Multilayer coating of a 3D-printed tracheal stent prevents tracheal stenosis

Stents are hollow tubular medical devices for unblocking conduits; the most common of these are coronary stents. Stents are also used for other organs, such as tracheal stents to treat airway stenosis. However, the clinical performance of conventional tracheal stents is limited by the improper size and lack of an active drug, leading to stent mitigation and restenosis. In the current study, a customized C-type tracheal stent (C-stent) was rationally designed and precisely three-dimensional (3D)-printed to match the individual tracheal geometry. The C-stent was layer-by-layer coated with curcumin chitosan nanoparticles and hyaluronic acid (HA) by electrostatic adsorption in turn, endowing the stent with better toughness, visible monitoring, and sustained drug release. The functional layers of the coated C-stent (curcumin-loaded C-stent, Cur-C-stent) effectively inhibited MRC-5 fibroblast cells by curcumin, and remarkably promoted Beas-2B epithelial cells in the presence of HA. The curcumin was sustainedly released from the implanted Cur-C-stent and took effect at the site of the injured airway. A 3D-printed muricate stick was used to establish tracheal stenosis in rat models by scratching the inner airway wall. The implanted Cur-C-stent effectively prevented tracheal stenosis by reducing collagen deposition and inflammation, while simultaneously promoting tracheal epithelial healing and alleviating secondary lung injury. The Cur-C-stent shows great promise in preventing airway stenosis after tracheal trauma and promoting wound healing.