The supply of kidneys for transplants falls tragically short of demand, leading many people to buy and sell kidneys on the black market (see http://www.empowher.com/news/herarticle/2009/09/14/transplant-kidneys-sale).
It's still science fiction to take one cell from a patient and grow a new kidney (or heart, liver, pancreas, etc.) instead of waiting for a donated organ to become available. However, researchers are learning that our bodies have more potential for repair than we have traditionally expected. Our immune systems are constantly on the attack against invaders, and this attack often damages our own tissues. Other cells repair the damage. Some researchers believe that we can tip the balance of damage and repair with stem cell therapy.
In chronic kidney disease, endothelial cells play a key role. These are the cells that line the inside walls of blood vessels. They were once thought to be just a static barrier between tissue and blood, but are now credited with regulating dilation and constriction of blood vessels. Endothelial cells also contribute to regulating transport of solutes through the blood vessel walls. This makes them vital to kidney function.
Patients with kidney failure may not need an entire new kidney; some researchers believe that replacement of the kidney endothelium could be sufficient. Stem cells from the bone marrow offer potential for repairing damaged endothelium. Ideally, doctors would like to use cells from the patient so that they will not be rejected. Cells in the bone marrow are well known candidates because they continually produce new blood cells. Under favorable conditions, these bone marrow stem cells may be able to produce other types of cells.
The team that cloned Dolly the sheep has found that extracts from embryonic stem cell cultures can sometimes jump start cell division in cells taken from adults. They are already at work on treatments for amyotrophic lateral sclerosis (Lou Gehrig's disease). See http://www.empowher.com/news/herarticle/2009/06/10/embryonic-stem-cell-research-amyotrophic-lateral-sclerosis-als