Healing with Cold Plasma
There is new hope for patients with chronic, poorly healing wounds: cold plasma destroys bacteria and stimulates the body’s self-healing powers. Scientists from Greifswald in Germany have developed a new wound dressing based on WACKER silicones that creates high-energy gas directly on the damaged skin.
A blue gas shimmers over damaged skin – with an unusual effect. It causes even chronic wounds to close up within just a few weeks. “Cold plasma can heal,” says Dr. Carsten Mahrenholz, a chemist at the Leibniz Institute for Plasma Science and Technology (INP) in Greifswald and one of the founders of the startup company Coldplasmatech. This cold plasma forms, for example, when a gas passes through strong electric fields – the electrons are dissociated from the molecules and the gas becomes electrically conductive and glows blue.
“Among other things, plasma emits ions, UV radiation and radicals – a mixture of different active substances,” explains Mahrenholz. The Greifswald scientists’ research showed that cold plasma can efficiently kill bacteria. It even effectively combats dreaded antibiotic-resistant hospital pathogens. It acts by purely physical processes, attacking the microbes’ cell membranes, among other targets. This involves several unspecified chemical reactions. Their characteristics prevent the pathogenic organisms from building up resistance in the first place – which eventually is the case with targeted antibiotics.
WACKER CLEAN OPERATIONS
Medical-grade silicones from WACKER come into direct contact with the human body. That’s why they must satisfy the highest of requirements. With WACKER CLEAN OPERATIONS, the Group not only guarantees consistent quality and verified purity, but also reliability, utmost care and safe manufacturing standards. The manufacturing processes and the origin of SILPURAN® silicone gels and rubbers are fully traceable – all the way from the raw-material source to the end product. Production, filling and logistics are physically separated and externally accessible only via special air-locks. Particularly strict regulations apply to filling and packaging operations: in addition to special work-apparel and hygiene regulations, sophisticated air and particle filters ensure compliance with Class 8 of the international ISO standard for cleanrooms. This guarantees that products leave the plant in an absolutely pure state.
Everyday Natural Phenomenon
In principle, plasma is an everyday natural phenomenon, a fourth state of matter after solids, liquids and gases. Further heating completely or partly dissociates free charge carriers such as ions and electrons in the gaseous particle mixture, which remains conductive yet outwardly electrically neutral. For example, the sun, lightning and northern lights all exhibit plasma properties.
For the past two decades, scientists at the Greifswald INP have been conducting research on a plasma state that – unlike the sun or lightning – is not scorching-hot, but cool. Furthermore, a project group headed by institute director Prof. Klaus-Dieter Weltmann has been working since 2005 on the development of cold plasma sources for wound care. As part of this research, the scientists intensively studied the effect of a number of spot emitters and larger-area prototypes on living cells. In 2013, a spot source – the plasma pen, which is the size of a fountain pen – obtained approval as a medical product. In addition, studies were started on large-surface plasmas that will allow for more effective treatment of large wounds.
Ingenious wound dressing – the patch only works when it glows. Cold plasma kills germs yet does not attack human cells – on the contrary, it activates the body’s self-healing powers.
Although cold plasma can kill microbes, it does not negatively impact human cells. On the contrary: “They respond by releasing cytokines, for example,” says Tobias Güra, medical economist of the Coldplasmatech team. “These messengers stimulate the immune system and cell growth and ensure that new blood vessels form.” Overall, the plasma activates the body’s self-healing powers.
Stimulation for the Immune System
Its antibacterial and immunostimulatory properties make the blue gas a valuable instrument for the medicine of tomorrow – especially for modern wound care. “And, due to demographic change, demand in this sector will increase greatly in the future,” says Dajana Westenberg, business development manager for wound care at WACKER. “People are getting older and are bedridden for longer – this increases the risk of bedsores, a pressure ulcer of the skin.”
According to a study by the Institute for Medical/Nursing Education and Nursing Science at Berlin’s Charité university hospital, 10 percent of all immobile patients in German nursing homes suffer from bedsores – this figure is as high as 27 percent in clinics. In addition, the number of diabetes patients is on the rise. Individuals with this metabolic disease tend to have circulatory disorders and poorly healing wounds as well. In Germany alone, approximately five million people suffer from chronic wounds, according to estimates by Helios Kliniken, a German clinic group. Moreover, damaged skin offers a portal of entry to pathogenic organisms that can put patients’ health at further risk – and thus also burden the healthcare systems.
“It was particularly important to us that the materials be biocompatible, in order to fulfill strict regulatory requirements,” explains medical economist Güra. This quickly led the team to silicones produced by WACKER that satisfied the highest of medical standards. “WACKER not only provided us with high-quality materials – we also received expert advice from technical service staff,” reports Güra. “In WACKER, we have found a partner with whom we can actively pursue this new, innovative therapeutic approach.”
