What is cold plasma?

Plasma is an ionized gas that produces a large number of chemically reactive molecules known as reactive oxygen and nitrogen species. These short-lived molecules can have a strong influence on biological processes such as the growth or death of tumor cells.

“The effect of plasma in tissue is very complex and little understood. We have therefore developed a 3D model made of hydrogels that mimics real tumor tissue. In this model, we were able to observe exactly how deep the molecules from the plasma penetrate—and which of these molecules are important for the effect on tumor cells,” explains Lea Miebach, first author of the study.

Particularly short-lived molecules such as peroxynitrite penetrated several millimeters deep into the tissue. Hydrogen peroxide, which had previously been considered the main active ingredient in laboratory research, showed little effect: even when it was specifically removed, the effect of the plasma remained strong.