## 3 Results  
Samples derived from prion (Chandler strain)-infected mouse brain homogenate on a glass surface were subjected to RENO-S130 treatment (Figure 1). RENO-S130 is composed of DBD plasma region, sterilization chamber, and corona plasma region. In DBD plasma step, the voltage waveforms had a V\({}_{\text{PP}}\) of 22 kV (maximal peak of + 11 kV; minimal peak of \(-\)11 kV) and frequency of 15 kHz at 760 Torr (Figure 2a), while the current waveforms showed I = 23 mA (Figure 2d). In corona plasma step, the voltage waveforms showed a V\({}_{\text{PP}}\) of 14 kV (maximal peak of + 7 kV; minimal peak of \(-\)7 kV) and frequency of 15 kHz at 760 Torr (Figure 2b), while the current waveforms showed I = 31 mA (Figure 2e). The voltage waveforms showed a V\({}_{\text{PP}}\) of 3 kV (maximal peak of +1.5 kV; minimal peak of \(-\)1.5 kV) and frequency of 15 kHz at 10 Torr (Figure 2c), while the current waveforms showed I = 68 mA (Figure 2f). The RENO-S130 instrument operates in two modes: a non-lumen mode that is suitable for medical devices that require surface sterilization only, or an Eco mode suitable for medical devices with an inner space or lumen [35]. The sterilization time for the non-lumen mode was 28 min, while that for the Eco mode was 45 min. Next, the RENO-S130-treated and untreated samples were subjected to PK treatment followed by Western blot analysis using an anti-PrP antibody (SAF83) (Figure 3). For the untreated sample (Control), a prominent band corresponding to PrPres (an indicator of PrP\({}^{\text{Sc}}\)), which is resistant to PK digestion, was detected. However, the intensity of the PrPres signal was markedly reduced for the RENO-S130-treated samples using either of the two process modes (non-lumen mode or Eco mode) compared with the untreated sample (Control). Similarly, the level of total PrP, including PrP\({}^{\text{Sc}}\) and PrP\({}^{\text{C}}\), was below the detection limit by Western blotting after treatment with the RENO-S130 device. These results suggest that both PrP\({}^{\text{Sc}}\) and PrP\({}^{\text{C}}\) were degraded by RENO-S130 treatment under both non-lumen mode and Eco mode conditions. Next, PMCA analysis was performed to investigate the change of in vitro proliferation activity of Chandler prion after treatment with the RENO-S130 device (Figure 4). In PMCA, uninfected C57 BL6/J mouse brain homogenate was used as a source of PrP\({}^{\text{C}}\) substrate. The prion samples were diluted (1:10) with PrP\({}^{\text{C}}\) substrate and analyzed in the 1 st round of PMCA to compare the change of amplification efficiency of PrP\({}^{\text{Sc}}\) induced by treatment with the RENO-S130 device. This procedure was then repeated using the resulting 1 st round samples to generate the 2 nd round of PMCA. Aliquots from the different samples were then incubated with (PK(+)) or without PK (PK(-)). Western blot analysis using an  
Figure 3: Western blotting of prions after treatment with the RENO-S130 device. Scrapie prion (Chandler strain) was treated with the RENO-S130 device using two process modes: non-lumen mode (nonL) and Eco mode (Eco). An untreated sample (C) was used as a negative control. Samples were retrieved from the spots on the cover glass (100 \(\upmu\)s protein per 50 \(\upmu\)) and incubated at 37 \({}^{\circ}\)C for 60 min with or without 20 \(\upmu\)g/mL of proteinase K (PK) prior to Western blotting to detect PrPres (**a**) and total prion protein (PrP) (**b**), respectively. Western blotting was conducted using SAF83, an anti-PrP antibody. Size markers (kDa) are shown on the left-hand side of each blot. Figure 2: Voltage and current waveforms during operation of the DBD plasma at atmospheric pressure conditions (**a**,**d**), the corona discharge plasma at atmospheric pressure conditions (**b**,**e**), and the corona discharge plasma at vacuum conditions (**c**,**f**) in the RENO-S130 device.