Investigation of noninvasive deep-tissue pathogen inactivation using microwave room-temperature atmospheric pressure plasma jet

The microwave-induced room-temperature atmospheric pressure plasma jet (MW-RTAPPJ) offers a noninvasive therapeutic approach for deep-tissue treatment, targeting subdermal pathogens. Despite its clinical potential, translational applications remain underdeveloped, with scarce quantitative microbial analyses. This study comprehensively evaluates MW-RTAPPJ's antimicrobial performance using equivalent human skin tissue (EHST), demonstrating robust efficacy even at 1.25 mm tissue thickness or subphysiological temperatures (33 °C). Systematic spectral profiling of MW-RTAPPJ emissions and post-penetration reactive nitrogen and oxygen species (RONS) quantification revealed a strong correlation between RONS concentration changes and disinfection rate, elucidating mechanistic foundations. Vesicular biosensors are employed to evaluate plasma-induced tissue effects under diverse experimental conditions. Furthermore, in vivo experiments with subcutaneous xenograft tumors validated MW-RTAPPJ's capacity for substantial tumor ablation through segmented noninvasive treatments. These results collectively validate MW-RTAPPJ's potential for deep-tissue disinfection and antitumor, particularly highlighting its transformative applications in noninvasive therapies such as dermatological disease management, cervical cancer prevention, and other subcutaneous malignancy treatments.