Ever since cell transplants were deemed as "ineffective and dangerous",there has been a "hold" on new research into them. This was the result of poor results, which put up a red light for the formation of tetratomas in various parts of the brain even when stereotactic surgery implanted fetal cells were used . Well, it turns out that these transplants were "dirty" as a whole host of stem cells proliferated in the brains of subjects who underwent the procedure. I have harped on this for at least 7 years. WE are not using the correct cells, and i don't know who is working on fixing this.
i had great hope that the "proper" cells could be made. by cloning of ones own biopsied material from the nigral area and that this method could "clean up" the type of cells that should proliferate and offer regrowth of new dopaminergic cells, specifically. i still strongly believe that bioengineering of cells which can ONLY reproduce into dopaminergic neurons CAN BE DONE. Why has this route to a cure for PD been forsaken. it seems so logical. if they can make skin grafts that can be grown on a substrate and then use them successfully in burn victims, then it is only a matter of time before "synthetic substantia nigra cells can be produced and harvested for an implant that will be well behaved, and do what we want them to do. iT seems so simple, no fetuses involved, so no questions of ethics. Why have we been dragging our feet (nice pun ha!) so long on this issue?