A self-expandable C-shaped 3D printing tracheal stent for combinatorial controlled paclitaxel release and tracheal support

Current tracheal stents palliatively relieve malignant tracheal stenosis but cannot treat the tumor, resulting in the occurrence of restenosis due to tumor progressive over-growth. Moreover, the stents block the entire tracheal mucosa contact with them and thus prevent mucus/sputum discharge, causing an airway blockage. In order to overcome those shortcomings, we study a novel self-expandable C-shaped tracheal stent loaded with paclitaxel (PTX), which consists of an inner poly (ε-caprolactone) layer, a middle Fe₃O₄ magnetic nanoparticles loaded poly (ε-caprolactone) layer and an outer PTX-loaded ethylene-vinyl acetate copolymer layer containing phase-change 1-hexadecanol. The C-shaped tracheal stents are easily fabricated on a roller by using a self-made specific three-dimensional printer. It is found that the stents present unidirectional PTX release, good self-expanding and appropriate trachea supporting properties, and generate heat to raise temperature under an alternating magnetic field, which facilitates temperature-responsive PTX release and permeation in tracheal tissue. The stents have good biosafety in rabbits and keep airway patency for the investigated period (1 month) without the occurrence of mucus/sputum blockage after implantation in rabbit trachea. This study provides a scientific basis for the development of novel self-expandable C-shaped tracheal stents with combinatorial tracheal support and local chemotherapy.