what do scientists hope to do with stem cells?

Answer 1

Besides being an overly broad question, the answer is very simple. Find ways to cure diseases that drugs, surgery, or lifestyle changes cannot fix. Such as congestive heart failure after a heart attack. Basically your heart can't pump well enough to keep the rest of your body oxygenated and thus to compensate will enlarge further weakening it as it does so (specifics are not too important here). Surgery can't help since the heart attack killed heart tissue needed to pump well and unfortunately heart tissue does not grow back. With stem cells, we can turn them into hopefully any type of tissue/cell we want. So why not heart cells, get them integrated into the heart to replace lost tissue and actually cure the heart failure rather than treat and delay it as we do now. Many diseases like this that cell replacement therapy can potentially cure.

Answer 2

Stem cells have the potential to differentiate into any kind of cell in the body (the potential is there, but scientists haven't been able to make it happen reliably in all cases). They hope to replace damaged cells with new ones grown from stem cells.

The other major hurdle is getting it where it needs to be. For example, it is possible to turn stem cells into nerve cells. If we placed them in the brain, they wouldn't do much good, since they would connect properly (since most of the major structural brain development takes place before birth). Once scientists figure out how to both reliably differentiate them and get them to properly integrate, then stem cell therapy will be closer to a reality.

Imagine if you had a car part that could turn into any part that you needed. Right now, the trick is getting it to turn into that part and getting it to work properly. The simpler the component, the easier it is. If you got it to turn into oil, as long as it's in the right place, it will work properly. If you turned it to something more complex like a transmission or even a headlight, it would be useless unless you knew how to get it to connect to the engine or the battery (like the problem of integration with neurons, mentioned above).