Investigating surface topology and cyclic-RGD peptide functionalization on vascular endothelialization.

The advantages of endothelialization of a stent surface in comparison with the bare metal and drug eluting stents used today include reduced late-stent restenosis and in-stent thrombosis. In this paper, we study the effect of surface topology and functionalization of tantalum (Ta) with cyclic-(arginine-glycine-aspartic acid-D-phenylalanine-lysine (cRGDfK)) on the attachment, spreading, and growth of vascular endothelial cells. Self-assembled nano-dimpling on Ta surfaces was performed using a one-step electropolishing technique. Next, cRGDfK was covalently bonded onto the surface using silane chemistry. Our results suggest that nano-texturing alone was sufficient to enhance cell spreading, but the combination of a nano-dimpled surfaces along with the cRGDfK peptide may produce a better endothelialization coating on the surface in terms of higher cell density, better cell spreading, and more cell-cell interactions, when compared to using cRGDfK peptide functionalization alone or nano-texturing alone. We believe that future research should look into how to implement both modifications (topographic and chemical modifications) to optimize the stent surface for endothelialization.