Growing Artificial Organs: Scientists One Step Closer to Creating Human Liver

Growing artificial organs has long been a dream of scientists. If possible, the organs could revolutionize the way we treat people who need transplants. Now, researchers may be one step closer to realizing that dream. They've focused on a liver's regenerative properties in order to potentially grow an entirely new liver.

Livers possess the amazing ability to regenerate themselves if part of the liver is removed. Yet mature liver cells, known as hepatocytes, quickly lose this function when removed from the body. This, in turn, has made it difficult for scientists to potentially create an artificial liver for patients.

"It's a paradox because we know liver cells are capable of growing, but somehow we can't get them to grow" said Sangeeta Bhatia, one of the researchers, in a news release.

Yet it turns out that the researchers may be one step closer. They've identified a dozen chemical compounds that can help liver cells not only maintain their normal function while grown in a dish, but also multiply to produce new tissue. The new technique could help scientists create engineered tissue to help treat patients in need of a liver donation.

The researchers had actually previously developed a way to temporarily maintain normal liver-cell function after they've been removed from the body. They precisely mixed the cells with mouse fibroblast cells in order to accomplish this. For this particular study, though, they modified the technique so that the liver cells could grow in layers with the fibroblast cells in small depressions in a lab dish. This, in turn, allowed the researchers to perform large-scale, rapid studies of how 12,500 different chemicals affect liver-cell growth and function.

After treating the cells, the researchers found a total of 12 compounds that helped cells maintain crucial functions, including drug detoxification, energy metabolism, protein synthesis and bile production. More specifically, they identified two of the compounds that seemed to work especially well in cells from younger donors.

It's not just chemicals that will help grow livers, though. The researchers also recently made progress in solving a problem with growing livers--getting the recipient's body to grow blood vessels to supply the new tissue with oxygen and nutrients. They found that if prerformed cords of endothelial cells are embedded into the tissue, they will rapidly grow into arrays of blood vessels after the tissue is planted.

These new findings could have enormous implications for creating livers for patients. Currently, about 500 million people suffer from chronic liver diseases, such as hepatitis C. These techniques could help better treat these patients and give them another chance at life.

"Together, these papers offer a path forward to solve two of the longstanding challenges in liver tissue engineering--growing a large supply of liver cells outside the body and getting the tissues to graft to the transplant recipient," said Bhatia in a news release.

The papers that detail the findings are published in Nature Communications and the Proceedings of the National Academy of Sciences.