Low‐Temperature Internal Sterilization of Medical Plastic Tubes Using a Linear Dielectric Barrier Discharge

Abstract

The use of a linear DBD for the internal sterilization of thin plastic tubes used in medical facilities is studied. We demonstrated that flexible, long, linear DBD plasmas were produced with a diameter of 0.2–3 mm and a length longer than 1 m. The internal sterilization experiments of medical plastic tubes were carried out using a thin, linear DBD. We confirmed that 106 Geobacillus stearothermophilus spores were killed inside the tube at room temperature after 12 min DBD irradiation under atmospheric conditions. The sterilization was attributed to UV radiation of the nitrogen molecules' second positive system, the ozone generated in the air, and/or their synergetic effect.

Cold Atmospheric Air Plasma Sterilization against Spores and Other Microorganisms of Clinical Interest

“…Other test specimens were PTFE (Goodfellow), polyvinylchloride (PVC) (Goodfellow), and glass (Menzel, Germany). The spores were treated with CAP, leaving the samples inside the Tyvek coupon, which had already been shown to be permeable for plasma (13,21).…”

Decontamination of objects in a sealed container by means of atmospheric pressure plasmas

“…Sterilization using plasmas at atmospheric pressure is mostly governed by chemically reactive species or radicals like atomic oxygen, ozone, hydroxyl, and NO (Brandenburg et al, 2009;Herrmann et al, 1999;Laroussi, 1996Laroussi, , 2002Laroussi & Leipold, 2004;Montie, Kelly-Wintenberg, & Roth, 2000). DBDs operating in ambient air (Heise, Neff, Muranyi, & Wunderlich, 2004;Leipold, Kusano, Hansen, & Jakobsen, 2010;Ma, Zhang, Shi, Xu, & Yang, 2008) as well as with a variety of different gases (Eto, Ono, Ogino, & Nagatsu, 2008a;Laroussi et al, 1999Laroussi et al, , 2002KellyWintenberg et al, 1999;Majumdar, Singh, Palm, & Hippler, 2009) have been shown to successfully decontaminate surfaces. Eto, Ono, Ogino, and Nagatsu (2008b) reported sterilization of packed matter in a Tyvek package, where a DBD located outside the package generates ozone.…”

Inactivation of Bacteria by Non-Thermal Plasmas

“…More recently, Hähnel et al (Hahnel et al, 2010) observed that air humidity in a dielectric barrier surface discharge has a significant influence on the bacterial inactivation rate: higher concentration of water vapour in the process gas leads to higher killing rates of micro-organisms. To enable the internal sterilization of complicated medical instruments, such as breathing circuits, catheders and endoscopes, different authors have developed special DBD configurations (Eto et al, 2008, Pointu et al, 2008, Sato et al, 2008. Eto et al (Eto et al, 2008) developed a so-called "linear DBD" with a diameter of 0.2-3 mm and a length of 40 cm and found that 10 6 B. stearothermophilus spores could be killed inside a medical plastic tube at room temperature after 12 minutes of air plasma exposure.…”

“…To enable the internal sterilization of complicated medical instruments, such as breathing circuits, catheders and endoscopes, different authors have developed special DBD configurations (Eto et al, 2008, Pointu et al, 2008, Sato et al, 2008. Eto et al (Eto et al, 2008) developed a so-called "linear DBD" with a diameter of 0.2-3 mm and a length of 40 cm and found that 10 6 B. stearothermophilus spores could be killed inside a medical plastic tube at room temperature after 12 minutes of air plasma exposure. Sato et al (Sato et al, 2008) also report on a special type of DBD and demonstrated the efficacy of their DBD for tube sterilization.…”