Accelerating in situ endothelialization while inhibiting thrombosis is critical for the success of small-caliber tissue-engineered vascular grafts (TEVGs). In this study, a lysine (Lys) doped polydopamine (PDA) coating strategy was exploited to functionalize the TEVGs for vascular tissue regeneration. Using electrospun aligned poly(L-lactide-co-caprolactone) (PLCL) fiber arrays as the demonstrating biomaterial, introduction of Lys to the dopamine polymerization process was found to promote the formation of PDA-Lys composite coating layer atop the fiber surface via Schiff base and Michael addition reactions. Such a surface functionalization remarkably improved the coating layer uniformity, wettability, and protein adsorption capacity. In vitro assessment showed that the PDA-Lys coating layer was anti-thrombogenic and anti-inflammatory, and accelerated the formation of confluent endothelial monolayer by promoting cell-fiber and cell-cell interactions. Upon implantation in a rabbit carotid artery replacement model for 3 months, the constructed TEVGs (2 mm inner diameter), with oriented fiber architecture parallel to the longitudinal axis of grafts, were confirmed to significantly suppress thrombosis and accelerate regeneration of endothelium and tunica media layer, thereby exhibiting a positive vascular remodeling and integration capability in revascularization. This study demonstrated that the lysine-doped PDA coating provided a facile and effective platform for the improvement of antithrombogenicity and endothelialization of TEVGs.

加速原位内皮化同时抑制血栓形成对于小口径组织工程血管移植物 (TEVG) 的成功至关重要。在这项研究中，利用赖氨酸 (Lys) 掺杂的聚多巴胺 (PDA) 涂层策略来功能化 TEVG，用于血管组织再生。使用电纺排列的聚（L-丙交酯-共-己内酯）（PLCL）纤维阵列作为演示生物材料，发现将 Lys 引入多巴胺聚合过程可促进通过 Schiff 在纤维表面形成 PDA-Lys 复合涂层碱和迈克尔加成反应。这种表面功能化显着提高了涂层的均匀性、润湿性和蛋白质吸附能力。体外评估表明，PDA-Lys 涂层具有抗血栓形成和抗炎作用，并通过促进细胞-纤维和细胞-细胞相互作用加速融合内皮单层的形成。在兔颈动脉置换模型中植入 3 个月后，证实构建的 TEVG（内径为 2 mm）具有平行于移植物纵轴的定向纤维结构，可显着抑制血栓形成并加速内皮和中膜层的再生，从而在血运重建中表现出积极的血管重塑和整合能力。该研究表明，掺赖氨酸的 PDA 涂层为改善 TEVG 的抗血栓形成和内皮化提供了一个简便有效的平台。