From the archive, originally posted by: [ spectre ]
10 October 2006
Researchers at the Massachusetts Institute of Technology, US, have
created a liquid that stops bleeding in any tissue in a matter of
seconds. It is a discovery that they claim has the potential to
revolutionise surgery and emergency medicine and could even make it
easier to reattach severed limbs.
Rutledge Ellis-Behnke and colleagues worked from the nanoscale, using
individual amino acids to create a self-assembling peptide. It looks
exactly like water but when applied directly onto injured tissue it
halts bleeding. This is the first time nanotechnology has been used to
control bleeding, claims Rutledge.
The remarkable discovery was made by accident during an experiment in
which the liquid was used to stimulate nerve repair in the brains of
rats. Ellis-Behnke’s group, whose work is focussed on central nervous
system repair, found that the liquid mended the nerve cells as
predicted, but caused a strange side effect.
‘When we used the liquid during the surgery we thought that the
animals had died. The bleeding in the brain stopped and that normally
indicates that the heart has stopped beating,’ Ellis-Behnke told
Chemistry World. ‘When we realised what had happened, we made a note
of it and then went back to the drawing board to test it.’
In tests on skin, liver, lung, blood vessels and a variety of other
tissue, Ellis-Behnke and his colleagues were able to use the liquid to
halt bleeds in less than 15 seconds. The mechanism for this ability
remains something of a mystery.
‘It isn’t clotting that we’re seeing. We tested for all of the
things you find in all blood clots; fibrin, thrombin and platelets and
none of them were there,’ said Ellis-Behnke. ‘Either this is acting
as some kind of molecular band aid or we are stopping bleeding via a
completely new direction that we have never seen before.’
Once the liquid touches an internal organ, it forms a gel; the amino
acids assemble into fibres and stop the bleed. The degradable peptide
then breaks down into non-toxic products as the tissue heals.
These products can even be used by cells to rebuild damaged tissue,
according to the researchers. During the study, the liquid was used
successfully internally and externally, before breaking down to be
incorporated into the healed tissue or excreted in the urine.
Surgeons currently spend up to 50 per cent of their time during surgery
packing wounds in order to reduce or control bleeding, so if
Ellis-Behnke’s liquid works it would make a profound difference.
Promising results in an animal model mean that human trials could begin
in as little as three years, he said.
‘This could even be used on the battlefield,’ added Ellis-Behnke.
‘If a limb is removed, this could be applied to the severed limb as
well as the wound on the body. It would stop the drying out and decay
of the tissue and keep it clean so it would be easier to reattach.’