Vascularization is crucial for providing nutrients and oxygen to cells while removing waste. Despite advances in 3D-bioprinting, the fabrication of structures with void spaces and channels remains challenging. This study presents a novel approach to create robust yet flexible and permeable small (600–1300 μm) artificial vessels in a single processing step using 3D coaxial extrusion printing of a biomaterial ink, based on tyramine-modified polyethylene glycol (PEG-Tyr). We combined the gelatin biocompatibility/activity, robustness of PEG-Tyr and alginate with the shear-thinning properties of methylcellulose (MC) in a new biomaterial ink for the fabrication of bioinspired vessels. Chemical characterization using NMR and FTIR spectroscopy confirmed the successful modification of PEG with Tyr and rheological characterization indicated that the addition of PEG-Tyr decreased the viscosity of the ink. Enzyme-mediated crosslinking of PEG-Tyr allowed the formation of covalent crosslinks within the hydrogel chains, ensuring its stability. PEG-Tyr units improved the mechanical properties of the material, resulting in stretchable and elastic constructs without compromising cell viability and adhesion. The printed vessel structures displayed uniform wall thickness, shape retention, improved elasticity, permeability, and colonization by endothelial-derived - EA.hy926 cells. The chorioallantoic membrane (CAM) and assays demonstrated the hydrogel's ability to support neoangiogenesis. The hydrogel material with PEG-Tyr modification holds promise for vascular tissue engineering applications, providing a flexible, biocompatible, and functional platform for the fabrication of vascular structures.

中文翻译：

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先进的 PEG-酪胺生物材料墨水，用于通过同轴打印对可灌注和柔性小直径血管结构进行精密工程

血管化对于为细胞提供营养和氧气同时清除废物至关重要。尽管 3D 生物打印技术取得了进步，但制造具有空隙空间和通道的结构仍然具有挑战性。这项研究提出了一种新颖的方法，使用基于酪胺改性聚乙二醇 (PEG-Tyr) 的生物材料墨水 3D 同轴挤出打印，在单个处理步骤中创建坚固而灵活且可渗透的小型 (600–1300 μm) 人造血管。我们将明胶的生物相容性/活性、PEG-Tyr 和藻酸盐的稳健性与甲基纤维素 (MC) 的剪切稀化特性结合在一种新型生物材料墨水中，用于制造仿生容器。使用 NMR 和 FTIR 光谱的化学表征证实了 PEG 与 Tyr 的成功修饰，流变学表征表明 PEG-Tyr 的添加降低了油墨的粘度。酶介导的 PEG-Tyr 交联允许在水凝胶链内形成共价交联，确保其稳定性。PEG-Tyr 单元改善了材料的机械性能，在不影响细胞活力和粘附的情况下形成可拉伸和弹性的结构。打印的血管结构显示出均匀的壁厚、形状保持性、改善的弹性、渗透性以及内皮衍生的 EA.hy926 细胞的定植。绒毛尿囊膜（CAM）和测定证明了水凝胶支持新血管生成的能力。PEG-Tyr 修饰的水凝胶材料有望用于血管组织工程应用，为血管结构的制造提供灵活、生物相容性和功能性的平台。