Copyright © 2009 by ASME 1 INTRODUCTION Cold atmospheric pressure plasma is currently being investigated for a wide range of clinical applications, including skin sterilization, blood coagulation [1, 2], malignant cell apoptosis [1], and wound healing [1]. However, the effect of non-thermal plasma on the vasculature is unclear. Blood vessels are affected during plasma treatment of all tissues, and vessels themselves may be an important potential target for clinical plasma therapy. We investigated the effect of cold plasma treatment on endothelial cells, which line the inner surface of blood vessels. Endothelial cells play a guiding role in angiogenesis, the growth of new blood vessels from existing vessels. In various disease conditions, healing may result from promoting or blocking angiogenesis. We hypothesize that plasma treatment can be varied to grow or regress blood vessels. We have previously demonstrated that high dose plasma treatment induces endothelial cell apoptosis, whereas low plasma doses are relatively non-toxic. In this paper, we present enhanced proliferation in low dose plasma treated endothelial cells in vitro, as well as mechanisms for the observed effect. MATERIALS AND METHODS Cell Culture Porcine aortic endothelial cells (PAEC) were maintained in low glucose Dulbecco’s Modified Eagle’s Medium (DMEM) supplemented with 5% fetal bovine serum, 1% L-glutamine, and 1% penicillin-streptomycin. For plasma treatment, cells were washed with phosphate buffered saline, detached with 0.1% trypsin and seeded near confluence on 18 mm diameter glass cover slips in 12-well plates. Cells were cultured for 24 hours prior to plasma treatment in 1.5 ml supplemented media in a 37°C, 5% CO 2 incubator to allow full attachment and spreading. Non-Thermal Plasma Treatment Non-thermal atmospheric pressure dielectric barrier discharge plasma was produced using an experimental setup similar to one previously described [2]. PAEC on glass cover slips were exposed to low power plasma for 0 to 60 seconds. Following plasma treatment, cover slips were immediately placed in a new 12-well plate, 1.5 ml of supplemented media was added to each well, and the samples were returned to the incubator. Endothelial Cell Counts and Proliferation Viable endothelial cell number was determined by counting trypsin-detached cells in a Coulter counter. Endothelial cell proliferation was measured through cell counts either on directly treated cells or through a conditioned media assay. For directly treated cells, fold proliferation was determined by taking the ratio of cell number on day five to day one. Endothelial Cell Fibroblast Growth Factor-2 Release Fibroblast growth factor-2 (FGF2) release from plasma treated cells was measured by enzyme linked immunosorbent assay (ELISA) using FGF Elisa Kit (R&D Systems) as per manufacturer instructions. FGF2 effects were blocked using an FGF2 neutralizing antibody (10 µg/ml), which was pre-incubated for 30 min with the conditioned media prior to adding it to cells. Statistical Analysis Data are mean ± SD. Statistical significance (p<0.05, #) was evaluated using Student’s t test (2 groups) and ANOVA (>2 groups). Proceedings of the ASME 2009 Summer Bioengineering Conference (SBC2009) June 17-21, Resort at Squaw Creek, Lake Tahoe, CA, USA SBC2009-XXXXXX NON-THERMAL ATMOSPHERIC PRESSURE DIELECTRIC BARRIER DISCHARGE PLASMA ENHANCES ENDOTHELIAL CELL PROLIFERATION VIA FIBROBLAST GROWTH FACTOR-2 RELEASE Sameer Kalghatgi (1), Alexander Fridman (2), Gary Friedman (1), Alisa Morss Clyne (2) (1)Electrical and Computer Engineering Drexel University Philadelphia, PA-19104 USA (2)Mechanical Engineering and Mechanics Drexel University Philadelphia, PA-19104 USA