Effects and mechanism of plasma-activated medium on angiogenesis of vascular endothelial cells

After cell culture medium is treated with low temperature plasma (LTP), the liquid is rich in reactive oxygen and nitrogen species (RONS), and becomes plasma-activated medium (PAM). PAM, as the supplier of RONS, can affect the angiogenesis of cells. The purpose of this study is to investigate the effects and related mechanism of PAM on human umbilical vein endothelial cells (HUVECs). Cell viability and cell cycle were evaluated after HUVECs were treated with PAM for 24 h. Changes in cell angiogenesis, migration and adhesion, secretion of cytokines such as VEGF and bFGF, expression of VEGFR-2 and phosphorylation of the key proteins in the MEK/ERK signaling pathway, concentrations of H2O2 and NO2⁻ in PAM and in cells were also investigated. The results showed that PAM obtained by LTP treatment had dual effects on the angiogenesis of HU-VECs: PAM obtained by short-term LTP treatment promoted the angiogenesis of HUVECs, while PAM obtained by long-term LTP treatment inhibited the angiogenesis of HUVECs. The mechanism may be that PAM treatment changes the content of RONS, affects the VEGF-VEGFR-2 signaling pathway, and ultimately affects the angiogenesis of HUVECs.