In pioneering new research, the holy grail in regeneration of lost limbs for amputees is coming to fruition. Scientists have now succeed in growing a new rat limb in the laboratory.
They want to refine the technology and attempt to regrow a new arm for a monkey. The goal to eventually use human stem cells to grow new limbs that would be transplanted in humans.
In June 2015, I was reading about a report in the media that regenerative scientists at the Massachusetts General Hospital (MGH) and with Harvard Medical School, had regenerated a rat bio-limb with functional vascular and muscle tissue. Thus researchers adapted an experimental procedure used to develop bio-artificial organs.
It is hoped that eventually the developing technology can regenerate human limbs suitable for transplantation on demand.
Professor Harald Ott is leading this research project and is the director of organ repair and regeneration lab at MGH in Boston. He points out that there is no real good options for replacing lost limbs at the moment.
In America alone, around 185,000 amputations happen each year and over 2 million Americans are living with limb loss.
Prosthetic limb technologies have certainly improved over the decades and especially in the past 10 years but nothing can be a substitute for the real natural limb.
It be great to put things back the way they were before the patient’s injuries. Making them whole and complete again. Well now with the advancements of science we can, as we start entering compelling and unknown territory.
Regenerative medicine is very much in its infancy but what is being revealed right now and being developed is highly significant.
No one really knows how regenerative medicine will take off over the next decade but one thing is for sure that it will be really big and is going to completely change our lives and how we live.
Not least in upgrading and improving the human experience and the quality of our lives, expanding our longevity.
In the past 20 years there have been a number of hand transplants from donors.
Also in a recent research project with the US Military, a marine who lost both his arms below the elbow, successfully had a double arm and hand transplant. I am aware that the outcome of this procedure is still a great success with the patient.
These kind of procedures are great achievements in improving the quality of the patient’s life.
However, they can expose the patient to a life long treatment with immune-suppressant drug treatments to combat any rejection from the body of the new body part. These treatments can have a damaging effect on the patient’s immune system making them vulnerable to viruses and diseases.
Regrowing New Limbs
The research being carried out is an ambitious project involving regeneration of limbs made up of cells from the recipient’s own body to grow an arm or leg. This means that it will unlikely be rejected by the patient’s immune system.
So far the research has been successful to regrow a rat’s arm and now they want to do the same with a monkey’s arm. Thus upgrading and attempting the process from the rodent to a primate.
In fact the scientists have successfully decellularized baboon forearms to clarify the feasibility of the study, therefore taking it to a level that would be required for human patients.
What is know as Progenitor cells are required to regenerate all of the tissues that make up the limb. These can be provided by the patient, however, what has been lacking was a scaffold on which the cells develop into the correct tissues.
The process involves stripping living cells from a donor using a detergent solution. The remaining matrix is then repopulated with the progenitor cells that is appropriate for the specific organ to grow. The same idea is used for growing a limb but is more complex as the primary vasculature and nerve matrix must be preserved.
Once all the cellular materials are removed which takes about a week, what you have left is the cell free matrix that provides the appropriate structure of all the limb’s composite tissues.
In other words, the frame work structure that is left, is similar to the shape of a car, but you have blasted everything away except the metal frame.
While a donor limb was used in this process mentioned above, in the future the cells will be taken from the recipient. Therefore, the outcome will be genetically compatible with the patient’s body.
So that suitable regeneration could take place, the limb was placed inside a bio-reactor that supplies oxygen, nutrients, along with electrical stimulation. This process took a few weeks for the limb to finish growing.
On testing, scientists stimulated the new grown limb with electricity and observed that the paw would close and open, meaning that the muscles were functional. Researchers then proceeded to attach the limb to the rat under sedation and found that blood circulation developed.
In addition, they tested electrical stimulation after the limb was attach and saw movement of the animals paws.
Nerve Cell Regeneration
Along with the plan to regrow an arm in a monkey, the next step is to ensure that the nerves develop within the new grown limb. Nerve signalling reintegration does occur with hand transplants but with a new bio “artificial” limb it may be more complex.
While scientists are now starting to set their sights on how they could apply this technology to humans one day, there is still many challenges ahead to overcome. They feel it could be 10 years before possible medical trials may occur, however, this is not that far away, and the 2020s should be very interesting in what is possible in medical science.
Ott feels that he will be working in science long enough to see this research come to manifestation. As he says: “I will live to the clinical application of this.”
A Moment Of Reflection
It is perhaps worth pondering on the implications of not just the above and how these technologies will eventually change society, but also regenerative medicine in general.
Today parents and rightly so, will tell their children how important looking after your second set of teeth, since it is the only ones you have. As when they are lost then they are gone for good.
However, that is not really true anymore, since the new kind of era we are entering now means we can just grow them back! In fact new experimental procedures are coming on the stage now in dentistry where they are starting to do this a little. With new methods in treatments for fillings instead of drilling the teeth.
While this website is focusing on limb regeneration, I have been researching in other specific areas of regeneration including organ and breast regeneration. Regrowing breasts for women whom have had a single or double mastectomy, is also been done in clinical trials.
As far back as 2009 a project in Australia where a clinical trial was taking place, using the patient’s own stem cells to regenerate the lost breast using a scaffold matrix. As a new treatment instead of using silicon implants with have their own problems.
Again we can now make a lady whole and complete again. However, this procedure was a trial and I believe some women were a success but there were problems with others. So the trials were stopped until further advancements and understanding of the technologies in regenerating a women’s breast.
I am not familiar with the latest developments in stem cell reconstruction breast surgery for mastectomy patients. Apart from in 2014 a New Zealand women in her 60s, has had a new procedure to regenerate her left breast that was removed due to cancer.
In the media back in 2012 the celebrity Suzanne Somers whom lost a breast due to cancer, was the first woman in America to have the treatment with great success. She mentioned that she wanted to wait until the stem cell technology became available and not have the current silicon implants.