Gene delivery of chitosan-graft-polyethyleneimine vectors loaded on scaffolds for nerve regeneration

As an important transcription factor, c-Jun could upregulate growth factors expression in Schwann cells (SCs). Arginine-Glycine-Aspartate (RGD)-functionalized chitosan-graft-polyethyleneimine (RCP) gene vectors were prepared through the maleic anhydride & the carbodiimide methods, and electrostatically bound with c-Jun plasmids (pJUN), finally loaded on poly-L-lactic acid/silk fibroin parallel fiber films to fabricate nerve scaffold (RCP/pJUN-PSPF@PGA), which could locally deliver c-Jun plasmids into SCs via the mediation of RGD peptides, and upregulate the expression of nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) in SCs. After the scaffold was bridged in sciatic nerve defect, the delivery of c-Jun plasmids from RCP/pJUN-PSPF@PGA facilitated SCs to sustain the expressions of NGF, BDNF and vascular endothelial growth factor in the injury field, promoting myelination, axonal growth and microvascular generation and nerve regeneration, muscle reinnervation and functional recovery. These results suggested that RCP/pDNA-PSPF@PGA, as an effective gene delivery platform, could provide a local gene therapy to improve nerve regeneration.

Future Challenges and Perspectives for Stem Cell Therapy of Neurodegenerative Diseases

Stem cell-based therapy has shown exciting efficacy in pre-clinical studies on different neurodegenerative diseases (NDs). However, no clinically applicable stem-cell-derived neurons are available to the patients with NDs. There exist some obstacles associated with stem cell therapy, which need to be overcome in future clinical studies. In this chapter, more challenges and new strategies will be explored to accelerate the clinical translation of a human embryonic stem cell (hESC)/induced pluripotent stem cell (iPSC)-derived neural cell product to patients with NDs.