De novo Tracheal Cartilage Regeneration in a Porcine Model According to a Proposed 5-Stage Chondrogenesis Process after Transplanting a 3D-printed Tracheal Graft

Abstract

Abstract Vivid neo-cartilage growth was detected with initially outnumbered chondrocytes in the porcine model following transplantation of a three-dimensional (3D)-printed tracheal graft. Virtual silicone tracheal grafts, each of 2 cm long, were first generated with a 3D printer, and underwent a physical stress test to resemble a trachea from the 3-month-old porcine. The grafts underwent end-to-end anastomosis for the proximal and distal parts of the trachea after cuff resection. Tissue samples were grossly examined, and their histological properties examined by protein expressions through the use of H&E, alcian blue, safranin O/fast green stain and immunohistochemistry (IHC) assay for Sox9, type II collagen, aggrecan and PCNA, respectively. These primitive cartilages showed chondrogenesis with outnumbered chondrocytes, and they evolved to a mature stationary status with cartilage corrosion through interim PP, PRL and VC chondro-modulators elaborated from perichondrium. Matrix degradation products with alcian blue staining were removed to VCs, and the adjacent mucosal and submucosal glands. Chondrogenesis underwent an incipient burst of growth in conjunction with the perichondrium involving a process of graduate consolidation, as evidenced by matrix degradation product emissions on the mucosa and submucosa. We proposed 5 stages to characterize the regenerative chondrogenesis of the tracheal cartilage.