Our bodies are made up of cells and acellular structural materials produced by cells. Structural material may be boney or collagenous. This material serves as a latticework for the cells, giving them a collective shape or configuration.
Cells are microscopic, specialized living units made up of a nucleus with DNA, surrounded by organelles swimming in a sea of cytoplasm, which in turn is bordered by a membrane. These tiny living units exist to function in unison to benefit the body as a whole.
There are over 30 trillion (>30,000,000,000,000) cells in the human body!
But, we know that cells have a defined lifetime and will eventually die. (Thankfully not all at the same time.) In this circumstance, dying cells are replaced by newer cells produced by nonspecialized progenitor cells.
The job of progenitor cells also called stem cells, is to replace aged or damaged specialized cells. Stem cells are notable for the ability to divide into daughter cells, which can be either other stem cells or more specialized cells. This way, tissues can be repaired throughout life, and the body can continue to have a supply of new stem cells.
Where do stem cells come from?
Most tissues have a local cache of stem cells available to protect the integrity of organs. However, there are ready supplies of huge numbers of stem cells in the pelvis bone as a constituent of bone marrow which can mobilize to repair tissues at points distant. It is easy to access these cells via bone marrow aspiration.
As well, immense numbers of stem cells are available and stored in fat. But their natural duty is to produce more fat cells and arteries with attendant veins to feed the new fat cells when the body is laying down more fat. Those from fat are less potent and less capable than stem cells found in the bone marrow. We call them “progenitor” cells rather than stem cells because of their limited abilities. For example, patients having progenitor cells obtained from fat (“adipose-derived”) injected for joint pain may find great relief at first, then find that the effect fades after a few months.
Very potent, very capable adult stem cells exist in the interior walls of umbilical cords (“umbilical cord matrix”) which, instead of being discarded, can be processed to obtain stem cells immediately after birth of the baby. The Human Leucocyte Antigen (HLA) from newborn babies and their related placental tissue is underdeveloped, thus not causing “graft vs host disease” or tissue rejection to occur. We term this “immunologic privilege”. When grafting tissue, such as a kidney, from one adult human to another, we must determine an exact HLA match. This immunologic privilege prevents the mother from immunologically rejecting the baby’s tissues during pregnancy.
Here are the problems encountered when using umbilical cord stem cells:
- The processed stem cells must be cleared for infectious agents, like bacteria and viruses, such as HIV or hepatitis. Stem cell product contaminated with E. coli have been injected into joints in the past.
- After being successfully screened for infectious agents, the stem cells must be quickly utilized, or they will die. In order to prevent decomposition and death, the stem cell product is frozen and then sent to the point of use for implantation while remaining frozen, sometimes many thousands of miles away. The vial of stem cell product must then be thawed and immediately implanted into the host. A certain percentage of stem cells can and do die when undergoing the trauma of freezing, and again when thawed. If they survive those two traumas, how likely are they to be vigorous and survive in the host long enough to provide benefit?
- The answer to that question varies according to who you are talking to. Stem cell company representatives tell me that 60 to 80% of the stem cells are alive after being frozen and thawed. I have engrafted umbilical cord product and achieved great benefit for the patient without knowing whether the benefit is derived from stem cells or accompanying noncellular growth factors. I have never counted stem cells in any umbilical cord product I have received. I didn’t want to waste any of a 1 ml vial pour a bit of it on a wet mount to go under the microscope.
Autologous Stem Cell Transplantation
This term refers to extracting stem cells from a patient, concentrating them, activating them, then injecting them back into the same patient with the goal of promoting health benefit, such as rejuvenation of a joint.
There are two types of autologous stem cells, adipose derived and bone marrow derived. Either method has the advantage of ruling out the possibility of tissue rejection, since there is a perfect HLA match.
Adipose Derived Progenitor Cells
Actually, 50% of cells in fat, by number (not by volume), are progenitor cells.
Fat cells are large, bloated cells that are huge in comparison to the progenitor cells. One milliliter (cubic centimeter or cc) of fat can contain 500,000 to 1,000,000 progenitor cells . But after the stem cells are extracted from the fat, they constitute a tiny dab at the bottom of a test tube. This resultant product is referred to as “Stromal Vascular Fraction” or SVF.
And, that is what I noted in 2011 when I first took my stem cell training.
What is new, and a superior technique is that no test tubes are now used. Instead of a separate laboratory room adjacent to the surgical procedure room, a counter-top device is placed next to the operating table within the procedure room itself. The fat is placed aseptically in a sterile chamber within the separation device. It is processed automatically, within the closed system, separate from open air, and the prospect of contamination. Thus, the collection and extraction of adipose-derived progenitor cells is a surgical procedure, not unlike cosmetic fat transplantation procedures that have been conducted for the past 20 years or so.
After separation of the SVF has been achieved, it is mixed with platelet-rich plasma (PRP), a product produced by centrifugation of a sample of the same patient’s blood. This mixture of growth factors promotes “activation” of the stem cells.
The resultant product is then injected into a joint that needs revision, or intravenously if solutions to systemic maladies are sought.
This type of stem cell therapy is available in the United States now, but the FDA contends that it involves the production of a new drug, the SVF, and thus is under their jurisdiction. They don’t want doctors to do it. At this point in time, the issue is in litigation.
Bone Marrow Derived Stem Cells
Everyone has stem cells, and powerful ones, sequestered in the bone marrow. The largest cache by far of such stem cells is in the pelvis bone. When trauma occurs, the body is programmed to activate stem cells in the matrix of the pelvic bone and send them to the damaged tissue to promote repair.
Inserting a trocar or specialized needle into the posterior iliac crest allows access to bone marrow from different sections of the pelvic bone. Such a procedure typically harvests 20 ml of marrow, containing some 20 million stem cells, with removal from the bone causes “activation”.
What do you do with the raw bone marrow? In the past, the marrow is spun in a centrifuge and only a certain layer of the resultant spun product is used as the stem cell injectate. Although I suppose such a product could be used in a variety of ways, such as injected into a joint or into a scalp to promote hair growth, I have been trained to inject it into the penis to fix erectile dysfunction, and have not as yet used it in other tissues.
Current practice is not to centrifuge the raw bone marrow but to immediately inject it where it needs to go without further processing. The result for erectile dysfunction has been phenomenal. As of the date of this writing, I have not seen any reports about injecting it into the scalp or into a
joint, but I do not see any logical reason to preclude it.
Just remember, that stem cell therapy, and the use of other regenerative biologics are in their infancy, and we will see many advances continuing over the next few years.
1. The Wonders of Immune Privilege.
3. Berman MD, Mark; Elliot Lander MD. The Stem Cell Revolution. AuthorHouse.(2015)
5. Canadian Cancer Society, How a stem cell transplant works
6. Revolutionary stem cell therapy boosts body's ability to heal itself. The Guardian.