Transplanted Epidermal Neural Crest Stem Cells In A Peripheral Nerve Gap

It has been a difficult clinical problem to repair the peripheral nerve defects after peripheral nerve. The first candidate to clinically deal with peripheral nerve defect is nerve autograft, but it is limited in the clinical practice on account of the shortage of available graft nerve, functional incapacitation of the donor area, limitation of bridging length, neuroma and spontaneous neuropathic pain resulted from the sacrifice of a healthy nerve. With the continuous development of synthetic material and bioengineering, the tissue-engineering artificial nerves give us a new hope to deal with peripheral nerve defect satisfactorily.The development of tissue engineering has provided a new strategy for the reparation of damaged nerves, the scaffold and seed cells are critical for the construction of tissue engineering nerve.The neural crest cell is located in the neuroectoderm of early embryo and migrates from the neural tube to its destinations. It is regarded as the cell with the most differentiation potential for differentiating into neuron, glial and diverse noneural cells.Neural crest stem cells originated from hair follicle (epidermal neural crest stem cells, EPI-NCSCs) are easy to obtain and have potentials to differentiate into neuron and glial which contribute to PNS. So it is considered as the primordium of PNS. Thus these cells were employed as the seed cells for tissue engineering. EPI-NCSCs are now used to repair nerve injury, especially, the spinal cord injury. To investigate their effects on repairing peripheral nerve injury, EPI-NCSCs from GFP-SD rat were primarily cultured on coated dishes and on a poly (lactic-acid-co-glycolic-acid) copolymer (PLGA) membrane. MTT assay showed that the initial adhesion rate of EPI-NCSCs was89.7%on PLGA membrane, and the relative growth rates were89.3%,87.6%,85.6%, and96.6%on the1st,3rd,5th,7th day respectively. Cell cycles and DNA ploidy analysis demonstrated that cell cycles and proliferation indexes of cultured EPI-NCSCs had the same variation pattern on coated dishes and PLGA membrane. Then cultured EPI-NCSCs were mixed with equal amount of extracellular matrix and injected into a PLGA conduit to connect a10mm surgery excision gap of rat sciatic nerve, DMEM was used to substitute EPI-NCSCs in the control group. After four weeks of transplantation, the defected sciatic nerve achieved a histological restoration, the sensory function of rat hind limb was partly recovered and the sciatic nerve index was also improved. Transplanted EPI-NCSCs can promote electrophysiological function. Transplanted EPI-NCSCs can improve the recovery of gastrocnemius muscle water weight, indicating that Transplanted EPI-NCSCs can improve the reinnervation of regenerated nerve to target tissues. The above results showed that a PLGA conduit filled with EPI-NCSCs has a good repair effect on the peripheral nerve injury.