Selective endothelialization and alleviation of neointimal hyperplasia by functionalizing the Ti-O surface with l-selenocystine and KREDVC.

Due to their relatively good biocompatibility and inactivity, titanium oxide films (Ti-O) are used in the coating of coronary stents, which reduces metal corrosion, slows metal ion release, and improves endothelial cell (EC) compatibility. Here, we report further functionalizing Ti-O with biological cues for selective endothelialization. Selenocystine with an l- or a d-enantiomer was first immobilized on the Ti-O film via polydopamine to generate nitric oxide (NO) endogenously, which inhibited smooth muscle cell (SMC) proliferation, followed by the grafting of a functional KREDVC peptide to induce EC adhesion. The synergistic effects of the immobilized KREDVC, surface chirality, and NO generation on selective endothelialization were investigated. The results showed that the surface chirality of the l-enantiomer and KREDVC grafting significantly enhanced the attachment and growth of ECs compared to SMCs. An in vivo study showed von Willebrand factor expression was increased and neointimal hyperplasia was significantly decreased in samples with l-selenocystine immobilization and KREDVC grafting. In summary, these findings provide new insights on the surface modification of cardiovascular implants with selective endothelialization.