Mechanism of Blood Coagulation by Non-Thermal Atmospheric Pressure Dielectric Barrier Discharge

Summary form only given. Blood coagulation by direct contact of nonthermal atmospheric pressure Dielectric Barrier Discharge (DBD) plasma in vitro has been reported previously. This discharge appears to promote rapid blood coagulation by enhancing natural coagulation processes. However, there is no detailed understanding of the specific mechanisms by which this nonthermal plasma coagulates blood. In this paper we investigate few different mechanisms and present some that seem to play an important role. Blood coagulation is, in general, a complex process that involves platelets, various coagulation proteins, and ions. In-vivo, platelet activation usually initiates the coagulation cascade which ends in platelet aggregation and conversion of fibrinogen into cross-linked fibrin. Therefore, non-thermal plasma could coagulate blood through multiple pathways including platelet activation, activation of intermediate protein factors and increasing concentration of ionic species. Previously it was hypothesized that direct exposure to DBD plasma initiates coagulation in blood through increase in concentration of Ca²⁺, an important factor in the coagulation cascade. We test this hypothesis experimentally by measuring pH and Ca²⁺ in the nonthermal plasma treated blood using standard pH meter and calcium selective electrode. These studies have shown that no significant change occurs in pH or calcium ion concentration during the typical time of blood coagulation in discharge treated blood. In this work we also tested the effect of the nonthermal plasma exposure on Fibrinogen, an important protein participating in the final stages of the coagulation cascade. Nonthermal plasma exposure of a buffered solution of fibrinogen for only five seconds results in clear change of the solution opacity. Interestingly, the effect of this discharge is highly selective as a similar solution of Albumin does not show any signs of change after even longer treatment. Activity and- structure of these proteins after non-thermal plasma treatment is analyzed via gel electrophoresis tests and linked to coagulation kinetics. Results and conclusions that will be presented in this paper indicate that selective conversion of Fibrinogen is clearly one of the mechanisms by which nonthermal plasma induces blood coagulation.