> Are they sure? They can now harvest stem cells from regular tissue and blood, as I understand it
There are adult stem cells which are differentiated or partly differentiated to particular systems, eyes, skin, blood etc, and there are induced pluripotent stem cells, where chemical or viral factors have been used to 'wind back the clock' for adult, differentiated cells back to completely non-differentiated (pluripotent) stem cells, equivalent to embryonic stem cells.
In the long run, it seems that embryonic stem cells won't be needed, but for the moment induced pluripotent cells are not 100% understood, everywhere apart from Japan clinical researchers are wary of using them in human trials, because they are not completely certain a particular preparation doesn't have abnormalities. Embryonic stem cells for the moment are the gold standard, and some work is needed to iron out the technology to standardize and check the process for inducing pluripotency.
But in principle any cure proven with embryonic stem cells could be 'ported' over to induced pluripotent stem cells once the iPSC process is standardized, it's just a question of whether you want to pursue these two research paths in parallel, or wait for the iPSC problems to be ironed out before even starting the process of running human trials.
Very well put. I would add that it could take decades to "iron out" the issues with iPSCs. It could also never actually happen. For example, the iPSC generation process induces oncogenic properties in the cells ( https://www.ncbi.nlm.nih.gov/pubmed/22998387 ). It could be that in the next few decades, iPSCs just turn out to be a lot less safe than embryonic stem cells.
Considering the hundreds of millions of dollars it could take to move stem cell therapies like this through the validation and regulatory approval process, it would be foolish to handicap the process by using "unproven" iPSCs in favor of "gold standard" embryonic stem cells.
There are adult stem cells which are differentiated or partly differentiated to particular systems, eyes, skin, blood etc, and there are induced pluripotent stem cells, where chemical or viral factors have been used to 'wind back the clock' for adult, differentiated cells back to completely non-differentiated (pluripotent) stem cells, equivalent to embryonic stem cells.
In the long run, it seems that embryonic stem cells won't be needed, but for the moment induced pluripotent cells are not 100% understood, everywhere apart from Japan clinical researchers are wary of using them in human trials, because they are not completely certain a particular preparation doesn't have abnormalities. Embryonic stem cells for the moment are the gold standard, and some work is needed to iron out the technology to standardize and check the process for inducing pluripotency.
But in principle any cure proven with embryonic stem cells could be 'ported' over to induced pluripotent stem cells once the iPSC process is standardized, it's just a question of whether you want to pursue these two research paths in parallel, or wait for the iPSC problems to be ironed out before even starting the process of running human trials.