The "mini-liver" resulting is the size of a coin but hopefully with the same technique developed in the near future, a full-size liver.

The mini-liver is useful as it is, within two years may be used to test new drugs, reduce the number of animal experiments and results can be achieved on the basis of a human liver (instead of animals).

The researchers, Dr. Colin McGucklin, Professor of Regenerative Medicine, University of Newcastle, and Dr. Nico Forraz, Senior Research Associate at the University of Newcastle, say that pieces of artificial liver could be used to repair livers damaged by injury, illness, alcohol abuse or other causes over the next five years.

These artificial livers could also be used outside the patient's body in a manner analogous to the process of dialysis used to keep alive patients whose kidneys have failed.

Within fifteen years, will be possible to grow whole livers in the laboratory that will later be transplanted into human patients.

Stem cells used by Drs. McGucklin and Forraz in this study were obtained from umbilical cord blood specifically cord, seen by some as a more ethical alternative to stem cells created from human embryos.

The cells are then placed in a bioreactor, a device developed by NASA for simulating the gravity environment of space. The cells are placed in a growth medium which is in constant rotation, which places the growing cells in a state of free fall without end.

Normal cell growth in a nutrient medium such as a plate, does not provide a suitable culture medium for three-dimensional tissue growth. Epithelial cells without a three-dimensional assembly environment lack the appropriate information for the cell growth of each particular tissue, while in a rotating bioreactor, scientists can fool cells to behave as if they were inside a human body.