Making pig livers humanlike in quest to ease organ shortage

Dec 26, 2022, 5:55 PM | Updated: Jan 17, 2023, 10:13 am
CORRECTS COMPANY NAME TO MIROMATRIX NOT MICROMATRIX - A pig kidney that has been "decelled" is held...

CORRECTS COMPANY NAME TO MIROMATRIX NOT MICROMATRIX - A pig kidney that has been "decelled" is held by a technician in a Miromatrix laboratory on Tuesday, Dec. 8, 2022, in Eden Prairie, Minn. This is a pig kidney that's gradually being transformed to look and act like a human one, part of scientists' long quest to ease the nation's transplant shortage by bioengineering replacement organs. (AP Photo/Andy Clayton-King)

(AP Photo/Andy Clayton-King)

              CORRECTS COMPANY NAME TO MIROMATRIX NOT MICROMATRIX - A pig kidney that has been "decelled" is held by a technician in a Miromatrix laboratory on Tuesday, Dec. 8, 2022, in Eden Prairie, Minn. This is a pig kidney that's gradually being transformed to look and act like a human one, part of scientists' long quest to ease the nation's transplant shortage by bioengineering replacement organs. (AP Photo/Andy Clayton-King)
            
              CORRECTS COMPANY NAME TO MIROMATRIX NOT MICROMATRIX - A pig liver growing in a bioreactors in a Miromatrix laboratory on Tuesday, Dec. 8, 2022, in Eden Prairie, Minn. (AP Photo/Andy Clayton-King)
            
              CORRECTS COMPANY NAME TO MIROMATRIX NOT MICROMATRIX - A technician replaces media in a bioreactors containing pig kidneys in a Miromatrix laboratory on Tuesday, Dec. 8, 2022, in Eden Prairie, Minn. (AP Photo/Andy Clayton-King)
            
              CORRECTS COMPANY NAME TO MIROMATRIX NOT MICROMATRIX - A pig kidney grows in a bioreactor in a Miromatrix laboratory on Tuesday, Dec. 8, 2022, in Eden Prairie, Minn. (AP Photo/Andy Clayton-King)
            
              CORRECTS COMPANY NAME TO MIROMATRIX NOT MICROMATRIX - A label on a bioreactor indicates it contains a pig kidney in a Miromatrix laboratory on Tuesday, Dec. 8, 2022, in Eden Prairie, Minn. (AP Photo/Andy Clayton-King)
            
              CORRECTS COMPANY NAME TO MIROMATRIX NOT MICROMATRIX - Technicians work with pig livers growing in a bioreactors in a Miromatrix laboratory on Tuesday, Dec. 8, 2022, in Eden Prairie, Minn. (AP Photo/Andy Clayton-King)
            
              CORRECTS COMPANY NAME TO MIROMATRIX NOT MICROMATRIX - Technicians add cells to media that will be used to add cells to the organs growing in bioreactors in a Miromatrix laboratory on Tuesday, Dec. 8, 2022, in Eden Prairie, Minn. Stripping away the pig cells removes some of the risks of xenotransplantation, such as lurking animal viruses or hyper-rejection, says Jeff Ross, CEO of Miromatrix. The FDA already considers the decellurized pig tissue safe for another purpose, using it to make a type of surgical mesh. (AP Photo/Andy Clayton-King)
            
              CORRECTS COMPANY NAME TO MIROMATRIX NOT MICROMATRIX - A technician works with bioreactors containing pig kidneys in a Miromatrix laboratory on Tuesday, Dec. 8, 2022, in Eden Prairie, Minn. Workers dissolve pig cells that made the organ function, leaving ghostly semi-translucent scaffolds floating in large jars. To complete the metamorphisis, they infuse those shells with human cells. (AP Photo/Andy Clayton-King)
            
              CORRECTS COMPANY NAME TO MIROMATRIX NOT MICROMATRIX -  A pig liver that has been "decelled" is held by a technician in a Miromatrix laboratory on Tuesday, Dec. 8, 2022, in Eden Prairie, Minn. The first step for workers in this suburban Minneapolis lab is to shampoo away the pig cells that made the organ do its work, its color gradually fading as the cells dissolve and are flushed out. What’s left is a rubbery scaffolding, a honeycomb structure of the liver, its blood vessels now empty. (AP Photo/Andy Clayton-King)
            
              A pig liver that has been "decelled" is held by a technician in a Micromatrix laboratory on Tuesday, Dec. 8, 2022, in Eden Prairie, Minn. The first step for workers in this suburban Minneapolis lab is to shampoo away the pig cells that made the organ do its work, its color gradually fading as the cells dissolve and are flushed out. What’s left is a rubbery scaffolding, a honeycomb structure of the liver, its blood vessels now empty. (AP Photo/Andy Clayton-King)
            
