General Objective, Strategy, and Directions

The goal of this Major Research Initiative is to build on our recent achievements in the application of plasma science to biology and medicine. These breakthrough developments grew out of productive collaborations between engineers, biological scientists and physicians. The existence of this energetic and mutually beneficial collaborative group provides a unique opportunity for revolutionary research in the application of plasma to selectively kill micro-organisms while sparing living mammalian tissues, and possibilities in therapeutic manipulation of proteins as in the process of coagulation or triggering of apoptosis pathways. These highly promising avenues of research were made possible through the development of non-equilibrium ‘cold’ plasma technology that can directly interact with living tissue without causing tissue damage. “Plasma Bio-Medicine” has therefore emerged as a new research area with huge potential for both scientific developments and biomedical applications.

Although many institutions are involved in plasma research, most, of these programs are focused on thermal plasmas which have few applications in biology and medicine. Drexel University is the leading research institution involved in research into non-thermal plasma science and its applications in the US. To date, we have demonstrated the direct sterilization effect of non-thermal plasma on pathogenic bacteria on human cadaver skin without tissue damage. In a live mouse model we demonstrated a 10-minute skin exposure with no toxicity. We have demonstrated in vitro coagulation with a time frame similar to that seen in the extrinsic pathways, implying that specific protein activation may be the mechanism of action. Also in the lab, we have sought to identify the effects of non-thermal plasma at the cellular level. Initial experiments identified a dose of plasma that caused minimal immediate toxicity, but then went on to stimulate apoptosis in a melanoma cancer cell line. We have shown that 20 second cold plasma treatment kills Leishmania promastigotes in vitro, while not effecting macrophages for as long as 2 minutes. For research and medical environments we have utilized plasma for fast and effective cold sterilization of air and water streams as well as temperature-sensitive surfaces. Each one of these areas is the basis for fundable projects and/or a translational product for industry. All these applications are most likely to be developed, funded and implemented when they are nurtured within the framework of an interdisciplinary research collaboration among Drexel's colleges and departments. Specific major research directions in the field of Plasma Bio-Medicine include the following: Creation and detailed characterization of the novel non-thermal plasma discharges and non-equilibrium plasma systems capable of providing non-damaging, direct treatment of biological objects, including human living tissue, cells and micro-organisms.

MEM, ECE & DUCOM

Characterization of physical, chemical and biological mechanisms of interaction of the plasma generated components (i.e., chemically active long-living neutrals, radicals, electronically excited species, ultra-violet radiation, charged particles etc.) with cells, living tissue and micro-organisms (viruses, bacteria, parasites).

MEM, ECE & BIOMED

Recent breakthrough inventions at Drexel University in plasma science and engineering have resulted in the opportunity for novel research and application of non-thermal plasma interactions with living organisms from viruses and bacteria to human tissue. Led by Drexel researchers, new exciting and promising research areas of plasma biology and medicine have been created recently on the border of medical and engineering sciences that will contribute to Drexel’s potential for international leadership in this area of research. The goal of this program is to examine the use of non-thermal plasmas in areas of clinical practice where plasma can be a more effective medical tool than existing procedures or in cases where no treatment presently exists. One area where the use of plasma is being investigated is in blood coagulation to stop bleeding in critical life threatening situations. For example, coagulation is a vital issue in severely injured individuals in situations involving accident victims. Methods of inducing coagulation rapidly in such cases are critical for emergency medical responders to treat victims at the scene of an incident. Non-thermal plasma provides this opportunity to induce coagulation very rapidly in a safe manner both at the accident site and in hospital emergency rooms.

Another important area where the non-thermal plasma may have a significant impact on healthcare is related to the prevention of infection in skin wounds including burns and ulcerations that occur, for example, in patients with diabetes. The use of plasma has been demonstrated to have the capacity to kill bacteria that cause infections in such wounds without having an adverse effect on human tissues. Such infections are often difficult to treat with conventional antibiotic treatment. Plasma treatment could potentially be used continuously in cases of severe burns as an adjunct to antibiotic therapy to attain sterilization of the affected areas thus preventing infections.

Non-thermal plasma is also proved to be effective in treating skin diseases. In particular, the plasma treatment effectively kills Leishmania promastigotes while not effecting macrophages. The plasmas has been also tested for ability to effectively treat melanoma, a cancer of the skin, by selectively killing cancer cells while leaving normal skin tissue unharmed. Experiments identified a dose of plasma that caused minimal immediate toxicity, but then went on to stimulate apoptosis in a melanoma cancer cell line.

The Bio-Medical Plasma Research will include: (1) continued development and characterization of novel non-thermal plasma discharges to provide clinically important treatments; (2) identification of major plasma components (e.g., charged particles, UV, free radicals, metastable electronically excited molecules, streamer electric field, ozone, NO) that are responsible for the desired clinical effects of the direct plasma treatments; (3) the effect of plasma on various pathogenic microbes, blood plasma components, and cancer cells; (4) the use of plasma discharges in surgical and other medical procedures. The academic units involved in this research program include the College of Engineering, the College of Medicine, the School of Biomedical Engineering and Health Systems, and the College of Arts and Sciences. Drexel team is in the process of formation and coordination of national and international collaboration in plasma medicine and biology, as well as making first steps in technology transfer in the new area of medicine.

Although first grants in the Plasma Biology and Medicine are already received from DARPA, NASA and USDA, further grants from these agencies as well as support from NIH and NSF requires today intensive feasibility research of faculty from four Drexel colleges and submission of new major multidisciplinary proposals, which is to be in focus of the Plasma Bio-Medicine program.