STEM CELL AND ITS TYPES
STEM CELL AND ITS TYPES
Stem cells are the primary cells that build up all of our body's tissues and organs. An organ contains a variety of cells. When cells in tissues or organs are injured, stem cells become those cells and treat the organs and tissues. They have an infinite capacity for reproduction. Stem cells, in reality, are continually active, replenishing our entire body and treating any places that require it. If they are directed collectively to a specific place, they will aid in its healing. Today, it has been shown that a large number of stem cells may be retrieved readily from our body's fat tissues, whose quantity is significantly higher than that taken from bone marrow. Similarly, it has been revealed that tissues obtained from human bodies may be replicated in the laboratory. As a result, stem cells may now be used to treat practically every illness.
Common characteristics of stem cells are:
● They can be reproduced in a suitable growth environment.
● They have unlimited capability of proliferation.
● They turn into the cells they touch and treat the tissues and organs formed by the cells.
● They can replenish themselves or maintain their own cell communities.
● Following an injury in one part of the body, they have the potential to repair that tissue and make it functional again.
● Adult Stem Cells
● Fetal Stem Cell
● Embriyonic Stem Cell
● Cord Stem Cell
Adult stem cells vary from embryonic and fetal stem cells in that they are present in tissues that grow in humans or animals after birth. However, the best source of these cells is bone marrow, which is found in the middle of certain bones. Bone marrow is often extracted from the "krista iliaca" bone part behind the upper hip bone. In bone marrow, there are several kinds of stem cells, including hematopoietic stem cells, endothelium stem cells, and mesenchymal stem cells. Endothelial stem cells are employed in vein therapys because they treat the vascular system (arteries and veins). On average, mesenchymal stem cells can differentiate into a hundred distinct cells, including bone, cartilage, muscle, neuron, liver, and pancreatic cells.
1. SVF – Stromal Vascular Fraction
When it is realized that stem cells may be retrieved from adipose tissue, the fat cells are separated using various enzymatic and mechanical methods in order to access the cells inside the fat, and the complex stem cell solution containing many distinct cells is referred to as SVF. It contains many different types of adult cells. They house 80-100 distinct therapeutic stem cell groupings, such as mesenchymal cells, which may transform into other cells, hematopoietic cells, which produce blood cells, endothelial cells, which cure veins, and fibroblasts, which build connective tissues. When delivered intravenously (through vascular access) to a patient, the cells contained inside it are utilised as therapeutic cells by the relevant areas. Cells can be isolated from the SVF using specific procedures, replicated independently, and employed in other therapys if required.
Similarly, in burns and autoimmune illnesses that necessitate the therapys of numerous cells collectively, the cells are employed as a whole, without being separated.
2. Mesenchymal Stem Cell
It is the name given to a cell that may transform into another cell. Adult mesenchymal stem cells and connective tissues contain it. These stem cells have the ability to move from the tissue in which they are found to a damaged tissue. They restore tissues that have been injured. If damage is found in one tissue, it is possible to identify damage in other tissues. Adult mesenchymal stem cells are collected from bone marrow and adipose tissue, where such cells are found four times more than bone marrow. A mesenchymal stem cell obtained from an adult has the capacity to change into around 100 distinct cells, the majority of which are still unknown.
Characteristics of mesenchymal stem cell:
● Mesenchymal stem cells can be transformed into other cells.
● They differ in appearance in lung, stomach and bone tissue. This is due to different conditions in the environment.
● Mesenchymal Stem Cells have the ability to fuse with damaged cells. Not only do they repair the damage in the tissue where they are present, they also pass to the other tissue in case of any damage in that tissue and repair that tissue.
● They are originating from connective tissues so they can contribute to the development and function of related tissue cells.
● They can differentiate into cells such as muscle, fat, bone, cartilage, tendon, ligament, which are connective tissue cells.
They should be multiplied in cultures that survive for weeks under particular laboratory conditions in order to boost their numbers. This needs advanced technology, infrastructure, and experience, and it is pricey. As a result, clinically useful mesenchymal stem cells are only generated in a few places throughout the world. All methods required for this operation must adhere to international standards (GMP Good manufacturing practice).
