Endothelial cell (EC) transplantation via injectable collagen hydrogel has received much attention as a potential treatment for various vascular diseases. However, the therapeutic effect of transplanted ECs is limited by their poor viability, which partially occurs as a result of cellular apoptosis triggered by the insufficient cell-extracellular matrix (ECM) engagement. Integrin binding to the ECM is crucial for cell anchorage to the surrounding matrix, cell spreading and migration, and further activation of intracellular signaling pathways. Although collagen contains several different types of integrin binding sites, it still lacks sufficient specific binding sites for ECs. Previously, using one-bead one-compound (OBOC) combinatorial technology, we identified LXW7, an integrin αvβ3 ligand, which possessed a strong binding affinity to and enhanced functionality of ECs. In this study, to improve the EC-matrix interaction, we developed an approach to molecularly conjugate LXW7 to the collagen backbone, via a collagen binding peptide SILY, in order to increase EC specific integrin binding sites on the collagen hydrogel. Results showed that in the in vitro 2-dimensional (2D) culture model, the LXW7-treated collagen surface significantly improved EC attachment and survival and decreased caspase 3 activity in an ischemic-mimicking environment. In the in vitro 3-dimensional (3D) culture model, LXW7-modified collagen hydrogel significantly improved EC spreading, proliferation, and survival. In a mouse subcutaneous implantation model, LXW7-modified collagen hydrogel improved the engraftment of transplanted ECs and supported ECs to form vascular network structures. Therefore, LXW7-functionalized collagen hydrogel has shown promising potential to improve vascularization in tissue regeneration and may be used as a novel tool for EC delivery and the treatment of vascular diseases.

中文翻译：

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开发具有整合素 αvβ3 配体的可注射纳米纤维细胞外基质水凝胶，以改善内皮细胞的存活、植入和血管化

通过可注射胶原水凝胶进行的内皮细胞 (EC) 移植作为各种血管疾病的潜在治疗方法受到了广泛关注。然而，移植的 ECs 的治疗效果受到其较差的生存能力的限制，这部分是由于细胞 - 细胞外基质 (ECM) 接合不足引发的细胞凋亡。整合素与 ECM 的结合对于细胞与周围基质的锚定、细胞扩散和迁移以及细胞内信号通路的进一步激活至关重要。虽然胶原蛋白含有几种不同类型的整合素结合位点，但它仍然缺乏足够的 ECs 特异性结合位点。此前，我们使用单珠一化合物 (OBOC) 组合技术，鉴定了 LXW7，一种整合素 αvβ3 配体，其对 ECs 具有很强的结合亲和力并增强了其功能。在这项研究中，为了改善 EC-基质相互作用，我们开发了一种方法，通过胶原蛋白结合肽 SILY，将 LXW7 分子偶联到胶原蛋白骨架上，以增加胶原蛋白水凝胶上的 EC 特异性整合素结合位点。结果表明，在体外二维 (2D) 培养模型中，LXW7 处理的胶原表面显着改善了 EC 的附着和存活，并降低了缺血模拟环境中的半胱天冬酶 3 活性。在体外 3 维 (3D) 培养模型中，LXW7 修饰的胶原水凝胶显着改善了 EC 的扩散、增殖和存活。在小鼠皮下植入模型中，LXW7 修饰的胶原水凝胶改善了移植内皮的植入并支持内皮形成血管网络结构。因此，LXW7 功能化胶原水凝胶显示出改善组织再生血管化的潜力，可用作 EC 递送和治疗血管疾病的新工具。