During the last decade Plasma Medicine has been established as a new field of research. Applying cold physical plasmas in the treatment of biological matter the inactivation of microorganisms was the focus at the beginning. In the meantime basic research realized the stimulation of eukaryotic cells by the same kind of plasmas. For a further understanding of the underlying molecular processes in plasma - cell interaction, a control and detailed diagnostic of the reactive plasma components is essential. On the biological side the disentanglement of the molecular mechanisms triggered by plasma in cell culture led to a deeper understanding of the signaling pathways and on gene regulation.

In this work we present first results of the molecular mechanisms triggered by non-thermal plasma in human skin biopsies. The biopsies have been analyzed by specific immuno-histochemistry to identify markers for stimulation (e.g. Ki67) in the stratum basale - the layer of the skin responsible for growth and regeneration. No harmful side effects were detected in these skin biopsies. We could proof that short term plasma treatment (up to 1 minute) indeed is able to stimulate the proliferation of human skin cells without the induction of cell death.