Incompletely Decellularized Tracheal Matrix Scaffold for Tissue Engineering

Dense cartilaginous extracellular matrix makes decellularization and repopulation of tracheal cartilage difficult. However, the dense matrix isolates cartilaginous antigens from the recipient's immune system. Therefore, allorejection may be avoided by removing antigens from non-cartilaginous tissues. In this study, incompletely decellularized tracheal matrix scaffolds were developed for tracheal tissue engineering.Brown Norway rat tracheae were decellularized with 4% sodium deoxycholate treatment. The cell and antigen removal efficacy, histoarchitecture, surface ultrastructure, glycosaminoglycan and collagen contents, mechanical properties, and chondrocyte viability of the scaffold were evaluated in vitro. Brown Norway rat tracheal matrix scaffolds (n = 6) were implanted subcutaneously into Lewis rats and observed for four weeks. Brown Norway rat tracheae (n = 6) and Lewis rat scaffolds (n = 6) were implanted as controls. Histological analysis of macrophage and lymphocyte infiltration was performed.One decellularization cycle removed all cells and antigens from non-cartilaginous tissue. Incomplete decellularization preserved the structural integrity of the tracheal matrix and chondrocyte viability. Except for 31% glycosaminoglycan loss, the scaffold had comparable collagen content and tensile and compressive mechanical properties to those of the native trachea. The allogeneic scaffold showed remarkably reduced CD68+, CD8+, and CD4+ cell infiltration compared with the allografts and demonstrated similar cell infiltration to the syngeneic scaffold. It also maintained the 3D tracheal structure and cartilage viability in vivo.Incompletely decellularized trachea did not induce immunorejection and maintained the integrity and viability of cartilage in vivo. Tracheal decellularization and repopulation can be significantly simplified for urgent tracheal replacement.The present study describes the development of an incomplete decellularization protocol that creates a decellularized matrix scaffold for tracheal tissue engineering, aiming to provide preliminary data that this method may generate suitable tracheal scaffolds for use in tracheal replacement.