Structural and functional analysis of lysozyme after treatment with dielectric barrier discharge plasma and atmospheric pressure plasma jet

Abstract

The variation in the biological function of proteins plays an important role in plasma medicine and sterilization. Several non-thermal plasma sources with different feeding gases are used worldwide for plasma treatment, including dielectric barrier discharge (DBD) and atmospheric-pressure plasma jet (APPJ) as the most commonly used sources. Therefore, in the present work, we used both DBD and APPJ plasma sources with N2 and air as feeding gases to evaluate the effects on the structural, thermodynamic, and activity changes of enzymes. In the current work, we used lysozyme as a model enzyme and verified the structural changes using circular dichroism (CD), fluorescence, and X-ray crystallography. In addition, we investigated the lysozyme thermodynamics using CD thermal analysis and changes in the B-factor from X-ray crystallography. The results showed that lysozyme activity decreased after the plasma treatment. From these analyses, we concluded that N2-feeding gas plasma disturbs the structure and activity of lysozyme more than Air feeding gas plasma in our experimental studies. This study provides novel fundamental information on the changes to enzymes upon plasma treatment, which has been absent from the literature until now.

Effects and safety of atmospheric low‐temperature plasma on bacterial reduction in chronic wounds and wound size reduction: A systematic review and meta‐analysis

“…Nine studies encompassing 268 patients, randomised either to treatment with AP or control, were identified . Four studies investigated the effect of AP on wound healing compared with conventional standard treatment, and five studies presented data on reduction of bacterial burden in wounds after AP application . All nine studies reported the occurrence of SAEs in the intervention and control arms of the respective studies.…”

“…6,8,[36][37][38][39][40][41][42] Four studies investigated the effect of AP on wound healing compared with conventional standard treatment, 8,36,38,40 and five studies presented data on reduction of bacterial burden in wounds after AP application. 6,8,32,36,39 All nine studies reported the occurrence of SAEs in the intervention and control arms of the respective studies.…”

“…Study criteria included the clinical use of low‐temperature APs to reduce the wound size and/or bacterial load in wounds, compared with a control, and the occurrence of SAEs in the intervention and control groups. The search was not restricted to direct AP application, where physical plasma is expelled from a nozzle as a visible flame‐like jet, or indirect AP application, where it is produced in one electrical voltage field between the head of the device and the skin or a wound surface, acting as the second electrode (also called “dielectric barrier discharge” [DBD] plasma) . The literature search was undertaken using terms identified by the authors.…”

“…The search was not restricted to direct AP application, where physical plasma is expelled from a nozzle as a visible flame-like jet, or indirect AP application, where it is produced in one electrical voltage field between the head of the device and the skin or a wound surface, acting as the second electrode (also called "dielectric barrier discharge" [DBD] plasma). 31,32 The literature search was undertaken using terms identified by the authors. Academic Search Premier, PubMed, Embase/ Medline, CINAHL, Scopus, the Cochrane Database of Systematic Reviews, and the Central Register of Controlled Trials were searched from 1980 to December 2017 using the following keywords and medical subject headings (mesh): "infection" OR "bio-burden" OR "bacterial reduction" AND "wound" OR "skin defect" OR "acute wound" OR "chronic wound" AND "trial" OR "randomly" OR "clinical trial" OR "controlled" OR "randomised" OR "randomized" OR "controlled clinical trial" OR "randomised/randomized controlled trial" AND "atmospheric pressure glow discharge" OR "atmospheric pressure plasma" OR "Cold atmospheric plasma" OR "Cold atmospheric pressure plasma" OR "cold plasma" OR "low-temperature plasma" OR "non-thermal atmospheric pressure plasma" OR "non-thermal dielectric barrier discharge" OR "non-thermal gas plasma" OR "plasma device" OR "tissue tolerable plasma."…”

Application of plasma jet to the inhibition of the proliferation of hepatic malignant cells via reactive oxygen species generation

“…The DBD devices have the simplest configurations because they are composed of only one or two dielectric layers between two metal electrodes, and there is an increasing interest in the DBD plasma jets and their applications . One problem regarding the applications of the DBD plasma jets is that they can treat only small areas of liquids or wounds due to the limited jet size, which is usually in the order of a few millimeters . This problem may be overcome by using multiple plasma jets that can cover a large area …”