Could titanium dioxide nanotubes represent a viable support system for appropriate cells in vascular implants?

Nanoscale topography on various titanium surfaces has already been shown to improve vascular response in vitro. To propose a novel strategy for translation into clinically used vascular implants, it is imperative that the surface should also be properly conditioned to provide a better environment for adhesion and proliferation of cells. Electrochemical anodization process is one of the well-established strategies to produce controlled nanotopographic features on the surface of titanium. By combining electrochemical anodization process and gaseous plasma surface modification, it would be possible to fine-tune surface properties to enable improved biological response for specific application. The key surface properties that may influence biological responses, such as surface topography, surface chemistry, and surface wettability were studied in detail and their influences on in vitro biological responses were evaluated. Performance of platelets, human coronary artery endothelial cells (HCAEC), and stem cells on those surfaces was studied. It was shown that altering nanotube diameter (electrochemical anodization) and changing surface chemistry and wettability (gaseous plasma modification) significantly influenced platelet adhesion and activation as well as proliferation of HCAEC. The results provide evidence that by combining specific nanotopographic features and surface chemical modification by gaseous oxygen plasma, the optimized surface features necessary for improved performance of vascular implants in coronary arteries could be achieved. © 2017 Elsevier Inc