The supply of donated organs and tissue that are used to treat diseases and disorders is far outnumbered by the need. Recently, there has been a lot of interest in the use of stem cells to treat such disorders, because these cells have a large proliferative potential while they can differentiate into every cell in the body under the appropriate stimuli. Recent reports from the University of Pittsburgh and the University of Düsseldolf have provided some evidence that autologous or homologous stem cell transplantation could one day treat lethal human diseases.
Duchenne Muscular Dystrophy
(Date: 31 December 2001, by Makarand Risbud, University of Pittsburgh)
Duchenne Muscular Dystrophy is a genetic regenerative disease in which the lack of the protein dystrophin leads to progressive muscle damage. As a result, patients (usually boys) suffering from the disease are in a wheelchair by the age of 12 and die in their 20s because their heart and respiratory muscles fail. Researchers from the University of Pittsburgh extracted mouse muscle stem cells (called myoblasts) and grew them in large numbers in the lab. These stem cells when injected into the muscles of Duchenne mice were differentiated into muscles that produced dystrophin. Previous attempts to inject donor adult muscle cells into dystrophic mice gave worse results because the recipient immune system rejected them as foreign cells. Stem cells, on the other hand, do not have the surface proteins that can trigger rejection, and even more are able to multiply and increase in number. Commenting about these findings, which are considered for publication in the Journal of Cell Biology, the University of Pittsburgh researcher said “If it all turns out to be true in humans, maybe you can have a single donor and you can inject 50 different recipients with the same cells.”
(Date: 28 September 2001, by Andreas Gröger, University of Düsseldolf)
The first clinical application of autologous stem cell transplantation, in a patient who had sustained an acute myocardial infarction, was recently reported by German cardiologists. While the 46-year-old man was initially treated by percutaneous transluminal catheter angioplasty and stent placement, some of his mononuclear bone marrow cells were harvested and six days after the infarction were transplanted in the infarct-related artery. Ten weeks after the stem cell transplantation the infarct area had been reduced from 24.65% to 15.7% of the left ventricular circumference, while injection fraction, cardiac index, and stroke volume had increased by 20-30%. Although no direct evidence has been provided, the therapeutic benefit may be ascribed to stem cell-associated myocardial regeneration and neovascularization.
Other Uses, and Controversy, on the Horizon
In addition to the aforementioned uses of stem cells, there is research evidence that stem cells can be potentially used to treat spinal cord injury, burns, osteoarthritis, diabetes, Parkinson’s and Alzheimer diseases. There are, however, many controversial issues, involving ethics, science, politics, and religion, associated with stem cell research from sacrificed human embryos. Research at any stage on human embryo is a violation of the religious conviction of a large number of people, while research involving the potential creation of life might be abused in some countries.
Despite all of this one thing is sure; the race using engineering, and with stem cells, toward the regeneration of human tissue is on. To read more on stem cells and tissue engineering you can visit the ETES Newsletter at http://etes.tissue-engineering. net.
IEEE ENGINEERING IN MEDICINE AND BIOLOGY
Tags: lethal diseases