WACKER already supplies numerous manufacturers of wound dressings with its SILPURAN® product line – and the trend is likely to continue. “Our silicone division views wound care as a focal topic that is likely to experience above-average growth over the coming years,” explains Dr. Peter Jerschow, head of the Industrial Solutions business team at WACKER. “Our innovative product solutions are our contribution toward better treatments in this field.”
Treating skin damaged by bedsores and the tissue beneath it is not just laborious, but often a lengthy process, too – and, above all, painful. Each routine change of wound dressings, though necessary, is an ordeal for the affected person, which slows down the healing process. “Patients suffer greatly,” reports Coldplasmatech’s Mahrenholz, who monitored conventional treatment methods together with his team. “In order to develop a cold-plasma-based treatment that is practical and suitable for everyday use, we contacted doctors, patients, nursing staff and clinics early on,” says the chemist. The team quickly realized that wound dressings are the preferred choice and optimally complement previously used medical products. The interdisciplinary INP team then took up the challenge of designing a dressing with which the healing plasma can be generated directly at the wound surface.
“The therapy will only take a few minutes and will be absolutely pain-free.”
Co-founder of Coldplasmatech
Silicones offer a range of advantages in the medical sector. They make atraumatic, i.e. very gentle, dressing changes possible – as the dressing does not adhere to the wound, it obviates pain and the tissue does not become irritated. Thanks to their water-vapor permeability and breathability, SILPURAN® silicones also create an optimum healing environment. Wounds close up more quickly and patients can leave the clinic sooner – a great advantage for the patient’s well-being.
A plasma patch based on WACKER silicones: the picture shows the conducting structures that aid plasma ignition on a wound. This plasma appears as a bluish opalescence (surface glow).
An Excellent Choice for Medicine
Silicones lend themselves to medical applications due to their basic material characteristics, too. Thanks to the high bond energy between the silicon and oxygen atoms, silicones are highly resistant to environmental influences and are thermally stable and highly flexible, and possess excellent mechanical properties.
“However, a prerequisite for the use of silicones in medical applications is that the products satisfy the highest of quality requirements,” adds WACKER manager Westenberg. “We ensure this by paying particular attention to purity, biocompatibility, high adhesive strength and top processing properties.” WACKER guarantees that the purity of its SILPURAN® products has been verified and can be traced from the end product back to the raw-material source. In addition, these medical-grade silicones are filled and packaged under cleanroom conditions in order to ensure top quality.
Collaboration between WACKER and the Coldplasmatech team was launched in January 2014 at their first meeting. “We were immediately inspired by the interesting idea and the highly motivated scientists – as well as the completely new application area for our silicones,” reports Westenberg. Mahrenholz and his colleagues use two different SILPURAN® silicones from WACKER in their innovative plasma patch:
a gelatinous, high-tack silicone to ensure that the plasma patch adheres well to the surrounding, intact skin, and a soft silicone rubber with a dry surface that does not stick to the wound surface.
How plasma heals – wound surfaces are often full of bacteria. Bacterial infestation exacerbates the healing process. Plasma, on the other hand, can decontaminate injured skin. An ionized gas layer of plasma builds up between the wound and the silicone. The ionized gas layers spread to the base of the wound. The natural healing process is accelerated by the activated gas and is initiated both by the wound base and the wound boundaries.
Serving primarily as an insulator, the silicone contains embedded electrical conductor paths that are supplied with the necessary energy. To this end, the plasma patch is connected to a voltage generator – the plasma cube. Furthermore, this innovative dressing is designed so that the plasma forms between the wound and the silicone. “Thanks to special electronic activation, we managed to generate the cold plasma on the inner surface of the dressing, directly over the wound,” explains Mahrenholz. It will be possible, with a minimum amount of effort, to treat patients with a plasma patch as part of the routine changing of dressings – for example, with disposable products. “Treatment will be absolutely painless and will take only a few minutes,” says Güra. Patients will experience merely a slight tingling sensation. Clinical trials conducted by various task groups from Munich, Göttingen, Berlin and Greifswald using different plasma sources have already shown that even persistent open wounds heal within just a few weeks.
The Greifswald scientists have won numerous awards for their innovative technology, including “invention” – a startup prize awarded by German family-owned businesses. In this competition, they were voted the most successful German startup team of 2014. The scientists have already set up a lab-scale production facility for plasma patches. This innovative wound dressing is currently in its final development phase. If everything goes according to plan, this novel medical product will be submitted for certification before the year is out – once approved, it can offer relief to patients with chronic wounds.