The lymphatic system is involved in various biological processes, including fluid transport from the interstitium into the venous circulation, lipid absorption, and immune cell trafficking. Despite its critical role in homeostasis, lymphangiogenesis (lymphatic vessel formation) is less widely studied than its counterpart, angiogenesis (blood vessel formation). Although the incorporation of lymphatic vasculature in engineered tissues or organoids would enable more precise mimicry of native tissue, few studies have focused on creating engineered tissues containing lymphatic vessels. Here, we populated thick collagen sheets with human lymphatic endothelial cells, combined with supporting cells and blood endothelial cells, and examined lymphangiogenesis within the resulting constructs. Our model required just a few days to develop a functional lymphatic vessel network, in contrast to other reported models requiring several weeks. Coculture of lymphatic endothelial cells with the appropriate supporting cells and intact PDGFR-β signaling proved essential for the lymphangiogenesis process. Additionally, subjecting the constructs to cyclic stretch enabled the creation of complex muscle tissue aligned with the lymphatic and blood vessel networks, more precisely biomimicking native tissue. Interestingly, the response of developing lymphatic vessels to tensile forces was different from that of blood vessels; while blood vessels oriented perpendicularly to the stretch direction, lymphatic vessels mostly oriented in parallel to the stretch direction. Implantation of the engineered lymphatic constructs into a mouse abdominal wall muscle resulted in anastomosis between host and implant lymphatic vasculatures, demonstrating the engineered construct's potential functionality in vivo. Overall, this model provides a potential platform for investigating lymphangiogenesis and lymphatic disease mechanisms.

淋巴系统参与各种生物过程，包括从间质到静脉循环的液体运输、脂质吸收和免疫细胞运输。尽管淋巴管生成（淋巴管形成）在体内平衡中起关键作用，但其研究范围不如其对应物血管生成（血管形成）。尽管在工程组织或类器官中加入淋巴管系统可以更精确地模拟天然组织，但很少有研究专注于创建包含淋巴管的工程组织。在这里，我们用人淋巴管内皮细胞填充厚胶原片，结合支持细胞和血液内皮细胞，并检查所得结构内的淋巴管生成。与其他报道的模型需要几周的时间相比，我们的模型只需要几天时间就可以开发出功能性淋巴管网络。淋巴管内皮细胞与适当的支持细胞和完整的 PDGFR-β 信号的共培养证明对淋巴管生成过程至关重要。此外，对结构进行循环拉伸可以创建与淋巴和血管网络对齐的复杂肌肉组织，更精确地仿生天然组织。有趣的是，发育中的淋巴管对张力的反应与血管不同。血管与拉伸方向垂直，淋巴管多与拉伸方向平行。将工程化的淋巴结构植入小鼠腹壁肌肉导致宿主和植入淋巴管系统之间的吻合，证明了工程化结构在体内的潜在功能。总体而言，该模型为研究淋巴管生成和淋巴疾病机制提供了一个潜在的平台。