Bio-Printed PCL Tracheal Graft in a Large Animal Model: Reproducible Short-Segment Regeneration and Preliminary...

Area of Science:

• Biomaterials Science
• Regenerative Medicine
• Surgical Innovation

Background:

• Three-dimensional (3D) bioprinting offers customizable, biodegradable scaffolds for airway reconstruction and tissue regeneration.
• Previous work demonstrated successful 2 cm bioprinted tracheal graft survival exceeding three months in a large-animal model.

Purpose of the Study:

• To explore the feasibility and regeneration patterns of long-segment (≥4 cm) 3D bioprinted polycaprolactone (PCL) tracheal grafts in a porcine model.
• To identify translational barriers for long-segment tracheal reconstruction.

Main Methods:

• Extrusion-based 3D bioprinting of PCL tracheal grafts.
• Implantation in a porcine model using end-to-end anastomosis and mechanical stabilization.
• Serial bronchoscopic surveillance, gross examination, and histological analysis.

Main Results:

• Two cm PCL grafts achieved reproducible survival (>3 months) with refined surgical techniques and postoperative care.
• Histological analysis confirmed multi-lineage tissue formation, including cartilage, muscle, glands, and epithelium.
• Cartilage regeneration showed staged maturation; epithelium remained immature by 12 weeks.
• A single long-segment graft demonstrated initial technical feasibility but lacked long-term data.

Conclusions:

• 2 cm PCL tracheal grafts show regenerative potential in a large-animal model.
• Long-segment tracheal reconstruction faces significant translational barriers, including fabrication, biomechanics, and epithelial maturation.
• Further systematic investigation is required before clinical application of long-segment bioprinted tracheal grafts.