Surface engineering at the nanoscale: A way forward to improve coronary stent efficacy

Abstract

Coronary in-stent restenosis and late stent thrombosis are the two major inadequacies of vascular stents that limit its long-term efficacy. Although restenosis has been successfully inhibited through the use of the current clinical drug-eluting stent which releases antiproliferative drugs, problems of late-stent thrombosis remain a concern due to polymer hypersensitivity and delayed re-endothelialization. Thus, the field of coronary stenting demands devices having enhanced compatibility and effectiveness to endothelial cells. Nanotechnology allows for efficient modulation of surface roughness, chemistry, feature size, and drug/biologics loading, to attain the desired biological response. Hence, surface topographical modification at the nanoscale is a plausible strategy to improve stent performance by utilizing novel design schemes that incorporate nanofeatures via the use of nanostructures, particles, or fibers, with or without the use of drugs/biologics. The main intent of this review is to deliberate on the impact of nanotechnology approaches for stent design and development and the recent advancements in this field on vascular stent performance.

Hypersensitivity and in-stent restenosis in coronary stent materials

“…The study showed that in patients with acute coronary syndromes, CoCr-titanium-coated stents were non-inferior to the platinum-chromium biodegradable polymer, EES, in inducing major cardiac events at 12 months ( Tonino et al, 2020 ). Despite the biocompatibility of the target moiety and improved tissue specificity and cellular uptake ( Yin et al, 2014 ), nanoparticles, as a new generation of smart drug delivery materials, still require extensive research to evaluate their safety issues ( Cherian et al, 2021 ). In addition, clinical evaluation of polymer-free DES is also underway.…”

Applying Principles of Regenerative Medicine to Vascular Stent Development

“…Specialized micro- and nano-patterns have been introduced on the stent surface to reduce the risk of blood clotting, expedite healing and improve endothelialization. The design of textures on the thin struts of a stent includes nanotubes, ridges, pores, diamonds, leafy structure, or even a pattern mimicking the shape of smooth muscle cells ( Cherian et al, 2021 ) ( Junkar et al, 2020 ). Importantly, the textures are assessed by preferential growth of endothelial cells over smooth muscle cells ( Cherian et al, 2020 ).…”

Drug-Eluting, Bioresorbable Cardiovascular Stents─Challenges and Perspectives

“…The exact parameters of the desired film can be customized by fine-tuning the electrostatic charge, the ion charge, the substrate, and the overall temperature. 168,169 The direct evaporation of an oligomer (Figure 6c) demonstrates the codeposition of monomers using a methodology where a polyelectrolyte aqueous solution containing one or two monomers was heated to evaporation and then selfassembled on the substrate.…”

“…The source material is heated under vacuum (generally up to 10 7 Torr) to achieve lower-temperature vaporization, completing the coating through deposition/sublimation on the substrate surface. The exact parameters of the desired film can be customized by fine-tuning the electrostatic charge, the ion charge, the substrate, and the overall temperature. , …”