What is the difference between embryonic and adult stem cells, what is a stem cell line, what is special about the stem cells in the umbilical cord, and what is a stem cell bank
* Embryonic stem cells: cells produced from an embryo, the result of successful fertilization of an egg by a sperm cell in the period before their implantation in the mother's uterine wall. Collection of such human cells is possible in the first five-six days from the moment of fertilization. They are taken from the inner part of the group of cells from which a whole person develops during pregnancy. Each such cell is identical to the other: it is multi-purpose. In a process called "differentiation", the cells adjust to form the various tissues and organs, with each embryonic stem cell able to develop into any organ or tissue. The scientists seek to control this process.
* Embryonic stem cell line: perpetuating the embryonic state and properties of primary stem cells. Biological and chemical agents form the "row", in which embryonic cells continue to divide without differentiation. The cells are then grown in the laboratory, on a special nutrient medium. Today, the feed layer in the experiments are mouse embryonic cells. The tendency of the scientists is to get rid of the mouse feed layer as quickly as possible and switch to using a feed layer of human origin or to find a way not to need it at all, when it comes to stem cells for human transplantation.
* Mature stem cells: cells that are present in the human body all his life, at least in some tissues. Not long ago it was discovered that they are also found in the brain. This is a dramatic discovery because until now it was believed that brain tissue does not regenerate. Their role is to ensure the continuous renewal of tissues, such as skin, intestinal lining, bone marrow and blood. A mature stem cell is divided into two: one cell from that division becomes the tissue in which it is found for its regeneration, and the second cell continues to function as a stem cell. In Israel, successful attempts have been made (for example at the start-up company SBT from the Science Park in Rehovot) to use adult stem cells for the purpose of creating bone tissue, cartilage and tendons for transplantation in case of an open fracture.
* Stem cells from the umbilical cord: blood stem cells. In the world, a demand has arisen for people to freeze blood from the umbilical cord of their offspring for a future transplant (if God forbid they need, for example, a bone marrow transplant). The preservation process is cheap and recently umbilical cord blood banks have been established in the world as well as in Israel. Recently, the CBS network reported on a 15-year-old American boy suffering from the rare genetic blood disease sickle cell anemia, whose frequent blood transfusions ceased to benefit him. He was injected with blood cells from the umbilical cord that were found in the blood bank in New York and that matched his body, and the result was amazing: following the injection, not only is the boy in an advanced healing process, but his blood type also changed from O to B.
* Stem cell bank: a bank that will be based on embryonic stem cell lines that will be used for transplants according to the patient's suitability. Another possibility is that genetic changes will be made to the embryonic stem cells that will turn them into universal cells, suitable for any purpose and for any transplant. This is a new idea, the implementation of which of course depends on the development of the required technology.
