Pluripotent stem cells are undifferentiated cells that can develop into any of three different kinds of cells corresponding to the three germ layers. The germ layers are groups of cells that develop during embryonic development. They include the endoderm, which develops into many internal organs, the mesoderm, which develops into the heart, skin, and muscles, and the ectoderm, which develops into mammary glands, nervous tissue, and hair. Pluripotent stem cells are of particular interest in modern biological and medical fields because of the many types of cells they can develop into. Scientists believe that they can use the pluripotent nature of these cells to treat a variety of illnesses and disorders.
There are two main sources for stem cells. Adult, or somatic, stem cells come from adults and tend to replicate and develop in response to illness or tissue damage. They are generally thought to be able to develop only based on the part of the body they exist in, though scientists have found some evidence to the contrary. Stem cells also come from developing embryos. Pluripotent stem cells are generally taken from embryos very early on as they are in the early stages of development.
The use of embryonic pluripotent stem cells is a very controversial practice because the embryo is destroyed as the cells are extracted. Many find the moral implications of this to be very grave, and some even consider it murder. Others believe that the lives that could potentially be saved by stem cell research far outweigh the problem of destroying the embryo. Both sides often seek political support to put their policies into practice, especially when it comes to funding. Stem cell research is expensive; without government funding it is often impossible.
For quite some time, scientists believed that it was only possible to get pluripotent stem cells from embryos. Several more recent trials have had some level of success inducing a pluripotent state in adult stem cells taken from simple skin samples. Continued success in the area of induced pluripotency could bypass the moral issues of embryonic stem cell use entirely.
The scientific community has high hopes for the medical uses of stem cells. since they could be used to produce patient-specific cell and organ transplants. Many lives could be saved every year if there was no risk of the immune system rejecting donated organs and tissues. Such risk would not exist if the new organ or tissues was grown from the pluripotent stem cells of the patient. Pluripotent stem cells could also be used to research and correct various genetic issues.