Plasma jet-induced tissue oxygenation: potentialities for new therapeutic strategies

Abstract

The lack of oxygen is a major reason for the resistance of tumor cells to treatments such as radiotherapies. A large number of recent publications on non-thermal plasma applications in medicine report cell behavior modifications and modulation of soluble factors. This in vivo study tested whether such modifications can lead to vascular changes in response to plasma application. Two in situ optical-based methods were used simultaneously, in real time, to assess the effect of non-thermal plasma on tissue vasculature. Tissue oxygen partial pressure (pO 2 ) was measured using a time-resolved luminescence-based optical probe, and the microvascular erythrocyte flow was determined by laser Doppler flowmetry. When plasma treatment was applied on mouse skin, a rapid pO 2 increase (up to 4 times) was subcutaneously measured and correlated with blood flow improvement. Such short duration, i.e. 5 min, plasma-induced effects were shown to be locally restricted to the treated area and lasted over 120 min. Further investigations should elucidate the molecular mechanisms of these processes. However, improvement of oxygenation and perfusion open new opportunities for tumor treatments in combination with radiotherapy, and for tumor blood vessel normalization based strategies.

The 2017 Plasma Roadmap: Low temperature plasma science and technology

“…The magnitude of typical electric fields experienced at tissue surfaces was shown to be comparable with field strengths that are known to be biologically important [90]. One of these possible effects is the observation that plasma jets applied to mouse skin induces a significant increase in local blood flow and blood O 2 content [91]. A similar result for human subjects was associated with the plasma-induced generation of nitric oxide (NO) [92].…”

Reactive Species from Cold Atmospheric Plasma: Implications for Cancer Therapy

“…Following Collet et al A 5 min application of a He plasma jet to the skin of five mice (two locations each) resulted in a significant increase in sub‐cutaneous tissue O 2 concentration (top) and blood flow (bottom). Averages are shown in the colored lines in the top and bottom panels.…”

“…Averages are shown in the colored lines in the top and bottom panels. Reproduced with permission . Copyright 2014, Institute of Physics.…”

Oxy-nitroso shielding burst model of cold atmospheric plasma therapeutics

“…Collet et al showed that a several minute long, He plasma jet application to the external skin of a mouse induced a substantial increase in subcutaneous blood O 2 content and blood flow that lasted for several hours. [81] Furthermore, the effect was limited to tissue near the part of the skin exposed to the plasma. The same effect was observed when gauze impregnated by de-ionized water was placed between the plasma jet and skin, suggesting a dissolved component is involved.…”

“…[83,84] Both mechanisms are speculative, clearly, but the fact that recent studies report blood flow/O 2 content effects suggests that they should also be investigated further. [81] …”