Kinetic characteristic of exosome effects on hPMEC migration.

The effect of exosomes isolated from pMSC-conditioned media on hPMEC in vitro migration. Data are expressed as half-maximal Stimulatory Time (ST50 in hours) and represent the mean ± SEM. Primary cultures of endothelial cells were exposed (24 h) to increasing concentration of exosome (0, 5, 10 or 20 µg exosomal protein/ml) obtained from placental mesenchymal stem cell exposed to 1%, 3% or 8% O2. hPMEC (CD31+) were used in passage 3 for migration assay. *p<0.005 versus control; †P<0.005 versus all condition for ST50.