Stem cells: what they are and their values?

Stem cells: what they are and their values?
Stem cell is the type of cell of the body which is the youngest and undifferentiated cell. It has the ability
to differentiate into any kind of cell of the human body. Stem cells can divide further into more daughter
cells under proper conditions. The daughter cells have the property of self-renewal to become new stem
cells and can regrow into specialized cells having a specific function as for example blood cells, heart
muscle cells, brain cells, etc.
Types of stem cells
Stem cells can be divided on the basis of two categories – source and potency.
According to the source, the stem cells can be divided into 3 types of stem cells – embryonic stem cells,
fetal stem cells and adult stem cells.
1. Embryonic stem cells – The name itself suggests that these stem cells are obtained from
embryos. These stem cells are the inner mass cells of the blastocyst. Embryonic stem cells are
pluripotent and can develop into any type of cell in the embryo. This potential of stem cells gives
rise to the development of more cells to the embryo which then grows into a baby.
2. Adult stem cells – Adult stem cells are the undifferentiated cells that are found in a human
body and have the ability to replace the damaged cells and regenerate the tissues. These stem
cells are also known as somatic stem cells and are found in children as well as human adults.
These stem cells can be isolated from the adults and can be grown in laboratory so that they can
be used for stem cell therapy of the patient. The adult stem cells can be extracted from any part
of the body but the bone marrow contains huge amount of stem cells
However, extraction of bone marrow is very painful, so researchers have found that stem cells
can also be extracted from umbilical cord blood and tissue which is the richest source of stem
cells
3. Foetal stem cells – Cells derived from a Foetus that retains the ability to divide, proliferate and
provide progenitor cells that can differentiate into specialized cells. The embryo is referred to as
a foetus after the eighth week of development. Once a foetal stem cell has been harvested, it
has the potential to live indefinitely in the laboratory. Foetal stem cells can be isolated from
foetal blood and bone marrow as well as from other foetal tissues, including liver and kidney.
Cell potency is the ability of the cells to differentiate into other types of cells. Greater the potency of the
cell more is the ability of a cell to differentiate into different cell types. According to potency, cells can
be divided into 5 types.
1. Totipotent

• Totipotent stem cells are the most powerful stem cell
• They can differentiate into embryonic cells and tissues
• Have the ability to develop into a living organism
• e.g. fertilized egg
2. Pluripotent
• These stem cells are having the ability to renew itself
• They can differentiate into 3 germ layers – ectoderm, endoderm and mesoderm
• Also, can develop into any kind of tissues or organs
• e.g. embryonic stem cells
3. Multipotent
• Multipotent stem cells possess the ability of self-renewing
• They can different into a specific kind of cell
• e.g. mesenchymal stem cells
4. Oligopotent
• Oligopotent stem cells have the self-renewing capability
• Restricted to differentiate into closely related cell types
• e.g. hematopoietic stem cell

5. Unipotent
• This stem cell is the least effective
• Have the power to differentiate only into a particular cell type.
• e.g. muscle stem cells
Benefits of stem cells
You may be wondering that despite so many other treatments what are the umbilical cord stem cell
benefits. Overall, the general benefits include minimal risk, minimal recovery time and minimum
concern because stem cell therapy uses biological material (cord blood stem cells) obtained directly
from the newborn baby. Here are five more specific advantages.
• Collection – Collection of cord blood from the umbilical cord is painless and risk-free method.
The cord blood is then processed and the stem cells are harvested in the laboratory.
• Outcomes of transplantation – During transplantation of cord blood stem cells, there is less
chance of rejection and the body of the recipient accepts it easily.
• Differentiative property – As the cord blood stem cells are young and undifferentiated so they
have the potential to regenerate themselves into any type of cells of the body.
• Storage – cord blood stem cells can be stored for lifetime in a maintained temperature (-190°C)
and in a particular freezer containing liquid nitrogen.
• Infection – When infused into the body of patient cord blood stem cells possess less chances of
having any type infection.
“Stem cells can be extracted from both cord blood and cord tissue.”