              A pig liver that has been "decelled" is held by a technician in a Micromatrix laboratory on Tuesday, Dec. 8, 2022, in Eden Prairie, Minn. The first step for workers in this suburban Minneapolis lab is to shampoo away the pig cells that made the organ do its work, its color gradually fading as the cells dissolve and are flushed out. What’s left is a rubbery scaffolding, a honeycomb structure of the liver, its blood vessels now empty. (AP Photo/Andy Clayton-King)
            
              A pig liver that has been "decelled" is held by a technician in a Micromatrix laboratory on Tuesday, Dec. 8, 2022, in Eden Prairie, Minn. The first step for workers in this suburban Minneapolis lab is to shampoo away the pig cells that made the organ do its work, its color gradually fading as the cells dissolve and are flushed out. What’s left is a rubbery scaffolding, a honeycomb structure of the liver, its blood vessels now empty. (AP Photo/Andy Clayton-King)
            
              A pig liver that has been "decelled" is held by a technician in a Micromatrix laboratory on Tuesday, Dec. 8, 2022, in Eden Prairie, Minn. The first step for workers in this suburban Minneapolis lab is to shampoo away the pig cells that made the organ do its work, its color gradually fading as the cells dissolve and are flushed out. What’s left is a rubbery scaffolding, a honeycomb structure of the liver, its blood vessels now empty. (AP Photo/Andy Clayton-King)
            
              A pig liver that has been "decelled" is held by a technician in a Micromatrix laboratory on Tuesday, Dec. 8, 2022, in Eden Prairie, Minn. The first step for workers in this suburban Minneapolis lab is to shampoo away the pig cells that made the organ do its work, its color gradually fading as the cells dissolve and are flushed out. What’s left is a rubbery scaffolding, a honeycomb structure of the liver, its blood vessels now empty. (AP Photo/Andy Clayton-King)
            
              A pig liver that has been "decelled" is held by a technician in a Micromatrix laboratory on Tuesday, Dec. 8, 2022, in Eden Prairie, Minn. The first step for workers in this suburban Minneapolis lab is to shampoo away the pig cells that made the organ do its work, its color gradually fading as the cells dissolve and are flushed out. What’s left is a rubbery scaffolding, a honeycomb structure of the liver, its blood vessels now empty. (AP Photo/Andy Clayton-King)
            
              A pig liver that has been "decelled" is held by a technician in a Micromatrix laboratory on Tuesday, Dec. 8, 2022, in Eden Prairie, Minn. The first step for workers in this suburban Minneapolis lab is to shampoo away the pig cells that made the organ do its work, its color gradually fading as the cells dissolve and are flushed out. What’s left is a rubbery scaffolding, a honeycomb structure of the liver, its blood vessels now empty. (AP Photo/Andy Clayton-King)
            
              A pig liver that has been "decelled" is held by a technician in a Micromatrix laboratory on Tuesday, Dec. 8, 2022, in Eden Prairie, Minn. The first step for workers in this suburban Minneapolis lab is to shampoo away the pig cells that made the organ do its work, its color gradually fading as the cells dissolve and are flushed out. What’s left is a rubbery scaffolding, a honeycomb structure of the liver, its blood vessels now empty. (AP Photo/Andy Clayton-King)
            
              A pig liver that has been "decelled" is held by a technician in a Micromatrix laboratory on Tuesday, Dec. 8, 2022, in Eden Prairie, Minn. The first step for workers in this suburban Minneapolis lab is to shampoo away the pig cells that made the organ do its work, its color gradually fading as the cells dissolve and are flushed out. What’s left is a rubbery scaffolding, a honeycomb structure of the liver, its blood vessels now empty. (AP Photo/Andy Clayton-King)
            
              A pig liver that has been "decelled" is held by a technician in a Micromatrix laboratory on Tuesday, Dec. 8, 2022, in Eden Prairie, Minn. The first step for workers in this suburban Minneapolis lab is to shampoo away the pig cells that made the organ do its work, its color gradually fading as the cells dissolve and are flushed out. What’s left is a rubbery scaffolding, a honeycomb structure of the liver, its blood vessels now empty. (AP Photo/Andy Clayton-King)
            
