Scientists are building a testing system that uses human liver cells for more rapid and realistic assessment of new drugs. Researchers hope to use this "bio-artificial liver" in a laboratory system which mimics the body's own metabolic processes.
The system may allow scientists to observe the effect of drugs as they are broken down, or metabolised, by the liver and their subsequent effect on downstream tissues. A laboratory system can be created, for example, to examine how a drug aimed at the kidney affects first the liver that breaks it down and then the drug's target - living kidney cells.
The creation of the bio-artificial liver and the test system for more effective drug testing involves research across a range of disciplines. The work is under way at Athlone Institute of Technology's (AIT) Centre of Biopolymer and Biomolecular Research (CBBR).
The liver is central to toxicological research. It turns certain nutrients into useful products in the body and processes and expels harmful substances. It also acts directly to break down drug compounds circulating in the blood.
Replicating liver function is vital to drug testing because some substances become toxic only after they are processed by the organ, explained Dr Eileen Lane of the CBBR who is involved in the research. There are a host of enzymes which have evolved to handle natural toxins in the environment, but the challenge is to observe how man-made com pounds are handled by the liver, stated Dr Paul Tomkins, acting head, School of Science, AIT.
In the body most tissue and cells are constantly given nutrition, but outside the naturally sustaining environment of the body, liver cells quickly decay, losing their function in around 24 hours.
In conjunction with AIT's polymer department living cells were attached to a variety of materials, which act as scaffolds for the cells. This creates an environment, similar to its situation inside the body, where liver cell cultures survive and will, researchers hope, retain their functions for at least seven to 10 days.
These toxicological experiments are currently performed on animal cells, but the AIT researchers eventually hope to use human cells. This would make the testing of novel drugs both cheaper and more effective. It would also reduce the need for animal tests.