Stem Cell Basics

Stem cells are defined as undeveloped or unspecialized cells capable of duplicating or replicating themselves into any of the body’s cell types. That means that stem cells can become cartilage, bone, muscle, tendon, skin, etc. To the contrary, mature cells are permanently committed to their fate and can’t become other cell types. Stem cells enable the body to renew and repair its damaged tissues.

In this capacity stem cells also have the potential to treat diseases such of the neurological disorders, heart disease, or diabetes. This has opened the exciting field of cell-based therapies, otherwise known as reparative or regenerative medicine.

los angeles stem cell therapy

Types

Pluripotent means “many potentials”. These cells have the potential to mature into more than 200 different specialized cell types found within the body. Experts in the field, refer to three different types of pluripotent stem cells:

  1. Embryonic Stem Cells
  2. Adult or “somatic” Stem Cells
  3. Induced Pluripotent Stem Cells

Embryonic Stem Cells

Human Embryonic Stem Cells

Embryonic stem cells in use today are created from embryos generated by in-vitro fertilization (IVF). In this process, researchers mix male sperm, and female eggs together in a Petri dish. A number of eggs will thereafter become fertilized. After fertilization, the cells are allowed to divide for about five days to form a ball of cells referred to as a blastocyst. This is essentially a hollow ball of cells containing an inner clump of additional cells that is referred to as the inner cell mass.

Embryonic Stem_cells_diagram (sean younai's conflicted copy 2016-06-27)

The researchers remove the outer layer of the hollow ball blastocyst, and place the remaining inner cell clump (known as the inner cell mass) in a Petri dish containing biological factors that allows this inner cell mass to grow and thrive. These pluripotent cells can continue dividing indefinitely and are known as embryonic stem cells.

All of the embryos generated by in-vitro fertilization for use in embryonic stem cell lines, are donated by the couples for research purposes. People who donate embryos for research have gone through an extensive consent process to ensure they understand embryonic stem cell research under state, national and international regulations. No embryonic stem cell lines can be undertaken by scientists without explicit consent from the donors.

The theoretic advantage of embryonic stem cells is that they can form any type of cell in the body. The downside is that when implanted into an animal, these embryonic stem cells have shown the ability to form tumors known as teratomas. The potential for this tumor development is one of the reasons it is necessary to first mature embryonic stem cells into adult stem cells before attempting to implant them into humans.

Embryonic stem cells isolated from IVF embryos will have a genetic makeup that does not match the donor person who receives the stem cell transplant. Transplanted embryonic stem cells, like any transplanted tissue, can be recognized by the donor immune system as foreign, and then destroyed. The likelihood of immune system rejection of a transplanted embryonic stem cell tissue will depend on the origin of that tissue. Nonetheless, tissue rejection still remains a problem for embryonic stem cell treatment, as does tumor formation.

Stem Cell Nuclear Transfer (SCNT)

Another method for obtaining pluripotent stem cells is designated stem cell nuclear transfer (SCNT). This involves removing the genetic material from a donated egg, then inserting a different set of genetic material from another adult person into that egg. This egg is then stimulated to begin dividing. After approximately five days this egg has developed into the blastocyst form as previously discussed above in the embryonic stem cell discussion. Once again, the outer layer of the blastocyst is removed, and the inner cell mass is placed in a Petri dish, creating a new embryonic-type stem cell line, but this time identical to the adult person’s genetic material that had been placed into the egg. The process of using nuclear transfer allows for the creation of an embryonic pluripotent stem cell line genetically identical to the donor who will be receiving the stem cell transplant.

Embryonic stem cells created through SCNT have the advantage of being genetically identical to a person’s own cells, therefore reducing the risk of immune rejection.

As in the use of any embryonic stem cell, the risk of tumor formation still exists.

