1947-5764/13/$35.00 © 2013 by Begell House, Inc. 71 Plasma Medicine, 3(1-2): 71–80 (2013) Viability of Human Blood Leukocytes Compared with Their Respective Cell Lines after Plasma Treatment Lena Bundscherer, 1,2, * Sander Bekeschus, 1,2 Helena Tresp, 1,2 Sybille Hasse, 1,2 Stephan Reuter, 1,2 Klaus-Dieter Weltmann, 2 Ulrike Lindequist 3 & Kai Masur 1,2 1 Center for Innovation Competence plasmatis, Greifswald, Germany; 2 Leibniz Institute for Plasma Science and Technology, Greifswald, Germany; 3 Institute of Pharmacy, University of Greifswald, Greifswald, Germany *Address all correspondence to: Lena Bundscherer, Leibniz Institute for Plasma Science and Technology, Felix-Hausdorff-Str. 2, 17489 Greifswald, Germany; lena.bundscherer@inp- greifswald.de. ABSTRACT: Non-thermal plasma application has become a promising feld of investigation in chronic wound healing research over the past few decades. In addition to its well-charac- terized antibacterial effects, plasma potentially promotes the growth of eukaryotic cells. To date, mainly epithelial skin cells have been examined regarding the impact of plasma treat- ment on chronic wound healing. However, immune cells also are involved in wound healing as well as the removal of pathogens. Therefore, we compared the survival behavior of 2 human leukocyte cell lines (a monocyte and a CD4 + T helper cell line) and their respective human blood counterparts after exposure to plasma. Measurements of early and late apoptotic cells demonstrate that freshly isolated blood cells were more susceptible to apoptosis induction than the cell lines. Furthermore, blood and cell line monocytes tolerated longer plasma exposure compared with blood and cell line CD4 + T helper cells. KEY WORDS: apoptosis, CD4 + T helper cells, Jurkat cells, monocytes, non-thermal plasma, pH effect, plasma medicine, THP-1 cells, wound healing I. INTRODUCTION Non-thermal plasma has drawn more and more attention worldwide in the feld of medi- cal applications over the past 2 decades. 1 Because of its complex composition (free radi- cals, excited and neutral species, ions, electrons, and ultraviolet, visible, and infrared radiation), 2,3 plasma can have lethal effects on bacteria and eukaryotic cells. In addition, it has potentially stimulating effects on mammalian cells. 4,5 Medical applications range from the removal of dental bioflms 6 and healing of infectious skin and nail diseases 7 to wound management. 8 In particular, chronic wounds pose one major target for plas- ma treatment. 9 However, future plasma applications require a thorough examination of plasma-cell interactions, ensuring the safety and reliability of devices in advance of their clinical use. So far, most studies concerning chronic wound healing have investigated the effect of plasma on skin cells. Nevertheless, immune cells play an important role in skin health, wound healing, and bacterial cleaning. 10,11 Epidermal T cells are known to