Effect of Nitrogen Gas Plasma Generated by a Fast-Pulsed Power Supply Using a Static Induction Thyristor on Scrapie Prion

Abstract

Previous studies show that nitrogen gas plasma generated by a fast-pulsed power supply using a static induction thyristor has both virucidal and bactericidal effects. In this study, nitrogen gas plasma was further evaluated for its potential effects on prions, which are well known to be the most resistant pathogen to both chemical and physical inactivation. Aliquots (10 μL) of mouse brain homogenate infected with Chandler scrapie prion were spotted onto cover glasses and subjected to nitrogen gas plasma. Treated samples were recovered and subjected to further analyses. Control prion samples were prepared in exactly the same way but without plasma treatment. Protein misfolding cyclic amplification (PMCA) showed that nitrogen gas plasma treatment at 1.5 kilo pulse per second for 15 or 30 min caused a reduction in the in vitro propagation level of PrPres (proteinase K-resistant prion protein), which was used as an index of abnormal prion protein (PrPSc). Moreover, mice injected with prion treated with plasma for 30 min showed longer survival than mice injected with control prion, indicating that nitrogen gas plasma treatment decreased prion infectivity. Altogether, these results suggest that nitrogen gas plasma treatment can inactivate scrapie prions by decreasing the propagation activity and infectivity of PrPSc.

Effect of Non-Concentrated and Concentrated Vaporized Hydrogen Peroxide on Scrapie Prions

“…An equal volume of 2× SDS gel-loading buffer (90 mM Tris/HCl pH 6.8, 2% ( w / v ) SDS, 0.02% ( w / v ) bromophenol blue, 20% ( v / v ) glycerol, and 10% ( v / v ) 2-mercaptoethanol) was added, and the samples were heated at 100 °C for 10 min to terminate the PK reaction. SDS-polyacrylamide gel electrophoresis (PAGE) using a 12% acrylamide gel was used for protein separation as described previously [ 46 ]. The proteins were then transferred to polyvinylidene difluoride (PVDF) membranes (Amersham Biosciences, Piscataway, NJ, USA) by using a semidry blotting system (Bio Rad, Cambridge, MA, USA).…”

“…PMCA of samples recovered from the treatment spots on the cover glasses was performed by using an automatic cross-ultrasonic protein-activating apparatus (ELESTEIN 070-GOT; Elekon Science Corp., Chiba, Japan) [ 46 ]. C57/BL6J mouse brain homogenates were used as the source of PrP C .…”

Inactivation of Prions by Low-Temperature Sterilization Technology Using Vaporized Gas Derived from a Hydrogen Peroxide–Peracetic Acid Mixture

“…To carry out PMCA, we used an automatic cross-ultrasonic protein-activating instrument (ELESTEIN 070-GOT, Elekon Science Corp., Chiba, Japan) [ 49 ]. Each samples derived from spots treated with VHPPA (SD and QC) or untreated (Control) were sealed in a capped polystyrene tube (catalogue number 035-12, Elekon Science Corp.) and subjected to 40 cycles of amplification, each comprising sonication and then 1 h of incubation at 37 °C.…”

Hydrogen Peroxide Gas Plasma Sterilizer Combined with Dielectric Barrier Discharge and Corona Discharge Inactivates Prions

“…The PK reaction was quenched by incubating the samples at 100 • C for 10 min. Proteins were separated by SDS-polyacrylamide gel electrophoresis (PAGE) in a 12% acrylamide gel as described previously [34]. Proteins were transferred onto polyvinylidene difluoride (PVDF) membranes (Amersham Biosciences, Piscataway, NJ, USA) using a semidry blotter (Bio-Rad Laboratories, Inc.).…”

“…PMCA amplification was carried out as described previously [34]. Briefly, samples retrieved from the treated spots on the cover glass were analyzed by PMCA in a capped and sealed polystyrene tube using 10% C57/BL6J mouse brain homogenates in PBS containing 1% Triton X-100, 4 mM EDTA, and protease inhibitor cocktail (Roche Diagnostics, Mannheim, Germany) as the PrP C substrate.…”