Combinations with Cold Atmospheric Pressure Plasma Therapy

Abstract

Achieved under ambient conditions when a gas is passed through an electric field, cold plasma, consisting of reactive gas species, has found biomedical applications similar to those of photodynamic therapy; it kills cancer and bacterial cells and biofilms, and is effective in wound healing through infusion of the affected disease area with the reactive gas species. Most of these species are reactive oxygen and reactive nitrogen species, not unlike those generated in the type II mechanism of photodynamic therapy. This has created increasing interest in this rapidly growing therapeutic technology because it is effective and because the plasma can be administered directly against disease cells or the reactive gas species generated can be stored in suitable stabilizing media for subsequent administration. The technology has been combined with chemotherapy, electro-chemotherapy, magnetic and photothermal therapy, and photodynamic therapy for wound healing, tissue regeneration, wound closure, and bacterial antiseptic sanitization, together with an increasing number of non-invasive combination applications. It has stimulated the development of a wide range of clinical applicator devices. It has also been combined with electro-chemotherapy with additive enhancement of the efficacy of bone fracture rehabilitation. Enhancement of the efficacy of the combinations with photodynamic therapy may be rationalized in terms of the enhancement of reactive gas species. Immunotherapy combinations were demonstrated by the delivery of a checkpoint protein inhibitor and a cold atmospheric pressure plasma activated fluid directly to cancer xenografts using microneedles.