A functional stent with near-infrared light triggered localized photothermal-chemo synergistic therapy for malignant stenosis of esophageal cancer.

Stent implantation is a widely used palliative treatment for relieving strictures in malignant esophageal cancer. However, conventional fully covered stents play a role in preventing the tumor from ingrowth but increasing the risk of migration. Therefore, there is an urgent need for a multifunctional stent that not only reduces migration but also provides synergistic therapeutic benefits to inhibit tumor growth. This study proposed a braided esophageal stent with synergistic photothermal and chemotherapy functions to achieve precise controllable drug release. The stent was braided of Nitinol fiber and polyethylene terephthalate fiber in one-step, in which Nitinol loaded with high-efficiency photothermal conversion agent gold nanoparticles and polyethylene terephthalate loaded anti-tumor drugs release mediated by a temperature-responsive coating. The stent showed anti-migration ability and orchestrated the localized hyperthermia plus thermal-stimuli drug release during the tumor lesion. Cell experiments confirmed that the stent showed a significantly synergistic tumor cell killing effect (28.29 %). In 3D tumor sphere model, the apoptosis rate of tumor cells reached 31.34 %. In summary, the composite stent design strategy integrates anti-migration features and photoheating-controlled drug release for synergistic cancer therapy, providing a new design idea for the application of nickel-titanium alloy stents in the treatment of malignant esophageal stenosis.