14 DAY TRIAL // A group of investigators from the Massachusetts General Hospital has recently managed to develop a new method for dealing with liver grafts. The researchers say that, in a few years, it may become possible to grow replacement livers using biocompatible tissue scaffolding derived from rat livers, and human-derived cells. Details of the new work will appear in print in an upcoming issue of the esteemed scientific publication Nature Medicine, but are also available online, in an advanced edition ahead of print. The research team was based at the MGH Center for Engineering in Medicine.
“Having the detailed micro-vasculature of the liver within a biocompatible, natural scaffold is a major advantage to growing liver tissue in a synthetic environment. Our technique of 'decellularizing' organs leaves the vascular system intact, which facilitates repopulation of the structural matrix and the subsequent survival and function of the introduced liver cells,” explains MGH-CEM research associate Basak Uygun, PhD, who was also the lead author of the Nature paper, and the investigation. The end result of the new reseeding method could be the creation of readily-available, transplantable replacement livers, which would be designed specifically for individual patients.
When a person's liver begins to fail, transplants are the only means that could save his or her life. Still, in the United States alone, more than 4,000 people with this condition die each year, because of the shortage in donor numbers. Devising a method of producing artificial livers could significantly reduce these mortality rates, and turn liver failure into a mere inconvenience, rather than a death sentence. Experts explain that one of the main reasons why the fields of tissue engineering and regenerative medicine appeared was precisely to try and find a solution to designing artificial organs.
“As far as we know, a transplantable liver graft has never been constructed in a laboratory setting before. Even though this is very exciting and promising, it is a proof-of-concept study only. Much more work will be required to make long-term functional liver grafts that can actually be transplanted into humans. We haven't been able to go beyond several hours in the rats, but it's a great start,” explains MGH-CEM expert Korkut Uygun, the senior author of the new investigation.
“There is great potential for constructing full-fledged liver lobes containing animal or human cells, but several thorny issues must first be tackled, including formation of a layer of endothelial cells to line graft blood vessels. Given enough careful work, this approach could ultimately revolutionize tissue engineering and provide real working grafts for the liver and other complex tissues,” adds the director of the MGH-CEM, Martin Yarmush, MD, PhD. He and Uygun both have faculty appointments at Harvard Medical School (HMS) as well.