| Artificial
glass livers being developed at Leeds could
help those suffering from liver failure, and
improve understanding of how the organ works,
researchers believe.
 Dr
Peter Walker (left) of mechanical
engineering is leading Leeds’ contribution
to a three-year £320,000 project that
aims to replicate the geometry of the liver,
using glass and liver cells.
“The liver is a very complex organ,
which we still don’t fully understand,”
said Dr Walker. “If we can mimic closely
how it’s constructed and how the cells
function within it, we should ensure an effective
‘replacement’. It may also provide
an alternative to animal testing for hepatic
drugs and bring us one step closer to being
able to engineer liver tissue.”
The
artificial liver – to be used like a
dialysis machine – will be constructed
of tiny hexagonal glass plates with channels
running from their edges to the centre.
Glass
is the ideal substance for etching the channels
– less than 1/200 of a millimetre wide
– which are lined with liver cells which
reproduce the cleaning work of the organ.
The
blood flows to the edge of each hexagon and
down the channels, cleaned by cells as it
goes, before exiting through a central ‘vein’.
The liver is the only organ in the body where
blood from veins and arteries is mixed together.
The
arterial blood, fresh from the lungs, provides
the cells with the oxygen they need to function,
while venal blood contains the impurities
for the liver to clean out.
A
major problem with artificial livers is that
as the blood runs through, it loses too much
oxygen, so cells at the end of the line are
no longer effective. “Reproducing the
exact layout of the liver should overcome
this problem, as cells will behave as they
do in the natural liver, performing different
cleaning functions dependent on their position
and the level of oxygen they receive,”
said Dr Walker.
He is creating computer simulations to model
the liver, so optimum channel size, flow rate
and density of cells can be calculated as
accurately as possible, before the artificial
liver is constructed in the laboratory.
The project is in collaboration with the Rutherford
Appleton Laboratory in Oxfordshire –
which is etching the glass plates –
and the University of Nottingham.
It
is funded for three years by the EPSRC. |