3. Hematopoietic Stem Cell (Blood Cell)
All of our blood cells are built up of young (immature) cells called hematopoietic stem cells. (The term hematopoietic refers to the formation of blood.) Stem cells are often found in bone marrow (the spongy center of the bones) and divide to generate new cells. They are distinct cells that were found earliest, best documented, and have been used successfully in the clinic for many years.
Functions of hematopoietic stem cells:
- Carry oxygen to tissues, maintain immune system function, and govern fundamental functions like as hemorrhage control.
- They are self-renewing cells capable of forming the whole blood tissue.
- They are used in hematopoietic cancers (leukemia-lymphoma-myeloma), non-hematopoetic cancers,
- Genetic and/or acquired bone marrow diseases such as:
- Aplastic anemia, thalassemia, sickle cell disease, and autoimmune diseases in a progressively frequent manner.
4. Endothelial Stem Cell
Endothelial Stem Cells develop in the bone marrow, circulate, and become concentrated in sites of vascular injury (vascular system), where they play an important role in damage healing. Endothelial Stem Cells can develop into adult endothelial cells after leaving the bone marrow, enduring alterations in cell surface markers. Endothelial stem cells divide and circulate to the degree that they can divide and cure existing arteries.
5. Autologous Stem Cell Production
Autologous stem cell generation refers to the creation in a laboratory of cells in our bodies that cannot differentiate into any other cells other than themselves and the delivery of those cells to an unfinished region.
The following are examples of cell types for autologous cell production:
Fibroblast cell:
These are the main cells that create the connective tissue in the skin's bottom layer and the collagen-producing tissues. Because these cells die, connective tissue begins to disintegrate and collagen synthesis declines with time. Skin aging is seen in this manner. These cells can be created in the laboratory and sent back to the skin in rejuvenation therapies to mend missing sections in these tissues under the skin.
Beta cell:
It is possible to treat diabetes by creating these cells in a lab and reintroducing them to the pancreas, where they are involved in the generation of insulin.
Keratinocytes:
These are the cells that make up the skin's outermost layer. In epidermal disorders of the outer skin, such as burns, acne scars, damage, and so on, epidermis can be generated in the laboratory
A "fetus" is an embryo that is around 7-8 weeks old following a development period. When a baby is developing, cells retrieved from the fetus between the ages of 8 and 12 weeks have the capacity to develop into cells in practically all tissues and organs, even if they do not fully become a human person. These are stem cells collected from children of women who miscarried between 8 and 12 weeks and have the potential to divide indefinitely and regenerate themselves. Antigens are not present in fetal stem cells. When a material enters the body, the immune system perceives it as a foreign substance and causes antibodies to be produced in order to destroy it. Because a fetal stem cell is not an antigen, it is not seen as a foreign material by the recipient's body, and so the fetal stem cells are entirely accepted even if given to another human being. As a result of fetal stem cells mimicking the cells in the tissues and organs they contact, the dysfunctional tissues and organs are treated.
The capacity of stem cells to differentiate is varied. The zygote, which is the initial state after the egg has been fertilized with sperm, is the cell with the greatest capacity to differentiate. The zygote can develop into every type of cell in the body as well as any extraembryonic tissue cell. A human being is therefore created from a single cell. In about 5 days after conception, a hollow sphere with roughly 150 cells termed a "blastocyte" is produced. These cells can be used to reproduce a human being and clone a thousand humans. As a result, all governments restrict research on embryonic stem cells.
When compared to other stem cell sources, cord blood stem cells are very young, and when they are preserved, their aging and wear processes are slowed. Their rates of reproduction are greater than those of other sources. Even in the absence of a complete tissue match (HLA) between the recipient and the donor during cord blood transplantation, the success rate is excellent.
Cord blood is extracted from the part of the umbilical cord that remains on the placenta side after the baby is born. The umbilical cord is clamped and cut immediately after a baby is born, the infant is taken, and the blood inside the cord connected to the placenta is collected into a sterile blood bag containing an anticoagulant agent using a special system. Within 48 hours, the collected blood is delivered to the cord blood bank laboratory.
The stem cells obtained from cord blood can be transformed into an estimated 200 different cells in the body. However, mesenchymal stem cells obtained after the birth of a baby, i.e. from adults, can differentiate into an estimated 100 different cells. As a result, cord blood obtained from a baby is more effective in the long term therapys of a disease.
