The history of research on adult stem cells began over 50 years ago. In the 1950s, researchers discovered that the bone marrow contains at least two kinds of stem cells. One population, called hematopoietic stem cells, forms all the types of blood cells in the body. A second population, called bone marrow stromal stem cells (also called mesenchymal stem cells, or skeletal stem cells by some), were discovered a few years later. These non-hematopoietic stem cells make up a small proportion of the stromal cell population in the bone marrow.
Mesenchymal stem cells can also be isolated from other tissues including cord blood, peripheral blood, fallopian tube, and fetal liver and lung. Multipotent stem cells, MSCs differentiate to form adipocytes, cartilage, bone, tendons, muscle, and skin.
Morphologically, mesenchymal stem cells have long thin cell bodies with a large nucleus. As with other stem cell types, MSCs have a high capacity for self renewal while maintaining multipotency. Thus, mesenchymal stem cells have enormous therapeutic potential for tissue repair.