Dose-Dependent Tissue-Level Characterization of a Medical Atmospheric Pressure Argon Plasma Jet

Area of Science:

• Plasma medicine
• Biophysics
• Cell biology

Background:

• Cold atmospheric plasma (CAP) is a nonthermal treatment with potential for mucosal diseases beyond wound healing.
• Atmospheric pressure plasma jets (APPJs) are versatile but their in vivo tissue effects require better understanding.
• Current characterization often focuses on solutions or plasma effluent, not direct tissue interaction.

Purpose of the Study:

• To investigate the physicochemical effects of APPJ treatment on human primary mucosal tissue and tissue models.
• To assess in vivo tissue-level responses to CAP, focusing on radical generation and cellular effects.
• To establish methods for monitoring CAP effects directly on tissues.

Main Methods:

• Utilized on-tissue infrared (IR) thermography and spatially resolved optical emission spectroscopy (OES) to assess thermal and emission properties.
• Employed electron-spin-resonance (ESR) spectroscopy to quantify CAP-derived radicals in human tissue samples.
• Correlated CAP dosage with radical generation, cell viability, and proliferation of primary human fibroblasts.

Main Results:

• IR thermography and OES showed no evidence of tissue-damaging effects.
• ESR spectroscopy demonstrated dose-dependent generation and distribution of CAP-derived radicals within tissues.
• CAP treatment induced apoptosis-independent antiproliferative effects on fibroblasts, with a dose-dependent G1 cell cycle arrest.

Conclusions:

• CAP treatment at the tissue level is feasible without causing thermal damage.
• Radical generation correlates with antiproliferative effects, suggesting a significant role in CAP's therapeutic mechanisms.
• Cell cycle regulation, particularly G1 arrest, is a key factor in the antiproliferative action of CAP on mucosal tissues.