Optimization of Extracellular Matrix for Three-Dimensional Culture of Vascularized Endometrial Organoids

Abstract:\u003cbr\u003e\u003cbr\u003eThe vascular system is essential for tissue regeneration and the success of bioengineered implants. In this study, we aimed to optimize the extracellular matrix (ECM) for the culture of endometrial triple-cell-type organoids. We combined human umbilical vein endothelial cells (HUVECs), endometrial epithelial organoids (EEOs), and endometrial stromal cells (ESCs) in a fibrin-matrigel hydrogel. We found that increasing the proportion of fibrin in the hydrogel promoted vascular network formation by HUVECs and improved adhesion of EEOs. The stiffness and pore size of the hydrogel scaffold were also affected by the ratio of fibrin to matrigel. Additionally, we established a dynamic 3D culture system using a microfluidic chip, which allowed for the formation of highly interconnected organoids with a capillary network-like structure. Transcriptome sequencing confirmed the similarity between the organoids and in vivo endometrial tissues. Furthermore, the organoids responded to sex hormones and exhibited regenerative potential in a mouse model of endometrial damage. Overall, our optimized ECM and dynamic culture system provide a valuable platform for studying endometrial biology and regenerative medicine applications.