Delayed effects of cold atmospheric plasma on vascular cells

We investigated the long-term behaviour of vascular cells (endothelial and smooth muscle) after exposure to a cold atmospheric plasma source. The cells were treated through a gas-permeable membrane, in order to simulate intravenous treatment with a gas plasma-filled catheter. Such indirect treatment resulted in (dose-dependent) apoptosis and necrosis in smooth muscle cells; these effects were visible 6-10 h after exposure. We ascribed cell damage to poisoning by active nitrogen species. A not yet resolved phenomenon of total (irreversible) cell inactivation without necrosis was observed in endothelial cells. Conditions for non-inflammatory plasma treatment (no cell necrosis) can be realized. Furthermore the current experiments have brought new insights in the mechanism of cell detachment, which was observed in many previous studies.