Low temperature plasma is currently used for the sterilization of surgical instruments. This is because plasma works at the atomic level and is able to reach all surfaces, even the interior of hollow needle ends. Its ability to disinfect is due to the generation of biologically active bactericidal agents, such as free radicals and UV light, which can be delivered to specific locations. Research into how and why these biologically active agents are generated has led to the construction of two prototype devices: one for the efficient disinfection of healthy skin in hospitals and public spaces where bacteria can pose a lethal threat; and another to treat infested chronic wounds.

Disinfecting healthy skin

A surgeons' disinfection procedure involves three minutes of hand rubbing or five minutes of hand scrubbing and has to be repeated many times a day. Negative side-effects include mechanical irritation, chemical and, possibly, allergic stress for the skin. For the hospital staff, the issue of hand disinfection is equally daunting. Over a typical working day, some 60 to 100 disinfections (in principle) are necessary – each requiring three minutes – adding up to a total of three to five hours! So it’s not hard to see how someone might skip a disinfection procedure here or there.

A new plasma device being built and trialed by the Max Planck Institute for Extraterrestrial Physics is capable of disinfecting human skin safely and quickly within seconds, cutting down the time taken to disinfect ones hands to around ten minutes a day. In addition to annihilating MRSA (methicillin-resistant Staphylococcus Aureus) and other drug-resistant kinds of bacteria that currently cause approximately 37,000 deaths from hospital induced infections every year in EU countries, only electricity is needed, no fluids or containers.

Disinfecting wounds

The second device, an "argon plasma torch", was developed by the Max Planck Institute for Extraterrestrial Physics, together with ADTEC Plasma Technology Ltd in Japan, specifically for disinfecting chronic non-healing wounds. It can be used to shoot bacteria-killing agents into infested chronic wounds and enable a quicker healing process.

One advantage of the argon plasma torch comes from regulating densities of biologically-active agents which are designed to ensure that the plasma is deadly for bacteria but harmless for human cells.

According to the researchers, plasma can be treated like a medical cocktail, which contains new and established agents that can be applied at the molecular level to cells in prescribed intensities and overall doses. They believe their work represents a first step in the direction of “plasma pharmacology”.