Advances in stem-cell--generated transplantation therapy for Parkinson's disease.

INTRODUCTION: Human pluripotent stem cells have the potential to differentiate into different cell lineages of the human body, including dopaminergic (DA) neurons. Previous studies have shown that stem-cell--derived DA neurons can improve the motor deficits of Parkinson's disease (PD) animal models. That is why current research interests focus on the development of stem-cell--derived neural cells for transplantation therapies for PD patients. AREAS COVERED: This review article emphasizes the safety and efficacy requirements of human pluripotent stem-cell--derived neural cells and usage of reliable preclinical animal models prior to clinical trials. The current advances and hurdles related to cell production, differentiation and transplantation are also summarized. EXPERT OPINION: Before entering the clinic, transplantable cell populations must be differentiated and characterized according to good manufacturing practice (GMP) regulations both in vitro and in vivo. Taking into account the rapid development of the stem-cell field and technological improvements in cell preparations and GMP facilities, we think that pluripotent stem-cell--derived DA neurons will offer a relevant cell therapy option for treatment of PD in the near future.