For people facing liver failure, a liver transplant is the only option, and it’s far from a perfect one. Donor tissue has to be as close a match as possible to the recipient, and even them the patient will need anti-rejection drugs—medications that keep the recipient’s immune system from attacking the donated organ, at the cost of scaling back all other immune functions—for life, meaning he or she will be forever more prone to infection. What’s more, there’s a chronic shortage of donors, with nearly 20 people waiting for each donated organ.
In some cases, and increasingly, it is possible to solve both these problems with stem cells. Stem cells are pluripotent, meaning unlike most tissue cells, which are specialized and only function properly in certain parts of the body, stem cells have the potential to sere any function that may be needed. That means that when someone’s liver is badly malfunctioning, it would be possible to use their stem cells to grow a new liver that won’t be rejected, without the need for a donor. However, the procedures for doing so are only just starting to be developed, and stem cells are difficult to harvest from adults. Cord blood banking has become possible in recent years, but for most people who need liver transplants, their window for that closed years before the technology was viable.
Now researchers have found a way to use cells that aren’t quite pluripotent to make liver cells. Using genetic engineering, scientists were able to transform skin cells into viable liver tissue that continued to thrive after nine months. In previous efforts, the liver cells made from stem cells died shortly after development.
"The cells began to take on the shape of liver cells, and even started to perform regular liver-cell functions", said one of the researchers, Dr. Milad Rezvani of the University of California at San Francisco, in a statement. "They weren’t fully mature cells yet—but they were on their way."
The long time frame suggests that this may be a functioning method for creating a new liver from a patient’s own tissue. Although human trials are still down the road, scientists hope this technique will benefit not just liver patients, but people with several types of organ failure in the future.