              A pig liver that has been "decelled" is held by a technician in a Micromatrix laboratory on Tuesday, Dec. 8, 2022, in Eden Prairie, Minn. The first step for workers in this suburban Minneapolis lab is to shampoo away the pig cells that made the organ do its work, its color gradually fading as the cells dissolve and are flushed out. What’s left is a rubbery scaffolding, a honeycomb structure of the liver, its blood vessels now empty. (AP Photo/Andy Clayton-King)
            
              A pig liver that has been "decelled" is held by a technician in a Micromatrix laboratory on Tuesday, Dec. 8, 2022, in Eden Prairie, Minn. The first step for workers in this suburban Minneapolis lab is to shampoo away the pig cells that made the organ do its work, its color gradually fading as the cells dissolve and are flushed out. What’s left is a rubbery scaffolding, a honeycomb structure of the liver, its blood vessels now empty. (AP Photo/Andy Clayton-King)
            
              A pig liver that has been "decelled" is held by a technician in a Micromatrix laboratory on Tuesday, Dec. 8, 2022, in Eden Prairie, Minn. The first step for workers in this suburban Minneapolis lab is to shampoo away the pig cells that made the organ do its work, its color gradually fading as the cells dissolve and are flushed out. What’s left is a rubbery scaffolding, a honeycomb structure of the liver, its blood vessels now empty. (AP Photo/Andy Clayton-King)
            
              Jeff Ross, CEO of Miromatrix, leads a team working towards developing organs that may someday be used in humans at the headquarters on Tuesday, Dec. 8, 2022, in Eden Prairie, Minn. “We essentially regrow the organ,” says Ross, CEO of Miromatrix. “Our bodies won’t see it as a pig organ anymore.”   (AP Photo/Andy Clayton-King)
            
              A pig liver growing in a bioreactors in a Micromatrix laboratory on Tuesday, Dec. 8, 2022, in Eden Prairie, Minn. (AP Photo/Andy Clayton-King)
            
              A technician replaces media in a bioreactors containing pig kidneys in a Micromatrix laboratory on Tuesday, Dec. 8, 2022, in Eden Prairie, Minn. (AP Photo/Andy Clayton-King)
            
              A pig kidney grows in a bioreactor in a Micromatrix laboratory on Tuesday, Dec. 8, 2022, in Eden Prairie, Minn. (AP Photo/Andy Clayton-King)
            
              A label on a bioreactor indicates it contains a pig kidney in a Micromatrix laboratory on Tuesday, Dec. 8, 2022, in Eden Prairie, Minn. (AP Photo/Andy Clayton-King)
            
              Technicians work with pig livers growing in a bioreactors in a Micromatrix laboratory on Tuesday, Dec. 8, 2022, in Eden Prairie, Minn. (AP Photo/Andy Clayton-King)
            
              Technicians add cells to media that will be used to add cells to the organs growing in bioreactors in a Micromatrix laboratory on Tuesday, Dec. 8, 2022, in Eden Prairie, Minn. Stripping away the pig cells removes some of the risks of xenotransplantation, such as lurking animal viruses or hyper-rejection, says Jeff Ross, CEO of Miromatrix. The FDA already considers the decellurized pig tissue safe for another purpose, using it to make a type of surgical mesh. (AP Photo/Andy Clayton-King)
            
              A technician works with bioreactors containing pig kidneys in a Micromatrix laboratory on Tuesday, Dec. 8, 2022, in Eden Prairie, Minn. Workers dissolve pig cells that made the organ function, leaving ghostly semi-translucent scaffolds floating in large jars. To complete the metamorphisis, they infuse those shells with human cells. (AP Photo/Andy Clayton-King)
            
              A pig kidney that has been "decelled" is held by a technician in a Micromatrix laboratory on Tuesday, Dec. 8, 2022, in Eden Prairie, Minn. This is a pig kidney that's gradually being transformed to look and act like a human one, part of scientists' long quest to ease the nation's transplant shortage by bioengineering replacement organs. (AP Photo/Andy Clayton-King)

EDEN PRAIRIE, Minn. (AP) — The ghostly form floating in a large jar had been the robust reddish-brown of a healthy organ just hours before. Now it’s semitranslucent, white tubes like branches on a tree showing through.

This is a pig liver that’s gradually being transformed to look and act like a human one, part of scientists’ long quest to ease the nation’s transplant shortage by bioengineering replacement organs.

The first step for workers in this suburban Minneapolis lab is to shampoo away the pig cells that made the organ do its work, its color gradually fading as the cells dissolve and are flushed out. What’s left is a rubbery scaffolding, a honeycomb structure of the liver, its blood vessels now empty.

