Design, fabrication, and in vitro studies of sustained paclitaxel release from 3D-printed TPU/P407 airway stents for treating airway stenosis

• The drug release rate can be regulated by adjusting Poloxam407 content or using drug carriers with different polarities. • TPU/Poloxam407 (90:10) extracts inhibit the proliferation of fibroblasts due to Poloxam407 presence, without inhibitory effect on epithelial cell proliferation. • The Improved First-Order model, incorporating a constant term into the original model, can better fit the drug release behavior. Airway stenosis, a significant cause of dyspnea, is commonly managed with airway stents. However, conventional stents frequently lead to restenosis. Excessive proliferation of fibroblasts and smooth muscle cells during abnormal repair processes is a key factor in airway restenosis. To address this challenge, a novel drug-loaded airway stent has been designed with personalized tailoring for the patient. This stent features a three-layered structure: an outer layer made from a blend of thermoplastic polyurethane (TPU) and Poloxamer 407 (P407), a drug-loading intermediate layer, and an inner layer made of TPU. This design aims to minimize airway irritation and enable adjustable drug release rates by adjusting the drug carrier and/or the content of P407 in the stent’s outer layer. Drug release profile conforms to the Improved First-Order model. Notably, P407 is released from the stent, serving a dual purpose: it creates micropores to regulate the drug release rate and synergizes with PTX to inhibit the proliferation of fibroblasts. This combination significantly enhances the inhibitory effect on the proliferation of fibroblasts and smooth muscle cells, without adversely affecting airway epithelial cells. This may represent a novel approach to reducing restenosis by addressing a critical complication associated with the use of airway stents.