Hematopoietic stem cells (HSCs) are cells that are capable of producing all blood type cells. The process through which blood is replenished in the body is called hematopoiesis. In this process, the HSCs create the necessary blood cells, which include lymphocytes, granulocytes, and red blood cells, and they also create new stem cells.
HSCs are generally found in the bones containing marrow. The umbilical cord blood during pregnancy contains a very high amount of HSCs, whilst the blood contains very little of them. HSCs are the most regularly used as they have the highest potential to replace and repair damaged cells. They are very helpful in repairing the damaged bone marrow in leukemia patients. HSCs can activate from the bone marrow and can enter the blood stream when needed.
Though HSCs have great potential, there are certain challenges when utilizing them. Unlike other types of stem cells, HSC cannot replicate and differentiate in a culture or artificial environment. They are also difficult to differentiate from white blood cells in terms of size, shape and behavior. The difficulty in recognition is also exacerbated by there being two types of HSCs. There are the long term HSCs which exist in the bone marrow and renew themselves indefinitely. The precursor or progenitor HSCs, also found in the bone do not replicate indefinitely. The long term HSCs are the most useful in medical treatments.
When HSCs become damaged or redundant, they are one of the few cells that can enable apoptosis or their own cell death.