Pigs could grow human organs in stem cell breakthrough

Human organs could be grown inside pigs for use in transplant operations following research using stem cells.

The researchers have already managed to produce pigs that were able to generate human blood by injecting blood stem cells from humans into pig foetuses Photo: ALAMY

By Richard Gray,
From http://www.telegraph.co.uk/

Scientists have found they can create chimeric animals that have organs belonging to another species by injecting stem cells into the embryo of another species.

The researchers injected stem cells from rats into the embryos of mice that had been genetically altered so they could not produce their own organs, creating mice that had rat organs.

The researchers say the technique could allow pigs to grow human organs from patient's stem cells for use as transplants.

By using a patient's own stem cells it could help to reduce the risk of the transplanted organ being rejected while also providing a plentiful supply of donor organs.

Current organ shortages mean that patients must endure long waiting lists for transplants.

Professor Hiromitsu Nakauchi, director of the centre for stem cell biology and regenerative medicine at the University of Tokyo in Japan and who led the research, said: "Our ultimate goal is to generate human organs from induced pluripotent stem cells.

"The technique, called blastocyst complementation, provides us with a novel approach for organ supply. We have successfully tried it between mice and rats. We are now rather confident in generating functional human organs using this approach."

Professor Nakauchi, who presented the study at the annual conference of the European Society of Human Genetics, used a type of adult stem cell known as induced pluripotent stem cells, which can be taken from a sample of tissue such as the skin and encouraged to grow into any type of cell found in the body.

Together with his colleagues, he injected these cells taken from rats into the embryos, or blastocysts as they can be called, of mice that were unable to grow their on pancreas, the organ that produces important hormones including insulin.

When the mice matured to adulthood, they showed no signs of diabetes and had developed a pancreas that was almost entirely formed from the injected rat stem cells.

The scientists claim the rat stem cells grew in the niche left by the absent mouse pancreas and so almost any organ could be produced in this way.

If replicated using human stem cells, the technique could produce a way of treating diabetic patients by providing a way of replacing their pancreas.

The project has echoes of the bestselling book and film Never Let Me Go where clones are used to provide organ donations for the wealthy. In reality researchers are not allowed to create human embryos that lack the ability to grow organs and so they hope to do the same using pigs.

Professor Nakauchi said they hoped to further test the technique by growing other organs and were also seeking permission to use human stem cells.

They have, however, already managed to produce pigs that were able to generate human blood by injecting blood stem cells from humans into pig foetuses.

He said: "For ethical reasons we cannot make an organ deficient human embryo and use it for blastocyst complementation.

"So to make use of this system to generate human organs, we must use this technique using blastocysts of livestock animals such as pigs instead.

"Blastocyst complementation across species had never been tested before, but we have now shown that it can work."

Professor Chris Mason, chair of regenerative medicine at University College London, said: "There is no doubt that curing diabetes is challenging, but this could be a potential way forward albeit a very long shot requiring sustained resources and major finance for its testing and development."

"For something like a kidney transplant where it is not urgent, it would be highly attractive to be able to take cells from a patient, grow them in this way and deliver a personalised kidney."

"There is a long way to go before it could result in useable transplants, but it is an exciting vision."

Artificial Lung "Breathes" in Rats: Study

Reuters: WASHINGTON

http://abcnews.go.com/

U.S. researchers have created a primitive artificial lung that rats used to breathe for several hours and said on Tuesday it may be a step in the development of new organs grown from a patient's own cells.

The finding, reported in the journal Nature Medicine, is the second in a month from researchers seeking ways to regenerate lungs from ordinary cells.

In the latest study, Harald Ott and colleagues at Massachusetts General Hospital and Harvard Medical School in Boston removed the cells from rat lungs to leave a scaffolding or matrix.

They soaked these in a bioreactor along with several types of human lung cells, creating pressures to simulate the pressure inside a body to make the lung workable and flexible.

The cells took up residence and grew into different tissue types seen in a lung, Ott's team reported.

When transplanted into rats, they worked for about six hours, although imperfectly.

The researchers said it may be possible to try the experiment with more immature stem cells, the body's master cells. These could include embryonic stem cells, which can mature into any cell type in the body, or induced pluripotent stem cells -- ordinary cells with genes added to make them behave like flexible stem cells.

The potential market is large and dozens of companies are launching into regenerative medicine, as are academic labs like those at Harvard.

"Nearly 25 million people live with chronic obstructive pulmonary disease and approximately 120,000 patients die from end-stage lung disease annually in the United States alone," Ott's team wrote.

"Lung transplantation remains the only definitive treatment for end-stage lung disease. As with other organs, however, the supply of donor lungs is limited. In 2005, only one out of four patients waiting for a lung underwent transplantation," they added, citing the United Network of Organ Sharing.

Last month, a team at Yale University in Connecticut implanted engineered lung tissue into rats that helped the animals breathe for two hours.

(Editing by Todd Eastham)

Copyright 2010 Reuters News Service. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.

