Harnessing Stem Cells and Neurotrophic Factors with Novel Technologies in the Treatment of Parkinson's Disease.

Parkinson's disease (PD) is characterized by loss of dopaminergic neurons, oxidative stress and neuroinflammation. The classical therapeutic approach with L-DOPA is not able to control motor symptoms in the long term, thus new disease-modifying or neuroprotective treatments are urgently required in order to match such yet unmet clinical needs. Success in cell-based therapy has been accomplished at a clinical level with human fetal mesencephalic tissue, but ethical issues and a shortage of organs clearly underline the need for novel sources of dopaminergic neurons. Mesenchymal stem cells (MSCs) can be obtained from different adult and fetal tissues that are normally discarded as waste, including adipose tissue, placenta, umbilical cord, and dental tissues. Their neuroregenerative, anti-inflammatory and immunomodulatory properties are mainly mediated by the secretion of an array of bioactive molecules and are heightened when MSCs form tri-dimensional structures called spheroids. Not only can MSCs spontaneously produce neurotrophic factors (NFs) but they can be engineered to synthetize and secrete them in vivo. The aim of this review is to provide a picture of results gained with MSC secretome and spheroids in PD, as well as the possibility of harnessing MSC-based therapy with the use of nano- and micro-structured materials for NF delivery.