Biomedical Engineering Reference
In-Depth Information
Chapter 1
Adult Stem Cells
Andreas Nussler and Sahar Olsadat Sajadian
Eberhard Karls Universität Tübingen, Department of Traumatology, Tübingen, Germany
Introduction
Humans and many animals share the ability to regenerate missing parts of the body.
Although humans are not able to replace missing parts of the body as a whole, like legs or
hands for example, the human body is able to perpetually regenerate various tissues and
blood. The “mysterious” cell type that enables the human body to perform this regeneration
was discovered in the 1950s and subsequently named “stem cell” [1]. The first stem cells
were discovered in the bone marrow. Therefore, at the beginning, stem cells were almost
exclusively isolated from human bone marrow. Later on, the routine isolation and manipu-
lation of bone marrow stem cells led to the development of a method of bone marrow
transplantation for the treatment of blood diseases, such as leukemia, that is used all over
the world today.
Regardless of their origin, stem cells have the following specific properties: their division
and self-renewal capacity over long periods of time, their lack of specification, and their
ability to differentiate into specialized cell types. Over the past 50 years, many important
discoveries have raised hope that stem cell research will achieve major breakthroughs in
medicine. A short history of stem-cell research is presented in Table 1.1, and the different
kinds of stem cells with their respective sources are displayed in Table 1.2.
Adult Stem Cells
Adult stem cells
(
ASCs) are also called stromal cells. Their regenerative potential has been
recognized several decades ago. For instance, it has been demonstrated that hematopoietic
stem cells that are derived from adult tissues are able to generate every type of blood cell [2].
However, adult stem cells were thought to have a rather restricted potential for generating
new tissue, but recent studies have changed this viewpoint. Recent observations have sug-
gested that, in addition to the production of the derivatives of the blood system, stem cells
from the bone marrow of the juvenile and adult organism can create muscle and neuron-like