Induced Pluripotent Stem Cell (iPSC)

An induced pluripotent stem cell, or iPSC, is a taken from an adult (usually skin or blood) and is genetically modified to function thereafter exactly like an embryonic stem cell. These new cells will then be pluripotent, and have the ability to form all types of adult cells.

ips-cells

Human iPS cells are created by inserting four transcription genes into the DNA of human skin cells. This is accomplished utilizing a virus to transport the genes into the skin cell, which then integrates into the cell’s DNA structure. These induction genes effectively revert the skin cells back to an embryonic-like state rendering them pluripotent, and therefore, having the ability to once again form all adult cell types.

The human iPS cells created have the advantage of being genetically identical to the donor’s own cells, reducing the risk of immune rejection.

The disadvantage of the iPS cells is that integration of the gene segments into the cell’s DNA could possibly cause hazardous mutations. Additionally, the risk of tumor formation and cancer-causing potential remains.

Use of Embryonic Pluripotent Stem Cells in Our Clinic

Our clinic does not utilize embryonic/pluripotent stem cells when treating patients. There are multiple reasons for this, including the political and moral controversy surrounding their use in medicine, because cells are taken from unborn embryos. Additionally, the possibility of tumor development, immune system rejection, and theoretic possibility of mutations continues to exist.

Our practice only utilizes adult stem cells which are multi-potent, and have not been demonstrated to cause tumors, and do not result in immunogenic rejection. Additionally, as the adult stem cells are harvested from the individual donor themselves, there is no concern for communicable disease transmission.

Adult Stem Cells / Somatic Stem Cells

An adult stem cell is an undifferentiated cell that lives among differentiated mature cells in most tissues or organs of the body. Also known as somatic stem cells are kept in quiescence until activated to help repair damaged tissue or regenerated lost tissue.

Click Here to Learn More

Multi-potent adult stem cells can be harvested from the donor’s own body (autologous stem cells); or can be harvested from other sources such as umbilical cord blood, the placenta, or amniotic fluid (allogenic stem cells).

Allogenic Stem Cell Harvesting

Umbilical cord, placenta, and amniotic tissue is still considered a type of adult stem cell as it is multi-potent, not pluripotent. In the past there has been a negative connotation to utilizing this type of tissue as it has been connected with abortion, which has made use of these types of stem cells controversial, and many laws have been passed regulating how these types of stem cells could be harvested and used. Most clinics to date, only use ethically harvested stem cell umbilical cord blood, placenta, or amniotic fluid taken from healthy delivered babies.

Use of Allogenic Stem Cells In our clinic

Utilizing umbilical cord blood, placenta, or amniotic fluid, still presents possible difficulties with communicable diseases. Additionally, as the stem cell source does not come from the patient being treated, the possibility of immune rejection still remains. For these reasons, our practice does not utilize allogenic stem cells such as umbilical cord blood, placenta, or amniotic fluid.

Autogenous Stem Cell Harvesting

Adult stem cells already reside within one’s own body, within different tissues. These undifferentiated cells have the ability to replace dying and injured cells. These specialized cells have the ability to seek out areas of injury, disease, and damage where they are capable of replacing or rejuvenating healthy cells, and enhance the patient’s natural healing processes. These adult stem cells come from the mesodermal section of your body, and are designated “mesenchymal stem cells”. These mesenchymal stem cells (MSCs) can differentiate into bone, cartilage, as well as other mesodermal elements, including fat, connective tissue, blood vessels, muscle, and nerve tissue.

Adult stem cells can be extracted from several areas of the body, including bone marrow, adipose tissue (fat), and peripheral blood. Once these cells have been appropriately harvested, they are sent to the lab where they are purified and assessed for quality before being reintroduced back into the patient. Since these stem cells come from the patient’s own body, there is no possibility for rejection, introduction of communicable diseases, or formation of tumors. Published studies have demonstrated these stem cells also secrete peptides and various proteins that stimulate healing of damaged tissue.

Experimental studies suggest that adipose derived stem cells not only can develop into new tissues, but also suppress pathological immune responses, as seen in autoimmune diseases.

