Regulation of endothelial functionality through direct and immunomodulatory effects by Ni-Ti-O nanospindles on NiTi alloy.

Stent implantation has become one of the most widely used methods for the treatment of cardiovascular diseases. However, endothelial dysfunction and abnormal inflammatory response following implantation may lead to delayed re-endothelialization, resulting in vascular restenosis and stent thrombus. To address the concerns, we constructed nanospindles composed of TiO 2 and Ti 4 Ni 2 O through hydrothermal treatment of amorphous Ni-Ti-O nanopores anodically grown on NiTi alloy. The results show the treatment can significantly improve hydrophilicity and reduce Ni ion release, essentially independent of hydrothermal duration. The nanospindle surfaces not only promote the expression of endothelial functionality but also activate macrophages to induce a favorable immune response, downregulate pro-inflammatory M1 markers and upregulate pro-healing M2 markers. Moreover, nitric oxide (NO) synthesis, VEGF secretion, and migration of endothelial cells are enhanced after cultured in macrophage conditioned medium. The nanospindles thus are promising as vascular stent coatings to promote re-endothelization. [Display omitted] • The nanospindles can be fabricated by hydrothermal treatment of Ni-Ti-O nanopores. • Nanospindle surfaces directly upregulate EC functionality. • Nanospindle surfaces can upregulate EC functionality through immunomodulation. [ABSTRACT FROM AUTHOR]