Ken Richardson

Rewriting Life

Can’t get new lungs? Try refurbished ones instead.

Spruced-up human and animal organs could someday be the solution for people needing transplants.

Harald Ott, a surgeon at Harvard Medical School, thinks that his lab’s unusual methods might someday solve the organ-transplant crisis. On average, 20 people in the United States die every day awaiting donor organs for transplant, according to the American Transplant Foundation. If Ott’s idea works, it could one day eliminate the need for an organ waiting list.

The process begins by hooking the circulatory system of an animal organ, in this case a pig lung, to a pump that sends detergent through the organ.
The lab has also used the same process to successfully remove cells from human lungs, as shown here, for use as scaffolds.

The lab chemically treats organs from rats and pigs to remove all their cells, leaving behind an empty scaffolding. The researchers then populate the scaffold with stem cells from a patient, hoping to create an organ that the human body will accept.

In the most recent work, the lab is using a technique Ott helped develop called lung regeneration, transforming lungs from rats and pigs into human--compatible ones. Though rat lungs aren’t suitable as human transplants, they provide an excellent means to test the regeneration procedure.

The first organs the Ott Lab used for testing came from rats. Rat lungs like these are still used because their cells can be removed in just two hours.
Three rat lungs are tested in an incubator under different conditions to find the best process for regenerating the organs.

Ott originally began to develop this technique while studying at the University of Minnesota (see “Creating a heart”). In the decade since then, his lab has made strides in deciphering the conditions under which stem cells develop into functioning organs.

So far the team has been able to transplant organs re-created with human stem cells back into pigs and rats. Given that the organs have human cells foreign to the animals, they stay alive for only about a week. But the experiments are evidence that these organs can work in a living organism.

A rat lung sits in an incubator where a culture medium is pumped through the organ, growth factors are added, and oxygen is introduced to make the lung “breathe.”