摘要

Growing clinical needs for less invasive endovascular treatments necessitate the development of advanced biomaterials that exhibit low-profile and enhanced biocompatible properties. One of the endovascular devices is a stent graft, which contains a metallic backbone, covered with thin polymeric membranes such as Dacron and expandable polytetrafluoroethylene (ePTFE). This device has been widely used for treating various vascular diseases and injuries. While the commercial materials including Dacron and ePTFE have demonstrated a good feasibility, they were found to induce inflammatory vessel wall reactions with neointimal hyperplasia. Consequently, it causes re-narrowing of the lumen space and thrombogenic issues that ultimately lead the treatment failure. In this paper, we introduced a thin film nitinol (TFN) as an alternative graft material and evaluated the growth behavior of endothelial cells (EC) both qualitatively and quantitatively. As a proof-of-concept study, both untreated nonpatterned film (TFN) and surface treated TFN (S-TFN) materials were used. We compared the adhesion, growth, and proliferation of ECs on a solid (non-patterned) TFN with the two most widely-used commercial graft materials (Dacron and ePTFE). The in vitro experimental results showed better adhesion and growth of ECs on TFN materials than either ePTFE or Dacron. Specifically, S-TFN showed approximately twice number of ECs attached on the surface than any other materials tested in this study. In addition, in vivo swine study demonstrated that ECs had a relatively high proliferation on the micropatterrned S-TFN with 50% surface.coverage within two weeks. Both in vitro and in vivo study results of cell growth suggested that TFN materials could be a promising graft material for low-profile endovascular devices.

  • 出版日期2017-3-20