Cardiac Stem Cell Developments
Scientists have developed a scaffold that supports the growth and integration of stem cell-derived cardiac muscle cells-a feat that offers hope for achieving what the body can’t do- mending broken hearts.
The scaffold, built by engineers and physicians at the University of Washington, supports the growth of cardiac cells in the lab and encourages blood vessel growth in living animals.
“Your body can’t make new heart cells, but what if we can deliver vital new cells in that damaged portion of the heart?” he added.
Ratner and his colleagues built a tiny tubular porous scaffold that supports and stabilizes the fragile cardiac cells and can be injected into a damaged heart, where it will foster cell growth and eventually dissolve away.
The new scaffold not only supports cardiac muscle growth, but potentially accelerates the body’s ability to supply oxygen and nutrients to the transplanted tissue.
Eventually, the idea is that doctors would seed the scaffold with stem cells from either the patient or a donor, then implant it when the patient is treated for a heart attack, before scar tissue has formed.
Ratner’s scaffold is a flexible polymer with interconnected pores all of the same size.
This one also includes channels to accommodate cardiac cells’ preference for fusing together in long chains.
“We’re very optimistic that this scaffold will help keep the muscle cells alive after implantation and will help transition them to working heart muscles,” said a co-author.
The scaffold is made from a jelly-like hydrogel material developed by first author, UW bioengineering doctoral student Lauran Madden.
A needle is used to implant the tiny (third of a millimeter wide by 4 millimeters long) scaffold rods into the heart muscle.
But the scaffold can support growth of larger clumps of heart tissue, said Madden.
The next steps will involve adjusting the scaffold degradation time so that the scaffold degrades at the same rate that cardiac cells proliferate and that blood vessels and support fibers grow in, and then implant a cell-laden scaffold into a damaged heart.
“What we have now is a really good system going in the dish, and we’re working to transition it to in the body,” said Madden.
The study has been published in the Proceedings of the National Academy of Sciences. (ANI)
Really interesting piece of News
Presenting at the UK National Stem Cell Network annual science conference (13 July), Professor Michael Schneider describes a new approach to treating heart attack and cardiomyopathy using stem cells.
Professor Schneider, British Heart Foundation Professor at Imperial College London, said “Recent clinical trials using stem cells to treat heart damage have been successful in terms of safety but unfortunately the bone marrow stem cells used tend to give only a small improvement in how well the heart is pumping.
“We really want to use stem cells from the patients themselves that we know can give rise to beating heart cells and these are not found in bone marrow. The good news is that we’re now finding ways to identify and purify such cells.”
Around 1000 patients have been treated in approximately 20 trials worldwide, mostly using bone marrow stem cells or derivatives of bone marrow cells to repair damage caused by heart attack. There has also been a significant body of work looking at ways of producing beating heart cells from stem cells. The best proven approaches to creating new beating heart cells are using embryonic stem cells, induced pluripotent cells and heart-derived stem cells.
Professor Schneider continued: “Using heart-derived stem cells to treat heart attack and cardiomyopathy has some advantages over embryonic and induced pluripotent cells as they are potentially safer. It’s also notable that of these three cell types, it’s only heart-derived cells that are in current human clinical trials for this sort of treatment.
“The biggest challenge is to make an ideal product for transplant, which would be either a mixture of heart muscle- and blood vessel-forming cells or a pure population of some sort of precursor that could give rise to both muscle and blood vessel cells.”
Professor Schneider’s team have discovered a way to identify heart stem cells so as to purify them for transplant. They first developed the method in mice and although the identifying markers are quite different in human cells, they have been able to successfully map their knowledge from mice onto humans. This research is funded by the British Heart Foundation, the European Research Council, the European Union (through the EU FP7 CardioCell consortium), the Leducq Foundation and the Medical Research Council.
Professor Schneider said “We’ve developed a method to identify cells that have three important characteristics: They are definitely stem cells; they have the right molecular machinery turned on in order to become heart muscle or blood vessel; and they don’t yet have any of the full characteristics of heart muscle or blood vessel cells such as producing cardiac myosin – an important protein in heart muscle cells.”
