Nontarget Biomolecules Alter Macromolecular Changes Induced by Bactericidal Low-Temperature Plasma

A Privat-Maldonado; Y Gorbanev; D O'Connell; R Vann; V Chechik; M W van der Woude

doi:10.1109/TRPMS.2017.2761405

Nontarget Biomolecules Alter Macromolecular Changes Induced by Bactericidal Low-Temperature Plasma

IEEE Trans Radiat Plasma Med Sci. 2017 Oct 11;2(2):121-128. doi: 10.1109/TRPMS.2017.2761405. eCollection 2018 Mar.

Authors

A Privat-Maldonado^{1

2

3}, Y Gorbanev^{2

4}, D O'Connell², R Vann², V Chechik⁴, M W van der Woude^{5

6}

Affiliations

¹ 1Department of BiologyCentre for Immunology and Infection.
² 2Department of PhysicsYork Plasma Institute, University of YorkYorkYO10 5DDU.K.
³ 3PLASMANTDepartment of ChemistryUniversity of Antwerp2610AntwerpBelgium.
⁴ 4Department of ChemistryUniversity of YorkYorkYO10 5DDU.K.
⁵ 5Centre for Immunology and Infection, Hull York Medical School.
⁶ 6Department of BiologyUniversity of YorkYorkYO10 5DDU.K.

Abstract

Low-temperature plasmas (LTPs) have a proven bactericidal activity governed by the generated reactive oxygen and nitrogen species (RONS) that target microbial cell components. However, RONS also interact with biomolecules in the environment. Here we assess the impact of these interactions upon exposure of liquid suspensions with variable organic content to an atmospheric-pressure dielectric barrier discharge plasma jet. Salmonella enterica serovar Typhimurium viability in the suspension was reduced in the absence [e.g., phosphate buffered saline (PBS)], but not in the presence of (high) organic content [Dulbecco's Modified Eagle's Medium (DMEM), DMEM supplemented with foetal calf serum, and Lysogeny Broth]. The reduced viability of LTP-treated bacteria in PBS correlated to a loss of membrane integrity, whereas double-strand DNA breaks could not be detected in treated single cells. The lack of bactericidal activity in solutions with high organic content correlated with a relative decrease of ^•OH and O₃/O₂(a¹[Formula: see text])/O, and an increase of H₂O₂ and [Formula: see text] in the plasma-treated solutions. These results indicate that the redox reactions of LTP-generated RONS with nontarget biomolecules resulted in a RONS composition with reduced bactericidal activity. Therefore, the chemical composition of the bacterial environment should be considered in the development of LTP for antimicrobial treatment, and may affect other biomedical applications as well.

Keywords: Bacterial inactivation; low-temperature plasma (LTP); plasma-treated media; reactive oxygen and nitrogen species (RONS).

Grants and funding

This work was supported in part by the Wellcome Trust under Grant WT095024MA, the Leverhulme Trust under Grant RPG-2013-079, and the EPSRC under Grant EP/H003797/1, Grant EP/K018388/1, and Grant EP/M027538/1.