Lubricious anti-adhesive interface prevents friction, biofilm, and encrustation in long-term indwelling ureteral stents.

Ureteral stents are essential for relieving urinary obstruction and preserving renal function. However, long-term indwelling often induces friction-mediated urothelial irritation, bacterial colonization, and mineral encrustation, which impair urinary drainage and complicate stent removal. Here, we developed a friction-lowering urinary interface for defense against encrustation (FLUID) by integrating a silicone-based primer and lubricant layer into a fully microporous thermoplastic polyurethane framework. Unlike conventional slippery liquid-infused porous surfaces that retain lubricant primarily within surface microstructures, the fully microporous TPU framework serves as an internal lubricant reservoir throughout the stent wall, replenishing the lubricating interface under dynamic urinary conditions. Under sterile conditions the FLUID coating suppressed planktonic bacterial adhesion (E. coli, B. cereus, S. aureus; 72 h adhesion assay) by more than 94% relative to uncoated substrates. In a P. mirabilis-spiked 14-day mature biofilm model, biofilm-associated bacterial recovery from FLUID was modestly lower than from the commercialized comparators (Log R ≈ 0.10 and 0.14; approximately 21% and 28% reduction). In a porcine model, the coated stent reduced inflammatory activity and attenuated mineral accumulation after 4 weeks, with magnesium and calcium deposition decreased by 84.1% and 45.1%, respectively. After 8 weeks, scanning electron microscopy confirmed clean surfaces with patent side holes and minimal debris accumulation. Overall, the FLUID stent establishes a self-replenishing lubricant interface integrated throughout the microporous stent wall, enabling simultaneous mitigation of friction, early biofouling, and mineral deposition, and providing a clinically relevant proof-of-concept strategy for safer long-term urinary drainage that will require further preclinical validation prior to clinical adoption.