Stem cells are cells that do not have a specific role in the body like a blood or nerve cell.
They can instead transform into almost any cell that is required.
”Stem cell research is the key to developing cures for degenerative conditions like Parkinson's and motor neuron disease from which I and many others suffer.Stephen HawkingPhysicist
Sources of Stem Cells
Stem cells originate from two main sources: embryos and adult body tissues.
They begin their work as you are growing in your mother’s womb and are present throughout your life.
Scientists are also working on ways to develop stem cells from other cells, using genetic “reprogramming” techniques in a process called iPSC.
Adult Stem Cells
Adult stem cells, also known as somatic stem cells, are undifferentiated cells found throughout the body that divide to replenish dying cells and regenerate damaged tissues.
Adult stem cells are able to divide or self-renew indefinitely and generate all the cell types of the organ from which they originate — potentially regenerating the entire organ from a few cells.
They remain in a non-specific state until the body needs them for a specific purpose, say, as skin or muscle cells.
Stem cells are present in many types of tissue. Scientists have found stem cells in tissues, including:
- the brain
- bone marrow
- blood and blood vessels
- skeletal muscles
- the liver
Stem cells can be difficult to find. Until the body summons them to repair or grow new tissue they can stay non-dividing and non-specific for years.
Adult stem cells can divide or self-renew indefinitely. This means they can generate various cell types from the originating organ or even regenerate the original organ, entirely.
This division and regeneration is how a skin wound heals, or how an organ such as the liver, for example, can repair itself after damage.
Scientists now suggest that adult stem cells are able to differentiate to become other cell types, whereas in the past they were believed to only have the ability to differentiate based on their tissue of origin.
Unlike embryonic stem cells, the use of adult stem cells in research and therapy is not controversial because the production of adult stem cells does not require the destruction of an embryo.
Embryonic Stem Cells
Embryonic stem cells are the Swiss Army knife of regenerative science, these cells are harvested in the early fetal stage and have the unique characteristic of pluripotency, meaning that they can turn into any one of more than 200 tissue types.
Embryonic stem cells are harvested at the very early pregnancy stage as the embryo takes the form of a blastocyst, just 3-5 days after fertilisation.
Embryonic stem cells are present when the blastocyst is 4-5 days old.
When scientists take stem cells from embryos, these are usually extra embryos that result from in vitro fertilization (IVF).
Hematopoietic Stem Cells (HSCs)
Hematopoietic Stem Cells (HSCs) are derived from babies’ umbilical cords and are collected after birth via a non-invasive procedure.
Most of the cells are precursors for blood and immune cells, so they aren’t as versatile as embryonic stem cells.
They can be frozen in cell banks, like Blueprint Biobank, for use in the future.
These cells have been successfully used to treat children with blood cancers, such as leukaemia, and certain genetic blood disorders.
Cord-blood stem-cell transplants have become a viable alternative to bone-marrow transplants in treating blood disorders like leukemia, especially when a bone-marrow match can’t be found.
Mesenchymal Stem Cells (MSCs)
Mesenchymal stem cells (MSCs) can be found in umbilical cord tissue and go on to form a person’s nervous system, sensory organs, circulatory tissues, skin, bone, cartilage and more.
MSCs collected from cord tissue are multipotent, meaning they have the ability to regenerate and differentiate into many different types of cells.
This important characteristic means that they could potentially be used to treat more conditions than cord blood alone can treat.
MSCs treatments are being developed to help repair bone and cartilage, such as injuries to the knee meniscus or long-term accumulated damage that leads to osteoarthritis, Autism, Alzheimer’s, Diabetes, Parkinson’s just to name a few.
Studies are further investigating reports that show MSCs help new blood vessels form in damaged tissue. This could have major implications for fixing tissue damaged by heart attacks and diseases.
Researchers are also examining the ability of MSCs to reduce inflammation, slow the progression of autoimmune diseases and prevent transplant rejection.
Induced Pluripotent Stem Cells (iPS)
These cells are as close as you’ll get to a fountain of youth.
Induced Pluripotent Stem Cells’ (iPSCs) potential has only recently been discovered by scientists.
By inserting genes responsible for embryonic pluripotency into adult skin cells effectively rewinds their developmental clock and gives them embryonic-like powers to morph into heart, cardiac and other tissue types.
An added bonus: No embryos necessary.
Types of Stem Cells
Stem cells are categorised by their potential to differentiate into other types of cells.
Embryonic cells are the most potent as it’s their job to form every cell in the human body to make you.
Totipotent: Totipotent (omnipotent) stem cells can transform into any of the 220 cell types found in an embryo as well as extra-embryonic cells (placenta).
Pluripotent: Pluripotent stem cells can give rise to all cell types of the body (but not the placenta).
Multipotent: Multipotent stem cells can differentiate into a number of cells, but only those of a closely related family of cells. These are true stem cells but can only differentiate into a limited number of types. For example, the bone marrow contains multipotent stem cells that give rise to all the cells of the blood but not to other types of cells.
Oligopotent: These can differentiate into a few different cell types. Adult lymphoid or myeloid stem cells can do this.
Unipotent: Unipotent cells can produce only one cell type, their own, but have the property of self-renewal, which distinguishes them from non-stem cells. Such Unipotent cells include muscle stem cells.
Embryonic stem cells are considered pluripotent instead of totipotent because they cannot become part of the extra-embryonic membranes or the placenta.