Bone Marrow Stem Cells

infog-auto1The bone marrow stem cell is the most studied of the stem cells, since it was first discovered in the 1976. It was originally used in bone marrow transplant for leukemias. However, numerous studies have now expanded the use of these cells for conditions, such as peripheral vascular disease, heart disease, and other degenerative disorders.

To perform bone-marrow-derived stem cell injections, the bone marrow is first extracted from the iliac crest pelvic bone. The area of the body is sterilized and numbed, but nonetheless it can be painful. This extraction will only yield, however, about 50,000 adult mesenchymal stem cells. Research has indicated that the success of treatment is directly related to the quantity of stem cells injected. Therefore, to increase the cell numbers, the bone marrow aspirate is cultured over several days/weeks to arrive at a final count of a few million stem cells, which can then be injected back into the patient at a later date. Because of the relatively small mesenchymal stem cell numbers obtained; the need to culture these cells over several days/weeks; the required several week time span between harvesting of the bone marrow cells and their eventual deployment into the patient; our practice does not utilize bone marrow stem cell treatment.

Adipose Derived Stem Cells (ADSC)

Cosmetic-Para-ImageMesenchymal stem cells (MSC’s) were first discovered in 1976 from bone marrow. Since that time, additional sources for MSC’s discovered in the laboratory include adipose tissue, pericyte, synovial membrane, and so forth. The discovery of these alternative sources of MSC’s helps widen the application of these cells in different areas of medicine. Recent technological breakthroughs enable us to now use adipose (fat) derived stem cells. Autologous stem cells (from a person’s own fat) are easy to harvest safely under local anesthesia and are present in abundant quantities. The multi-potent stem cells within adipose tissue are one of the most promising stem cell populations identified thus far, since human adipose tissue is ubiquitous and easily obtained in large quantities with little donor site morbidity or patient discomfort. The harvesting procedure generally lasts a few minutes, and can be done under local anesthesia. The stromal vascular fraction (SVF) which contains mesenchymal cells and growth factors, is processed from 2 ounces of fat using a closed sterile system to avoid contact with the environment. SVF is ready for deployment into the patient within 90 minutes or less.

The harvesting process yields approximately 500,000 to 1,000,000 stem cells per cc of fat, and therefore it is possible to obtain as much as 10 to 40 million cells from a single treatment. This is up to 2,500 times the quantities seen in bone marrow.

Because of the much higher number of cells harvested from adipose tissue compared with bone marrow; the current research indicating that success of treatment is directly related to the quantity of cells injected; the minimally invasive liposuction-type harvesting procedure to obtain these stem cells; and the ability to harvest and deploy these stem cells during the same procedure; our practice exclusively utilizes adipose derived stem cells in the treatment of degenerative orthopaedic and spinal conditions.

How Stem Cells Heal Damaged Tissue

img_fatGrafting10Stem cells are defined as undeveloped biological cells capable of proliferation, self-renewal, and conversion to differentiated cells. To date, there have been numerous scientific publications demonstrating that adipose-derived stem cells (ADSC’s) possess the potential to differentiate toward a variety of cell types. ADSC’s can differentiate into fat, bone, cartilage, muscle, tendon, vessel, and dental lineages. It has also been demonstrated that ADSC’s can differentiate into neuro-precursor cells under appropriate culture conditions.

It has progressively become clear that mesenchymal stem cells (MSC’s) could be the basis for a natural system of tissue repair. Multiple studies have shown that the ability of adipose derived MSC’s to repair is secondary to the secretion of various soluble factors by the MSC’s which then alter the tissue microenvironment. In other words, these adipose derived MSC’s provide a “trophic activity” (mediated by the actions of various cytokines and growth factors) capable of manipulating a broader range of biological functions.

Overall, it is not yet entirely clear whether the adipose derived adult stem cells change into the type of injured tissue needed for repair; if they send out signals that induce the repair by some other mechanism; or by a combination of both factors.