Stem Cells, Regenerative Medicine, and Tissue Engineering

Treatments classed as regenerative medicine help our natural healing processes work more rapidly and more effectively. These technologies can enable regeneration in missing or damaged tissue that would not ordinarily regrow, producing at least partial regeneration, and in some promising animal studies complete regeneration.

Strategies presently either under development, in clinical trials, or available via medical tourism include stem cell transplants, manipulation of a patient's own stem cells, and the use of implanted scaffold materials that emit biochemical signals to spur stem cells into action. In the field of tissue engineering, researchers have generated sections of tissue outside the body for transplant, using the patient's own cells to minimize the possibility of transplant rejection. Regenerative therapies have been demonstrated in the laboratory to at least partially heal broken bones, bad burns, blindness, deafness, heart damage, worn joints, nerve damage, the lost brain cells of Parkinson's disease, and a range of other conditions. Less complex organs such as the bladder and the trachea have been constructed from a patient's cells and scaffolds and successfully transplanted.

Work continues to bring these advances to patients. Many forms of treatment are offered outside the US and have been for a decade or more in some cases, while within the US just a few of the simple forms of stem cell transplant have managed to pass the gauntlet of the FDA in the past few years.

What Are Stem Cells?

Some of the most impressive demonstrations of regenerative medicine since the turn of the century have used varying forms of stem cells - embryonic, adult, and most recently induced pluripotent stem cells - to trigger healing in the patient. Most of the earlier successful clinical applications were aimed at the alleviation of life-threatening heart conditions. However, varying degrees of effectiveness have also been demonstrated for the repair of damage in other organs, such as joints, the liver, kidneys, nerves, and so forth.

Stem cells are unprogrammed cells in the human body that can continue dividing forever and can change into other types of cells. Because stem cells can become bone, muscle, cartilage and other specialized types of cells, they have the potential to treat many diseases, including Parkinson's, Alzheimer's, diabetes and cancer. They are found in embryos at very early stages of development (embyonic stem cells) and in some adult organs, such as bone marrow and brain (adult stem cells). You can find more information on stem cells at the following sites:

Embryonic and adult stem cells appear to have different effects, limitations and abilities. The current scientific consensus is that adult stem cells are limited in their utility, and that both embryonic and adult stem cell research will be required to develop cures for severe and degenerative diseases. Researchers are also making rapid progress in reprogramming stem cells and creating embryonic-like stem cells from ordinary cells.

Progress in Stem Cell Research

Stem cell research is a growing, well-funded field, and as a result it is also a hot topic in the press. Not a week goes by without the announcement of a new and amazing advance, but these days most simply slip by without comment. The pace of progress is rapid, and so what would have been trumpeted in the popular science press a decade ago is now routine, carried out in scores of laboratories worldwide.

The first crop of simple stem cell therapies for regenerative medicine has reached widespread availability in the developed world. "Simple," because these therapies are on the level of transfusions. In most cases stem cells are obtained from the patient, then grown in a cell culture and the greatly expanded number of cells injected back into the body. New medicine doesn't get much simpler than that in this day and age. This is merely the start of a revolution in medicine, however, one will grow to become as large and as influential on health as the advent of blood transfusion or the control of common infectious diseases.

If you read enough of the literature, stem cells from your own body begin to sound like a miracle cure-all: extract them, culture them, return them to the body, and injured tissue begins to heal. It isn't anywhere near that straightforward, however, and this throwaway summary hides the many years of hard work by thousands of scientists required to bring us to this point, as well as the further years of hard work that lie ahead. Research continues, with a tone of excitement coming from the scientific community. They know they are onto something big.

Creating Recellularized Organs

Researchers have found what may be a shortcut to the growth of replacement organs from a patient's own stem cells. Called recellularization or decellularization, the process takes a human or animal donor organ and chemically strips the cells from it, leaving only the scaffolding of the extracellular matrix behind. Stem cells from the recipient are then used to repopulate the scaffold, and following the chemical instructions issued by the matrix they create a functioning organ ready for transplant that has little to no risk of rejection.

Since pigs could be used as a source of organs for transplantation, being of about the right size, decellularization is one potential way to eliminate donor organ shortages. The use of animal organs is still some years away from practical implementation, however. Human transplants have moved ahead, and in recent years decellularization has been used in the transplantation of tracheas and bladders in clinical trials. Meanwhile in the laboratory researchers have successfully transplanted decellularized lungs, kidneys, and hearts in mice and rats.

Ultimately decellularization is a stepping stone technology. It is necessary and useful because researchers cannot yet create an entirely artificial scaffold for a complex organ such as a kidney or a heart, complete with all of the chemical cues, fine structure, and mesh of capillaries necessary for its full function. That will become possible, however, at which point donor organs will no longer be needed.

