A Versatile Macroscale Platelet Membrane Coating: A Biomimetic Strategy to Balance Antithrombogenicity and Proendothelialization on Vascular Stents

Vascular stents require biointerfaces that simultaneously prevent thrombosis and promote endothelialization, yet achieving a balance of these conflicting demands on a single surface remains a challenge. While cell membrane coatings have demonstrated biomimetic potential, their application to macroscale devices has been largely limited to unstable noncovalent nanoparticle-focused approaches, which suffer from disordered assembly and poor stability under physiological flow. In contrast, we introduce a platelet membrane armor strategy facilitated by epigallocatechin gallate (EGCG) cross-linking, creating a robust macroscale coating that integrates both antithrombogenicity and proendothelialization. This covalent stabilization, achieved through EGCG's unique chemistry, effectively anchors platelet membrane vesicles to form a stable coating that ensures uniform modification across various substrates. The coating is resistant to mechanical deformation and maintains its structural continuity even after over 30 d of rinsing. Importantly, the EGCG-cross-linked platelet membrane (EPM) coating preserves functional membrane proteins (CD47 and integrins). When stents coated with EPM armor were implanted in rabbits, they exhibited a marked reduction in acute thrombus formation, alongside enhanced endothelial cell proliferation and anti-inflammation effects, without introducing smooth muscle cell hyperplasia. This EPM coating strategy offers a promising approach to biomimetic interfaces for cardiovascular implants.