I recently read a research paper.
Researchers at the University of Saskatchewan are teaming up with colleagues at Harvard Medical School in Boston, to use stem cells to treat PD.
The process involves taking stem cells from a patient's skin or blood, and converting them into a brain stem cell which is rich in dopamine neurons. Once they are injected into the brain, the dopamine is released and the broken links begin to be repaired.
Currently, a dopamine chemical is injected into the body with heavy immune suppression so the body will accept the chemical. In the new method, because a person's own cells are used, the theory is their body will accept the treatment more easily.
ref: harvard medical school