From Stem Cells To New Organs: Scientists Cross Threshold In Regenerative Medicine
Stem cells can thrive in segments of well-vascularized tissue temporarily removed from laboratory animals, say researchers at the Stanford University School of Medicine. Once the cells have nestled into the tissue’s nooks and crannies, the so-called “bioscaffold” can then be seamlessly reconnected to the animal’s circulatory system.
The new technique neatly sidesteps a fundamental stumbling block in tissue engineering: the inability to generate solid organs from stem cells in the absence of a reliable supply of blood to the interior of the developing structure.
“Efforts to use tissue engineering to generate whole organs have largely failed,” said Geoffrey Gurtner, MD, associate professor of surgery, “primarily due to the lack of available blood vessels. Now we’ve essentially hijacked an existing structure to overcome this problem.” The key, the researchers discovered, is to keep the tissue adequately supplied with oxygen and nutrients while outside of the body.
In the near future, the researchers believe that the stem cells in the tissue could be induced to become an internal, living factory of healthy, specialized cells churning out proteins missing in people with conditions such as hemophilia or diabetes. In the long run, they hope to encourage the cells to become entire transplantable organs such as livers or pancreases.
Gurtner, who is also a member of Stanford’s Cancer Center, is the senior author of the study, which is featured in the March issue of the FASEB Journal.
The technique devised by Gurtner and his colleagues does more than provide the versatile stem cells with a readily accessible blood supply and a pre-formed cellular framework within which to begin differentiating. It also eliminates the chance of rejection or complications caused by the use of artificial or donor scaffolding materials by utilizing the animal’s own tissue.
The researchers capitalized on a portion of the circulatory system shared by animals and humans called microcirculatory beds. To understand what they are, spread the fingers of each of your hands apart and then touch your fingertips together. One wrist represents the inflow of blood, and the other, the outflow. The fingers are the tiny capillaries that supply oxygen and nutrients to the surrounding tissue wrapping itself invisibly around your hands.
In many cases these beds create a flap of expendable tissue that can be easily removed. (With your fingertips still touching, bring your elbows together. Now imagine lopping off your hands midway down the forearm. Your fingers and wrists now represent a free microcirculatory bed.)
Gurtner and his colleagues removed microcirculatory beds about the size of a half-dollar coin from the groin of laboratory rats and attached the ends of the two main blood vessels to a modified piece of equipment called a bioreactor designed to keep livers and kidneys healthy outside the body. The modified bioreactor pumps an oxygenated soup of nutrients into one vessel and recovers it from the other; Gurtner referred to it as a “kind of life support, or cardiopulmonary bypass, machine for tissue.”
The scientists showed that, once the appropriate blood pressure and nutrient balance was achieved, the bioreactor could keep the tissue healthy enough for reimplantation into a second, genetically identical animal for up to 24 hours. In many cases, the tissue became nearly indistinguishable from surrounding skin within 28 days of transplant, although the success rate of the procedure decreased as time spent on the bioreactor increased. In contrast, control tissue not connected to the bioreactor after removal died within six hours of transplantation.
The team then used the bioreactor to pump multipotent stem cells from a variety of sources, including bone marrow and fat tissue, through the tissue. Unlike embryonic stem cells, which can become any type of cell in the body, multipotent cells are more restricted in their potential. The researchers found that the cells could migrate out of the vascular spaces and into the surrounding tissue. Once there, they set up shop and began to form colonies. Unlike stem cells injected directly into the tissue, the stem cells that had been seeded into the tissue continued to thrive even eight weeks after reimplantation.
“This is an incredible opportunity to bulk-deliver cells that don’t just die,” said Gurtner. “Conceivably, we could use this technique at least to supply the synthetic function of an organ by stimulating the cells to form insulin-producing pancreas cells or albumin-producing liver cells.”
Members of Gurtner’s team are now trying to use the technique to deliver Factor VIII and Factor IX — crucial blood-clotting components that are missing in people with hemophilia. The researchers concede, however, that much remains to be done before the technique could be used to generate whole organs. Indeed, Gurtner readily agrees that other methods might be developed that could be more effective. But for now, they’ve overcome a major hurdle in tissue engineering.
“Eventually science will find a way to fabricate an organ in all its complexity,” said Gurtner. “But in the short term we need to find more options for patients who are dying while waiting for transplants.”
Stanford collaborators on the research include postdoctoral scholars Edward Chang, MD, Robert Bonillas, MD, Eric Chang, MD, and Denise Chan, PhD; and medical students Samyra El-ftesi and Ivan Vial. The research was supported by grants from the National Institutes of Health and the National Institute of Biomedical Imaging and Bioengineering.