Next human liver cells — taken from donated organs unable to be transplanted — will be oozed back inside that shell. Those living cells move into the scaffolding’s nooks and crannies to restart the organ’s functions.

“We essentially regrow the organ,” said Jeff Ross, CEO of Miromatrix. “Our bodies won’t see it as a pig organ anymore.”

That’s a bold claim. Sometime in 2023, Miromatrix plans first-of-its-kind human testing of a bioengineered organ to start trying to prove it.

If the Food and Drug Administration agrees, the initial experiment will be outside a patient’s body. Researchers would place a pig-turned-humanlike liver next to a hospital bed to temporarily filter the blood of someone whose own liver suddenly failed. And if that novel “liver assist” works, it would be a critical step toward eventually attempting a bioengineered organ transplant — probably a kidney.

“It all sounds science fiction-ey but it’s got to start somewhere,” said Dr. Sander Florman, a transplant chief at New York’s Mount Sinai Hospital, one of several hospitals already planning to participate in the liver-assist study. “This is probably more of the near future than xenotransplantation,” or directly implanting animal organs into people.

More than 105,000 people are on the U.S. waiting list for an organ transplant. Thousands will die before it’s their turn. Thousands more never even get put on the list, considered too much of a long shot.

“The number of organs we have available are never going to be able to meet the demand,” said Dr. Amit Tevar, a transplant surgeon at the University of Pittsburgh Medical Center. “This is our frustration.”

That’s why scientists are looking to animals as another source of organs. A Maryland man lived two months after receiving the world’s first heart transplant from a pig last January — an animal genetically modified so its organs didn’t trigger an immediate attack from the human immune system. The FDA is considering whether to allow additional xenotransplantation experiments using kidneys or hearts from gene-edited pigs.

Bioengineering organs is markedly different — no special pigs required, just leftover organs from slaughterhouses.

“That is something that in the long term may very likely contribute to the development of organs we can use in humans,” said Pittsburgh’s Tevar. He’s not involved with Miromatrix — and cautioned that the planned outside-the-body testing would be only an early first step.

The Miromatrix approach stems from research in the early 2000s, when regenerative medicine specialist Doris Taylor and Dr. Harald Ott, then at the University of Minnesota, pioneered a way to completely decellularize the heart of a dead rat. The team seeded the resulting scaffolding with immature heart cells from baby rats that eventually made the little organ beat, garnering international headlines.

Fast forward, and now at university spinoff Miromatrix sit rows of large jugs pumping fluids and nutrients into livers and kidneys in various stages of their metamorphosis.

Stripping away the pig cells removes some of the risks of xenotransplantation, such as lurking animal viruses or hyper-rejection, Ross said. The FDA already considers the decellularized pig tissue safe for another purpose, using it to make a type of surgical mesh.

More complex is getting human cells to take over.

“We can’t take billions of cells and push them into the organ at once,” Ross said. When slowly infused, “the cells crawl around and when they see the right environment, they stick.”

The source of those human cells: donated livers and kidneys that won’t be transplanted. Nearly a quarter of kidneys donated in the U.S. last year were discarded because hospitals often refuse to transplant less than perfect organs, or because it took too long to find a matching recipient.

As long as enough cells still are functioning when donation groups offer up an organ, Miromatrix biologists isolate usable cells and multiply them in lab dishes. From one rescued human organ the company says it can grow enough cells to repopulate several pig liver or kidney scaffolds, cells responsible for different jobs — the kind that line blood vessels or filter waste, for example.

In 2021, researchers with Miromatrix and the Mayo Clinic reported successfully transplanting a version of bioengineered livers into pigs.

That set the stage for testing a “liver-assist” treatment similar to dialysis, using bioengineered livers to filter the blood of people in acute liver failure, a life-threatening emergency. Doctors now have little to offer except supportive care unless the person is lucky enough to get a rapid transplant.

“If you can just get over the hump, then you might actually recover” — because the liver is the only organ that can repair itself and regrow, said Mount Sinai’s Florman. “I’ll be excited when they get their first patient enrolled and I hope that it’s with us.”

It’s not clear how soon that testing can begin. The FDA recently told Miromatrix it has some questions about the study application.

If the outside-the-body liver experiment works, what’s next? Still more research aimed at one day attempting to transplant a bioengineered organ — likely a kidney, because a patient could survive with dialysis if the operation failed.

While regrowing kidneys isn’t as far along, “I was completely stunned” at the progress so far, said Dr. Ron Shapiro, a kidney transplant expert at Mount Sinai.

He treats many older patients on dialysis who “will wait for years and years to get a kidney and likely die waiting on the list who would be perfect” for such experiments — if they come in time.

