Before we deep-dive into the topic, have a look at the TED talk below.

Broadly speaking, Stem cells is a naïve/immature/unspecialized cell that can 

i. divide to form similar cells (self renewal) and

ii. develop into different specialized cells that perform distinct function

A. Classification of Stem Cells

Depending on their ability (potency) to develop into different specialized cells, stem cells can be

• Totipotent – can form all cells of the body including the ones in the extra embryonic membranes (placenta). In humans, the 2 cell staged zygote is totipotent
• Pluripotent – can become virtually any cell in the body except those needed to support and develop a fetus in the womb
• Multipotent(limited ability to differentiate) -can give rise only to a small number of different cell types. Eg. bone marrow contains multipotent stem cells that can give rise to all blood cell types but not other cells.   
• Unipotent – Found in adult tissues, unipotent stem cell has the lowest differential potential of all the stem cells.

Depending on from where they come from different places in the body or are formed at different times in our lives. These include

 Embryonic stem cells (ESCs) which exist only at the earliest stages of development

 Adult stem cells also called somatic stem cells that appear during fetal development and are present in different tissues of our bodies throughout life.

 Induced pluripotent stem cells or iPSCs cells are not found in the body but engineered in a laboratory from cells of the body, such as those from the skin. The iPSC cells have properties similar to those of embryonic stem cells.

A fertilised egg has a totipotency for about 3-4 days. It then remains turns into a multipotent cell. Finally specializes further.

B. Stem Cell Therapy

• It is a type of treatment option that uses a patient’s own stem cells to repair damaged tissue and repair injuries.
• It is used to treat more than 80 disorders including neuromuscular and degenerative disorders. Eg. Bone-marrow transplant is used in Leukemia(blood cancer), sickle-cell anemia, immunodeficiency disorders. 
• Stem cells are usually taken from one of the two areas in the patient’s body: bone marrow or adipose (fat) tissue in their upper thigh/abdomen. Because it is common to remove stem cells from areas of stored body fat, some refer to stem cell therapy as “Adipose Stem Cell Therapy” in some cases.
• Once stem cells are removed from one of these locations, they are placed in a “centrifuge machine” that spins them very, very quickly and concentrates the substances that are most valuable (including up to seven different types of natural growth factors).
• The sample of concentrated stem cells is then injected directly into the patient’s affected, painful area− allowing the cells’ growth factors to go to work immediately, building new skin cells, connective tissue and so on.

C. Advantages

• Immense Medical Benefits: It offers a lot of medical benefits in the therapeutic cloning and regenerative medicine
• Treatment of Conditions and Disorders: It shows great potential in the treatment of a number of conditions like Parkinson’s disease, spinal cord injuries, Alzheimer’s disease, schizophrenia, cancer, diabetes and many others.
• A Better Knowledge of human growth: It helps the researchers know more about the growth of human cells and their development.
• The stem cell research can allow the scientists to test a number of potential medicines and drugs without carrying out any test on animals and humans. The drug can be tested on a population of cells directly.
• Cure development defects before they happen: The stem cell therapy also allows researchers to study the developmental stages that cannot be known directly through the human embryo and can be used in the treatment of a number of birth defects, infertility problems and also pregnancy loss. A higher understanding will allow the treatment of the abnormal development in the human body.
• Reduced risk of rejection: The stem cell therapy puts into use the cells of the patient’s own body and hence the risk of rejection can be reduced because the cells belong to the same human body.

D.Challenges in SCT

• Destruction of blastocysts: The use of the stem cells for research involves the destruction of the blastocysts that are formed from the laboratory fertilization of the human egg.
• Unknown side-effects: Like any other new technology, it is completely unknown what the long-term effects of such an interference with nature could be
• Limitations of adult cells: The disadvantage of adult stem cells is that the cells of a particular origin would generate cells only of that type, like brain cells would generate only brain cells and so on.
• Potential Rejection: If the cells used in the therapy are embryonic, then the cells will not be from the same human body and there are chances of rejection.
• Potential use in negative activities: It can be used to create bio-weapons or weapons of mass destruction

E.Applications of SCT

• Orthopedic injuries and musculoskeletal problems
• Wounds and incisions following surgeries
• Spinal cord injuries, brain trauma and spinal stenosis
• Cardiovascular diseases, including hypertension, coronary heart disease, stroke and congestive heart failure
• Hair loss
• Vision impairment
• Diabetes and other pancreatic dysfunctions
• Neurodegenerative diseases such as Parkinson’s, multiple sclerosis and Alzheimer’s

F. India and Stem Cell Therapy

• According to the Indian Council of Medical research, all stem cell therapy in India considered to be experimental except bone marrow transplants
• Stem cell therapy is legalized in India
• Umbilical cord and adult stem cell treatment are considered permissible
• Embryonic stem cell therapy and research is restricted