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The Effects of Physiological Flow on Endothelial Cell Function on Nanostructured Coated Vascular Stent Materials
Margaret Merritt1, Jing Lu1, Karen M. Haberstroh1, and Thomas J. Webster1
1Department of Biomedical Engineering, Brown University, Providence, RI, USA

Abstract:
Titanium and stainless steel are widely used in vascular stent design.  Unfortunately, these materials have suffered from problems including stent migration and restenosis.  Therefore, the present study investigated properties of novel nanostructured coatings on titanium and stainless steel for improving vascular stent efficacy. To test cell density on these nanostructured coated materials, rat aortic endothelial cells (RAEC; Vec Technologies) were pre-seeded at 3,500 cells/cm2 for a 24-hour culture period. Samples and adherent cells were then transferred to fresh media and were cultured under static conditions for 4 additional hours. Adherent RAEC were stained, imaged using fluorescence microscopy, and counted.  Overall, the stainless steel nanostructured coating had the highest cell density compared to any other sample.  A traditional parallel plate flow chamber was further modified and used to analyze both coating strength and RAEC behavior under a flow environment. Preliminary results suggested that the stainless steel nanostructured coated remained in tact under physiological relevant flow conditions.  In summary, results of this study suggest that nanostructured coatings on stainless steel should be further studied for improving vascular stent efficacy. Such nanostructured coatings which promote endothelialization may reduce the need for stent drug elution which has been problematic as of late.