# Application of Plasma Technology in Bioscience and Biomedicine
## 4 Medical Applications  
The versatility of atmospheric pressure plasmas is reflected in the five papers related to medical/therapeutic applications in this issue.  
Interesting fundamentals were provided by [PERSON] et al. by using glutathione as a marker to establish a correlation between plasma parameters and the resultant liquid chemistry from two distinct sources to predefined biological outcomes. Specific glutathione modifications appeared to be associated with biological responses elicited by plasma. The findings implied that short-lived species and other plasma components were required for the induction of cellular responses, as well as for glutathione modifications. Importantly, the results indicate that comparisons of medical plasma sources should not rely on measurements of long-lived chemical species; rather, modifications of biomolecules (such as glutathione) might be better predictors of cellular responses to plasma exposure [10]. Another paper with a fundamental and methodological focus was provided by [PERSON] et al., who investigated the effects of plasma on fish cell lines and compared to mammalian cells towards potential applications in wound healing for farmed fish, where skin lesions may occur as a result of intensive fish farming. The authors varied cell density, culture medium, and pyruvate concentration in the medium to conclude that it is mandatory to use similar cell densities and an identical medium, or at least a medium with identical antioxidant capacity, when studying plasma effects on different cell lines. In agreement with this, a standardized protocol for research in plasma medicine can be found in [11]. Altogether, fish cells showed a higher sensitivity towards plasma treatment than mammalian cells [12].  
The paper by [PERSON] and co-workers examined the effect of cold plasma on the morphofunctional state of human bone marrow stem cells (BMSC), with particular attention to the dual effects of plasma-induced oxidative stress on the state of stem cells (promotion of proliferative processes vs. destructive processes leading to cell death). The paper discusses the role of mitochondria and reactive oxygen species (ROS) in the cellular response to plasma [13].  
With a specific interest in cold plasma jet as a topical skin treatment, [PERSON] et al. observed that direct plasma treatment was very destructive to mouse skin cells in vitro, leading to low cell viability [14]. This research touches on important points that have been under discussion in the field in recent years and that should be taken into consideration for all further research in this field, the urgent need to: upgrade and standardize existing plasma treatment protocols of cell lines [11]; monitor gas and liquid chemistries; and standardize plasma discharge parameters [14].  
With a more specific focus on cancer, [PERSON] et al. based their research on the finding that in different tumors, high amounts of hyaluron (HA) are correlated with tumor progression. Therefore, new tumor therapy strategies are targeting HA production and degradation. The authors found that plasma-treated cell culture medium impaired the HA pericellular coat of HaCaT cells. This diminished the time-dependent adhesion of cells, although this disturbed HA coat alone was not the reason for the inhibition of cell adhesion [15].