Ischemic events associated with coronary heart diseases (CHD) are the leading cause of death worldwide for both genders. They are directly associated with restricted blood flow caused by accumulation of atherosclerotic plaque in vesselâ€™s lumen. Percutaneous coronary intervention (PCI), including stent deployment, is currently considered as the dominant procedure for mechanically recovering myocardial perfusion to avoid lethal ischemic events. As vascular prosthesis, coronary stents suffer from two major and common complications; thrombosis and restenosis. Thrombosis is linked with insufficient migration of endothelial cells (EC) and proliferation at site of tissue injury. Restenosis is caused by unwanted proliferation of underlying vascular smooth muscle cells (VSMC). With drug eluting stents (DES) as a strategy to mitigate aforementioned complications, it only results in reducing VSMC proliferation. However, it directly causes poor endothlialization through undifferentiated inhibition of endothelial cells as well. This can result in high risk of late thrombosis, leading to death. Different strategies are being investigated to reach optimum duration and conditions for endothelium healing as a critical aspect of enhancement for drug eluting stents. In this thesis, a nanoarchitectured system is proposed as surface enhancement for drug eluting stents. Highly oriented nanotubes were vertically grown on the surface of a biocompatible Ti-based alloys, as potential material for self-expandable stents. The fabricated nanoarchitectured system is self-grown from the potential stent substrate. This material is also proposed to enhance endothelial proliferation while acting as drug reservoir to hinder VSMC proliferation. Two morphologies were prepared to investigate the effect of structure homogeneity on the intended application. They were characterized for morphological investigation using Field-emission scanning electron microscope (FESEM), X-ray diffraction (XRD), Raman spectroscopy, Energy dispersive X-ray spectroscopy (EDX) and X-ray photoelectron spectroscopy (XPS). Nanoindentation technique was used to study the mechanical properties of the fabricated material. Cytotoxicity and proliferation studies were done and compared for the two fabricated nanoarchitectures versus smooth untextured samples using in-vitro cultured endothelial cells. Finally, drug loading capacity was investigated practically and supported by computational study of release profile using COMSOLÂ® Multiphysics software.
MS in Nanotechnology
Committee Member 1
El Sayyed, Mayyada
Committee Member 2
Library of Congress Subject Heading 1
Library of Congress Subject Heading 2
Coronary heart disease -- Treatment.
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(2015).Ti-based functional nanoarchitectures for enhanced drug eluting stents [Master's Thesis, the American University in Cairo]. AUC Knowledge Fountain.
Saleh, Yomna Emad. Ti-based functional nanoarchitectures for enhanced drug eluting stents. 2015. American University in Cairo, Master's Thesis. AUC Knowledge Fountain.