Fig. 3

In vitro functional assay of paracrine factors. a Angiogenic properties were assessed by endothelial tube formation assays using HUVECs (scale bar 400 μm). Fluorescence images of tube structure formed by HUVECs and quantification data of the area of the tube structure (ratio to control) are shown. b Stem cell homing property was assessed by migration assay using MSCs (scale bar 100 μm). Fluorescence signals of the migrated cells, ratio to control, are indicated. HUVEC, human umbilical vein endothelial cells. *p < 0.05, **p < 0.01