Bile Duct Inner Structure–Inspired Tantalum Nanopatterned Nitinol Stent for Photothermal and Drug-Responsive Modulation of the Biliary Microenvironment
Biliary stents are commonly used to treat biliary strictures caused by cholangiocarcinoma, gallstones, and pancreatic cancer. Nevertheless, the implanted stent surface is susceptible to bacterial colonization, promoting biofilm formation and leads to stent occlusion. To address this limitation, we developed a near-infrared (NIR)–responsive nitinol stent integrates photothermal antibacterial capability with controlled drug delivery. Tantalum nanopatterns were fabricated on the surface via target ion plasma sputtering (TIPS) to inhibit bacterial adhesion while promoting biliary epithelial cell attachment. Polydopamine (PDA) was used to immobilize polydeoxyribonucleotide (PDRN) within the nanopatterned pores, enabling drug loading inside the surface structures. A thermoresponsive phase-change fatty acid–drug matrix was applied to regulate NIR-triggered drug release. In vitro results demonstrated enhanced antibacterial performance and biocompatibility compared to bare stents.