Plasma For Medicine

PLASMA FOR MEDICINE

Plasmas are ionized gases. Hence, they consist of positive (and negative) ions and electrons, as well as neutral species. The ionization degree can vary from 100% (fully ionized gases) to very low values (e.g. 10-4 – 10-6; partially ionized gases).

The plasma state is often referred to as the fourth state of matter. Much of the visible matter in the universe is in the plasma state. This is true because stars, as well as all visible interstellar matter, are in the plasma state. Besides the astroplasmas, which are omnipresent in the universe, we can also distinguish two main groups of laboratory plasmas, i.e. the high-temperature or fusion plasmas, and the so-called low-temperature plasmas or gas discharges.

Very first applications of plasma for health care date back to the middle of the 19th century, emerging from the popularity of electrotherapy. Beginning with the use of ozone in the 1850s by Siemens generated by dielectric barrier discharges to clean biologically contaminated water, followed by carbon arc lamps to treat high blood pressure and electrotherapeutic devices such as ‘‘violet ray’’ machines first experimental approaches to therapeutic plasma applications have been made — without describing it as ‘‘Plasma Medicine’’.

From a more general perspective, medical application of physical plasma can be subdivided into two principal approaches:

‘Indirect’’ use of plasma-based or plasma-supplemented techniques to treat surfaces, materials or devices to realize specific qualities for subsequent special medical applications.

One important field is the plasma-based modification of material surfaces. Modifications of biomaterial surfaces by plasma treatment range from changes of surface morphology and texture to special physically and/or chemically designed surface properties. These include increase of surface wettability or specific functionalization of surfaces to increase and optimize adhesion of living cells on the one side as well as realization of nonfouling surface conditions to inhibit adhesion of organic matter like proteins, bacteria or cells on the other.

A further important field of plasma application closely related to plasma treatment of surfaces is the use of plasmas for sterilization or bio-decontamination of materials or devices for medical purposes. The increasing replacement of glass and steel in medically used devices by polymeric materials in the middle of the last century resulted in an urgent need of sterilization procedures which are no longer based on heat treatments.

“Direct”. Application of physical plasma on or within the human (or animal) body to realize therapeutic effects based on direct interaction of plasma with living tissue.

In contrast to the Argon Plasma Coagulation

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