title: Stabilizing the cold plasma-stimulated medium by regulating medium's composition.
abstract: Over past several years, the cold plasma-stimulated medium (PSM) has shown its remarkable anti-cancer capacity in par with the direct cold plasma irradiation on cancer cells or tumor tissues. Independent of the cold plasma device, PSM has noticeable advantage of being a flexible platform in cancer treatment. Currently, the largest disadvantage of PSM is its degradation during the storage over a wide temperature range. So far, to stabilize PSM, it must be remained frozen at -80 °C. In this study, we first reveal that the degradation of PSM is mainly due to the reaction between the reactive species and specific amino acids; mainly cysteine and methionine in medium. Based on this finding, both H2O2 in PSM and the anti-cancer capacity of PSM can be significantly stabilized during the storage at 8 °C and -25 °C for at least 3 days by using phosphate-buffered saline (PBS) and cysteine/methionine-free Dulbecco's Modified Eagle Medium (DMEM). In addition, we demonstrate that adding a tyrosine derivative, 3-Nitro-L-tyrosine, into DMEM can mitigate the degradation of PSM at 8 °C during 3 days of storage. This study provides a solid foundation for the future anti-cancer application of PSM.
authors.affiliation: Department of Mechanical and Aerospace Engineering, The George Washington University, Science &Engineering Hall, 800 22nd Street, NW, Room 3550, Washington, DC 20052, USA.
authors.forename: Dayun
authors.initials: D
authors.lastname: Yan
authors.affiliation: Department of Biological Sciences, The George Washington University, Lisner Hall, 2023 G Street, NW, Suite 340, Washington, DC 20052, USA.
authors.forename: Niki
authors.initials: N
authors.lastname: Nourmohammadi
authors.affiliation: Department of Biochemistry and Molecular Medicine, The George Washington University, Ross Hall 2300 Eye Street, NW, Washington, DC 20037, USA.
authors.forename: Ka
authors.initials: K
authors.lastname: Bian
authors.affiliation: Department of Biochemistry and Molecular Medicine, The George Washington University, Ross Hall 2300 Eye Street, NW, Washington, DC 20037, USA.
authors.forename: Ferid
authors.initials: F
authors.lastname: Murad
authors.affiliation: Neurological Surgery, The George Washington University, Foggy Bottom South Pavilion, 22nd Street, NW, 7th Floor, Washington, DC 20037, USA.
authors.forename: Jonathan H
authors.initials: JH
authors.lastname: Sherman
authors.affiliation: Department of Mechanical and Aerospace Engineering, The George Washington University, Science &Engineering Hall, 800 22nd Street, NW, Room 3550, Washington, DC 20052, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Keidar
mesh_terms: D000970:Antineoplastic Agents; D003470:Culture Media / Q000737:chemistry / Q000528:radiation effects; D003545:Cysteine / Q000737:chemistry; D005609:Free Radicals / Q000737:chemistry; D005615:Freezing; D006371:Helium; D006801:Humans; D006861:Hydrogen Peroxide / Q000737:chemistry; D008715:Methionine / Q000737:chemistry; D009369:Neoplasms / Q000628:therapy*; D011827:Radiation; D014443:Tyrosine / Q000031:analogs & derivatives / Q000378:metabolism
chemical_list: D000970:Antineoplastic Agents; D003470:Culture Media; D005609:Free Radicals; D006371:Helium; C002744:3-nitrotyrosine; D014443:Tyrosine; D008715:Methionine; D006861:Hydrogen Peroxide; D003545:Cysteine