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Did you know? Stem cells from tissues with heavily vascular systems show promise in organ regeneration. After these stem cells get into the tissues needing repair, they can be reattached to the animal circuatory system! “In most cases attempts to generate complete organs have normally been unsuccessful.”says, Geoffrey Gurtner MD,associate surgery professer.Now we have been able to use a working sturucture to bypass the problem.
1.Stem cells can live in segments of well-vascularized tissue temporarily removed from lab animals.
2.Once the cells have settled into the tissue’s nooks and crannies, the “bioscaffold” can then be seamlessly reconnected to the animal’s circulatory system.
3.The new technique neatly sidesteps a fundamental stumbling block in tissue engineering: the inability to generate solid organs from stem cells in the absence of a reliable supply of blood to the interior of the developing structure.
4.”Efforts to use tissue engineering to generate whole organs have largely failed,” said Geoffrey Gurtner, MD.
5.In the near future, the researchers believe that the stem cells in the tissue could be induced to become an internal, living factory of healthy, specialized cells churning out proteins missing in people with conditions such as hemophilia or diabetes.
Stem cells from tissues with heavily vascular systems show promise in organ regeneration. After these stem cells get into the tissues needing repair, they can be reattached to the animal circuatory system! “In most cases attempts to generate complete organs have normally been unsuccessful.”says, Geoffrey Gurtner MD,associate surgery professer.Now we have been able to use a working sturucture to bypass the problem.
Researchers believe that in the future stem cells will be able to be transplanted into the body to give extra protein to people who need them if they have diabetes. In the long run researchers hope that the stem cells can be transplantable to organs. Researchers looked at a portion of the circulatory system that animals and humans share called microcirculatory beds. The testing showed that once the blood pressure and nutrient balance was good, the bioreactor could keep the tissue healthy so that they could put it in another animal in the same family for up to 24hrs.
1.Cells can fit into the small spaces and this is called the bioscaffold.
2.A new technique is used to make up for the inability to make slid organisms from stem cells
3.When people tried to create tissue to make whole organisms have failed.
4.Reasearcher think that soon enough thet may be able to make special cells that can help people with diabetes.
5.Reasearchers found a link beyweem animal and human cells.
Article Summary:
1.Stem cells can thrive in segments of well-vascularized tissue.
2. The Researchers at the Stanford University School of Medicine has studied this.
3. Geoffrey Gurtner is also a member of Stanford’s Cancer Center.
4.Geoffrey Gurtner is an associate professor of surgery.
5.Gurtner and his scientists showed that, once the appropriate blood pressure and nutrient balance was achieved, the bioreactor could keep the tissue healthy enough for reimplantation into a second, genetically identical animal for up to 24 hours.
stem cells come from tissues with heavily vascular systems
The new technique neatly sidesteps a fundamental stumbling block in tissue engineering
In the near future, the researchers believe that the stem cells in the tissue could beinduced to become an internal
The scientists showed that, once the appropriate blood pressure and nutrient balance was achieved
Eventually science will find a way to fabricate an organ in all its complexity,” said Gurtner. “But in the short term we need to find more options for patients who are dying while waiting for transplants.”
1) Stem cells can live in segments of well-vascularized tissue temporarily from lab animals.
2)Researchers found a link between animal and human cells.
3)Cells can fit into small spaces called biosfolds.
4)People have tried to make tissue for whole organisms but have failed.
5)Once the cells have settled into the tissue the “biosfolds” can then be seamlessly reconected to the animals circulatory system.
1.Stem cells can live in segments of well-vascularized tissue.
2. The Researchers at the Stanford University School of Medicine have studied this.
3. Geoffrey Gurtner is a member of Stanford’s Cancer Center.
4.Geoffrey Gurtner is an associate Professor of Surgery.
5.Gurtner and his scientists showed that, once the appropriate blood pressure and nutrient balance was achieved, the bioreactor could keep the tissue healthy enough for reimplantation into a second, genetically identical animal for up to 24 hours
1. Stem cells can thrive in segments of well-vascularized tissue temporarily from laboratory animals, say researchers at the Stanford University School of Medicine.
2. efforts to use tissue engineering has largely fail says scientists.
3. Scientists are using techniques to deliver Factor VIII and Factor IX
4. Scientists will eventually find a way to fabricate an organ in all its complexity
5. Reseachers were supported by alot of national institutes.
1.stem cells can thrive through segments of well-vasclarized tissue.
2.scientist and researchers belive that the cells can be introduced to the cell membrane.
3.some belive that it causes canser.
4.cells live in the all types of walls
5.all cells are blood in a human body.
