I’m no expert on stem-cell therapy research and I won’t try to say too much, but anyone who thinks miracles are guaranteed by any form of stem-cell therapy, morally acceptable or otherwise, should read this mostly optimistic but realistic article, Carving the Neural Stem Cell ‘Niche’ .
Researchers have known for a while that many diseases which once seemed to be a problem in a very particular sort of cell are in fact caused by problems in their context, perhaps neighboring cells or cells they depend upon for some biochemicals. The small support cells, glias, which surround neurons seem to be involved in some neurological disorders, indicating they aren’t ‘just’ support cells. Replace the neurons with cells grown from stem-cells and the surrounding glias will soon enough ‘poison’ the neurons — the disease will return.
This article is more concerned with what might be called the biochemical bath in which new cells might be inserted. Can that bath be supplemented to add the necessary biochemicals for successful treatment by stem-cells. Probably, at least in many cases, but researchers are going to be asking a variety of tough questions as they advance towards viable treatments. For example, did the diseased cells become such because the biochemcial bath is itself somehow wrong? Then you have to worry that the blood-cell problem involves the liver or a problem with the hippocampus in the brain involves other brain regions, perhaps those which produce common brain chemicals such as dopamine.
We’re organisms and even the different parts of our bodies have environments or contexts, relationships to biochemical baths and flows of other biochemicals, perhaps being constrained to specific areas or being thrown out of balance by another organ’s production of a biochemical with multiple uses and effects throughout the organism.
We have to think of ourselves and other living creatures as being complex and particular organisms. We aren’t just a sack of bones and organs and miscellaneous cells to be manipulated, tuned-up, fixed by a mechanic of the heart or a chemical technician specializing in blood.
DNA isn’t some sort of independent master of organisms — it is part of those organisms which are very complex environments indeed. Neither are the particular organs or types of cells or individual cells of that organism independent of their environmental context as part of that organism. Neither is the organism itself, especially a social mammal such as a human being, independent of its context, including its social, economic, political, cultural environments.
Oh, the world is so complicated for those who like to draw flow-charts thinking them to be definitive rather than just indicative.