London, November 19: Researchers at the Massachusetts Institute of Technology have developed a technology to create tiny colonies of living human liver cells that model the full-sized organ.

The researchers say that their method may pave the way for better screening of new drugs that may be potentially harmful to the liver, and reduce the cost of drug production thereby.

Liver toxicity often compels pharmaceutical companies to pull drugs of the market. Such dangerous drugs slip through approval processes due in part to the shortcomings of liver toxicity tests.

Existing procedures for the screening of drugs rely on liver cells from rats, which do not always show the same response to toxins as human cells do. Some times dying human cells, which survive for only a few days, are used in the tests.

With the advent of new technology, the researchers will be able to arrange human liver cells into tiny colonies, only 500 micrometers in diameter, which act much like a real liver and survive for up to six weeks.

The researchers use micropatterning technology to build these model livers. It is the same technology that is used to place tiny copper wires on computer chips.

Salman Khetani, a postdoctoral associate in the Harvard-MIT Division of Health Sciences and Technology (HST), has revealed that this technology allows precise arrangement of human liver cells and other supporting cells on a plate.

Such precisely arranged cells results in a “high-fidelity tissue model” because it mimics the behaviour of a human liver very closely, says Dr. Sangeeta Bhatia, HST associate professor.

The researchers say that their model tissue is very similar to real liver tissue in terms of gene expression profiles, a reason behind their confidence that these models should be having other characteristics of the real liver too.

Being similar to the human liver, these models may provide new insight into how the real organ responds to a drug, without having to expose human patients to the drug in a clinical trial, says Bhatia.

The longevity of the engineered tissue provides it the potential to make new types of toxicity tests possible — like opening the door to testing the effects of long-term drug use akin to taking one pill a day over multiple weeks. It also will allow more extensive testing of drug-drug interactions.

A start-up company called Hepregen has licensed the technology and is working to introduce it into the pharmaceutical marketplace.

“My hope is that this new model will make drugs safer, cheaper, and better labelled,” Nature Biotechnology quoted Bhatia as saying. (ANI)