Rejuvenating Aged Stem Cells

Stem cells in the adult body gradually relinquish their job of repair and maintenance with age, eventually causing tissue and organ failure. Based on the past decade of research, this occurs because stem cells become dormant in increasing numbers as rising levels of age-related cellular damage change the mix of chemical signals propagating through tissues. This reaction probably reduces the chances of cancer due to a damaged stem cell running amok, but at the cost of failing tissues. Researchers have found that by restoring signals to a more youthful mix, such as through infusing old tissue with young blood, aged stem cell populations can be restored to action and some of the impact of aging on our tissues might be reversed.

In recent years some of these stem cell activating signals have been identified. Researchers already regularly manipulate the genes and biochemistry of stem cells taken from patients for use in trials of new therapies: there is every reason to expect that future medicine will involve the repair and restoration of aged stem cells either prior to transplant or for existing cell populations within the body.

Regenerative Medicine and Human Longevity

Regenerative medicine will help to produce extended healthy longevity. In the decades ahead clinics will be able to repair some of the mechanical damage caused by aging, such as occurs in worn joints, but more importantly also reverse the decline in function of our stem cells, restoring stem cell maintenance tissue by tissue and organ by organ. At worst a regenerative treatment would be the replacement of a failing organ with a tissue engineered organ built to order from the patient's own cells, thus requiring major surgery, and at best such a treatment would adjust the cells within the failing organ, instructing them to repair the damage, with no surgery needed.

Aging damages every part of our bodies, however, including the stem cells required for regenerative therapies! Thus regenerative medicine on its own is not the full solution to aging: researchers must also address the root causes of age-related degeneration, the damage that accumulates within the molecular machinery of cells, and the metabolic waste products that accumulate in and around cells.

To add to this list, clinics must also become capable of reliably preventing and defeating cancer in all its forms, and also able to repair age-related damage to the brain in situ. Increasing risk of cancer with age cannot be prevented with regenerative medicine, and the brain cannot be removed and replaced with a new tissue engineered organ as will be the case for a liver or even a heart.

All in all these tasks will be a mammoth undertaking. Nonetheless, like all great advances in medicine, this is a worthy and noble cause. Today, hundreds of millions of people live in pain and suffering, and will eventually die, as a result of degenerative conditions of aging, many of which will be alleviated or even cured with near future advances in regenerative medicine. We stand within reach of the means to prevent all this death and anguish. We should rise to this challenge by supporting the researchers and research programs most likely to lead to meaningful progress.

Last updated: May 10th 2014.


When will this so called ''future'' medicine be available for the people who need it now? Are millions of people gonna be dead before the ''future'' medicine comes?

Posted by: carlos angulo at December 12th, 2010 6:23 PM

i agree with carlos, this medicine will never be out until, the stupid united states government lets these kinds of medicines into american culture, there are 100's and 1000's of people dying everyday, because of diseases and these medicines have not even made their way into USA, once i grow up and become someone, i will finish what the united states never started... i will upgrade this medicine and find a cure for the horrible diseases that people suffer from... where there's a will there's a way!!

Posted by: Arnold at February 12th, 2011 5:15 PM

The medical community doesn't want to heal. That takes money out of their pockets. It's all just a money-making scam, not life-saving. My 21yr. old suffered a spinal cord injury. I believe that they could use his "still young" stem cells and help the spinal cord regrow. How long will it take them to figure it out? As long as they keep getting big bucks for NOT figuring it out.

Posted by: Vicki Gibbs at March 17th, 2011 8:57 AM

If interested in making this happen in our lifetimes, consider sending this letter, which I sent to my congressman and senators a few years ago:

Thank you for your work on the stimulus plan. Today the markets are the biggest challenge to our economy. Looking forward, spending will be our greatest problem, in particular Social Security and Medicare. Republicans would eliminate them, if they could. Democrats would tax more to try to make them solvent. Most Americans want neither solution.
The alternative solution requires rethinking demographics, and some scientific investment.
The reason 65 was the age set for retirement during the New Deal was because most workers died before 64 in the 1920’s. Life was harder. Most jobs involved heavy physical labor. Healthcare was poorer.
Today’s entitlement problem is not a financial problem. It’s a demographics problem. Today’s average life expectancy is 78 and rising. Healthcare’s better. Work’s less strenuous. But most Americans resist retiring at 78 because they believe old age will rob them of the strength to work that long. But as more retirees are supported by fewer workers, the system will fail.
The alternative is to cure the diseases of old age so people can work at 80 as though they were 60 again. Much work has been started on this, but a concerted effort to finish it is needed now to make a difference in solving the coming entitlement crisis.
Below is a partial list of people working on the problem.
With enough government support, a sustained scientific effort, like that of the space program, could yield substantial benefits before the worst of the demographic pressures hit. Pooling and coordinating the effort in one place, perhaps UVA or Virginia Tech, will provide a focus for information services to persuade an aging work force that working longer and maintaining a good quality of life are compatible.
Ciao e Buona Fortuna,

