Nano and microcarriers to improve stem cell behaviour for neuroregenerative medicine strategies: Application to Huntington's disease.

The potential treatments for neurodegenerative disorders will be revolutionized by the transplantation of stem cells or neuronal progenitors derived from these cells. It is however crucial to better monitor their proliferation, improve their survival and differentiation and hence ameliorate their engraftment after transplantation. To direct stem cell fate, a delicate control of gene expression through RNA interference (RNAi) is emerging as a safe epigenetic approach. The development of novel biomaterials (nano and microcarriers) capable of delivering proteins, nucleic acids and cells, open the possibility to regulate cell fate while achieving neuroprotection and neurorepair and could be applied to Huntington's disease. This review first provides an overview of stem cell therapy for the neurodegenerative disorder Huntington's disease. Within that context, an integrative discussion follows of the control of stem cell behaviour by RNAi delivered by different nanocarriers in vitro prior to their transplantation. Finally, combined in vivo strategies using stem cells, biomaterials and epigenetic cell regulation are reported.