Over 17,000 Americans are currently waiting for liver transplants, with millions more living with chronic liver disease. There simply aren’t enough healthy organs to go around. So why not engineer them? Growing a liver “from scratch” by using its constituent cells could replace the need for whole organ transplants.

Researchers at the Massachusetts Institute of Technology generated hydrogels containing three different types of human cells, arranged to mimic the natural structure of the liver. They interspersed aggregates of liver cells and connective tissue between rows of cells from blood vessels, making up an engineered tissue unit referred to as a “seed”. When implanted in mice with injured livers, these seeds grew over 50-fold in 11 weeks and successfully augmented liver function by generating various liver-specific proteins.

This approach has only been tested in mice, and it’s unknown how the seeds respond to different types of liver injury – such as Hepatitis C, drug and alcohol-induced toxicity, or resection following tumor removal. Nonetheless, this work conjures the exciting possibility of one day supplementing patient liver function using bioengineered livers. Planting the seeds for a new organ, and with it, a healthier life.

Acknowledgments: Many thanks to Olivia Weeks, a Ph.D. student in the Developmental and Regenerative Biology Program at Harvard Medical School, for providing her expertise and commentary on the topic.

Managing Correspondent: Benika Pinch

Original Research: In Situ Expansion of Engineered Human Liver Tissue in a Mouse Model of Chronic Liver Disease. Science Translational Medicine.

Media Coverage: Growing Liver Tissue from Seed. Chemical & Engineering News.