# Slippery dopamine–fluoropolymer hybrid surface for improving biliary stent longevity

## TL;DR

A new coating called ELFS improves biliary stent longevity by reducing inflammation and biofilm formation.

## Contribution

The ELFS coating prevents stent occlusion through anti-fouling properties and inhibits early immune responses.

## Key findings

- ELFS reduced neutrophil recruitment by over 20-fold compared to non-coated stents.
- ELFS-coated stents remained free of biofilm for over six months in mice.
- Coated stents maintained patency in a rabbit model for two months without occlusion.

## Abstract

Biliary obstruction leads to bile retention and triggers a cascade of pathological events. Bile accumulation induces cholestasis and inflammation, progressing to hepatocellular injury, fibrosis, and ultimately liver failure. To restore bile flow, biliary stents are a necessary option due to their immediate patency. However, their high susceptibility to foreign body reaction (FBR) associated fibrosis, biofilm formation, and biliary sludge accumulation leads to frequent occlusion. To address this limitation, we developed the Enhanced Longevity by anti-fouling Functional coating for Stent (ELFS), a lubricant-infused coating that prevents stent occlusion. ELFS can be readily fabricated via a simple dip-coating solution process and employ a polydopamine (PDA) adhesion layer. Intravital imaging in mice confirmed that ELFS suppressed the FBR by blocking early neutrophil adhesion, which in turn prevented downstream immune-fibrotic cascades. At 3 h, neutrophil recruitment in the non-coated group was >20-fold higher than in ELFS-coated groups. Additionally, ELFS-coated stents remained free of biofilm for over six months in mice and maintained full open for two months in a rabbit common bile duct model. In contrast, non-coated stents resulted in complete occlusion, bile duct dilation (over 4 times), hepatomegaly (over 2 times), and fibrosis.

Image 1

•Clinical challenge: Biliary stents often fail due to bile viscosity, foreign body reaction, fibrosis, and biofilm-driven occlusion.•ELFS, a lubricant-infused antifouling coating, shows high mechanical stability without delamination under physiological flow.•ELFS is fabricated via a simple dip-coating process using a PDA adhesion layer.•ELFS reduced neutrophil recruitment by >20-fold, prevented biofilm for 6 months in mice, and maintained patency in rabbits.

Clinical challenge: Biliary stents often fail due to bile viscosity, foreign body reaction, fibrosis, and biofilm-driven occlusion.

ELFS, a lubricant-infused antifouling coating, shows high mechanical stability without delamination under physiological flow.

ELFS is fabricated via a simple dip-coating process using a PDA adhesion layer.

ELFS reduced neutrophil recruitment by >20-fold, prevented biofilm for 6 months in mice, and maintained patency in rabbits.