Researchers have developed a new approach to rapidly expand the number of human liver cells in the laboratory without losing their unique metabolic function.

"This is the holy grail of liver research," said the study's lead author Yaakov Nahmias from Hebrew University of Jerusalem in Israel.

The research could help advance a variety of liver-related research and applications, from studying drug toxicity to creating bio-artificial liver support for patients awaiting transplantations.

"Our technology will enable thousands of laboratories to study fatty liver disease, viral hepatitis, drug toxicity and liver cancer at a fraction of the current cost," Nahmias noted.

Thus far, attempts to expand human hepatocytes - cells that comprise 85 percent of the liver - in the laboratory resulted in immortalised cancer cells with little metabolic function.

The scarce supply of human hepatocytes and this inability to expand them without losing function is a major bottleneck for scientific, clinical and pharmaceutical development.

The new method, described as the "upcyte process," allows expanding human hepatocytes, resulting in a quadrillion cells from each liver isolation, compared to only a billion cells that can be isolated from a healthy organ.

"The approach is revolutionary," said Joris Braspenning from Germany-based biotechnoloy company Upcyte Technologies.

"Its strength lies in our ability to generate liver cells from multiple donors, enabling the study of patient-to-patient variability and idiosyncratic toxicity," Braspenning said.

The study appeared in the journal Nature Biotechnology.