Gary Andrews
-Cynthia Kenyon, Hillblom Center for the biology of Aging, San Francisco
-David Scaddon, M.D. & Anthony Komaroff, M.D., Harvard Medical School
-Brian Kennedy & Matt Kaeberlain, University of Washington, Seattle
-T. Keith Blackwell, Harvard Medical School
-Nir Barzilai, Institute for Aging, Albert Einstein College of Medicine, NY,NY
-Thomas Rando, Stanford University
-D. Leanne Jones, Salk Institute for Biological Studies, La Jolla, CA
-Norman Sharpless, University of North Carolina, Chapel Hill
-Woodring Wright, University of Texas Southwestern Medical Center, Dallas
-Hemachandra Reddy, Oregon Health & Science University, Beaverton
-Mark Mattson, National Institute on Aging, Baltimore
-Gencia Corp, UVA, Charlottesville, VA

Posted by: Gary Andrews at April 26th, 2011 7:33 PM

I wonder if it would be possible to stimulate/genetically alter our bone marrow to constantly produce stem cells and then have these stem cells transported round the body via the circulatory system. If so, then maybe old, damaged cells would be constantly replaced by fresh, new cells, completely free of damage or mutation.

Posted by: Sam at July 28th, 2011 5:15 AM

This is truly incredible. To even take a glimpse at what life would be like if people could live indefinitely, so long as trauma is not experienced. We need to create a greater acceptance of this life saving study, and teach those who appose it that it is for the good of everyone and all of mankind. The only possible issue I see with this is when the world's population quadruples every year. Either way, I only see good things coming from stem cell research.

-Kyle Perez

Posted by: Kyle Perez at August 25th, 2011 7:23 PM

"...sound like a miracle cure-all; extract them, culture them, return them to the body, and injured tissue begins to heal. It isn't anywhere near that simple..." No, actually it IS that simple. The comments above about the government not wanting people to be cured is absolutely true. Sick people spend a lot of money on drugs. The government will find a way to profit from stem cell therapy, or they won't allow it. Give them time to figure out a scam. In the meantime, if you are ill, go to Panama or another country that has verifiable results from their stem cell therapy. Most of the clinics in Mexico are a bit suspicious, so research carefully and choose wisely.

Posted by: marty at September 7th, 2011 10:02 PM

In Germany, they are using stem cells from patients own body, harvesting them and then injecting them into the patients spinal fluid or brain tissue of stroke victims. Some of them had their stroke 10 years ago. Many of them are now walking due to this cutting edge therapy. Like Carlos Angulo said, "When will this so called 'future' medicine be available for the people who need it now". I had a stroke in 2007 and I wish the US had this therapy now. If this does become available in the US, I doubt if anyone but the rich could afford the treatment. Right now it costs about $60,000 to have the treatment done in Germany and stay there in what is described as a 4 star hotel for approximately 4-10 days. The only thing I don't know is what it would cost to fly to Germany. Actually it would probably be worth going to Germany. As I said, it will be too expensive when it becomes available in the US and insurance probably won't pay for the therapy. I guess we have to go to Germany to obtain this therapy. When will the US catch up to all that Europe has to offer now?

Posted by: Joan at November 10th, 2011 9:33 AM

Is regenerative medicine play God or good science? And how do we even know that people want regenerative medicine if there is no data to prove that congressmen should fund it?

Posted by: Jay at January 25th, 2012 8:20 PM

I harvested my adult peripherical blood, hoping there are some good stem cells still there, since I am a healthy 72 year old female, and stored it in a cryogenic lab, awaiting expected progress in biogenetic engineering that could give me healthy longevity. This is the least invasive way, of several options of harvesting stem cells, that might serve us well in a not too distant future. Of course, the younger you are, the better, but this field is so new!

Posted by: beatriz at January 29th, 2012 7:11 AM

I definitely think that regenerative medicine will help us to see the light at the end of the dark tunnel we call despair and possible death. It will also possibly give us all a much better future and help us understand genetic engineering.

Posted by: Greta at February 7th, 2012 6:40 AM

Is the stem cell therapy good only for the young? Anything for the old ones?

Posted by: George Kurian at March 25th, 2012 2:56 AM

I have already saved my peripheral HSC about 5 years ago and had one reinfusion which 'cured my neuropathic pain from my cervical spondylosis. I still have a few bags of stem cells that I would reinfuse in the near future for antiaging purpose. I hope to coinfuse allogenic cord derived MSC with my own HSC . Any comments on this?

Posted by: peter chua at April 1st, 2012 8:39 PM

any reserch done on arthrogryposis? The knees and arms and hands are affected.

Posted by: s quinn at April 3rd, 2012 4:38 PM

i agree with you guys too about that medicine stuff that you guys were talking about.