The next stage of the research is to develop this technique into a method for extracting, purifying and multiplying heart stem cells in the clinic to be used to repair heart damage arising from heart attack or cardiomyopathy. Professor Schneider’s laboratory uses advanced robotics, automated microscopy and other high-throughput methods to screen many thousands of experimental conditions in order to devise the best ways to grow the cells and instruct them to go down the route of becoming heart muscle.
I thought I would share this with you. It is a very simple explanation of where we are with Stem Cell research. It is a press release by Cryo-Cell International INC
Dr. Joshua Hare believes medicine is close to a goal long thought to be impossible: healing the human heart.
The way to get there? Stem cells.
“These could be as big as antibiotics were in the last century,” said Hare, who leads the University of Miami ‘s new Stem Cell Institute. “Stem cells have the potential to have that kind of impact. Diseases like heart attacks, strokes, kidney failure, liver failure and Heart Failure — we will be able to transition them into things you live with.”
Hare spends his days peering through powerful microscopes, recruiting scientists from top universities and attending to patients betting on improving their conditions through his clinical trials.
Stem cells, only one-thousandth the size of a grain of sand, are the master cells of the body, the source from which all other cells are created.
The most basic are embryonic stem cells, which are “totipotent,” meaning they can divide into any other type of cell — heart tissue, brain tissue, kidney tissue — all 220 cells that exist in the human body. They’re controversial because when they are harvested, the embryo is destroyed, ending potential life.
But coming into view are new kinds of stem cells — immature adult stem cells that can be extracted from bone marrow, from organs such as the heart or kidney or even from the skin. These can be taken without destroying embryos.
While researchers until recently believed adult stem cells were limited because they could develop only into cells similar to them — bone marrow cells only into cord blood stem cells, for example — evidence is growing that they, too, may become the tissue for hearts, brains, kidneys and other organs.
Hare expands on these developments:
Q. You’ve said that the basic idea behind your work is that a healthy human body is creating stem cells all the time to keep its organs healthy, and you’re trying to tap into this ability to expand its powers?
A: That’s the theory. It does sound fantastic. Actually, it happens in the body all the time, in tiny amounts. In our blood, to survive, we have red blood cells that carry oxygen, white cells that regulate the immune system and platelets, which are tiny cells that seal off cuts. They come from stem cells in the bone marrow. The marrow is the source for all red blood cells, platelets and some white blood cells.
The cells circulate in the blood all the time. Unless there’s a signal that says, “Come here and do this,” they will just keep circulating. If you get a cut, the cells will be recruited to that area to do what they do.
Q: Could such cells heal a heart attack all by themselves?
A: Experts believe the ability of the body to heal itself without help is limited. The system can slowly replace missing cells here and there, over a lifetime. But it’s not designed to repair a massive injury like a heart attack. That’s where we as doctors can intervene.
Q: In fact, you are intervening. You’ve led two studies at Johns Hopkins University and University of Miami in which you have harvested immature, or “mesenchymal” adult cord blood stem cells from the bone marrow, multiplied them many times in the lab, then injected them into the damaged heart. Is the idea that the bone marrow stem cells become heart cells?
A: This is where the biology gets somewhat murky. We don’t understand all the elements. We do have evidence that the cells differentiate, develop into healthy heart tissue.
Q: And this could be true with a damaged liver, kidney or brain?
A: In theory.
Q: You’ve said other kinds of adult stem cells are at work too?
A: Many cells are involved in the body’s attempts to heal itself. Some are from blood cells from bone marrow. But also, within the organs themselves, there are resident precursor cells that are stem cells. They’re sitting there like front-line soldiers in an injury. We think those stem cell cord blood collections that talk to each other and can go out and do healing. So we are engaging in a new study that will look at cardiac stem cells.
We can take pieces of heart tissue during surgery, multiply the stem cells in the lab and have a large amount to give back to the patient.
Q: Could an organ stem cell from, say, heart tissue, become a stem cell in the brain or kidney?
A: It’s possible, but not certain. We’re interested in studying how many degrees of freedom these cells have.
Q: And now researchers are getting stem cells even from the skin?
A: We’re starting to look at that. We know that stem cells in the skin replenish every 120 days. Researchers a year ago took regular stem cells from the skin and genetically reprogrammed them by introducing four genes. They were able to turn them into stem cells with a nearly unlimited capacity.
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