Potential of Induced Pluripotent Stem Cells for the Regeneration of the Tracheal Wall

Objectives: Our previous studies focused on basic research and the clinical applications of an artificial trachea. However, the prefabricated artificial trachea cannot be utilized for pediatric airways, because the tracheal frame needs to expand as the child develops. The purpose of this study was to evaluate the potential of induced pluripotent stem (iPS) cells for the regeneration of the tracheal wall. Methods: We cultured iPS cells in a 3-dimensional (3-D) scaffold in chondrocyte differentiation medium (bioengineered scaffold model), and the results were compared with those in a 3-D scaffold without iPS cells (control scaffold model). The 3-D scaffolds were implanted into tracheal defects in 8 nude rats. After 4 weeks, the regenerated tissue was histologically examined. Results: Implanted iPS cells were confirmed to exist in all 5 rats implanted with bioengineered scaffolds. Cartilage-like tissue was observed in the regenerated tracheal wall in 2 of the 5 rats in the bioengineered scaffold model, but in none of the 3 rats in the control scaffold model. Conclusions: Implanted iPS cells were confirmed to exist in the bioengineered scaffold. Cartilage-like tissue was regenerated in the tracheal defect. This study demonstrated the potential of iPS cells in the regeneration of the tracheal wall.