Artificial livers and pancreases

A technique using living cells heralds the creation of artificial livers and pancreases in the near future.

Dr Helen Grant of Strathclyde University, Scotland, said that one of the main restrictions to the development of bio-artificial organs was the supply of cells. At Strathclyde, frozen pig cells in liquid nitrogen have been thawed out to treat liver failure in a process akin to kidney dialysis. Pancreatic cells preserved in the same way could be transplanted into diabetic patients to restore their ability to make insulin.

There is no specific treatment for acute liver failure other than transplantation and intensive care management of patients to prevent death by multiple organ failure while waiting for a donor liver. Dr Grant found that by attaching fresh pig-liver cells to a flat plate and supplying oxygen through tiny fibres attached to the other side, the cells can be kept alive and even frozen in liquid nitrogen at minus 70 degrees Celsius.

By using these cells for artificial livers, Dr Grant believes it is possible to eliminate the need for transplants in many patients. Bio-artificial pancreas devices have been shown to function well in animal models but a number of problems have to be solved before they can be used for patients.

One problem is that all implanted devices cause a fibrotic response in the host tissue and this, together with protein deposits on the membranes, results with time in decreased permeability. Dr Grant said that the potential source of unlimited cells for bio-artificial organs will be with the use of stem cells. They will ultimately provide replacements of those that die from injury or disease.