Zinc(II) metal-organic framework eluting titanium implant as propulsive agent to boost the endothelium regeneration

The advent of antiproliferative drug-eluting vascular stents can dramatically reduce in-stent restenosis via inhibiting the hyperproliferation of vascular smooth muscle cells. However, the antiproliferative drugs also restrain the repair of the injured endothelial layer, which in turn leads to the very later in-stent restenosis. Evidence points that competent endothelium plays a critical role in guaranteeing the long-term patency via maintaining vascular homeostasis. Boosting the regeneration of endothelium on the implanted vascular stents could be rendered as a promising strategy to reduce stent implantation complications. In this regard, bioactive zinc(II) metal-organic framework modified with endothelial cell-targeting Arg-Glu-Asp-Val peptide was embedded in poly(lactide-co-caprolactone) to serve as a functional coating on the surface of titanium substrate, which can promote the proliferation and migration of endothelial cells. The in vitro cell experiments revealed that the zinc(II) metal-organic framework embedded in the polymer coating was able to modulate the behaviors of endothelial cells owing to the bioactive effects of zinc ion and peptide. Our results confirmed that zinc(II) metal-organic framework eluting coating represented a new possibility for promoting the repair of the damaged endothelium with potential clinical implications in vascular-related biomaterials and tissue engineering applications.