At the weekend, Oliver Lieleg cut a carrot at home, he wasn’t careful – and the knife slipped into his thumb. No big deal, he put a plaster on it, everything will be fine in a few days. One of the problems that Lieleg deals with in his everyday work is superficially related to the adhesive bandage from the medicine cabinet: the professor of biomechanics at the Technical University (TUM) works at the Garching research center on a plaster that sticks to a damp surface. That, if necessary, can deliver medication to the injured tissue. And that, when it has done its job, simply dissolves.
Oliver Lieleg is Professor of Biomechanics at the Technical University of Munich.
(Photo: Astrid Eckert/TU Munich)
Which means he’s researching it: Actually, all the work is done, the product is ready for clinical testing. Lieleg and his team build a film thinner than a sheet of paper that consists of two layers. When dry, it does not stick and can be applied to the wound, for example in the mouth, with tweezers. When the film comes into contact with liquid, the lower layer softens like a gel – and the plaster sticks.
This bottom layer consists of hyaluronic acid and dopamine. The former, mainly used in cosmetics and aesthetic medicine, is known to promote wound healing. But dopamine? It acts as a neurotransmitter in the central nervous system. However, researchers have found that mussels use dopamine to attach themselves to ship walls – it’s the glue that makes Lieleg’s plasters stick.
The top layer of the film is something like Lieleg’s speciality: it initially consists of a biodegradable plastic that gives the patch stability. They are mixed with so-called mucins: “These are molecules,” explains the researcher, “that occur naturally on mucous membranes or in tear fluid. We have now used them for plaster-like films for the first time. Here they take on particularly important properties for the biological protection of the skin wound. They have an antibacterial effect, inhibit inflammation and prevent unwanted cells from settling in the wound.” In addition, they inhibit friction, which is advantageous in the event of an injury to the tongue, for example.
The mucins that Lieleg and his team use are obtained from pig stomachs straight from the butcher. They have developed a process that produces more end product in less time and with less manpower than previous methods – this process has now been patented.
Purified and freeze-dried mucin.
(Photo: Astrid Eckert/TU Munich)
As is usual in medical research, the plaster was first tested on tissue samples, for which the scientists used the butcher in Garching. When that worked well, the animal model continued: rats were injured on their backs, which were closed with the plaster. The result: Better healing in less time.
Oliver Lieleg sees a wide range of possible uses: in the mouth, for example, but also in abdominal operations, for example on the intestines. Another advantage: the plaster dissolves after a while without leaving any residue – at the moment the range is one to two days, the researchers would like to increase it to a week.
In addition to the positive properties that the film already has due to its construction, there is also the possibility of introducing drugs into the lower layer, which are then continuously released into the wound – and only there, because the upper layer prevents them from being released about to be wasted in the oral cavity. For example, an antibiotic can be used in a targeted manner.
Lieleg reacts cautiously to the question of when the miracle patch could be used in everyday medical practice: A manufacturer would have to be found, production on an industrial scale would have to make economic sense, and one or more clinics would then be needed to show the film to people patients would test. That’s why the professor doesn’t want to get involved with a year. After all, after the study was published, two companies got in touch and signaled their interest.