Preclinical Cold Atmospheric Plasma Cancer Treatment

Abstract

CAP is an ionized gas generated under atmospheric pressure conditions. Due to its reactive chemical components and near-room temperature nature, CAP has promising applications in diverse branches of medicine, including microorganism sterilization, biofilm inactivation, wound healing, and cancer therapy. Currently, hundreds of in vitro demonstrations of CAP-based cancer treatments have been reported. However, preclinical studies, particularly in vivo studies, are pivotal to achieving a final clinical application. Here, we comprehensively introduced the research status of the preclinical usage of CAP in cancer treatment, by primarily focusing on the in vivo studies over the past decade. We summarized the primary research strategies in preclinical and clinical studies, including transdermal CAP treatment, post-surgical CAP treatment, CAP-activated solutions treatment, and sensitization treatment to drugs. Finally, the underlying mechanism was discussed based on the latest understanding.

Cold atmospheric plasma (CAP) treatment increased reactive oxygen and nitrogen species (RONS) levels in tumor samples obtained from patients with low-grade glioma

“…The observation of two-fold increase in intracellular RONS in CAP jet-treated LGG samples compared to untreated samples (figure 3(a)) is consistent with previous reports indicating the efficacy of CAP jet in promoting RONS accumulation in various glioma cell lines as well as in vivo animal models [51]. This finding underscores the potential of CAP jet treatment as a valuable approach for enhancing RONS levels in glioma tumor tissues, aligning with previous research on its effectiveness.…”

The shift in the laminar‐to‐turbulent transition flow mode in atmospheric pressure plasma jet

“…These components, atomic oxygen, and hydroxyl radicals act as strong oxidizing species which make plasma jet favorable for more biomedical applications. [ 49,50 ] The UV‐range 200–450 nm presented in Figure 7 ensures the existence of OH band 305–312 nm (A 2 ∑ + → X 2 $${\rm{\pi }})$$ and the N 2 2nd positive system (C 3 $${\rm{\pi }}$$ u → B 3 $${\rm{\pi }}$$ g ) appear. The highest intensities spectra of the second positive system bands were belonged to the vibrational transitions (0–0) at 337.1 nm, (1–0) at 315.9 nm, and (0–1) at 357.7 nm.…”

“…It is known that the emission spectra of NAPPJ expelled in argon shows many lines of excited and reactive species, such as reactive nitrogen species (RNS) and reactive oxygen species (ROS) as observed in previous research. [ 49,51 ] Nitrogen and oxygen species are created because the plasma is ejected into air where its active electrons, Ar metastable ionize and excite air molecules. [ 52 ] These lines or bands are produced from ionization and dissociation of the ambient air which contains oxygen, nitrogen, and water vapor.…”

“…Therefore, plasma jet length increases with broader pulse width due to the longer duration of the external electric field. [48]…”

Higher N2 gas-flow rate ratios in O2- and Ar-containing feed gas mixtures enhance the cytotoxic effects of radical-activated medium against murine melanoma B16F10 cells

“…6,7) Thus, a new interdisciplinary field of medicine known as plasma medicine has been established that focuses on therapeutics and other biophysical applications of CAP. 8) Furthermore, CAP technology is used in the sterilization of medical instruments 9) and for clinical applications in wound healing. 10) CAP is now recognized as a promising new approach for treating cancer.…”