UMBILICAL CELLs Are a type of adult stem cells derived from umbilical cord blood. More specifically, umbilical cells refer to the hematopoietic stem cells, also known as undifferentiated blood cells, found in the umbilical cord. Because the umbilical stem cells are the precursor blood cells, they can develop into other cell types such as platelets, macrophages, and thymus cells, commonly known as T-cells. In light of this unique property, physicians use umbilical cord stem cells to treat patients who cannot generate normal blood cells as a result of genetic diseases such as leukemia.
Because these cells exhibit characteristics similar to embryonic stem cells, some researchers state that umbilical cord cells could have the potential to differentiate into liver cells, neurons, heart muscles, or even cartilage—a property known as plasticity. Because the umbilical stem cells possess a degree of plasticity similar to that of embryonic stem cells, researchers have engaged in rigorous investigation and hope to use umbilical cells in extensive stem cell therapy.
Considering the aforementioned properties, umbilical cord cells can have lifesaving therapeutic effects and may be useful in treating more diseases. In light of these beneficial characteristics, more and more parents are choosing to store umbilical blood for future use. Compared with adult stem cells derived from bone marrow, umbilical stem cells yield fewer complications during treatment and are also more responsive to drugs.
Controversy surrounds the use of embryonic stem cells because the extraction of cells results in the destruction of the embryo—an act some equate to the destruction of human life. The use of umbilical cord stem cells, in contrast, does not raise the aforementioned concern. Although the use of umbilical cord stem cells raises less debate, some disagreement still exists regarding the viability of the cells after long-term storage and the therapeutic efficacy of umbilical stem cells.
Public or private umbilical cord banks are available for those who wish to donate or store their cord blood cells. Otherwise, parents can choose to discard the umbilical cells.
Depending on the consensus reached between the physician and the chosen cord blood bank, umbilical cord blood can be obtained in one of two ways. First, the cord blood can be collected by draining the blood into a sterile bag that is sealed on completion. The second method obtains umbilical cord cells by drawing the blood into a syringe.
To ensure the quality of the umbilical cells, health professionals consider the first 15 minutes after birth to be the prime time to collect cord blood. Collecting cord blood after this window results in poor cell quality. On receiving the collected umbilical blood, scientists conduct a series of tests to eliminate bacterial contamination. Once the cord bank has conducted all the necessary tests, the sample is then processed and stored cryogenically (in liquid nitrogen). During regular intervals, umbilical cord blood banks would perform viability tests on the stored cells to determine the percentage of live cells. At present, there is no indication as to how long the umbilical cells will stay viable.
The breakthrough in stem cell research brought hope to patients suffering from cancers and rare genetic disorders. More specifically, ailments such as sickle cell anemia, non-Hodgkin’s lymphoma, Kostmann syndrome, and osteoporosis can now be treated with stem cells. In the aforementioned illnesses, implanted healthy stem cells in the patients can replace blood cells either damaged or destroyed by the diseases or during chemotherapy. In addition to treating the patients suffering from cancers and various genetic disorders, umbilical cord cell therapy could also benefit those plagued by cardiovascular diseases. Japanese researchers discovered that implanting umbilical cells in the heart would not only stimulate new vessel growth but also increase blood flow. Such discovery holds promise for patients for whom heart bypass surgery and angioplasty have proven to be ineffective.
Aside from the ability to give rise to many different blood cell types and stimulating vessel growth, umbilical stem cells also demonstrate the potential to develop into other cell types such as neuron and muscle cells. In a recent experiment performed on rats with amyotrophic lateral sclerosis, a debilitating and lethal neurodegenerative disease, scientists reported that umbilical cells injected into the blood vessels slowed down the disease’s progression and increased the rats’ survival rate. Moreover, the umbilical cells migrated to the damaged areas such as the spinal cord and the brain.
A different study involving rats with spinal cord injuries also showed that umbilical cells could travel directly to the damaged area and restore certain functions lost as a result of the injury. These results provide hope for patients who have multiple damaged regions because stem cells implanted surgically are unable to circulate to other areas. Furthermore, once the umbilical cells’ pluripotency (cells’ ability to give rise to many different cell types) is fully realized, then these cells may be able to treat diseases ranging from diabetes to other neurological and autoimmune diseases such as Alzheimer’s, Parkinson’s, and lupus.
ADVANTAGES AND DISADVANTAGES
Umbilical cells and embryonic cells have many differences. Although embryonic stem cells offer greater versatility, umbilical cells are less controversial. Researchers have observed that embryonic stem cells exhibit the ability to differentiate into all kinds of cells in a body. Until now, umbilical cells (a type of adult stem cells) were thought to be able to give rise to certain types of cells. However, evidence suggests that umbilical cells appear to exhibit a degree of versatility very similar to that of embryonic stem cells. Once versatility of umbilical cells is fully realized, scientists foresee a major advancement in stem cell therapy. Cells derived from embryonic cells can be rejected by the patient’s immune system. However, if umbilical stem cells are given back to the patient from which they were derived, the patient is less likely to reject the cells. Furthermore, using a patient’s umbilical cord stem cells also reduces the rate of disease transmission.
Moreover, extracting embryonic stem cells not only raises ethical concerns but also poses technical difficulties of obtaining embryos and isolating the cells. Often, surgeons are unable to acquire enough cells from embryos. Recent research findings claim that extracting stem cells from umbilical cord blood could overcome these obstacles because umbilical cord stem cells can be extracted and stored without encountering the ethical issues raised by embryonic stem cell research. In many parts of the world, extracting umbilical stem cells is socially and ethically acceptable.
Although extracting umbilical cells would not raise the same controversy as that of embryonic cells, umbilical cells also have disadvantages. Some argue that certain congenital disorders cannot be detected at the time of birth, and so the collected umbilical cells could be rendered useless once the disorder develops. Another disadvantage lies in the limited quantity of stem cells that are present in the umbilical cord blood; it is not possible to obtain additional umbilical cells. Although umbilical cells are hailed as an alternative to embryonic stem cells, researchers continue to examine their properties and expand their applications.
