Postfunctionalization of Biological Valve Leaflets with a Polyphenol Network and Anticoagulant Recombinant Humanized Type III Collagen for Improved Anticoagulation and Endothelialization

This study presents a postfunctionalization strategy for glutaraldehyde-crosslinked bioprosthetic heart valves (BHVs) to mitigate thrombosis, calcification, and inflammatory responses. The BHVs were modified with tannic acid/iron (TA/Fe) metal–phenolic networks (MPNs), followed by immobilization of anticoagulant recombinant humanized type III collagen (rhCOLIII). The dual-modified TA/Fe–rhCOLIII coatings demonstrated enhanced mechanical strength, enzyme resistance, and antithrombogenic behavior, while promoting endothelialization both in vitro and in vivo. Compared to unmodified GLUT-treated pericardium, the coated valves exhibited reduced platelet adhesion, minimal inflammatory infiltration, and decreased calcium deposition after subcutaneous implantation. The work demonstrates a feasible surface modification route to improve the long-term hemocompatibility and biological performance of clinical BHVs.