Department of Biomedical Engineering, Georgia Institute of Technology/Emory University, Atlanta, GA, USA.
Wiley Interdiscip Rev Nanomed Nanobiotechnol. 2011 May-Jun;3(3):256-68. doi: 10.1002/wnan.123. Epub 2011 Jan 31.
Intravascular stents were first introduced in the 1980s as an adjunct to primary angioplasty for management of early complications, including arterial dissection, or treatment of an inadequate technical outcome due to early elastic recoil of the atherosclerotic lesion. Despite the beneficial effects of stenting, persistent high rates of restenosis motivated the design of drug-eluting stents for delivery of agents to limit the proliferative and other inflammatory responses within the vascular wall that contribute to the development of a restenotic lesion. These strategies have yielded a significant reduction in the incidence of restenosis, but challenges remain, including incomplete repair of the endothelium at the site of vascular wall injury that may be associated with a late risk of thrombosis. A failure of vessel wall healing has been attributed primarily to the use of polymeric stent coatings, but the effects of the eluted drug and other material properties or design features of the stent cannot be excluded. Improvements in stent microfabrication, as well as the introduction of alternative materials may help to address those limitations that inhibit stent performance. This review describes the application of novel microfabrication processes and the evolution of new nanotechnologies that hold significant promise in eliminating existing shortcomings of current stent platforms.
血管内支架最初于 20 世纪 80 年代被引入，作为经皮腔内血管成形术的辅助手段，用于治疗早期并发症，包括动脉夹层，或因动脉粥样硬化病变早期弹性回缩导致治疗效果不理想。尽管支架置入具有有益的效果，但较高的再狭窄率仍然存在，这促使人们设计药物洗脱支架以输送药物，从而限制血管壁内的增殖和其他炎症反应，这些反应有助于再狭窄病变的发生。这些策略显著降低了再狭窄的发生率，但仍存在挑战，包括血管壁损伤部位内皮修复不完全，这可能与晚期血栓形成的风险相关。血管壁愈合失败主要归因于聚合物支架涂层的使用，但洗脱药物的作用以及支架的其他材料特性或设计特征不能被排除。支架微加工的改进以及替代材料的引入可能有助于解决抑制支架性能的这些局限性。本文综述了新型微加工工艺的应用和新纳米技术的发展，这些技术在消除当前支架平台的现有缺陷方面具有重要的应用前景。
