18 June 2010
ByAppeared in BioNews 563
Functional lab-grown livers could become a reality within five to 10 years, suggests a new study published by Nature Medicine, offering hope to liver transplant patients.
Researchers chemically stripped rat livers to produce a 'cellular scaffold'. This 'decellularisation' keeps the fundamental liver structure of connective tissue and blood vessels intact. Scientists then pumped approximately 50 million rat liver cells into each scaffold, which were incubated and connected to genetically similar rats. Utilising this framework liver cells (not yet a whole liver) were re-grown. When re-connected to the rat's artery and veins, the graft successfully filled with blood, leaving minimal damage to the new cells.
Such a scaffold technique offers hope for liver transplant patients: by leaving the blood vessels intact, and preserving the donor liver's structures for transporting oxygen and nutrients, this technique by-passes the need to develop a tissue-engineered liver with an appropriate oxygen and nutrient transport system.
'As far as we know, a transplantable liver graft has never been constructed in a laboratory setting before', explains lead researcher Dr. Korkut Uygun, from Harvard Medical School. He continues: 'If we succeed it'll definitely revolutionise how liver diseases are treated. If all goes well to be doing this with humans in 5 to 10 years is quite possible, which is why this is a significant step forward'.
Dr. Uygun is quoted as being 'cautiously optimistic', acknowledging the further hurdles and extent of work needed before an entire liver can be reconstituted, including the inclusion of other types of specialised cells. The study concludes, 'further studies are required to determine whether the techniques described here can be scaled up for use in humans'.
Over 600 liver transplants are performed every year. However, it is estimated that over 20 per cent of patients die whilst on waiting lists, reports The Telegraph. The new technique offers further hope to transplant patients by enabling doctors to utilise donated livers which would have otherwise been rejected.
Eventually, the researchers hope livers grown in labs could be harvested on artificial scaffolds or pig livers, removing the need for human donation.