The use of electric fields in vivo to deliver DNA, called electroporation, has the potential to broadly impact vaccination and disease treatment. The evidence for this has emerged from a large number of recently completed and ongoing clinical trials. The methods for applying electric fields to tissues traditionally involve contact between metal electrodes and the tissue. In this study, we investigated the use of helium plasma as a noncontact method for electrically treating tissue in a manner that results in the uptake and expression of foreign DNA in murine skin. More specifically, our goal was to demonstrate that DNA encoding a model-secreted protein could be delivered, detected in the blood, and remain functional to produce its known biological effect. Murine erythropoietin (EPO) was the model-secreted protein. Results clearly demonstrated that an intradermal DNA injection followed by plasma treatment for 2 min resulted in elevated levels of EPO in the blood and corresponding hemoglobin increases that were statistically significant relative to DNA injection alone.
Plasma pharmacy is a subset of the broader field of plasma medicine. Although not strictly defined, the term aqueous plasma pharmacy (APP) is used to refer to the generation and distribution of reactive plasma-generated species in an aqueous solution followed by subsequent administration for therapeutic benefits. APP attempts to harness the therapeutic effects of plasma-generated oxidant species within aqueous solution in various applications, such as disinfectant solutions, cell proliferation related to wound healing, and cancer treatment. The subsequent use of plasma-generated solutions in the APP approach facilitates the delivery of reactive plasma species to internal locations within the body. Although significant efforts in the field of plasma medicine have concentrated on employing direct plasma plume exposure to cells or tissues, here we focus specifically on plasma discharge in aqueous solution to render the solution biologically active for subsequent application. Methods of plasma discharge in solution are reviewed, along with aqueous plasma chemistry and the applications for APP. The future of the field also is discussed regarding necessary research efforts that will enable commercialization for clinical deployment.