Donor organs created by dissolving and rebuilding pig livers

Will we ever be able to grow transplant organs like the heart, lungs and liver on demand? A method that uses pig organs as scaffolding for creating new organs suggests it may be possible. 

In an effort to tackle lengthy waiting lists for organ transplants, researchers have been trying several approaches for creating replacement organs. One approach is to grow organs in the lab from stem cells. Another would be to take organs from pigs that have been genetically altered so their cells are more human-like, and less likely to be attacked by a person’s immune system.

Now an in-between method is taking off. The approach starts with an organ from an ordinary pig, but involves dissolving the cells away from it to leave a protein scaffold in the original shape of the organ. This is then reinfused with human cells.

Until now this technique – dubbed “decel/recel” – has been mainly investigated for small or thin structures such as layers of skin because it is hard to dissolve away the inside a large organ. But a new technique is now making that possible, leading a US biotech firm called Miromatrix to announce this month that it has successfully created livers this way.

They managed to decellularise whole livers by pumping detergent through the blood vessel network of the organ, so it reaches everywhere. This removes every living cell, leaving behind only the structural proteins that held the organ in shape. With a pig liver, this process takes 24 hours.

The liver scaffold is then reinfused with new cells, pumped through the same blood vessel network. The three main types of cell within a liver – liver cells, blood vessel wall, and bile duct cells – automatically home in on their right places within the scaffold, says Jeff Ross, of Miromatrix. “It takes tissue engineering from a single layer to whole organs,” he says.