Embryonic vs Adult Stem Cells - A Comparison

Embryonic and adult stem cells -- though both stem cells -- are uniquely different and should not be confused with each other. In addition to differences at a cellular level, the two are at very different stages of understanding, research, and clinical use.

One is stringently regulated, in the early stages of research, not used in treatments and won’t be for years, and raises several ethical questions.

The other is FDA compliant, has a large body of research and trials under its belt, has been used in treatments for decades, and raises no ethical dilemmas.

Embryonic stem cells may have potential for the future. Adult stem cells are helping people today.

Here, we attempt to emphasize the very large differences between embryonic and adult stem cells for people who may be considering stem cell therapy.

Key Differences Between Embryonic & Adult Stem Cells?

Embryonic stem cells and adult stem cells have a lot in common. As stem cells they both possess the amazing gift of differentiation and dividing. But there are significant differences, too.

Source: Embryonic stem cells are derived from donated, in vitro fertilized (IVF) eggs, and the process to obtain the embryonic stem cells destroys the human embryo. As a result, the process is laden with controversy. Adult stem cells, like mesenchymal stem cells (MSCs), are not taken from an embryo but from the person to be treated, and when taken from the same person, no harm is done -- thus, no controversy exists.

Autologous vs Allogeneic: Second, embryonic stem cells are -- as implied above -- derived from another person. That makes it an allogeneic transplant. When these “foreign” stem cells are injected into another person for treatment, the recipient body will reject them and further complications may occur. Meanwhile, adult stem cells -- as mentioned above -- are taken from you and then injected back into you. This is an autologous transplant and the risk of allergic reaction or rejection of the stem cells is virtually zero.

Potency: Embryonic stems cells are desired for research in spite of the controversy surrounding them because they can divide perpetually into more stem cells, and they have the potential to become any type of cell in the body. They are pluripotent. Adult stem cells are multipotent with the ability to develop into more than one cell type. Technically they are more limited in differentiation ability than embryonic stem cells. But they can differentiate into every cell type relevant to orthopedic conditions, and they do so naturally, in response to the signals present in the adult human body.

Stage of research: Embryonic stem cell research is still in the early stages. Therapies derived from embryonic stem cells have not been approved by the Food & Drug Administration (FDA) and are not in use -- except for some clinics outside the United States claiming erroneously and dangerously that their embryonic stem cell therapies cure incurable diseases. Adult stem cells, particularly MSCs taken from a person’s own bone marrow, are widely used in legitimate therapies to treat many injuries and conditions.

Do Embryonic & Adult Stem Cells Address the Same Types of Diseases and Medical Conditions?

In research conditions, embryonic stem cells can be carefully manipulated in the lab to become different types of cells. But when placed in a lab animal, they can change and may not differentiate as directed, creating negative reactions like fast-growing tumors. While they may have the potential to address a wider range of diseases and disorders than adult stem cells, embryonic stem cells cannot yet be used safely and effectively to treat any medical conditions.

Some may say that adult stem cells are more limited in their ability to treat disorders and diseases, because adult stem cells can differentiate only into a certain number of cell types. For instance, MSCs from bone marrow can differentiate into bone, muscle, and cartilage. This makes them helpful in almost all orthopedic conditions and injuries. But MSCs have some incredible advantages over embryonic stem cells: they come from the same patient they treat, and they know how to do the right thing in that patient. These qualities make them immeasurably more useful and flexible in clinical use than embryonic stem cells.  

Hematopoietic stem cells from various sources are used to address blood disorders such as leukaemia and lymphoma. MSCs cannot be used to treat blood disorders, and hematopoietic stem cells cannot be used to treat orthopedic conditions.

Which Patients Are Best Suited for Stem Cell Therapy?

Patients are best suited for stem cell therapy if their illness or medical condition is one that can be safely and effectively treated by clinically proven stem cell therapies (e.g., hematopoietic stem cell therapy to treat some blood disorders and bone marrow concentrate (BMC) therapy to treat some osteo- or muscular-related disorders or injuries).

These patients may have tried other methods of treatment without much benefit. There may also be physical or mental limitations that make invasive treatments less ideal for some patients.  

But patients best suited for stem cell therapy may simply be patients who want a treatment which has proven to be effective, safe, and less invasive than the alternatives.

Are Stem Cell Therapies & Research Regulated by the FDA?

The FDA regulates medical devices, drugs, and biologics. The FDA considers all products containing live human cells or tissues to be biologics or drugs, and requires stringent regulation of such therapies. However, regulators recognize that a physician may move a patient’s own tissues from one location to another, within the same patient, to treat certain conditions. As such, the FDA has created a set of requirements which allow a physician to use a patient’s own cells or tissues without them being considered a drug or biologic. The cells or tissue must be:

  1. Minimally manipulated

  2. Implanted in the patient who donated them

  3. Serving the same purpose in their implant location as they served in the donor location

  4. Used in a single surgical procedure (i.e. can’t be frozen or stored and used later)

  5. Not combined with active chemical or biological agents

Judgment of minimal manipulation is at the FDA’s discretion, but they have made public statements indicating certain processing techniques which do and do not qualify. When stem cells are manipulated, then there is potential for consequences and risks. Therapies using manipulated embryonic stem cells, for instance, must proceed via clinical trials that can take years to ensure safety and efficacy.

Embryonic stem cells, therefore, are heavily regulated by the FDA because they are created and manipulated in a laboratory and that manipulation goes beyond minimal.

Stem cell therapies using MSCs derived from bone marrow (a procedure called bone marrow concentrate or BMC) are considered a part of the practice of medicine as long as they adhere to the requirements mentioned above.

The stem cells are not manipulated or tweaked in anyway but are concentrated. As such, the FDA considers them safe for physicians to use at their discretion.

 FDA regulations hope to prevent unwarranted claims that various stem cell therapies can treat illnesses or conditions when there is actually no proof that it can. Fortunately, BMC stem cell therapies using MSCs for bone, muscle, tendon, and/or joint treatment are fully FDA compliant, use FDA regulated devices, and are supported by decades worth of published clinical use.

Cord blood stem cells are heavily regulated by the FDA because they are taken from blood found in the umbilical cord and placenta following childbirth. These cells can technically be stored for some time, require manipulation in the lab, and may also be used in therapy for someone other than the person from whom the cord blood originated. There are currently no FDA approved cord blood therapies with live stem cells. Some cord blood products do exist, but their cells have been killed by the sterilization process in their originating lab. They depend upon the leftover proteins, which are less active versions of the proteins found in PRP, for their therapeutic action.

How Many People Have Been Helped by Stem Cell Therapy?

It is difficult to track every person who has benefited from safe, effective stem cell therapy. When it comes to adult mesenchymal stem cells from bone marrow, patients have been receiving this therapy in and out of clinical studies for more than 30 years now. Physicians and researchers have been tracking clinical publications of this therapy. From their efforts we know that 10,000 patients’ worth of safe and effective treatment were published between 1997 and 2018. And that only accounts for patients whose experiences were published, which is a tiny fraction of the number of patients who received this type of therapy.

We also know that no one has benefited from embryonic stem cell therapies, because they are not legally available in the United States. Embryonic stem cell research and trials are underway, but it’ll be years before they are in clinical use.

On the contrary, thousands of people annually are treated with and benefit from adult stem cell therapies using MSCs. These stem cell therapies have been offering promising results in regenerative medicine for decades. Adult stem cells also continue to be studied and are undergoing thousands of other clinical trials so that the stem cell therapies of today may multiply to benefit many more people tomorrow.