Identification of the Molecular Basis of Non-thermal Plasma-Induced Changes in Human Keratinocytes

A comprehensive gene expression profiling was conducted to explore cellular effects after non-thermal plasma atmospheric pressure plasma treatment. We performed a high-content microarray comparison by assessing several categories of target probes in identical conditions of labeling, hybridization, and data analysis to compare specific gene expression profiles of human epithelial skin cells with their nontreated counterparts. For assessment of transcriptome changes, cell culture medium was plasma treated and applied to the HaCaT keratinocyte cell culture. We show that even this indirect argon plasma treatment performs as well as incubation time−dependent effects on gene expression. These effects range from cell proliferation and growth to the induction of cell death pathways. It is hypothesized that these effects are evoked through plasma-based formation of reactive oxygen and nitrogen species. Several significant biological pathways, such as oxidative stress, repair, and inflammation signaling, as well as >300 transcription factors (e.g., zinc finger or homebox) were identified. Our results contribute to a better understanding of plasmamediated changes in cells at the transcriptional level. In addition, plasma may serve as a promising biomedical tool for stimulation of skin cells with regard to wound healing.