| AVS 57th International Symposium & Exhibition | |
| Plasma Science and Technology | Thursday Sessions |
| Session PS2+BI-ThA |
| Session: | Plasmas for Medical and Biological Applications |
| Presenter: | T. Hirata, Tokyo City University, Japan |
| Authors: | T. Hirata, Tokyo City University, Japan C. Tsutsui, Tokyo City University, Japan A. Mori, Tokyo City University, Japan T. Yamamoto, Tokyo City University, Japan A. Taguchi, Tokyo City University, Japan |
| Correspondent: | Click to Email |
The researches in the case of “novel plasma” have been widely conducted in the fields of chemistry, solid physics, and nanomaterial science. Such plasma uses a boundary reaction field in a liquid or gaseous-liquid phase based on application of liquid plasma, micro plasma, and atmospheric pressure plasma. In particular, atmospheric pressure plasma is indispensable not only for sterilization, disinfection, decomposition of hazardous materials, and surface modification but also for the cultivation and development of complex new areas which require a diverse perspective, involving biomedical science. From the above-mentioned background, we are conducting basic experiments on direct irradiation of cells using a micro-spot atmospheric pressure plasma source.
The device is a coaxial structure having a tungsten wire (1 mm I.D.) installed inside a glass capillary (plasma generation area: 8 mm I.D.; tip area: 1 mm I.D.), and a grounded tubular electrode wrapped on the outside. The high voltage for the plasma generation is provided by the high voltage power supply. The conditions of plasma generation are as follows: applied voltage: 5-9 kV, frequency: 1-3 kHz, helium (He) gas flow rate: 1 L/min, and plasma irradiation time: 1-300 sec. The experiment was conducted by preparing a culture medium containing mouse fibroblasts (NIH3T3) on a culture dish (made of polypropylene). A culture dish irradiated with plasma was introduced into a CO2-incubator.
According to the dependency of cell numbers against the plasma irradiation time, when only He gas was flowed, the growth of cells was inhibited as the floatation of cells caused by gas agitation inside the culture was promoted. On the other hand, there was no floatation of cells and healthy growth was observed when plasma was generated. Therefore, it appears that the interaction due to ion/radical collisions on the culture surface causes a substantial effect on the proliferation of growth factors such as epidermal growth factor ( EGF), nerve growth factor (NGF), and transforming growth factor ( TGF) that are present in the cells.