EG Coated Stents Exhibit Enhanced Endothelial Wound Healing Characteristics

Belen Rodriguez-Garcia,Christophe Bureau,Abdul I Barakat

doi:10.1007/s13239-021-00542-x

Abstract

PurposeDespite their widespread use, a significant fraction of coronary stents suffer from in-stent restenosis and stent thrombosis. Stent deployment induces extensive injury to the vascular endothelium. Rapid endothelial wound closure is essential for the success of a stenting procedure. A recent study has demonstrated that the BuMA Supreme® sirolimus-eluting stent exhibits particularly attractive strut coverage characteristics. A unique feature of this stent is the presence of a thin brush layer of poly-butyl methacrylate (PBMA), covalently bonded to the stent’s cobalt-chromium frame via electro-grafting (eG™). The present study aimed to determine whether the PBMA coating has an effect on endothelial cell wound healing and stent strut coverage.MethodsWe used an in vitro coronary artery model whose wall consisted of an annular collagen hydrogel and whose luminal surface was lined with a monolayer of endothelial cells. Mechanical wounding of the endothelial lining was preformed prior to deployment of a bare cobalt-chromium stent either with or without the PBMA layer. The migration of fluorescently labeled endothelial cells was monitored automatically over a period of 48 h to determine endothelial wound healing rates.ResultsQuantitative assessment of endothelial wound healing rates within the simulated arterial model is achievable using automated image analysis. Wound healing is significantly faster (44% faster at 48 h) for stents with the PBMA eG Coating™ compared to bare metal stents.ConclusionThe PBMA eG Coating™ has the effect of promoting endothelial wound healing. Future studies will focus on elucidating the mechanistic basis of this observation.

Highlights

Millions of coronary stents are deployed in patients worldwide every year
In an effort to gain insight into the basis for the seemingly excellent performance of the BuMA SupremeÒ sirolimus-eluting stent (SES), we investigated if the thin (~ 200 nmthick) poly-butyl methacrylate (PBMA) brush layer that is electro-grafted onto the Co–Cr frame of the BuMA SupremeÒ SES has an impact on stent strut coverage
The comparisons were performed using automated analysis of images of fluorescently labeled endothelial cells (ECs) in an in vitro coronary simulated arterial model that we had previously described within which endovascular stents can be deployed and cellular responses monitored continuously.[3]

Summary

Introduction

Millions of coronary stents are deployed in patients worldwide every year. Despite this widespread use and significant progress over the past couple of decades, coronary stenting procedures continue to suffer from complications, most notably in-stent restenosis and stent thrombosis, that pose significant risk to patients. Stent thrombosis risk has been estimated at ~ 1% after 1 year and approximately 0.2–0.4% per year thereafter, while rates of in-stent restenosis appear to be in the 5–10% range.[10] There is evidence that stent-related complications depend on a complex combination of several considerations including stent materials, strut thickness, and detailed stent design[17–19]; the precise connection among these physical parameters and the incidence of complications remains incompletely understood. Rapid endothelial wound healing is considered to be a critical factor in the success of a stenting procedure

Methods

Results

Conclusion