Copyright © 2010 ABC News Internet Ventures

'Grow-your-own' organs hope after scientists produce liver in lab from stem cells

By Fiona Macrae

From : http://www.dailymail.co.uk/

Scientists have grown a liver in a laboratory, offering fresh hope to hundreds of thousands of patients with diseased and damaged organs.

It raises the prospect of those in need of transplants one day being offered livers that are ‘made to order’.

The first pieces of lab-grown livers could be used in hospitals within just five years, the researchers said.

A decellularised rat liver retaining its network of blood vessels, a technique grown by scientists which could be used to grow livers for human transplants

Patches of artificial tissue could be used to repair livers damaged by injury, disease, alcohol abuse and paracetamol overdose.

Other possibilities include sections of artificial livers to keep those needing transplants alive – in much the same way as a dialysis machine is used to treat kidney failure.

HOW TO GROW OWN LIVER

1. Donated but damaged liver bathed in detergent to remove the cells.

2. All that remains is a 'scaffold' made of collagen and blood vessels.

3. Scaffold is seeded with healthy liver cells, made from the stem cells created from the patient's skin.

4. The new liver is used to replace the patient's damaged one. As it is made from their own cells, the body will not reject it.

At least one million of Britons live with liver disease and it claims more than 16,000 lives a year – more than diabetes and traffic accidents combined. Up to 600 transplants are carried out a year.

The latest experiments, which were carried out on animal livers, are still in the early stages but could one day lead to an alternative supply of organs.

The process began with a donor liver being ‘washed’ in detergent, stripping it of its cells, leaving only a collagen and blood vessel ‘scaffold’ in which the new liver cells could grow.

The U.S. scientists then injected it with up to 200 million healthy liver cells, in four shots, each ten minutes apart.

The cells spread across the scaffold, and, provided with an artificial blood supply, the liver survived in a petri dish for up to ten days, the journal Nature Medicine reports.

Tests showed that, just like a real liver, it was capable of breaking up toxins.

The researchers, from Massachusetts General Hospital, Boston, also transplanted the liver into a rat, for several hours.

Lead researcher Dr Korkut Uygun said: ‘As far as we know, a transplantable liver graft has never been constructed in a laboratory setting before.

‘Even though this is very exciting and promising, it is a proof-of-concept study only. Much more work will be required to make long-term functional liver grafts that can actually be transplanted into humans.

‘We haven’t been able to go beyond several hours in rats, but it’s a great start.’

Hurdles to overcome include creating a liver with all the types of cells needed for full function, including specialised cells that destroy bacteria and other invaders.

Anthony Atala on growing new organs

Kinko's for Kidneys: 3D Printing Your Own Body Parts

by Lloyd Alter, Toronto

3D printing to order is a regular subject on TreeHugger; we love the idea of making things when you need them, where you need them. And soon you will be able to order up body parts, at a sort of Ponoko for pancreas. Now people sit on waiting lists, hooked up to expensive equipment while they wait for donors and fly body parts all over the world; soon you will order them up fresh and hot. Perhaps, like Philip K. Dick did, we might even call them artif-orgs.

Printing kidneys

Organovo is trying to build "tissue on demand", building 3D printers that work with living cells.

"By marrying a knowledge of biophysics and cell biology with the precision of computer aided design and high precision deposition, we can recreate the microarchitecture of even the most complex human tissue. By precisely placing cells with an organ printer, and providing them with the proper natural developmental cues, the cells do exactly what they do in nature: they self assemble into fully formed, functional tissue."

They have just taken delivery of their first commercial printers from Australian manufacturer Invetech.

Ken Murphy, President of Organovo said in a press release:

"Scientists and engineers can use the 3D bio printers to enable placing cells of almost any type into a desired pattern in 3D," said Murphy. "Researchers can place liver cells on a preformed scaffold, support kidney cells with a co-printed scaffold, or form adjacent layers of epithelial and stromal soft tissue that grow into a mature tooth. Ultimately the idea would be for surgeons to have tissue on demand for various uses, and the best way to do that is get a number of bio-printers into the hands of researchers and give them the ability to make three dimensional tissues on demand."

So instead of having to find kidney or liver donors, doctors could grow new ones from a patient's own cells, solving the donor supply and rejection problems. Via Next Big Future

The future of 3D printing? from On Art and Science: Bioprinting & Pygmalion's Dream? Vladimir Mironov MD, PhD

Growing Body Parts: 60 Minutes

Watch CBS News Videos Online

Morley Safer reports on the emerging technology of growing body parts from human cells taken directly from patients, providing new hope for amputees and patients on organ-transplant lists.

Growing Organs in the Lab

Written on June 8, 2009 – 3:19 pm | by Drew Halley |

Why transplant an organ when you can grow yourself a new one?

A homegrown bladder (Photo courtesy of BBC)

This research isn’t something that might happen in the distant future. It’s being used today to grow fresh organs, open up new ways to study disease and the immune system, and reduce the need for organ transplants. Organ-farming laboratories are popping up across the planet, and showing impressive results. Here we look at the state of the union of a rapidly advancing field called tissue engineering: what’s been accomplished so far, and what’s right around the corner.

