An Endothelium‐Mimicking, Healable Hydrogel Shield for Bioprosthetic Heart Valve with Enhanced Intravascular Biocompatibility

Bioprosthetic heart valves (BHVs) for transcatheter replacement often face deterioration due to thrombosis, inflammation, and calcification, which are irreversible. Here, a multidimensional endothelium‐mimicking healable hydrogel shielded BHV that not only withstand the complex valvular physiological and hemodynamic environment but also able to reverse damage‐induced structural degeneration by in situ healing is proposed. Polydopamine/selenocystamine nanoparticles with photothermal effect are embedded to achieve light‐triggered healing and catalytic nitride oxide generation in polyvinyl alcohol hydrogel coating on BHV surface. Additionally, platelet inhibitor Tirofiban is encapsulated in the hydrogel shield to block acute coagulation cascade in early stage after implantation. A rodent intravascular leaflet‐like implantation model is developed to reveal the long‐term hemocompatibility of BHVs in abdominal aorta. The shielded BHVs exhibit enhanced antithrombotic properties, reduced inflammation, superior endothelialization, and improved vascular patency. Transcriptome analysis indicates better endothelial functions on shielded BHVs. Moreover, the endothelium‐mimicking hydrogel shield maintains both mechanical properties and biological functions after healing, facilitated great hemocompatibility and fast re‐endothelialization. Collectively, the multidimensional endothelium‐mimicking strategy provides new insight for preventing and reversing BHV damage instead of solely replacement.