Cord blood
Cord blood (umbilical cord blood) is blood that remains in the placenta and in the attached umbilical
cord after childbirth.
Cord blood is made up of these components - Red blood cells, Blood, Plasma, platelets, which are found
in the whole blood. In comparison with the whole blood, there are some differences in the cord blood,
such as the cord blood contains more natural killer cells, lower absolute numbers of the T-cells and a
higher immature T-cells are available. However, it is mainly the observation that cord blood contains
various types of stem and progenitor cells, mostly hematopoietic stem cells, that contributes to the
interest of cord blood. Many non-hematopoietic stem cell types are also present in cord blood, such as
Mesenchymal stem cells, but in a lesser amount than bone marrow. Cord blood can also include
endothelial progenitor cells and multipotent adult stem cells. Cord blood stem cells are frequently
confused with embryonic stem cells. Cord blood stem cells are the type of adult stem cells which is
different from the embryonic stem cells.
• Use of cord blood
Cord blood is used the same way that hematopoietic stem cell transplantation is used to
reconstitute bone marrow following radiation treatment for various blood cancers, and for
various forms of anaemia. Its efficacy is similar as well.
• Diseases treated by cord blood stem cells
Cord blood is rich in hematopoietic stem cells those are pluripotent that means they have the
potency to regenerate themselves into any kind of cell of the body. The hematopoietic stem
cells can treat diseases related to blood and immune system such as leukaemia, anemia, SCIDs,
hypoplasia, etc.

Cord lining
The outermost layer of the umbilical cord is known as cord lining, umbilical cord lining and cord tissue.
The umbilical cord itself is an extended part of the placenta and is a prolongation of the amniotic
membrane which covers the placenta. The cord tissue membrane is made up of the amniotic layer
which the epithelial layer and the sub-amniotic layer which is the epithelial layer. Umbilical cord tissue is
the rich source of two types of stem cells, the epithelial stem cells and the mesenchymal stem cells.
• Use of cord lining
Mesenchymal stem cells have enormous potential to heal and cure different diseases in
damaged tissues and organs. EpSC forms the soft tissue that binds, protects and covers the
cornea, skin and liver of other body structures and organs. MSCs are the building blocks of bonecartilage,
muscle, fibrous tissues and fat tissues in our body.
• Diseases treated by stem cells harvested from cord lining
The cord lining also contains stem cells as it is the rich source of mesenchymal stem cells (MSCs)
and epithelial stem cells (EpSCs). These mesenchymal stem cells can help in treating diseases
such as autism, multiple sclerosis, spinal cord injury and epithelial stem cells help in treating
diseases related to skin, the cornea of the eye, etc.
Cord blood collection method and storage
Once your baby is born and separated, the umbilical cord is clamped and then the cord blood is
collected in a single-use sterile 250mL blood bag. This cord blood along with cord tissue and mother’s
blood sample is then kept in the Kit box which is transported to the storage laboratory by maintaining a
controlled temperature. In the laboratory, the cord blood is processed by an advanced automated
technology known as AXP®II for harvesting hematopoietic stem cells. These stem cells are then stored in
compartmentalized cryopouches at -190°C in liquid nitrogen. This complete method of collection,
processing and storage is known as cord blood banking.

Reasons for choosing cord blood stem cells for treatment
Children with blood-related disorders such as leukemia and inherited blood diseases like Fanconi's
anemia are used for the treatment of cord blood. The patient who is suffering from these types of
diseases is first provided with chemotherapy to destroy the damaged and diseased cells of the body.
Then the young and undifferentiated stem cells are infused into the body of the patient. These stem
cells can treat diseases by regenerating themselves into daughter stem cells which further replace the
damaged cells of the body to repair the tissues and organs.
Therefore, cord blood provides a beneficial option for patients when compared to bone marrow
transplants. The process of collection of cord blood is easier than bone marrow and can be stored when
frozen. The risk of immune failure and infections, including Graft and Host Disease, often seems less
than bone marrow. This means that cord blood does not need to be as perfectly matched to the patient
as bone marrow.
Nevertheless, there are also restrictions on cord blood transplants. Cord blood care for adults usually
requires two cord blood units for treatment. Clinical studies using adult dual cord blood transplantation
have shown similar results to other HSC sources, like bone marrow or peripheral blood mobilized. There
are currently experiments to extend a single blood cord for adult use.