Uses of Stem Cells and Research
One of the most important uses of stem cells is for tissue regeneration.
Until today, people needing a kidney or blood would have to wait to find a matching donor, if ever one is found that is.
Donor organs are in shortage but, by using stem cells such as those found in umbilical cord tissue to differentiate in a certain way, scientists could use them to grow a specific tissue type or organ.
Doctors have already grown human skin from human embryonic stem cells which could provide an unlimited resource for temporary skin replacement in patients with large burns who are waiting for autologous skin grafts.
Cardiovascular Disease Treatment
In 2013 it was reported that scientists had created blood vessels in laboratory mice, using human stem cells.
Within 2 weeks of implanting the stem cells, networks of blood-perfused vessels had formed. The quality of these new blood vessels was as good as the nearby natural ones.
It is hoped that this type of technique could eventually help to treat people with cardiovascular and vascular diseases.
Brain Disease Treatment
Soon, doctors may be able to use stem cells to treat brain diseases such as Parkinson’s and Alzheimer’s.
In Parkinson’s, for example, damage to brain cells leads to uncontrolled muscle movements.
If stem cell therapy research is successful, using stem cells as a source of transplantable dopamine-producing nerve cells could revolutionize the care of Parkinson’s patients in the future.
A single surgery could potentially provide a transplant that would last throughout a patient’s lifespan, reducing or altogether avoiding the need for dopamine-based medications.
Cell Deficiency Therapy
Scientists hope one day to be able to develop healthy heart cells in a laboratory that they can transplant into people with heart disease.
Cardiovascular heart disease is the cause of 17 million deaths worldwide every year.
The effects of heart attacks cause damage to the heart muscle thereby making it less efficient at pumping blood through your circulatory system.
Current treatments for heart failure focus on managing symptoms (like reducing blood pressure) but do not address the root problem.
Stem cells offer ways to replace damaged heart tissue. Using cellular therapy, researchers hope to repair or replace heart tissue damaged by congestive heart failure and heart attacks.
Cellular therapy could provide a durable treatment for heart deficiencies, rather than symptom-focused treatment.
Blood Disease Treatments
Blood stem cells (HSCs) like the kind found in umbilical cord blood and bone marrow, are routinely used by doctors in the treatments of Leaukaemeias, anaemia and other immunodeficiency disorders.
The blood stem cells in your body need to make just the right number of each type of blood cell to keep the body healthy.
This carefully controlled process may result in a blood disease such as leukaemia or anaemia if something goes wrong in the process.
This is why blood stem cells (HSCs) are used in the treatments of such diseases in the form of a blood infusion usually from a donor if one can be found or from the patients own umbilical cord blood.
Stem cells are currently being used to treat certain neurological conditions such as Cerebral Palsy.
Cerebral Palsy is a neurological disorder caused by a non-progressive brain injury or malformation that occurs while the child’s brain is under development. Cerebral Palsy primarily affects body movement and muscle coordination.
Some patients, such as Patrick Rooney in the video below, have used their banked umbilical cord blood stem cells to treat their condition via an infusion.
Patrick made a full recovery.
Using Stem Cells to Test New Drugs
Researchers are also using differentiated stem cells to test the safety and effectiveness of new medications.
Testing drugs on human stem cells eliminates the need to test them on animals.
Donating and Harvesting Stem Cells
People donate or harvest stem cells for their own future use or to help others.
Stem cells can be harvested from the following sources:
Bone marrow: While you are under anaesthesia, a needle will be inserted into your rear pelvic bone where a large quantity of bone marrow is located. The bone marrow will be extracted with a syringe and then isolate the stem cells.
Peripheral cells: The peripheral blood stem cell collection involves having a course of injections to stimulate the bone marrow and release stem cells and white blood cells in the blood. Next, a specialised machine will separate the stem cells from the blood before returning the blood back into the body.
Umbilical cord blood: Stem cells can be collected from the umbilical cord blood after birth via a non-invasive procedure, making it 100% safe for the baby and mother. These stem cells are often cryogenically frozen ready for future use in treatment.
Stem Cell Controversy
Use of Embryos for Research
Embryonic stem cells offer hope for new therapies, but their use in research has been hotly debated. Different countries have chosen to regulate embryonic stem cell research in very different ways.
The argument against using embryonic stem cells is that it destroys a human blastocyst, and the fertilized egg cannot develop into a person.
Nowadays, scientists are looking closely at producing stem cells without the use of embryos, for example via Induced Pluripotent Stem Cells (iPS).
Mixing Humans and Animals: Hybrids
A medical breakthrough was made in 2017 in which scientists were able to create the second successful human-animal hybrids: sheep embryos that are 0.01-per cent human by cell count.
This research is bringing researchers one step closer to being able to grow human organs for transplant.
Some people argue that this could create an organism that is part human.
Do Stem Cell Beauty Cosmetic Products Really Work?
Extracts of stem cells – almost always from plant cells – have become a popular beauty ingredient in recent years, with claims that their use can offer such benefits of reducing wrinkles, repairing elastic, and even regenerating cells.
The truth is, these products do not work as claimed; they simply cannot deliver the promised results.
They are likely to have no effect at all because stem cells must be alive to function as stem cells, and by the time these stem cells are added to skin care products, they are long since dead and therefore useless.