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Science Building a Beating Heart
Levi Beckerson (Blog) - January 14, 2008 12:27 PM
Print E-mail del.icio.us 16 comment(s) - last by wonderhat7.. on Jan 17 at 6:59 PM
Researchers at the University of Minnesota have successfully built a safer heart in the lab

Tissue engineering is a big business, and for good reasons -- vat grown tissue and organs could be used to save lives of trauma patients, or simply those in need of new organs due to various circumstances. Growing tissue in labs isn't a new science, it's been going on for years, and we've even seen researchers trying to grow "human" organs in animals.

The science does continue to evolve however. Researchers at the University of Minnesota Center for Cardiovascular Repair took another step in cell progenerated organ growth, growing a beating heart in a laboratory.

The process used by the UMN team is called "whole organ decellularization." A donor heart from a cadaver -- pigs and rats were used in the research -- is decellularized, which is the process of removing all of the cells from the organ. This leaves only an extracellular matrix, or the framework between the living cells of the heart.

Once the dead cells had been removed, the researches added a mixture of progenitor cells to the empty scaffolding and let it grow in sterile lab conditions. The cells used to seed the structure were gathered from the hearts of newborn and neonatal rats. In only four days, the scientists were able to observe contractions in the new hearts and after eight days the hearts were pumping away.

"We used immature heart cells in this version, as a proof of concept. We pretty much figured heart cells in a heart matrix had to work. Going forward, our goal is to use a patient's stem cells to build a new heart," explained Doris Taylor, Ph.D., director of the Center for Cardiovascular Repair, Medtronic Bakken professor of medicine and physiology, and principal investigator of the research.

Stem cells would make for a more ideal approach where human transplants are concerned as the risk for rejection and subsequent immunosuppression, which can wreak as much or more havoc on a human body as the failing organ may have, are theoretically much lower since the replacement organ would be grown from the donor's own cells. Not only could these organs mitigate the threat of rejection, but if the body recognizes the new organ as its own, it would be cared for like the original.

Taylor hopes that their research in the decullarization process will lead to more organs being able to be rebuilt for patients. "It opens a door to this notion that you can make any organ: kidney, liver, lung, pancreas -- you name it and we hope we can make it."

Nearly 50,000 people in the United States die yearly while waiting for a suitable donor heart.

Comments     Threshold


This article is over a month old, voting and posting comments is disabled
By Marlin1975 on 1/14/2008 12:59:12 PM , Rating: 5
We can rebuild him, we have the technology, but I don't want to spend a lot of money

http://www.baltimoresun2.com/talk/image.php?u=9378...




By Mitch101 on 1/14/2008 2:44:45 PM , Rating: 2
Hopefully before you know it this will replace the chia pet as long as the people behind it aren't the same ones with the OLED patents.


By KristopherKubicki (blog) on 1/14/2008 3:09:48 PM , Rating: 4
OLED is OK -- avoid the guys with the SED patents like the plague!


By Mitch101 on 1/14/2008 4:12:47 PM , Rating: 2
Ah my bad. Thank you for the correction.


By therealnickdanger on 1/14/2008 3:21:53 PM , Rating: 2
Probably my favorite FG joke... right next to "Touché salesman".


By wonderhat7 on 1/17/2008 6:59:13 PM , Rating: 2
I think this is a great display of human abilities
now how many years until we build a thinking brain?


Recognition is key
By GhandiInstinct on 1/14/2008 1:02:54 PM , Rating: 2
It seem recognition is the science we have yet to master. I believe understand the "psychology" of cells so to speak and learning what makes them accept and reject will make these types of advancement grow astronomically.

All transplants live and die by accepting or rejecting by cells.

So this is what fascinates me more than anything.




RE: Recognition is key
By rodrigu3 on 1/14/2008 1:57:11 PM , Rating: 2
The science of tissue rejection or acceptance lies within the branch of immunology.


RE: Recognition is key
By geddarkstorm on 1/14/2008 2:25:05 PM , Rating: 2
Exactly. It all has to do with the MHC proteins, more specifically HLA's in humans. These proteins present peptide fragments on the outside of cells for immune cells to scan, so that if you have a viral infection, the immune cell (CD8+, CD4+, or NK) will recognize the cell in question as being infected and start the immune response. Immune cells not only look at what peptide is being displayed (and if it's a self or non-self peptide) but also at if the MHC in question is a self or non-self. Thus, if a non-self peptide or a non-self MHC is seen, you get an immune response that can lead to rejection in donor organs. There are about 7 loci in the human genome for MHC's and over 100 variations at each site, meaning that it's very rare that two individuals would have the exact same 7 MHCs displayed on their cells. This is also why only stem cells derived from the person in question really hold the promise of being regenerative.

Of course, things get even more complex than this when you throw in the compliment system and interferons, but that is the gist of the issue. This breakthrough is great in that it now gives another avenue for driving stem cell production of replacement organs in vitro.


RE: Recognition is key
By GhandiInstinct on 1/14/2008 3:48:10 PM , Rating: 2
So the medication they give after transplants to prevent rejection has to do with matching those MHC variations? Or matching the exact MHC the organ has to the individual accepting the organ?

Great info btw ty.


RE: Recognition is key
By jtemplin on 1/15/2008 2:43:50 AM , Rating: 2
I believe it is cortisol or cortisol-like drugs. The goal (of cortisol and likely the medication you have heard is given after transplants) is to suppress the immune response. It does not attack the mechanism by which the immune system can recognize self from other, merely the result of the mechanism: rejection.


RE: Recognition is key
By LordanSS on 1/15/2008 8:30:19 AM , Rating: 2
Yes, the medication given to transplant pacients are immuno-suppressive drugs.

In order to keep the organism from "more effectively" attacking the new organ, the patient's immune suffers suppression. On one hand, it gives you a longer life expectancy for the new organ. On the other hand, makes the patient more susceptible to infections. The patient has to avoid them at all costs, as a simple flu could escalate to full blown pneumonia.

That is why the "new life" of a transplant patient is usually very different than that of another person, having to follow an "ultra-healthy" guidebook. Specific diet, exercise, no smoking, no drinking, etc (even get to see some of them wearing masks)... some may think it's rough, but compared to the other option (death), I'd say it's a good choice.


Bring on the liver clones....
By Amiga500 on 1/14/2008 1:33:20 PM , Rating: 3
It means our student years won't kill us off quite so quickly!




By initialised on 1/16/2008 8:27:32 AM , Rating: 2
Sod me liver, I want a new brain!


First Hand Knowledge
By lmccrary on 1/14/2008 3:00:41 PM , Rating: 2
I have first hand experience with the issue here. I had a bone marrow transplant 18 years ago for a very rare type of Leukemia. I wasn't given much hope of surviving the transplant. They had just exited the experimental stage. I was forced to have an unrelated donor, since my sibling didn't match. The transplant was a success, I'm still here and still in remission. The thing people don't understand is the rejection, Graph Versus Host Disease, was 100 times worse than the cancer! So for someone like me, controlling the immune response is just as important. I hope this research continues to show results.




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