Stem Cell Preservation: Why Is It Important?
Stem Cells are referred to as progenitor cells meaning that they form the origin for different forms of adult cells. A broad classification of stem cells can be made into two types:
• Embryonic stem cells are found in a budding embryo and help in forming tissues as they differentiate.
• Adult stem cells are mainly repair cells that help in repair and regeneration of lost cells.
The capacity of stem cells to differentiate into adult cells have been utilized in modern day medicine to control and cure diseases, many of which were thought incurable a few years ago. Stem cells have helped in generating a cure for an astonishing 70 diseases and the list is growing every day.
There is controversy and opposition from several quarters to the use of embryonic stems cells, both for therapy as well as for scientific purposes. This is because to isolate the embryonic stem cells, the embryo may have to be destroyed. For this reason, adult stem cells are preferred for use. These are harvested either through the bone marrow or from blood drawn through the umbilical cord during child birth. The placenta is another source for the stem cells.
These days due to the advent of newer methods of therapy using stem cells, there are many stem cell banks that have emerged all over the world which deal in stem cell preservation. There are many public and private cord blood banks available. Public cord blood banks do not preserve the stem cells for the particular person from whom they are being derived but hold it for public use, as in organ banks. A private cord blood bank performs stem cell preservation for the use of the family undertaking this service, for a particular fee.
The cord blood and the placenta that is available during the delivery of a child contains viable stem cells if the collected blood is of an adequate quantity (about 75ml at least). This collection is performed by the medical team involved in the child delivery and sent by prior arrangement in a specialized bag to the cord blood bank for processing and stem cell preservation.
Once the bags containing the blood and the placenta reach the cord blood bank, they undergo various processes for disinfection, processing to obtain the stem cells, and addition of a cryopreservative to help the stem cells remain viable. The processing of the cord blood is done either by a separation of red blood cells or by keeping them intact with the specimen.
The blood derived from the mother before delivery and the cord blood are both tested for the presence of communicable diseases. After the preservative is added, the process of stem cell preservation is begun by a slow cooling process which is necessary to maintain the stem cells intact. This slow cooling is performed by maintaining the temperature first at -90 degrees and then slowly to -190 degrees by placing the stem cells in liquid nitrogen.
The stem cell preservation in liquid nitrogen helps cells remain useful for therapy in the future. This process of stem cell preservation not only helps the individual to fight some disorder if it arises, but it also helps other members in the family too if they need the stem cells for therapy.