___

The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute’s Science and Educational Media Group. The AP is solely responsible for all content.

Copyright © The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

AP

U.S. Second Gentleman, Douglas Emhoff, speaks to the press as he visits to the Oskar Schindler Enam...
Associated Press

Emhoff says somber Auschwitz visit key to antisemitism work

KRAKOW, Poland (AP) — Doug Emhoff, the husband of Vice President Kamala Harris, described being deeply moved by a “solemn and sad” visit to Auschwitz-Birkenau, and said Saturday that it was an important part of his work combating antisemitism for the Biden administration. Emhoff told reporters that he will never forget his emotional visit to […]
1 day ago
FILE -Speaker of the House Kevin McCarthy, R-Calif., speaks during a news conference in Statuary Ha...
Associated Press

Inside McCarthy’s House: Famous friends and hard realities

WASHINGTON (AP) — In an almost forgotten slice of marbled real estate at the Capitol, the Kevin McCarthy era is taking shape in Congress. It was here that the new House speaker was chatting last week with Donald Trump Jr. on the former president’s son’s podcast, their laughter spilling into the halls from behind closed […]
1 day ago
A migrant from Michoacan, Mexico, uses the CBPOne app Tuesday, Jan. 24, 2023, in Tijuana, Mexico. A...
Associated Press

Online system to seek asylum in US is quickly overwhelmed

TIJUANA, Mexico (AP) — Hours before sunrise, migrants at one of Mexico’s largest shelters wake up and go online, hoping to secure an appointment to try to seek asylum in the U.S. The daily ritual resembles a race for concert tickets when online sales begin for a major act, as about 100 people glide their […]
1 day ago
FILE- Members of the Independent Higher Authority for Elections count the votes one day after the p...
Associated Press

Challenge for Tunisian democracy: Getting voters to show up

TUNIS, Tunisia (AP) — Tunisia was once the Arab world’s hope for a new era of democracy. Now it’s in the midst of an election that’s more of an embarrassment than a model. Barely 11% of voters turned out in the first round of parliamentary elections last month, boycotted by opposition Islamists and ignored by […]
1 day ago
Extinction Rebellion activists and sympathisers block a busy road in The Hague, Netherlands, Saturd...
Associated Press

Climate activists block main road into The Hague

THE HAGUE, Netherlands (AP) — Hundreds of climate activists blocked one of the main roads into The Hague on Saturday, defying attempts to prevent their protest that have sparked concerns about restrictions on the right to demonstrate in the Netherlands. The protesters, many waving colored flags with the symbol of environmental group Extinction Rebellion and […]
1 day ago
Associated Press

Philippines probes labor abuses in Kuwait after new killing

MANILA, Philippines (AP) — The Philippine government said Saturday it will take steps to assess and prevent abuses including rape and maltreatment of Filipino workers in Kuwait, after a housemaid was killed and dumped in a desert in the oil-rich emirate. The remains of Jullebee Ranara were flown home Friday night from Kuwait, where the […]
1 day ago

Sponsored Articles

safety from crime...

As crime increases, our safety measures must too

It's easy to be accused of fearmongering regarding crime, but Seattle residents might have good reason to be concerned for their safety.
Comcast Ready for Business Fund...
Ilona Lohrey | President and CEO, GSBA

GSBA is closing the disparity gap with Ready for Business Fund

GSBA, Comcast, and other partners are working to address disparities in access to financial resources with the Ready for Business fund.
SHIBA WA...

Medicare open enrollment is here and SHIBA can help!

The SHIBA program – part of the Office of the Insurance Commissioner – is ready to help with your Medicare open enrollment decisions.
Lake Washington Windows...

Choosing Best Windows for Your Home

Lake Washington Windows and Doors is a local window dealer offering the exclusive Leak Armor installation.
Anacortes Christmas Tree...

Come one, come all! Food, Drink, and Coastal Christmas – Anacortes has it all!

Come celebrate Anacortes’ 11th annual Bier on the Pier! Bier on the Pier takes place on October 7th and 8th and features local ciders, food trucks and live music - not to mention the beautiful views of the Guemes Channel and backdrop of downtown Anacortes.
Swedish Cyberknife Treatment...

The revolutionary treatment of Swedish CyberKnife provides better quality of life for majority of patients

There are a wide variety of treatments options available for men with prostate cancer. One of the most technologically advanced treatment options in the Pacific Northwest is Stereotactic Body Radiation Therapy using the CyberKnife platform at Swedish Medical Center.
Making pig livers humanlike in quest to ease organ shortage