Tick-derived protein Qinghaienin-based anticoagulant coating inhibits activation of the zymogen FXII

Thrombus formation and thrombosis-related complications have consistently limited the safe use of blood-contacting medical devices in clinical practice. Qinghaienin, a novel tick-derived protein, inhibits activation of the intrinsic coagulation pathway by competing with factor XII for anionic surfaces. In this study, to create an anticoagulant coating, Qinghaienin was grafted onto the surface of commonly used medical polyvinyl chloride (PVC) material, which was premodified by polydopamine-polyethyleneimine (PDA-PEI). A series of studies verified that Qinghaienin immobilized on the PVC surface significantly enhanced the hydrophilicity of the material while retaining its biological activity. The PDA-PEI/Qinghaienin coating inhibited nonspecific protein adsorption, platelet adhesion, and thrombus formation in vitro. Furthermore, the PDA-PEI/Qinghaienin coating exhibited outstanding anticoagulant performance, which was superior to that of the PDA-PEI/Hep coating in static whole blood tests. In a rabbit arteriovenous shunt model, the coating effectively prolonged extracorporeal blood circulation time compared with control trials. These results demonstrate that the PDA-PEI/Qinghaienin coating exhibits excellent hemocompatibility and anticoagulant activity, highlighting its potential use in blood-contacting medical devices.