Stem Cell Research
Stem cells are uncoded “generic” cells from which virtually all tissues of the body develop. These blank slates can be programmed into any organ, tissue type, or blood cell with the right set of genetic influences, or expressions.
The stem cells that have shown the most promise in diabetes research are those derived from in vitro fertilization (IVF), which are more commonly known as embryonic stem cells. These cells have the unique capacity to become any type of cell, tissue, or organ as they mature and develop, yet they cannot themselves develop into a full human being. The feature that makes them most useful as a source for islets is that they can replicate themselves while remaining in an immature or “undifferentiated” state, thus offering a potentially unlimited source of cells for organ transplantation.
Growing Stem Cells
Stem cells are grown, or cultured, in a laboratory. The cells grow in a culture dish treated with a growth medium. The culture is sometimes treated with embryonic skin cells from mice, called feeder cells, to prevent the stem cells from dividing (or differentiating) and to provide nutrients to the culture. Because of the possibility of virus transmittal between human stem cells and feeder cells, researchers have been attempting to move away from this method of culturing cells.
Once cells have been cultured many times over, usually over the course of six months or longer, and have continued to reproduce without dividing or differentiating, they are said to be an established stem cell line, the basic materials that researchers use for specific experimentation.
Adult stem cells have also been used in diabetes research. These undifferentiated cells come from bone marrow or other areas of the body and act as a built-in first-aid kit, repairing tissue injury in the body. Scientists have also found that some of these adult stem cells can be coaxed into new tissues and organs.
A Matter of Controversy
Stem cell research has become a political, social, and ethical hot button issue in the past decade because of the nature of embryonic stem cells. These cells are derived from a blastocyst — a hollow ball of cells from a four- or five-day-old embryo derived from an egg fertilized outside of the body in an IVF clinic. The current status of federally funded research in the United States does allow study of embryonic cells, but only those currently available from a limited number of existing cell lines.