Angiogenesis assay
To investigate whether LEAP‐purified pEVs induce angiogenesis, tube formation by human dermal endothelial cells (HDMECs, PromoCell, Germany) was observed. Briefly, 7500 cells per well were seeded on 96‐well plates (Corning, USA) and allowed to adhere for 2 h. Cells were then treated with 15 μg/mL of pEVs. Tube formation capacity was assessed by observing the vessel‐like structures formed over 120 h after treating the cells using a light microscope.