Can a Mouse Embryonic Stem Cell Be Directed to Differentiate into a Particular Cell Type in Vitro?
One goal for embryonic stem cell research is the development of specialized cells such as neurons, heart muscle cells, endothelial cells of blood vessels, and insulin secreting cells similar to those found in the pancreas. The directed derivation of embryonic stem cells is then vital to the ultimate use of such cells in the development of new therapies. By far the most common approach to directing differentiation is to change the growth conditions of the ES cells in specific ways, such as by adding growth factors to the culture medium or changing the chemical composition of the surface on which the ES cells are growing. For example, the plastic culture dishes used to grow both mouse and human ES cells can be treated with a variety of substances that allow the cells either to adhere to the surface of the dish or to avoid adhering and instead float in the culture medium. In general, an adherent substrate helps prevent them from interacting and differentiating. In contrast, a nonadherent