1. Cells can fit into the small spaces and is called the bioscaffold.
2. Geoffrey Gutner is an associate proffesor of surgery.
3. Researchers found a link between animal and human cells.
4. Some believe that it causes cancer.
5. When people tried to create tissue to make whole organisms have failed.
Article Summary for December 7, 2009
1. Cells can fit into small places called biosfolds.
2. Researchers have found a link between human cells and animals cells.
3. Cells live in all types of walls in our body system.
4. Stem cells live in segments of well-vascularized tissue.
5.Geoffrey Gurtner is a member of Stanfords cancer center.
-Stem cells thrive in segments of well-vascularized tissue.
- Inability to generate solid organs from stem cells in the absence of a reliable supply of blood.
- Scientists eventually will find a way to fabricate an organ in all its own complexity.
-Geoffrey Gurtner is a member of Stanford’s Cancer Center.
-It’s an Incredible opportunity to bulk deliver cells that don’t just die out.
1. Stem cells can thrive in segments of well-vascularized tissue temporarily removed from laboratory animals.
2. Say researchers at the Stanford University School of Medicine.
3. Once the cells have nestled into the tissue’s nooks and crannies.
4. The so-called “bioscaffold” can then be seamlessly reconnected to the animal’s circulatory system.
Andrew Rice Jan 16 5th period
1.Stem cells can thrive inn some segments
2.Once the cells have nestled into the tissue’s nooks and crannies, the so-called “bioscaffold” can then be seamlessly reconnected to the animal’s circulatory system
3.The new technique neatly sidesteps a fundamental stumbling block
4.Geoffrey Gurtner is a great professor
5.science will find a way to fix organs
1. Stem cells can thrive in well vascularized tissue temporarily removed from laboratory animals.
2 that is what the researchers said at Stanford Medical school.
3 Once the cells have been put into the tissue, the biocasfold can be reconnected
to the animal’s circulatory system.
4 The technique avoidss a fundamentul block in tissue engineering
5 the inability to make solid organs from cells in the absence of a supply of blood to the inside of a developing structure is the problem
1.Cells can fit into the small spaces and this is called the bioscaffold.
2.A new technique is used to make up for the inability to make slid organisms from stem cells
3.When people tried to create tissue to make whole organisms have failed.
4.Reasearcher think that soon enough thet may be able to make special cells that can help people with diabetes.
5.Reasearchers found a link beyweem animal and human cells.
1.Stem cells can live in segments of well-vascularized tissue.
2. The Researchers at the Stanford University School of Medicine have studied this.
3. Geoffrey Gurtner is a member of Stanford’s Cancer Center.
4.Geoffrey Gurtner is an associate Professor of Surgery.
5.Gurtner and his scientists showed that, once the appropriate blood pressure and nutrient balance was achieved, the bioreactor could keep the tissue healthy enough for reimplantation into a second, genetically identical animal for up to 24 hours
1. Stem cells can live in segments of well-vascularized tissue says researchers at the Stanford University School of Medicine.
2 “Bioscaffold” can then be seamlessly reconnected to the animal’s circulatory system.
3. Many have tried to use tissue engineering to generate whole organs, but many failed.
4. Stem cells in the tissue could be lead to an internal, living factory of healthy.
5. These specialized cells churn out proteins missing in people with conditions like hemophilia or diabetes and more.
1. Stem cells can live in segments of well-vascularized tissue says researchers at the Stanford University School of Medicine.
2. Say researchers at the Stanford University School of Medicine.
3. all cells are blood in a human body.
4. People have tried to make tissue for whole organisms but have failed.
5. Reasearchers found a link beyweem animal and human cells
1.Stem cells can thrive in segments of well-vascularized tissue.
2.The researchers believe that the stem cells in the tissue could be induced to become specialized cells churning out protein.
3.The stem cells can make proteins missing in people with conditions such as hemophilia or diabetes
4.They hope that the cells can become entire transplantable organs
5.The bioreactor pumps an oxygenated soup of nutrients into one vessel and recovers it from the other.
1.Stem cells can thrive in segments of well-vascularized tissue temporarily removed from laboratory animals.
2.In the near future, the researchers believe that the stem cells in the tissue could be induced to become an internal, living factory of healthy, specialized cells.
3.Gurtner, who is also a member of Stanford’s Cancer Center, is the senior author of the study.
4.In many cases these beds create a flap of expendable tissue that can be easily removed.
5.Members of Gurtner’s team are now trying to use the technique to deliver Factor VIII and Factor IX.
1. Stem cells can thrive into tissue.
2. Once the cells have been nestled in the tissue’s nook, the bidcoffed can be rejoined with the animals cardiovascular system.
3. The researchers found the key, which is to keep the tissue supplied with oxygen and nutrients while outside of the body.’
4. Researchers believe that in the near future, stem cells in tissue could become an internal factory of specialized cells churning out proteins missing in people.
5. Researchers hope that the cells could become entire transplantable organs like the liver.