The effects of UV irradiation and gas plasma treatment on living mammalian cells and bacteria: a comparative approach

Living mammalian cells and bacteria were exposed to irradiation from narrow-band UV lamps and treated with a nonthermal gas plasma (plasma needle). The model systems were: Chinese Hamster Ovary (CHO-K1) cells (fibroblasts) and Escherichia Coli bacteria. UV irradiation can lead to cell death (necrosis) in fibroblasts, but the doses that cause such damage are much higher than those needed to destroy Escherichia Coli. The usage of UV radiation in combination with active oxygen radicals lowers the UV dose sufficient to kill the cells. However, in any case the fibroblasts seem to be fairly resistant to UV radiation and/or radicals. Possibly, the lamps may be used for decontamination of infected wounds. The most important active species in an atmospheric plasma are the radicals; the role of UV is less pronounced. Treatment of CHO-K1 cells with the plasma needle can lead to cell necrosis under extreme conditions, but moderate doses cause only a temporary interruption of cell adhesion. Plasma needle may be used for fine tissue treatment (e.g., controlled cell removal without inflammation) and also for bacterial decontamination.