British scientists grow liver from stem cells

Newcastle: British scientists have produced a minature liver using stem cells from umbilical cord blood.

The technique could be used to create whole organs for use in transplant surgery or for repair of damaged livers, although this is some years away.

Scientists at Newcastle University expect that pieces of artificial tissue could be available within five yers to repair livers damaged by injury, disease, alcohol abuse and paracetamol overdose.

The liver tissue is created from stem cells, the master cells capable of developing into different types of tissue, found in blood from the umbilical cord.

The cells are cultivated in a ‘ bioreactor’ – a machine developed by NASA to mimic the effects of weightlessnes, allowing the cells to multiply more quickly than usual.

Various hormones and chemicals are then added to coax the stem cells into turning into liver tissue. Other researchers have grown heart tissue from stem cells, and injections of stem cells have successfully been used to strengthen damaged heart muscle.

Currently, experiments on new drugs are carried out in the test tube, before being tried out first on animals then on humans. The effects can be catastrophic, as in the Northwick Park scandal this year in which six healthy young volunteers were left fighting for their lives.

But lab-grown human tissue could iron out any difficulties before drugs are given to humans.

The researchers envisage sections of artificial liver being used to keep patients needing transplants alive – in much the same way as a dialysis machine is used to treat kidney failure. This technique would take advantage of the liver’s remarkable ability to regenerate itself.

Patients would be hooked up to an artificial liver which would take over all the functions usually carried out by their own liver.

With several ‘dialysis’ sessions a day over a period of several months, the patient’s own liver would be given enough resting time to regenanderate and repair any damage. Alternatively, vital months could be bought in search for a suitable donor for transplant.

While other researchers have created liver cells using stem cells taken from embryos, the Newcastle team are the first to create sizeable sections of tissue from stem cells from the umbilical cord. They believe their technique is better suited to growing larger sections of tissue.

Use of cord stem cells is also more ethically acceptable than the use of embryonic stem cells – a process which leads to the death of the embryo.

The Newcastle researchers foresee a time when cord blood from millions of babies born each year is banked, creating a worldwide donor register for liver dialysis and transplant.

Computerised registers could then be created to match the cord blood with tissue type or immune system of patients with liver problems.