New material could enable self-healing wound dressings

A new material developed by scientists in the UK that heals itself at body temperature could modernise wound dressings and regenerative medicines such as artificial skin.

Self-healing polymers have a wide range of uses, from paints to impact resistant coatings for mobile devices. Now researchers from the universities of Reading and Oxford have developed an adhesive and elastic polymer that repairs itself at body temperature, which could find use in biomedicine.

‘If we cut ourselves we have to apply a plaster and after a period of time, that plaster starts to fail, its stickiness wears off, it gets damaged – you have to pull that plaster off a damaged part of skin, which is a very painful process,’ explains Reading’s Wayne Hayes, who led the team. ‘One of the key targets for our research was to develop materials that could automatically heal when damaged. In particular, we were interested in materials that could heal at 37°C – body temperature – to maintain protective barriers.’

When cut with a razor, strips of the polyurethane material flow back together as its supramolecular network has been disrupted, lowering viscosity at the affected area. Samples of the material are stable under simulated physiological conditions and initial testing on human skin cells suggests it would be safe for medical use. The polymer also retains its self-healing ability while adhering to pig skin.

At higher temperatures the polymer’s supramolecular network dissociates. ‘By an appropriate trigger, in this case heat, you can remove the polymer very easily by getting the network to break apart into its low molecular weight components which flow like a fluid.’ explains Hayes, ‘So there’s potential for developing reversible scaffolds for regenerative medicines.’

Bert Meijer, an expert on materials chemistry and supramolecular systems based at Eindhoven University of Technology in the Netherlands, describes the research as beautiful and finds the mild conditions required for self-repair particularly impressive: ‘It is remarkable how at body temperature the self-healing is performed rather quickly, while the structural integrity is maintained and thus the mechanical properties conserved.’