Fabrication of a three-dimensional scaffold-free trachea with horseshoe-shaped hyaline cartilage

Abstract OBJECTIVES Tracheal regeneration is challenging owing to its unique anatomy and low blood supply. Most tracheal regeneration applications require scaffolds. Herein, we developed bio-three-dimensional-printed scaffold-free artificial tracheas. METHODS We fabricated bio-three-dimensional-printed artificial tracheas. Their anterior surface comprised hyaline cartilage differentiated from mesenchymal stem cells, and their posterior surface comprised smooth muscle. Human bone marrow-derived mesenchymal stem cells were cultured and differentiated into chondrocytes using fibroblast growth factor-2 and transforming growth factor-beta-3. Initially, horseshoe-shaped spheroids were printed to cover the anterior surface of the artificial trachea, followed by the application of human bronchial smooth muscle cells for the posterior surface. After a 3-week maturing process, the artificial trachea was subjected to histological and immunohistochemical analyses. RESULTS The anterior surface of the artificial trachea comprised well-differentiated hyaline cartilage from human bone marrow-derived mesenchymal stem cells. Immunohistochemistry revealed that the smooth muscle expressed α-smooth muscle actin and smooth muscle myosin heavy chain 11. CONCLUSIONS A bio-three-dimensional-printed scaffold-free artificial trachea comprising different tissues at the front and back was successfully fabricated. Tracheal replacement is challenging because of the unique anatomy and physiology of the trachea. Graphical Abstract