What part of the umbilical cord do your cells come from, and are they culture-expanded?

The mesenchymal stem cells isolated from this tissue are expanded in the laboratory, under controlled and hypoxic (low-oxygen) conditions, until they reach the dose your doctor prescribes. We do not use cord blood, amniotic fluid, amniotic membrane or your own (autologous) cells.

Patients who research stem cell therapy quickly learn that "umbilical cord stem cells" can mean several different products. The umbilical cord has different parts, each with different cell types, and laboratories process them in different ways. This guide explains which part of the cord we use, why, what "culture-expanded" means and why expansion is needed to reach a therapeutic dose.

The parts of the umbilical cord

The umbilical cord connects the baby to the placenta during pregnancy. After birth, it is usually discarded as medical waste, which is why donated cords are an ethical source of cells. The cord contains several compartments:

• Cord blood: the blood that remains in the cord and placenta. It is rich in hematopoietic stem cells, the cells that form blood. Cord blood is used in transplant medicine for blood disorders, and it is a different product from the one we use.
• Wharton's jelly: the soft, gel-like connective tissue that surrounds and protects the cord's blood vessels. It contains a high number of mesenchymal stem cells (MSCs).
• Blood vessels: the cord has two arteries and one vein. Some laboratories isolate cells from the tissue around these vessels.
• Cord lining: the outer membrane of the cord, closely related to the amniotic membrane.

At Stem Cell Mexico, we use only mesenchymal stem cells from Wharton's jelly.

Why Wharton's jelly?

Wharton's jelly MSCs have several characteristics that make them practical for regenerative treatments:

• They are young cells. They come from newborn tissue, so they have not been exposed to decades of aging, illness or medications, unlike cells taken from an adult's fat or bone marrow.
• They grow well in the laboratory. Wharton's jelly MSCs show strong proliferation capacity, which allows the laboratory to reach therapeutic doses from a donated cord.
• They have strong signaling activity. MSCs release growth factors, cytokines and extracellular vesicles that help regulate inflammation and support tissue repair.
• They have low immunogenicity. MSCs express low levels of the molecules that usually trigger rejection, which is why they can be used from a donor without matching blood type or tissue type.
• The collection is noninvasive for the donor. The cord is collected after birth, with consent, without any procedure on the mother or the baby.

A comparative study published in Scientific Reports in 2020 analyzed MSCs from different sources, including umbilical cord, bone marrow and adipose tissue, and found that cells from different sources share the core MSC features but differ in growth rates and in the factors they secrete. This is one reason why the source of the cells matters, and why we work with a single, consistent source.

What does "culture-expanded" mean?

A single umbilical cord contains a relatively small number of MSCs at the moment of collection. To treat a patient with tens or hundreds of millions of cells, the laboratory needs to multiply them. This process is called culture expansion.

Here is how it works, in simple terms:

1. Isolation: the Wharton's jelly is separated from the rest of the cord, and the MSCs are isolated from the tissue.
2. Culture: the cells are placed in sterile flasks with a nutrient medium and incubated at body temperature. MSCs naturally attach to the surface of the flask and start dividing.
3. Expansion: as the cells multiply, they are transferred to new flasks. Each transfer is called a "passage."
4. Quality control: before release, the cells are tested for identity, sterility and viability.
5. Preparation for your treatment: the cells are prepared in the dose your doctor prescribes, in the format needed for your route of application.

In the treatment proposals we send to patients, our cells are described as "mesenchymal expanded stem cells from ethically derived donated umbilical cord." They are grown under hypoxic, or low-oxygen, conditions. Low oxygen resembles the natural environment of these cells in the body, and the laboratory uses it to support cell health; in our proposals we describe viability of up to 98% at release.

Why expansion matters for your dose

Without expansion, it would not be possible to offer the doses used in our treatment plans:

• Joint applications: usually 20 to 40 million cells per treated area.
• IV infusions: usually 100 to 200 million cells.

These numbers are only reachable when cells are expanded in culture. Products that are not expanded, such as some minimally processed tissue preparations, often contain far fewer living MSCs, and some contain none at all once processed.

How scientists define a mesenchymal stem cell

The International Society for Cell and Gene Therapy (ISCT) published minimal criteria in 2006 to define a mesenchymal stromal cell. According to those criteria, the cells must:

• Adhere to plastic when grown in standard culture conditions.
• Express specific surface markers, CD73, CD90 and CD105.
• Lack markers of blood cells, such as CD34, CD45 and HLA-DR.
• Be able to differentiate into bone, cartilage and fat cells in the laboratory.

In 2019, the ISCT published a position statement on nomenclature that recommends describing these cells with their tissue source and their characteristics. These international criteria are the reference that laboratories use to confirm that a product contains MSCs.

Ethical donation

The cords used to produce our cells are donated voluntarily, with informed consent, after healthy full-term births. Collecting the cord does not change the delivery, and it does not involve any procedure on the mother or the newborn. Because the cord would otherwise be discarded, this source avoids the ethical concerns associated with embryonic stem cells. Our cells are not embryonic, and they do not come from fetal tissue.

Laboratory standards

In the information we share with patients, our partner laboratories are described as operating under Good Manufacturing Practice (GMP) and Good Laboratory Practice (GLP) standards, with ISO 9001 quality management systems. Each batch goes through screening, testing and quality control before it is released for clinical use. Donors are screened before their cord is accepted, including a medical history review and infectious disease testing.

The regulatory context

Regulations about culture-expanded cells vary by country. In the United States, the Food and Drug Administration (FDA) considers culture expansion to be more than "minimal manipulation." Under FDA rules, culture-expanded MSC products are regulated as biological drugs, and no umbilical cord MSC product has been approved by the FDA for orthopedic, neurological or anti-aging uses. This is one reason why patients from the United States travel to receive these treatments.

In Mexico, cell therapies are regulated by COFEPRIS, the federal health authority, and Stem Cell Mexico operates with the corresponding sanitary licenses. The International Society for Stem Cell Research (ISSCR) encourages patients to ask about the source of the cells, how they are processed and how the treatment is supervised, and we welcome those questions.

Common questions

Do you use cord blood? No. Cord blood contains a different type of cell, used for blood-related transplants.

Do you use amniotic fluid or amniotic membrane products? No. We use only Wharton's jelly MSCs.

Do you use my own cells? No. Our treatments use allogeneic (donor) cells, so there is no need to harvest fat or bone marrow from your body.

Are the cells changed genetically? No. Culture expansion multiplies the cells. It does not modify their genes.

Do I need to match the donor? No. MSCs have low immunogenicity, so blood type or tissue matching is not required.

Can I ask more technical questions? Yes. If you have specific questions about laboratory processing, you can raise them during your consultation with the doctor and the stem cell specialist.

Questions to ask during your consultation

• What dose is recommended for my condition, and why?
• How will the cells be applied, by direct injection, IV infusion or both?
• How are donors screened?
• What quality checks are done before the cells are released?

Bottom line

Stem Cell Mexico uses mesenchymal stem cells from Wharton's jelly, the connective tissue inside donated umbilical cords from healthy, full-term births. The cells are culture-expanded under controlled, low-oxygen conditions to reach the therapeutic doses your doctor prescribes, and they go through quality control before release. We do not use cord blood, amniotic products or autologous cells. Results vary between patients, and expansion does not guarantee a specific outcome, but it is what makes consistent, well-defined doses possible. A medical evaluation can help determine whether this type of regenerative treatment is appropriate for your condition, goals and medical history.