Plasma Catheter: An Electrically Floating, Nanosecond-Pulsed, in-Liquid, Cold-Atmospheric-Plasma Source for Treatment of Infective Endocarditis*

The abundance of matter in the fourth state and its breadth from thermal to non-thermal, vacuum to atmospheric pressure, solid to gaseous mediums, seed unimaginable applicability. Biomedicine is one of the more novel applications of physical plasma that is gaining popularity in recent years. We have seen promise in various aspects of biomedicine including, but not limited to, oncology, dermatology, infection prevention and control, dentistry, material modification, etc. Today, one of the primary obstacles in the adoption of plasma medicine is device applicability. For instance, an atmospheric-pressure plasma jet cannot be applied to certain internal organs or used in intravascular therapies, due to flow of a carrier gas through the device. One possible solution is a device capable of generating a cold-plasma discharge directly inside biofluids. We present the Plasma Catheter, an electrically-floating, nanosecond-pulsed, in-liquid, cold-plasma source, capable of generating bubble-free discharge inside various biologically-relevant liquids. Investigated biofluids include phosphate-buffered saline (PBS), LB broth, platelet-poor blood plasma, and whole blood. This device is currently being investigated for its efficacy in treating antibiotic-resistant, bacterial biofilms. The three main foci of this presentation: design and characterization; efficacy; and safety of the Plasma Catheter. In-vitro experiments with S. aureus and S. epidermidis have shown 1-log reduction in bacteria with a 15-minute treatment in PBS. Combined with vancomycin treatment efficacy increases to 2-log reduction. In-vitro coagulation times, platelet activation, and hemolysis data signal the possibility of safe application within the cardiovascular system.