(MEND)技术确实可以很容易地 再细胞化，具有与天然气管软骨相同数量级的机械性能。此外， 软骨前体细胞被认为是一种快速增殖、高度软骨形成的细胞来源。至 利用这些细胞，我们开发了一种微创活组织检查程序来采集耳软骨 祖细胞(ECCs)。我们的主要假设是，Mend和ECPC可以结合在一起创建 具有适合个性化的机械强度、尺寸和表型稳定性的软骨植入物， 微创LTR。我们建议使用含有内皮祖细胞的Mend来组织工程化软骨。 特性与天然软骨的特性相匹配。然后我们将在证明中验证修复工程的软骨- OF-概念性兔LTR模型。我们期望我们的发现将提供强有力的临床前证据 通过我们创新的ECPC-Mend技术修复喉气管软骨，从而促进进一步 最终将这项技术应用于恢复儿童呼吸道的研究。

PROJECT SUMMARY/ABSTRACTS Severe subglottic stenosis, the narrowing of the airway just below the vocal folds, develops as a response to intubation in close to 10% of the > 20,000 premature births per year in the United States. Severe cases require laryngotracheal reconstruction (LTR), in which surgeons split the cricoid and add a piece of autologous patient- derived cartilage to expand the airway and restore proper airflow. However, in children, the success rate is as low as 50% with a high incidence of restenosis requiring revision surgery. Graft failure is tied directly to the lack of sufficiently sized autologous cartilage in the child, and tissue engineering has been proposed to develop alterative grafting options for pediatric LTR. Some approaches, including some of our previous work, have been effective in producing functional cartilage, but the overall timeframe required for the construct to match the mechanical properties of native cartilage (>24 weeks) is not compatible with clinical translation (<8 weeks). Furthermore, current cell sources such as expanded autologous chondrocytes and mesenchymal stem cells frequently result in hypertrophic and calcified tissue. Our objective is to engineer a new type of cartilage implant that is populated with patients’ cells, mechanically viable and suitable for LTR within a clinically relevant timeframe. Our approach is to exploit the blood vessels and elastin fibers that are uniquely present in the fibro-elastic cartilage of the meniscus to form microchannels for effective recellularization after enzymatic decellularization. Our patent-pending Meniscal Decellularized scaffold (MenD) technology can indeed be easily recellularized and has mechanical properties of the same order as native tracheal cartilage. Furthermore, cartilage progenitor cells have been proposed as a rapidly proliferating, highly chondrogenic cell source. To harness these cells, we have developed a minimally invasive biopsy procedure to harvest ear Cartilage Progenitor Cells (eCPCs). Our overarching hypothesis is that MenD and eCPCs can be combined to create cartilage implants with suitable mechanical strength, dimensions, and phenotypic stability for personalized, minimally invasive LTR. We propose to use MenD recellularized with eCPCs to engineer cartilage with tissue properties matching those of native cartilage. We will then validate the MenD-engineered cartilage in a proof- of-concept rabbit LTR model. We expect that our findings will provide strong pre-clinical evidence of functional laryngotracheal cartilage repair by our innovative eCPC-MenD technology and will thereby prompt further studies to eventually apply this technology to restore children’s airway.