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September 16, 2012

Induced Regeneration and tissue engineered organs

Huffington Post / AP - The Associated Press conducted more than a dozen interviews and reviewed the latest medical research to measure the progress and extent of novel treatments under way for wounded warriors. The results point to some surprising feats of surgery and bioengineering.

Scientists are growing ears, bone and skin in the lab, and doctors are planning more face transplants and other extreme plastic surgeries. Around the country, the most advanced medical tools that exist are now being deployed to help America's newest veterans and wounded troops.

_In Los Angeles, surgeons used part of Michael Mills' forehead to rebuild his nose after a bomb disfigured him in Iraq.

_In Pittsburgh, doctors used an experimental therapy from pig tissue to help regrow part of a thigh muscle that Ron Strang lost in a blast in Afghanistan.

_In Boston, scientists are making plans for the first implants of lab-grown ears for wounded troops after successful experiments in sheep and rats.

_In San Antonio and other cities, doctors are testing sprayed-on skin cells and lab-made sheets of skin to heal burns and other wounds. The ingenuity is impressive: One product was developed from foreskin left over from circumcisions.

Much of this comes from taxpayer-funded research. Four years ago, the federal government created AFIRM, the Armed Forces Institute of Regenerative Medicine, a network of top hospitals and universities, and gave $300 million in grants to spur new treatments using cell science and advanced plastic surgery.

"The whole idea is to bring all these researchers together to develop these great technologies that were in early science to eventually be ready for the troops," said AFIRM's recently retired director, Terry Irgens.



Inducing regeneration using extracellular matrices

Dr. Stephen Badylak, a regenerative medicine specialist at the University of Pittsburgh is testing implants of an "extracellular matrix" – connective tissue that holds cells together – to boost muscle mass. The matrix is thought to release chemical signals that promote regrowth of healthy tissue instead of scar tissue.

"It changes the body from thinking, `I need to respond to injured tissue,' to `I need to rebuild this tissue,'" Badylak said.

The material is supplied by a private company – ACell Inc. of Columbia, Md. – and comes from pigs. The immune system tolerates it because it doesn't contain cells. It comes in multi-layered sheets like slightly stiff gauze and can be cut or molded to fit the needed shape.

Strang, who lost half of a thigh muscle, is among the five patients treated so far in an 80-patient study. Doctors wait at least six months after an injury to make sure all natural healing has occurred, and put patients through intensive physical therapy before implanting the matrix.

"We want to be able to say after the surgery that they were as good as they could be" and that the matrix accounted for any improvement, Badylak explained.

In early testing, "They've shown up to 10 to 20 percent improvement" in strength of the muscle after treatment, said Irgens, the director of AFIRM, which funded some of the early work. The Department of Defense is sponsoring the study under way now, which includes non-military patients as well as former troops. The new study is measuring changes in strength and muscle volume, and doctors are aiming for the kind of quality-of-life improvement Strang has enjoyed.

Progress in Tailor Made Organs

NY Times - researchers like Dr. Macchiarini are building organs with a different approach, using the body’s cells and letting the body itself do most of the work.

So far, only a few organs have been made and transplanted, and they are relatively simple, hollow ones — like bladders and Mr. Beyene’s windpipe, which was implanted in June 2011. But scientists around the world are using similar techniques with the goal of building more complex organs. At Wake Forest University in North Carolina, for example, where the bladders were developed, researchers are working on kidneys, livers and more. Labs in China and the Netherlands are among many working on blood vessels.

To make an organ, it helps to know how nature does it.

That is why Philipp Jungebluth, a researcher in Dr. Macchiarini’s lab, had mounted a heart and a pair of lungs inside a glass jar on a workbench and connected them by tubing to another jar containing a detergent-like liquid. The organs, fresh from a sacrificed rat, had slowly turned pale as the detergent dripped through and out of them, carrying away their living cells. After three days the cells were gone, leaving a glistening mass that retained the basic shape of the organs.

These were the heart and lungs’ natural scaffolds, or extracellular matrix — intricate three-dimensional webs of fibrous proteins and other compounds that keep the various kinds of cells in their proper positions and help them communicate.

Labs around the world are now experimenting with scaffolds. In some cases the goal is to use the natural scaffolds themselves to build new organs — to take a donor lung, for example, strip all its cells and reseed it with a patient’s own cells. Why not use what nature has perfected, this line of thinking goes, rather than try to replicate it in a synthetic scaffold?

Dr. Macchiarini is planning even more operations. But there needs to be a less complex and cumbersome solution, he said, beyond procedures that can cost up to half a million dollars.

Because the need for this kind of work is potentially so enormous, “we cannot pretend that we can reseed with the specific cells outside the body,” he said. 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.

“Don’t touch the patient,” Dr. Macchiarini said. “Just use his body to recreate his own organ. It would be fantastic.

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