3D-printed resilient biomass-based covered stents for tracheal implants

Commercial airway stents often slip and deform, leading to severe complications such as mucosal injury, granulation tissue formation, and stent migration, which can cause recurrent airway obstruction and necessitate repeated interventions. Here, we introduce a 3D-printed tracheal stent composed of continuous bamboo fiber reinforced shape memory polylactic acid (BF/SMP). These naturally derived fibers (tensile strength ~ 1.90 GPa, modulus ~ 91.30 GPa) exhibit excellent mechanical resilience. Following an instantaneous thermal treatment, their interfacial compatibility with SMP is notably improved. The 30% BF/SMP stent can undergo over 1,000 three-point bending cycles under a 20 N load, with a bending deflection of 30.85%. In vitro, it promotes bronchial epithelial cell proliferation. Preliminary animal studies suggest that the biomass-based stent provides airway support without causing significant inflammation or organ abnormalities. Overall, this work demonstrates a biomass-reinforced, thermally deployable airway stent concept and provides a foundation for future studies on catheter-compatible delivery and long-term in vivo performance.