Australian scientists on Thursday hailed a latest study by Japanese researchers as breaking new ground in the ability to grow working organs, without the need for a donor.

The Japanese team, based at the Okohama City University Graduate School of Medicine in Japan, grew an adult human liver in mice using laboratory-created "liver buds" from stem cells -- work that may one day side-step the need to harvest organs from the deceased altogether.

"To our knowledge, this is the first report demonstrating the generation of a functional human organ from pluripotent stem cells, " the researchers wrote in the journal Nature.

The pluripotent stem cells can turn into any type of cell in the body and are therefore extremely useful for regenerative medicine, said Martin Pera, Program Head of Stem Cells Australia.

However, it has previously been quite difficult to grow a fully mature, functioning organ in a petri dish, Pera added, but this latest study solved the problem by developing the tissue further inside a mouse.

"The grafted human livers have the full functional capability of the adult organ, such as the capacity to metabolize drugs," said Pera.

"The results demonstrate that the rich and complex environment of tissues in the adult body can help immature stem cell grafts to develop to an adult stage.

"The report provides hope that even primitive tissues made from stem cells will one day restore function of dead or diseased organs in patients," he added.

Ernst Wolvetang, group leader of the Stem Cell Engineering Group at the University of Queensland's Institute for Bioengineering and Nanotechnology, said that organs created through the body's own stem cells had a number of advantages over spare parts harvested from strangers.

"Reprogramming of the patient's own skin cells into so-called induced pluripotent stem cells (iPSC)...does not involve the use of embryos, and the resulting stem cells have the same genetic make-up as the patient's own cells, thereby preventing rejection by the immune system," Wolvetang said.

However, he added that there is more work to be done to establish whether the artificially regrown livers are safe in the long-term.

Kuldip Sidhu, associate professor at the University of New South Wales' Center for Healthy Brain Ageing, said similar studies in pigs will be a next step, as most of the organ sizes in pigs match that of humans -- but growing human parts in animals still raises ethical and safety concerns.

"Only a few countries, like Japan and the U.K., have allowed the mixing of human and animal cells to produce chimeric embryos and to achieve organ production in animals," Sidhu said.

"It does open up new vistas and hope for alleviating the suffering of those who need organ transplants," he added.



Even there is a well-established donation system in Australia, around 1,600 people are currently waiting for a live-saving organ transplant in the country.