Establishing and maintaining a healthy endothelium on vascular and intravascular devices is crucial for the prevention of thrombosis and stenosis. Generating a biofunctional surface on vascular devices to recruit endothelial progenitor cells (EPCs) and endothelial cells (ECs) has proven efficient in promoting in situ endothelialization. However, molecules conventionally used for EPC/EC capturing generally lack structural stability, capturing specificity, and biological functionalities, which have limited their applications. Discovery of effective, specific, and structurally stable EPC/EC capturing ligands is desperately needed. Using the high-throughput One-Bead One-Compound combinatorial library screening technology, we recently identified a disulfide cyclic octa-peptide LXW7 (cGRGDdvc), which possesses strong binding affinity and functionality to EPCs/ECs, weak binding to platelets, and no binding to inflammatory cells. Because LXW7 is cyclic and 4 out of the 8 amino acids are unnatural D-amino acids, LXW7 is highly proteolytically stable. In this study, we applied LXW7 to modify small diameter vascular grafts using a Click chemistry approach. In vitro studies demonstrated that LXW7-modified grafts significantly improved EPC attachment, proliferation and endothelial differentiation and suppressed platelet attachment. In a rat carotid artery bypass model, LXW7 modification of the small diameter vascular grafts significantly promoted EPC/EC recruitment and rapidly achieved endothelialization. At 6 weeks after implantation, LXW7-modified grafts retained a high patency of 83%, while the untreated grafts had a low patency of 17%. Our results demonstrate that LXW7 is a potent EPC/EC capturing and platelet suppressing ligand and LXW7-modified vascular grafts rapidly generate a healthy and stable endothelial interface between the graft surface and the circulation to reduce thrombosis and improve patency. STATEMENT OF SIGNIFICANCE: In this study, One-Bead One-Compound (OBOC) technology has been applied for the first time in discovering bioactive ligands for tissue regeneration applications. Current molecules used to modify artificial vascular grafts generally lack EPC/EC capturing specificity, biological functionalities and structural stability. Using OBOC technology, we identified LXW7, a constitutionally stable disulfide cyclic octa-peptide with strong binding affinity and biological functionality to EPCs/ECs, very weak binding to platelets and no binding to inflammatory cells. These characteristics are crucial for promoting rapid endothelialization to prevent thrombosis and improve patency of vascular grafts. LXW7 coating technology could be applied to a wide range of vascular and intravascular devices, including grafts, stents, cardiac valves, and catheters, where a "living" endothelium and healthy blood interface are needed.

中文翻译：

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通过特异性靶向内皮祖细胞和内皮细胞的生物活性整合素结合配体对小直径血管移植物进行快速内皮化。

在血管和血管内装置上建立和维持健康的内皮对于预防血栓形成和狭窄至关重要。在血管装置上生成生物功能表面以募集内皮祖细胞 (EPC) 和内皮细胞 (EC) 已被证明在促进原位内皮化方面是有效的。然而，传统上用于 EPC/EC 捕获的分子通常缺乏结构稳定性、捕获特异性和生物功能，这限制了它们的应用。迫切需要发现有效、特异性和结构稳定的 EPC/EC 捕获配体。利用高通量单珠单化合物组合文库筛选技术，我们最近鉴定了二硫环八肽LXW7（cGRGDdvc），对EPCs/ECs具有很强的结合亲和力和功能性，与血小板的结合力较弱，与炎症细胞不结合。因为 LXW7 是环状的，并且 8 个氨基酸中有 4 个是非天然 D-氨基酸，所以 LXW7 具有高度的蛋白水解稳定性。在本研究中，我们应用 LXW7 使用 Click 化学方法修改小直径血管移植物。体外研究表明，LXW7 修饰的移植物显着改善了 EPC 附着、增殖和内皮分化，并抑制了血小板附着。在大鼠颈动脉搭桥模型中，LXW7 修饰小直径血管移植物显着促进 EPC/EC 募集并迅速实现内皮化。在植入后 6 周，LXW7 修饰的移植物保持 83% 的高通畅率，而未经处理的移植物具有 17% 的低通畅率。我们的研究结果表明，LXW7 是一种有效的 EPC/EC 捕获和血小板抑制配体，LXW7 修饰的血管移植物在移植物表面和循环之间迅速产生健康稳定的内皮界面，以减少血栓形成并提高通畅性。意义声明：在这项研究中，单珠单化合物 (OBOC) 技术首次应用于发现用于组织再生应用的生物活性配体。目前用于修饰人工血管移植物的分子通常缺乏 EPC/EC 捕获特异性、生物功能和结构稳定性。使用 OBOC 技术，我们鉴定了 LXW7，这是一种结构稳定的二硫环八肽，对 EPCs/ECs 具有很强的结合亲和力和生物学功能，与血小板的结合非常弱，与炎症细胞没有结合。这些特征对于促进快速内皮化以预防血栓形成和改善血管移植物的通畅性至关重要。LXW7 涂层技术可应用于需要“活”内皮和健康血液界面的各种血管和血管内装置，包括移植物、支架、心脏瓣膜和导管。