Promotion of neuronal regeneration by using self-polymerized dendritic polypeptide scaffold for spinal cord tissue engineering.

Tissue engineering technology is applicable for study of nerve regeneration after spinal cord injury. Many natural and artificial scaffold are not applicable because of poor mechanical properties and cell compatibility. Polypeptides with fine three-dimensional structure and cell compatibility and are widely used in tissue engineering research. The purpose of this study was to verify the neuronal differentiation of neural stem cells by using self-polymerize dendritic polypeptide for spinal cord tissue engineering. Neural stem cells were isolated from cerebral cortex of neonatal SD rats.Conventional media was triggered the 1wt% nano peptide solution self polymerizated to formed a nano gel. The gel was tested by scanning electron microscope and transmission electron microscope. Neural stem cells were inoculated onto gel or on Polylysine-coated slides with fetal bovine serum or not. SD rats were randomized divided into four groups. neural stem cells and self-polymerized peptide were transplanted into spinal cord injury models. Then we test the Density of NF-positive axons in the spinal cord injury area at 8 weeks after surgery and MS score of the locomotive function of hind limbs among mice of four groups. Neural stem cells were showed anti Nestin (+), anti NSE (+), anti GFAP (+). The gel tested by scanning electron microscope was showed thick wall structure, another one tested by transmission electron microscope was showed self-polymerized dendritic nanofibers, which contains several spacings. The cells in serum group were differentiate into neurons, but non serum group were not. These results suggest that the self-assembling peptide nanofiber scaffold(SAPNS) were cytocompatible to neural stem cells which were differentiated into neurons. A large number of axonal regeneration and recovery of joint function of hind limb were appeared. The self-polymerized Peptide maybe used as practical tissue engineering materials as future.