Stem cells have always been controversial as a tool for research and also potentially therapeutic applications.
The fact that the stem cell originally had to be derived from embryos was one of the most contentious ethical issues.
Recently, though, several advances have made it possible to take one's own skin cells and then reprogramme them to become stem cells. The resulting stem cell can then be developed into various cells such as heart cells, bone cells or virtually any type of a specific cell.
In addition, it is now also possible to directly convert one's own skin cell into a specific cell and completely skip the stem cell intermediate. The resulting cell can then, in theory, be useful for autologous (replacing one's own tissue) transplant therapies.
Of course this part is still undergoing heavy research as there may be other effects when transplanting tissue but at least there is minimal risk if the tissue is coming from one's own body.
A more immediate application of this type of work, however, is for something called "stratified medicine" which is the next version of personalised medicine.
Stratified medicine relies on large pools of patients who have similar characteristics for reaction to specific drugs and this is a much more feasible way of making personalised medicine as it would be impossible to make a specific drug for each individual.
A powerful use of individualised stem cell derived specific cells is to use them for toxicity and other effects from various drugs. In fact, a few pharmaceutical companies are already employing them for testing, for example, on cardiovascular cells to see if the potential drug might have adverse heart effects.
Using genetic information from large groups of people, the companies could test heart cells from various groups and thus alter the medicine or dose. Previously this work would have been done only using mice but the use of human specific cells allows us to have a much better picture of effects on humans. Obviously we don't have sharp teeth and tails!
My laboratory has been involved in engineering proteins to make the stem cell production process more efficient. This has been done by looking at atomic resolution three-dimensional structures of the proteins as well as DNA involved in making stem cells.
Using this information we were even able to inter-convert the functions of a stem cell and a gut-forming protein so that they would now carry out each other's roles.
Thus the science is now moving closer to more predictive and rational engineering of systems so that we can make designer cells efficiently and, in the process, we are also learning the mechanisms by which biological machinery carries out critical tasks in our own development.
You can Google "kolatkar sox17" to find out more about this work.