Purpose

Despite 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.

Methods

We 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.

Results

Quantitative 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.

Conclusion

The PBMA eG Coating™ has the effect of promoting endothelial wound healing. Future studies will focus on elucidating the mechanistic basis of this observation.

中文翻译：

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eG 涂层支架表现出增强的内皮伤口愈合特性

目的

尽管它们被广泛使用，但仍有相当一部分冠状动脉支架存在支架内再狭窄和支架血栓形成。支架部署对血管内皮造成广泛损伤。快速内皮伤口闭合对于支架植入手术的成功至关重要。最近的一项研究表明，BuMA Supreme® 西罗莫司洗脱支架具有特别吸引人的支柱覆盖特性。该支架的一个独特之处在于存在聚甲基丙烯酸丁酯 (PBMA) 的薄刷层，通过电接枝 ( e G™) 共价结合到支架的钴铬框架上。本研究旨在确定 PBMA 涂层是否对内皮细胞伤口愈合和支架支柱覆盖有影响。

方法

我们使用了体外冠状动脉模型，其壁由环形胶原水凝胶组成，其管腔表面衬有单层内皮细胞​​。在部署带有或不带有 PBMA 层的裸钴铬支架之前，对内皮衬里进行机械损伤。在 48 小时内自动监测荧光标记的内皮细胞的迁移，以确定内皮伤口愈合率。

结果

使用自动图像分析可以实现模拟动脉模型内内皮伤口愈合率的定量评估。与裸金属支架相比，使用 PBMA eG Coating™ 的支架的伤口愈合速度明显更快（48 小时快 44%）。

结论

PBMA eG Coating™ 具有促进内皮伤口愈合的作用。未来的研究将集中于阐明这一观察的机制基础。