Vascular Intima‐Biomimetic Bilayer Hydrogel Coating of Central Venous Catheters with Dual‐Modal Anti‐Coagulation and Self‐Adaptive Immunomodulation

Abstract Although central venous catheters (CVCs) exhibit promising hemocompatibility and interfacial stability, their clinical applications are constrained by the inability to counteract thrombus and acute inflammation. Herein, a novel vascular intima‐biomimetic bilayered hydrogel coating is designed to mitigate clinical thrombotic and inflammatory complications. Firstly, passive anti‐coagulation shield established by hydrophilic groups orchestrated robust hydration shells, which achieved non‐specific adhesion resistance against blood compositions. Active anti‐coagulation mode was simultaneously established by dynamic thiol/sulfonic redox moieties, realizing synergetic inhibition effects on the activity of coagulation factors and self‐activation of coagulation cascade. Secondly, the hydrogel presented a free radicals‐scavenging rate of 79.42% ± 1.34% coupled with macrophage phenotype remodeling, effectively constructing an ideal anti‐bacterial microenvironment for repair of oxidative stress‐mediated endothelial damage. More interestingly, such biomimetic bilayered hydrogel coating achieved exceptional adhesion stability toward CVCs, meanwhile its vascular intima‐mimetic modulus reduced mismatch‐induced endothelial injury, thereby ensuring long‐term interfacial integrity and implant safety. According to in vivo and ex vivo results of rat subcutaneous implantation and rabbit arteriovenous (AV) shunts model, the coating significantly decreased catheter occlusion rate (0.90% ± 0.64%), suppressed F1+2 accumulation, and inhibited TNF‐α expression. Overall, the hydrogel coating with synergetic anti‐coagulant/anti‐inflammatory functionalities established an effective bio‐interfacial for clinical indwelling device safety, demonstrating particularly promising applications.