Construction of multifunctional tracheal substitute based on silk fibroin methacryloyl and hyaluronic acid methacryloyl with decellularized cartilaginous matrix for tracheal defect repair

The regeneration and functional recovery of tracheal tissue are of paramount importance in the research of tissue-engineered trachea. Current constructs still face some limitations in simulating the complex natural microenvironment and achieving better regenerative capacity and functional recovery. To address these challenges, the application of hydrogels with three-dimensional (3D) network structure and extracellular matrix derived from decellularized tissues and cells has become a more promising strategy. This study aims to introduce a novel bilayer multifunctional tissue-engineered tracheal substitute. Firstly, the mesh polycaprolactone (PCL) scaffold was printed by 3D printing technology, and the concentration of Silk Fibroin Methacryloyl (SilMA) hydrogel suitable for cell adhesion and proliferation and the concentration of Hyaluronic Acid Methacryloyl (HAMA) hydrogel suitable for 3D culture of chondrocytes were selected. Subsequently, the decellularized cartilaginous matrix (DCM) solution was obtained and the concentration that promotes chondrocyte proliferation and migration was screened. Finally, the multifunctional tracheal substitute, which features a HAMA-DCM composite hydrogel loaded with autologous chondrocytes as the basic framework to simulate the outer cartilaginous layer, and a 3D-printed PCL mesh scaffold coated with SilMA hydrogel loaded with autologous epithelial cells serves as internal support to simulate the inner airway epithelial layer, was prepared. Whether it was for repairing window-shape defect for 8 w or conducting long-segment in situ transplantation for 12 w, it achieved satisfactory surgical outcomes, including epithelial crawling, cartilage regeneration, and vascular remodeling.