Nitric Oxide-Releasing Catheters with Phenol-Amine Catalytic Coatings for Improved Anti-Inflammatory Performance

Nitric oxide (NO) is a signaling molecule critical for vasodilation, bacterial inhibition, and inflammation modulation, making it valuable for medical devices, such as catheters. However, existing NO-releasing catheters face challenges, including maintaining stable NO release over time and complex manufacturing processes. In this study, a robust nanocoating made from tannic acid (TA) and selenocystamine (SeCA) is presented, designed to catalytically generate NO from S-nitrosoglutathione in the presence of glutathione. Surface characterization techniques confirmed successful coating formation, with optimal NO generation achieved at a 1:4 TA:SeCA molar ratio. The coated catheters maintained over 96% viability of human coronary artery smooth muscle cells (HCASMCs) after 72 h. It has been demonstrated that the modified catheters significantly increased endogenous NO production in HCASMCs from intracellular S-nitrosothiols, highlighting their potential to support vascular function. The coating sustained NO release at 7 × 10^-10 mol cm^-2 min^-1 for at least 3 days, exceeding the typical release rate of healthy endothelium. Notably, the coating effectively reduced pro-inflammatory cytokine (TNF-α and IL-6) production in RAW 264.7 macrophages upon lipopolysaccharide stimulation, demonstrating anti-inflammatory effects. This material-driven approach simplifies NO delivery and offers an effective strategy to enhance catheter efficacy to support vascular function and minimize inflammation.