动物造模 z-bio 2022-04-03 436

　　Objective: To explore the feasibility of chitosan catheter combined with simvastatin/poloxamer 407 hydrogel as acellular artificial nerve scaffold to repair sciatic nerve defect.

　　Methods: Chitosan catheters and simvastatin/poloxamer 407 hydrogels were prepared, and the properties of the composites were observed by stereo microscopy, scanning electron microscopy, in vitro degradation experiments and rheological tests. A total of 40 SD rats of SPF grade were selected and divided into 4 groups: simple catheter group, catheter combined with simvastatin 0 mg group, catheter combined with simvastatin 0.5 mg group, and catheter combined with simvastatin 1 mg group. The control group and the last two groups were simvastatin treatment groups, with 10 rats in each group. A 10 mm defect model of the left sciatic nerve was created, and the defect was bridged with a chitosan catheter, which was filled with different concentrations of simvastatin hydrogel. Ten weeks after transplantation, the middle segment of the regenerated nerve was harvested for HE staining and transmission electron microscopy to observe the morphological changes of the regenerated nerve, and the number of axons, myelin sheath thickness, G-ratio, etc. of the regenerated nerve were statistically analyzed; immunohistochemistry The expressions of NF200 and S100 proteins and the expressions of neurotrophic factors PTN, HGF, GDNF and VEGF in the regenerated nerve were observed.

　　RESULTS: Chitosan catheter and simvastatin/poloxamer 407 hydrogel were suitable acellular repair materials for nerve defects. Ten weeks after implantation, regenerated nerves were seen in all four groups, but HE staining showed that the nerve trunks in the simvastatin-treated group were significantly thicker than those in the control group; transmission electron microscopy showed that the number of regenerated axons and myelin sheaths in the simvastatin-treated group increased significantly. G-ratio showed that the degree of myelination was also significantly better than that of the control group; immunohistochemistry showed that the positive expression of NF200 marking axons and S100 marking Schwann cells in the regenerated nerves of the simvastatin treatment group was significantly enhanced, and endogenous The neurotrophic factors PTN, HGF, VEGF and GDNF were highly expressed.

　　Conclusion: Chitosan catheter combined with simvastatin/poloxamer 407 hydrogel can significantly promote the reconstruction of nerve defect histology and can be used to repair sciatic nerve defect.