Nanosurface Engineering of Bare Metallic Coronary Stents for Combating In-Stent Restenosis
Endovascular stents, used commonly for the treatment of occlusive vascular diseases, have historically been manufactured using metals and metal composites. Although stents have reduced the restenosis rate from 40% to 20% compared to angioplasty alone, in-stent restenosis still remains a major limitation for this approach.
Owing to the inadequacies of bare metallic stents, researchers have explored various kinds of materials, designs as well as techniques to further optimise stent design, which includes the development of coated metallic stents, biodegradable stents and drug eluting stents.
An alternate cost-effective approach to tackle the problem of restenosis would be to engineer the surface of bare metal stents to generate a uniform surface nanotexture that improves the cellular behaviour and tissue integration of biomedical implants. Nanotexturing would help to create a biocompatible, anti-thrombogenic surface that promotes rapid endothelialisation, by simultaneously inhibiting high smooth muscle cell proliferation. Such biocompatible metals would present a superior treatment modality without the use of costly drug eluting stents that demand continual use of anti-platelet therapy for prolonged durations and have long term toxicity effects.
In this project, the team proposes to evaluate stent patency and neointimal hyperplasia of clinically used Stainless Steel and Cobalt-Chromium stents after appropriate surface modification and implantation in pig coronary artery. Thus, in this attempt, the aim is to strive to improve the features of the existing bare metallic stents through simple nanostructuring, without using any anti-proliferative drugs.