Biomechanical properties of a customizable thermoplastic polyurethane/ polycaprolactone blended esophageal stent fabricated by 3D printing

Esophageal stents were widely used in the clinical therapy of esophageal diseases. However, commercial esophageal stents had fixed sizes and cannot be personalized according to esophageal geometry of patient. A thermoplastic polyurethane (TPU)/polycaprolactone (PCL) blend esophageal stent was prepared by melt blending combined with 3D printing technology. Based on the adjustment of TPU/PCL component ratio, the mechanical properties of the stent were regulated. The physicochemical properties of TPU/PCL blends and the key parameters of the stents were investigated by differential scanning calorimetry, thermogravimetric analysis, mechanical tests, in vitro degradation tests and cytotoxicity assays. The results show that the TPU/PCL blends exhibit favorable compatibility and mechanical properties, and the cellular activity is 72.9% with no potential toxicity to cells. The weight of the stents is less than 2%, and the mechanical properties do not change significantly after 8-week in vitro degradation test. The superior mechanical and biologic features of 3D printed TPU/PCL blended stent demonstrate the potential application in the clinical personalized treatment of esophageal stenosis.