<b>Background:</b> Pulmonary valve replacement is performed with excellent resultant hemodynamics in patients that have underlying congenital or acquired heart valve defects. Despite recent advancements in right ventricular outflow tract reconstruction, an increased risk of developing infective endocarditis remains, which has a more common occurrence for conduits of bovine jugular vein origin compared to cryopreserved homografts. The reason for this is unclear albeit it is hypothesized to be associated with an aberrant phenotypic state of cells that reendothelialize the graft tissue post implantation. The aim of this study was to develop an <i>in vitro</i> model that enables the analysis of endothelial cell attachment to cardiac graft tissues under flow. <b>Experiment:</b> Endothelial cell attachment was optimized on bovine pericardium patch using HUVECs. Different biological coatings, namely gelatin, fibronectin, plasma or a combination of fibronectin and plasma were tested. After cell adaptation, graft tissues were exposed to laminar flow in a parallel-plate flow chamber. Cell retention to the tissue was analyzed after nuclear staining with YO-PRO-1 and a membranous localization of VE-cadherin. <b>Results:</b> Combined coating with fibronectin and blood plasma together with a two-phased shear pattern resulted in a relevant cell monolayer on bovine pericardium patch and cryopreserved homograft. For bovine jugular vein tissue, no adherent cells under both static and shear conditions were initially observed. <b>Conclusion: </b>Presented <i>in vitro </i>system can serve as a competent model to study cell phenotypes on cardiac grafts under close-to-physiologic conditions. Lower affinity of bovine jugular vein conduit for cell attachment might be implicative of the risk of late-onset infective endocarditis.

中文翻译：

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一个体外模型，以下流动的心脏移植物组织的研究内皮

<b>背景：</ b>对于患有先天性或后天性心脏瓣膜缺损的患者，进行肺动脉瓣置换术具有出色的最终血流动力学。尽管最近在右心室流出道重建方面取得了进展，但仍然存在发生感染性心内膜炎的风险增加，与冷冻保存的同种异体移植相比，牛颈静脉起源的导管更为常见。原因尚不清楚，尽管据推测是与植入后使移植组织重新内皮化的异常表型细胞状态有关。这项研究的目的是建立一个<i>体外</ i>模型，该模型能够分析流动条件下内皮细胞对心脏移植组织的附着。<b>实验：</ b> 使用HUVEC在牛心包膜片上优化内皮细胞附着。测试了不同的生物涂层，即明胶，纤连蛋白，血浆或纤连蛋白与血浆的组合。细胞适应后，将移植组织在平行板流动室中暴露于层流中。在用YO-PRO-1进行核染色和VE-钙粘着蛋白的膜定位后，分析了对组织的细胞保留。<b>结果：</ b>结合纤连蛋白和血浆的涂层以及两相剪切模式在牛心包膜上和冷冻保存的同种异体移植物上形成了相关的细胞单层。对于牛颈静脉组织，最初在静态和剪切条件下均未观察到粘附细胞。<b>结论：</ b> <i>体外展示</ i> 该系统可以用作在接近生理条件下研究心脏移植物细胞表型的有效模型。牛颈静脉导管对细胞附着的较低亲和力可能暗示了迟发性感染性心内膜炎的风险。