Scientists create replacement organs using body's own cells

One of the problems of organ transplants is the potential for the body to reject the foreign organ. For this reason, organ donor recipients have to take drugs that suppress the immune system.

So far, only a few such organs have been created and transplanted, and the they aren't complex organs -- just simples one like bladders and a windpipe. But, the New York Times reports, scientists are working on creating more complex organs such as kidneys and livers with these techniques.

A windpipe made to order

The Times article features the case of Andemariam Beyene, whose doctors discovered a golf ball-sized tumor growing in his windpipe two-and-a-half years ago. When he was nearly out of options for treatment, he went to see Dr. Paolo Macchiarini, at the Karolinska Institute in Stockholm, who suggested making Mr. Beyene a windpipe out of plastic and his own cells.

In order to make it, Dr. Macchiarini began by using a porous, fibrous plastic to make a copy of Mr. Beyene's windpipe. He then seeded it with stem cells from Mr. Beyene's bone marrow and placed the windpipe in an incubator that spun the windpipe "rotisserie-style," says the Times, in a nutrient solution.

Then, he substituted that in for Mr. Beyene's cancerous windpipe.

Fifteen months after surgery, Mr. Beyene is cancer-free.

The blueprint

Scientists are looking to nature to guidance on how to create these bioartificial organs.

In Dr. Macchiarini's lab, a researcher named Philipp Jungebluth took a heart and lungs from a rat and put them in a glass jar. A detergent-like liquid connected via tube dripped into the jar and out, slowly stripping the organs of their living cells. After all the cells were gone (in three days), what was left of the organs was the scaffold, the basic shape of the organ, composed of a matrix of proteins and other compounds that keep the right cells in the right places.

Human scaffolds could be better for building new organs than synthetic scaffolds that just try to imitate nature. For example, donor lungs could be stripped of cells and re-seeded with a patient's own cells before implantation.

Dr. Macchiarini has used scaffolds to successfully replace windpipes from cadavers in about a dozen patients who don't have the major problem facing other organ donor recipients: the risk of organ rejection.

But scaffolds still have some problems of traditional organ transplants: They require donor organs, for which there is a long waiting list, and the patient has to wait for the organ to be stripped of cells. Also, when it comes to windpipes, a donated windpipe may not be the right size. For that reason, Mr. Beyene's windpipe, made of the plastic replica of his own windpipe, fit perfectly.

"Instead, he envisions developing even better scaffolds and implanting them without cells, relying on drugs to stimulate the body to send cells to the site. His ultimate dream is to eliminate even the synthetic scaffold. Instead, drugs would enable the body to rebuild its own scaffold."

via: The New York Times

photo: Gray's anatomy/Wikimedia

This post was originally published on Smartplanet.com