Bloody clots, natural wall against infections

New research has identified the way nature creates its own plaster to try and prevent bacteria and other micro- organisms from penetrating open wounds.

Scientists have found that a protein film forms rapidly over a wound as part of the natural clotting process, and it provides protection for at least 12 hours.

They believe this biofilm gives the immune system time to marshal its defences to deal with any infection.

The researchers also observed that oil- based substances disrupted the process and warn that treating breaks in the skin with petroleum jelly, a technique used in some contact sports and following minor surgery, may increase the risk of infection.

The study, involving an international collaboration of scientists led by the University of Leeds and published in the Journal of Clinical

Investigation, changes scientific understanding of the mechanism of blood clotting.

Clotting is a vital process to prevent lifethreatening blood loss following an injury. At the site of the wound, platelets and red blood cells clump together to try and plug any haemorrhage.

Seen through an electron microscope, clots appear to be meshed together by spaghetti- like fibres of a protein called fibrin.

For decades, scientists have been baffled about the precise structure of the fibrin fibres because they seemed to be neverending, just coiling themselves around the platelets and red blood cells.

The electron microscope images also revealed that the film had ‘ breathability’ properties, allowing air to reach the wound through tiny pores which were too small to allow bacteria and some virus to pass through.

Professor Jeremy Pearson, our associate medical director, said: “By looking at how blood clots form, with a view to designing better clotbusting drugs, this team have discovered a mechanism. This discovery portrays the complex nature of our bodies, in that the very substance which can make blood clots can also protect us from harm when we wound ourselves,” said Pearson.