Posted by: name at May 16th, 2012 4:30 PM

Is there a stem cell study to regrow nerves in the prostate area?

Posted by: John David at June 3rd, 2012 6:49 AM

What would happen if this medicine were to say, mix with the cells of bacteria and/or viruses? Would it make them unstoppable if not appropriately tested? I believe that we need to find a way to access a higher part of our brain to create our own regenerative cells that could heal different types of wounds and in some cases, sickness

Posted by: Drew at July 26th, 2012 3:16 PM

can we regenerate the toes which has fully imputed.

Posted by: jitendra at September 4th, 2012 6:40 AM

hi just thought i should tell you that you have spelt ageing wrong x

Posted by: hope at November 30th, 2012 5:56 AM

In response to Mr. Chua:
I would like to know where Peter Chua got his treatment. I've suffered from cervical spondylosis for over forty years. I don't even know where to begin getting stem cell therapy.

peter chua (first wrote) at April 1, 2012 8:39 PM

I have already saved my peripheral HSC about 5 years ago and had one reinfusion which 'cured my neuropathic pain from my cervical spondylosis. I still have a few bags of stem cells that I would reinfuse in the near future for antiaging purpose. I hope to coinfuse allogenic cord derived MSC with my own HSC . Any comments on this?

Posted by: Roger Wilkensen at December 16th, 2012 1:25 AM

I would like to know how possible for a spinal cord injuries of incomplete or complete T12-L1 get cure through stem cells Regeneration?

Posted by: S. P at June 8th, 2013 2:44 AM

is there any good places that do stem cell therapy for penis damaged by priapism

Posted by: james at November 25th, 2013 5:35 PM

To answer how possible for a spinal cord injuries of incomplete or complete T12-L1 get cure through stem cells Regeneration, the difficulty is with the loss of spinal fluid flow in the damaged area of the spinal cord. If the damaged are of the spinal cord has been deprived of spinal fluid, it will atrophy. There are only two fluids in the body that cannot be reproduced or synthesized at the present time: Spinal fluid and Retinal fluid. If there were a way to synthesize spinal fluid, many spinal cord injury patients could have the damaged area of the spinal cord repaired or replaced and then have synthetic fluid placed in the area that has been deprived of fluid however, as we have no artificial or synthetic fluid with which to place in the new spinal apparatus, the flow of fluid will not occur as it does naturally. It is not the same process as replacing a blood vessel and re-establishing the flow of blood throughout a limb. This is what makes spinal injuries so devastating and difficult to reverse.

Posted by: Rebecca C Brumm at February 16th, 2015 9:01 PM

It appears you can spell ageing or aging either way, both are correct. At any rate very interesting article.

Posted by: Angela at February 17th, 2015 8:26 PM

Since this technology, stem cell, is not available in the United States (aging process) where does one have to go out of the U.S. for treatment.

Thank you,

Susan Lock

Posted by: Susan Lock at February 19th, 2015 12:14 AM

I have been keeping up with this research myself. I am 28 my mother is still around and most my aunts as well. I am hoping this regenerative medicine against aging will be around for their lifetime as well as mine. I think this will be a big breakthrough for all of us and a way to learn how to make life bearable for all of us. Humanity has came along way from cavemen. Stem cells seem to work for the most part. I read articles about Peter Nygard and Gordie Howe. Very interesting stuff.

Posted by: Timothy Kaliszewski at June 12th, 2015 7:31 AM

ok yes there are 100s and thousands of people dying now. so what. there will still be hundreds and thousands of people dying tomorrow. and people dying 40 years from now. you can't rush delicate stuff like this. or else people mess up and one miss calculation means rapidly reproducing cells which causes tumors and possibly cancer

Posted by: ryan at September 9th, 2015 6:54 PM

even the allogeneic transplants had boosted P16. I'm hoping that this is all because of the chemo.

Posted by: trying2survive at September 14th, 2016 7:04 PM

Late answer to Sam above. Using LLLT (Low Level Laser Therapy) on the shins is thought to cause migration of stem cells throughout the body, where they tend to find places they are needed. There is research on repairing the hearts of animals in this fashion.

Posted by: Rob at April 24th, 2018 5:02 PM

I would really like to see stem cell therapy or gene replacement therapy be applicable to my younger brother's hearing loss. He has never been able to hear since the day he was born. I strongly believe that he has been forced to settle for his lower-paying job at Syracuse University as a grounds keeper because of his hearing loss. It would be wonderful to see what his actual potential could be. He is 56 years old and has a wife and 2 grown daughters. Just before he was born something happened in his brain. He has nerve deafness and now, related to whatever happened before he was born, he is being treated for epileptic seizures. He is such a good man. This should NOT be happening to him.

Posted by: diane at May 23rd, 2018 10:18 PM
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