Patients who undergo organ transplants require loads of toxic drugs to suppress their immune systems; otherwise their body might reject the organ. But tissue engineering could make organ transplants a thing of the past. By using a patient’s cells to grow new types of tissue in the lab, researchers are finding new ways to custom-engineer you new body parts by using your own cells.

At the cutting edge of organ engineering is Tengion, a clinical-stage biotech company based outside of Philadelphia. Their most successful research to date led to the creation of the Neo-Bladder. Tengion takes some of your cells and grows them in culture for five to seven weeks around a biodegradable scaffold. When the organ is ready, it can be transplanted without the need to suppress the patient’s immune system (because the organ was grown from the patient’s own cells, it carries no risk of rejection). Once the organ is in, the scaffold degrades and the bladder adapts to its new (old) home.

The Tengion Neo-Bladder is in Phase II testing, meaning that they have already implanted the organ into individuals and studied how the body adapts to it. After 5 years, the company was able to show that the homegrown organs are safe and effective, capable of treating the bladder effects of spina bifida (a neural tube defect that effects bladder function, among other things). After another round of Phase II trials, Tengion will move on to Phase III testing; after that, the Neo-Bladder should be approved and be made commercially available.

Atala wants to grow you an organ

Tengion’s Neo-bladder is nearing the completion of its clinical trials, but they weren’t the first to grow one. If anyone on Earth deserves the job title “Organ Farmer,” it’s Dr. Anthony Atala. He and his research team at Wake Forest University Medical Center pioneered the world’s first lab-grown bladder, and they remain at the forefront of the organ-growing field (Atala is also the chairman of Tengion’s scientific advisory board). Wake Forest is the world’s largest regenerative medicine research center, and their current research is growing 22 different types of tissue: heart valves, muscle cells, arteries, and even fingers.

So how many different types of human organs have been grown and transplanted? The lab-grown bladders are among the only transplants of an entire organ, but a wide variety of partial organ transplants have taken place. Skin cells are regularly grown in culture and grafted onto patients’ bodies. A graft was grown from a patient’s trachea cells and transplanted to replace part of her airway that had degraded due to disease. Cartilage has been grown and transplanted into a patient’s knee.

A number of technologies are under development but have yet to be transplanted into human bodies. Recently, Dr. Nicholas Kotov and his lab at the University of Michigan have engineered artificial bone marrow, a task that was previously doomed to failure. Kotov and his colleagues realized that in the body, stem cell differentiation relies on chemical signals in three dimensions (whereas in a petri dish, it takes place in two dimensions). This insight led to a new methodology that more closely replicated the natural environment of stem cell differentiation in bone marrow tissue. The resultant homegrown marrow grew and divided normally, even releasing antibodies in fight off an introduced influenza strain. It can be used to study the role of bone marrow in fighting disease within the body, as well as creating a “bioreactor”: harnessing the artificial marrow within a device to grow cells and tissues.

Tengion is pretty busy these days as well. Their new website lists a variety of new applications on the horizon, including a Neo-Kidney augment, artery replacements (including in the heart), and variations on their bladder technique to replace cancerous organs. Their company pipeline gives a general idea of the relative stages of each project.

A number of initiatives are under way to create an artificial pancreas, which would revolutionize the way we treat diabetes. By providing diabetics with a healthy pancreas, doctors could restore their natural control of blood glucose by giving them an endogenous source of insulin. Anyone with experience of diabetes knows the difficulty of manually monitoring and controlling your sugar levels, not to mention regularly injecting insulin. A lab-grown pancreas replacement would be an incredible benefit to the 23.6 million individuals in America alone who suffer from diabetes.

The Minnesota rat heart

As we previously reported, researchers at the University of Minnesota grew an entire rat heart in a laboratory last year. Their next goal is to grow a pig heart, a significant milestone towards growing a human heart due to their similar structure. Researchers hope to combine the scaffold of a pig heart with human cardiac tissue to grow a hybrid heart suitable for transplant.

Another exciting frontier is the field of printable tissue and organs, which is just what it sounds like. Inkjet cartidges are cleaned out and loaded with a mixture of live human cells and “smart gel.” Then, layer by layer, the cells are printed atop one another until a 3D organ is constructed. Just as a normal printer can deposit different colored ink, organ printing allows scientists to specify where to place different cell types. Organ printing has already created beating cardiac cells, and could soon produce organs that are viable for transplant. But unlike other 3D printers, I wouldn’t want this one in my living room.

The hottest areas in tissue growth are the types hardest to make: nerve, liver, kidney, heart and pancreas cells. But these are precisely where Alata and Tengion are heading, pushing the industry into fresh territory. Coupled with new regenerative treatments like Cook biotech’s foams and stem-cell organ patching, tissue engineering will be keeping our organs young and healthy in the years to come.

Merely a decade ago, tissue engineering was still a new field that struggled to find funding and support. Today, thousands of scientists worldwide are coordinating efforts to reach new breakthroughs, and the demonstrated potential of these methods has helped bring in investors. That should keep the organ growing field moving forward in the future months and years, and we’ll be covering new advances as they emerge.

Check out this Wired Science video that tours around Atala’s lab:

WIRED SCIENCE | Body Builders | PBS
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