Tissue-engineered tracheal reconstruction using three-dimensionally printed artificial tracheal graft: preliminary report.

Abstract

Three-dimensional printing has come into the spotlight in the realm of tissue

engineering. We intended to evaluate the plausibility of 3D-printed (3DP)

scaffold coated with mesenchymal stem cells (MSCs) seeded in fibrin for the

repair of partial tracheal defects. MSCs from rabbit bone marrow were expanded

and cultured. A half-pipe-shaped 3DP polycaprolactone scaffold was coated with

the MSCs seeded in fibrin. The half-pipe tracheal graft was implanted on a 10 x

10-mm artificial tracheal defect in four rabbits. Four and eight weeks after the

operation, the reconstructed sites were evaluated bronchoscopically,

radiologically, histologically, and functionally. None of the four rabbits showed

any sign of respiratory distress. Endoscopic examination and computed tomography

showed successful reconstruction of trachea without any collapse or blockage. The

replaced tracheas were completely covered with regenerated respiratory mucosa.

Histologic analysis showed that the implanted 3DP tracheal grafts were

successfully integrated with the adjacent trachea without disruption or

granulation tissue formation. Neo-cartilage formation inside the implanted graft

was sufficient to maintain the patency of the reconstructed trachea. Scanning

electron microscope examination confirmed the regeneration of the cilia, and

beating frequency of regenerated cilia was not different from those of the normal

adjacent mucosa. The shape and function of reconstructed trachea using 3DP

scaffold coated with MSCs seeded in fibrin were restored successfully without any

graft rejection.