(250d) Non-Thermal Plasmas for Biomedicine: A New Frontier in Plasma Processing

Authors: 
Graves, D. B., University of California - Berkeley



Thirty years ago, low temperature, low-pressure, non-thermal glow discharge plasmas were being explored for the rapidly growing semiconductor industry and related thin film technologies. Challenges in thin film device plasma processing continue to this day due to the remarkable evolution of semiconductor devices associated with nano-scale features, many new materials, new lithographic approaches, introduction of larger wafers and so forth.

A new field of non-thermal plasma processing associated with biomedicine has emerged that is reminiscent of the earlier transformation in thin film materials plasma processing. In this new field, plasmas are used to interact directly and therapeutically with living tissue. [1] Researchers throughout the world have shown that atmospheric pressure, near-room temperature plasmas can be used to shrink tumors, promote wound healing and sterilization, and treat dermatological and dental disease, among other things. As before, the inherent complexities and coupled, often synergistic mechanisms associated with plasmas are being investigated. In this new field, however, using plasma to alter complex biological ‘targets’ make the challenges even greater.

In this talk, I will highlight some of the recent advances in the rapidly changing field of plasma biomedicine and focus on the role of reactive oxygen species (ROS) and reactive nitrogen species (RNS). ROS and RNS (or RONS), in addition to a suite of other radical and non-radical reactive species, are essential actors in an important sub-field of aerobic biology termed ‘redox’ (or oxidation-reduction) biology. I will review the evidence suggesting that RONS generated by plasmas are responsible for their observed therapeutic effects. [2]

References:

[1] M.G. Kong, et al., New Journal of Physics, 11, article no. 115012, 2009.

[2] D.B. Graves, Journal of Physics D-Applied Physics, 45(26), article no. 263001, 2012.