A protective coating for blood-contacting materials by the combination of passive antifouling and active nitric-oxide generation

The blood compatibility of blood-contacting catheters is frequently challenged by fibrinogen, platelets, and bacteria. Adhesion and denaturation of any of these can lead to device failure and damage. Although passive antifouling coatings effectively inhibit the adhesion of proteins and platelets, their performance may degrade in the complex blood environment. Here, we propose an antifouling coating based on an active-passive synergistic strategy that mimics both cell membrane and endothelial functions. A copolymer PMLA layer simulates the cell membrane structure, providing passive antifouling properties and effectively inhibiting coagulation at an early stage. Additionally, Cu²⁺ ions are introduced into the coating interface <i>via</i> EGCG, catalyzing the release of nitric oxide (NO) to impart active antifouling ability to the coating. This combined strategy of endothelial mimicry and cell membrane simulation effectively suppresses platelet and protein adhesion and endows the coating with excellent antibacterial properties. Results from <i>ex vivo</i> thrombogenicity studies demonstrate that the proposed active/passive strategy effectively prevents thrombosis formation, offering a promising approach for the functional modification of blood-contacting catheter materials.