Cold Atmospheric Plasma Destruction of Solid Proteins on Stainless-Steel Surface and on Real Surgical Instruments

Summary form only given. The capability of cold atmospheric plasmas to inactivate microorganisms is well established. By comparison, their ability to destruct solid proteins from surgical instruments is much less understood with only a few studies reported. Yet surgical instruments are typically contaminated by both pathogenic microorganisms and infectious protein. In this contribution, we present a systematic study of protein destruction using cold atmospheric pressure helium discharge. Helium-oxygen mixture is preferred as the working gas, because it can reduce the gas temperature near room temperature and as such allow its application to polymer- based instruments. Our study has two components the first being plasma destruction of solid protein deposited on stainless-steel disks as a model of surgical instruments and the second being plasma destruction of three different sets of surgical forceps that have already been autoclaved. A number of characterization techniques are used, including laser- induced fluorescence, scanning-electron microscope, electron energy dispersion X-ray analysis and electrophoresis. The objective of our study is to demonstrate the intrinsic capability of cold atmospheric plasmas to destruct surface proteins and also the benefits and challenges of implementing this technique for medical sterilization. A supplementary study is also presented to study and differentiate possible protein destruction mechanisms using optical emission spectroscopy and protein destruction kinetics and through a series of experiments aimed to differentiate the production of different plasma species. The results from this study suggest that (1) intrinsically cold atmospheric plasmas are capable of both protein destruction and microbial inactivation; (2) the technology can be adapted for decontamination of real surgical instruments: and (3) atomic oxygen and excited nitride oxide are key decontaminating agents.