Regenerative Process of Tracheal Epithelium Using a Collagen Vitrigel Sponge Scaffold

Objectives/Hypothesis: Our group has developed a collagen vitrigel sponge scaffold containing basic fibroblast growth factor (b-FGF) for tracheal reconstruction. In this study, we have investigated the regenerative process of tracheal epithelium histologically and morphologically. Study Design: A preliminary animal experiment. Methods: A collagen vitrigel sponge scaffold was fabricated with simultaneous addition of 100 ng b-FGF. Tracheotomies were performed, and collagen vitrigel sponge scaffolds were implanted on tracheal defects in rats. At 5, 7, and 14 days after implantation, the intraluminal surface of the regenerated tracheae was observed using endoscope. Histological examination of the intraluminal regenerated trachea was performed using light microscope and scanning electron microscope. Results: Endoscopic images showed epithelial regeneration at 7 days after implantation. Light microscopic examination detected stratified epithelium at 5 days, columnar cells at 7 days, and ciliated cells at 14 days after implantation. Scanning electron microscopy images showed regenerated epithelial cells at 5 and 7 days, and ciliated cells at 14 days after implantation. Conclusions: The horizontal section and luminal area of the regenerated epithelium were investigated. The epithelium was formed at 5 days, and mature cilia were found at 14 days after implantation. Epithelium of equality equivalent to normal trachea was regenerated in a rat model with collagen vitrigel-scaffold containing b-FGF at 14 days.