When patients in Star Trek: The Next Generation were sent to the sick bay, they were often treated using an instrument called a dermal regenerator (Fig 1). This device emitted a bright, glowing light that was used to heal minor skin wounds such as cuts and burns, as well as to remove scars. It is interesting to see how futuristic technology from TV and the movies can become a reality.
A number of new devices similar to the dermal regenerator are being developed, which use cold atmospheric plasmas for the treatment of wounds and skin ageing. One example of such a device is the kINPen Med system from NeoPlas (1), which was recently approved for clinical trials. It emits a 2-3mm diameter cold plasma jet (as shown in main image).
In order to help understand how these plasma devices work, it is important to provide some background on plasma itself. Plasma is one of the four states of matter in physical science, in addition to solid, liquid, and gas phases. Plasmas are excited gases and consist of many active components, such as radicals (reactive species), ions, electrons and photons.
HOT AND COLD PLASMAS
[caption id="attachment_3996" align="alignright" width="628"] Fig 1: Dermal regenerator in Star Trek (copyright: CBS Corporation and/or Paramount Pictures)[/caption]
Hot plasmas are widely used to sterilise medical devices and to remove, cut and cauterise tissue. The plasmas exhibit bactericidal and fungicidal effects, due to reactive species generated. Cold atmospheric plasmas, which are the focus of the technology known as plasma medicine, have many of the benefits of high-temperature plasmas without the enormous heat production. They therefore have no ablative or coagulative effects.
Cold plasmas provide a degree of surface sterilisation, but not to as high a level as obtained with hot plasmas. They do, however, generate active species such as nitrous oxide and oxygen radicals, which have been found to be important in enhancing wound healing. These plasmas have been found to regulate many biochemical reactions that are normally unaffected by light-based therapies.
Examples of plasma medicine research that has been published in the technical literature includes the use of a microwave-generated plasma jet to increase the expression of anti-ageing genes in skin cells, including collagen, fibronectin and vascular endothelial growth factor without causing cellular damage (2). Another study, which used a radiofrequency atmospheric plasma system, showed that after three months of treatment, there was a 37% reduction in facial rhytids (3). The same study reported that participants observed a 68% improvement in overall facial appearance without the occurrence of scarring or hypopigmentation.
REJUVENATING PHOTODAMAGED SKIN
To confirm the long-term effect of plasma treatment on a cellular level, skin biopsies taken three months following the end of treatment revealed a band of new collagen at the dermo-epidermal junction with less dense elastin in the upper dermis, which indicates that the plasma treatment was successful in rejuvenating photodamaged facial skin.
Plasma medicine may find a role alongside other skin rejuvenation treatments such as those based on the use of laser-based devices, which used thermal energy from specific light spectra to remove dots and other skin imperfections. Even though the mechanisms of action on a cellular level are not fully understood, these systems are used successfully for the removal of wrinkles without causing epidermal injury.
[caption id="attachment_5838" align="alignright" width="1024"] Plasma therapy participants observed a 68% improvement in overall facial appearance without the occurrence of scarring or hypopigmentation[/caption]
Another application of plasma therapy is its use in the treatment of chronic dermatological conditions such as Haily-Haily disease, which is genetic disorder characterised by blisters and rashes on skin. In trials involving the treatment of a patient who had a 25-year history with this disease, the use of plasma treatments in conjunction with traditional corticosteroid therapy resulted in a marked clinical improvement. The patient went from a condition where he had severe irritation from oozing skin lesions which failed to heal, to the point where he could play active sports such as tennis without discomfort (4).
The running costs of plasma medicine devices are anticipated to be relatively low, as most use relatively inexpensive argon gas in the plasma and low levels of input power is required. Patients are likely to require five-to-ten treatments using the plasmas over period of weeks, but the average treatment time is only a few seconds on a given area of skin.
Plasma medicine devices using cold atmospheric plasmas for the treatment of skin and wounds are not as yet commercially available. Further in-depth clinical trials are required before the wider adoption of this technology for both wound and skin treatments. It may not be too long, however, before the plasma medicine version of the dermal regenerator is available for achieving enhanced rates of wound healing, during your next visit to the doctor’s surgery.
The research work is focused on both applied and fundamental studies on the use of plasma medicine in the treatment of skin. The latter, which is funded by Science Foundation Ireland under the Precision CLUSTER (08/SRCI1411), is focused at understanding the mechanisms of interaction between an atmospheric plasma jet, with both mammalian and bacterial cells.
The study correlates the active species in the discharge with the type of cell damage. The applied research funded by Enterprise Ireland is aimed at assisting the commercialisation of novel plasma medicine-based treatments – specifically, how plasmas, in combination with natural agents, can be used to reduce wound-healing times.
Dr Denis Dowling CEng MIEI directs the surface engineering research activity at UCD. More information about this activity can be obtained from www.ucd.ie/surfaces.