Cold Plasma Systems and their Application in Surface Treatments for Medicine.

In this paper, a review of cold plasma setups and the physical and chemical processes leading to the generation of active species is presented. The emphasis is given to the interaction of cold plasmas with materials used in medical applications, especially medical implants as well as live cells. An overview of the different kinds of plasmas and techniques used for generation of active species, which significantly alter the surface properties of biomaterials is presented. The elemental processes responsible for the observed changes in the physio-chemical properties of surfaces when exposed to plasma are described. Examples of ongoing research in the field are given to illustrate the state-of-the-art at the more conceptual level.

Therapeutic effect of cold atmospheric plasma and its combination with radiation as a novel approach on inhibiting cervical cancer cell growth (HeLa cells).

Cervical cancer is one of the important cancers in women. Research on novel treatment approach can reduce the mortality and burden. Although radiotherapy is a common treatment, its negative side effects have concerned physician. In our study, we studied impact of cold atmospheric pressure plasma on the Hela cancer cells, as an alternative treatment. The effect of three different types of such plasma; dielectric barrier discharge (DBD), plasma jet, and afterglow plasma, on the cancer cells were studied. Moreover, some effective operating parameters such as exposure time, applied voltage, composition of working gas in plasma treatment were investigated on the survival of the afterglow plasma. Finally, treatments by the afterglow plasma, gamma radiation (1 Gy), and combination of both were compared. Analysis showed that DBD and plasma jet (direct exposure) effectively killed the cancer cells, even by a minimum applied voltage. But a fraction of the cells survived after the exposure of indirect diffused afterglow plasma. In the case of this plasma, we realized that higher applied voltage and exposure time led to less cell viability. Fewer fractions of survival cells were detected in the case of argon afterglow plasma comparing to oxygen afterglow. Cold atmospheric plasma and its combination with radiation therapy showed a significant decrease in viability of the cells, comparing to the radiation alone. Our research showed that plasma and its combination with radiation therapy have superiority over radiation therapy.

Cold Plasma Reticulation of Shape Memory Embolic Tissue Scaffolds.

Polyurethane shape memory polymer (SMP) foams are proposed for use as thrombogenic scaffolds to improve the treatment of vascular defects, such as cerebral aneurysms. However, gas blown SMP foams inherently have membranes between pores, which can limit their performance as embolic tissue scaffolds. Reticulation, or the removal of membranes between adjacent foam pores, is advantageous for improving device performance by increasing blood permeability and cellular infiltration. This work characterizes the effects of cold gas plasma reticulation processes on bulk polyurethane SMP films and foams. Plasma-induced changes on material properties are characterized using scanning electron microscopy, uniaxial tensile testing, goniometry, and free strain recovery experiments. Device specific performance is characterized in terms of permeability, platelet attachment, and cell-material interactions. Overall, plasma reticulated SMP scaffolds show promise as embolic tissue scaffolds due to increased bulk permeability, retained thrombogenicity, and favorable cell-material interactions.

Computer aided modeling of a new microwave plasma cavity with the H-type excitation at microwave frequency.

Computer modeling of the semi-lumped H field-generating multi helical coil, which can be used for generation of H-type discharges at microwave frequencies is presented in this paper. The aim of modeling was to support the design of model plasma source based upon a set of realistic dimensions, which should enable excitation of maximal values of H field at the axis of the discharge tube. As a result, a Microwave-Driven Inductively Coupled Plasma cavity (MICP) has been constructed and its assembly is presented in this paper. The new cavity can be applied in the emission and mass spectroscopy but also can find another applications where maximum H-type coupling is essential.