Engineering Three-Dimensional\nSpheroid Culture for\nEnrichment of Proangiogenic miRNAs in Umbilical Cord Mesenchymal Stem\nCells and Promotion of Angiogenesis

In the field of regenerative medicine, umbilical cord-derived\nmesenchymal\nstem cells (UC-MSCs) have a plausible potential. However, traditional\ntwo-dimensional (2D) culture systems remain limited in replicating\nthe complex <i>in vivo</i> microenvironment. Thus, three-dimensional\n(3D) cultures offer a more physiologically relevant model. This study\nexplored the impact of 3D culture conditions on the UC-MSC secretome\nand its ability to promote angiogenesis, both <i>in vitro</i> and <i>in vivo</i>. In this study, using two distinct\nmethods, we successfully cultured UC-MSCs: in a monolayer (2D-UC-MSCs)\nand as spheroids formed in U-shaped 96-well plates (3D-UC-MSCs). The\npresence and expression of proangiogenic miRNAs in the conditioned\nmedia (CM) of these cultures were investigated, and differential expression\npatterns were explored. Particularly, the CM of 3D-UC-MSCs revealed\nsignificantly higher levels of miR-21-5p, miR-126-5p, and miR-130a-3p\ncompared to 2D-UC-MSCs. Moreover, the CM from 3D-UC-MSCs revealed\na higher effect on endothelial cell proliferation, migration, and\ntube formation than did the CM from 2D-UC-MSCs, indicating their proangiogenic\npotential. In an <i>in vivo</i> Matrigel plug mouse model,\n3D-UC-MSCs (cells) stimulated greater vascular formation compared\nto 2D-UC-MSCs (cells). 3D culture of UC-MSCs’ secretome improves\nthe promotion of angiogenesis.