Researchers from an NIA member The University of Leeds, have identified the fundamental molecular level processes that go into one of the most common natural healing processes – the scab. It has been known that prior to the hard scab forming, that the blood clots at the site of the wound. The researchers from Leeds have studied and imaged this clotting process to find that a protein biofilm also forms over the skin to protect the wound from infection. Whilst it is not the ‘scab’ itself, it has been found that this biofilm (touted as a natural plaster) is the first protective film that develops, which then enables a more hardened protective layer (i.e. the scab) to form.

The human body is full of interactions that occur at the nanoscale, so much so, that we could be classified as a walking nanotechnology reactor. While a lot of biological mechanisms are not often considered nanotechnology, the fact that they occur at the nanoscale brings these mechanisms into the realm of nanotechnology.

This protective biofilm helps to not only prevent infection but helps to stem the flow of blood from the wound. This initial biofilm is also thought to provide protection for up to 12 hours before a more substantial barrier is formed.

Further research into this biofilm showed that it is fibrin which forms the film. During the clotting process, the fibrin fibres wrap themselves around the red blood cells and blood platelets to form a clot. However, it has been discovered that fibrin molecules are also natural shape-shifters and form a sheet-like film when the blood clot encounters air at the site of the wound. The self-assembled sheet was also found to possess ‘breathability pores’ which enables air to pass through the film, but the pores are too small for bacteria and viruses to pass through.

Another interesting discovery was the effect that oils, particularly petroleum jelly, had on the stability of the film. Applying petroleum jelly is a common way of trying to block access to a wound. However, the researchers found that the presence of petroleum jelly perforates the protective film; so, applying petroleum jelly to a wound actually increases the chance of infection instead of reducing it.

Source: The University of Leeds