Cytotoxicity of plasma-irradiated lactate solution produced under atmospheric airtight conditions and generation of the methyl amino group

Ringer's lactate solution was irradiated with non-equilibrium plasma under airtight conditions. The plasma-activated lactate (PAL) was produced with argon, oxygen, and nitrogen gases following purging of Ar. Cytotoxicity could be controlled by diluting PAL, and a killing effect was selectively obtained on cancer cells compared to normal cells for Ar+O-2+N-2 PALs. Nonetheless, cytotoxicity was partly reproduced by similar concentrations of H2O2 and NO2 (-) in the PALs. The organics produced by plasma irradiation to lactate were investigated using nuclear magnetic resonance, and the generation of methyl amino species was confirmed.