Experimental Study Of Repairing Peripheral Nerve Injury With Salidroside Combined With Tissue Engineering Technique

Part1THE PROTECTIVE EFFECTS OF SALIDROSIDE ON SCHWANN CELLS IN VITRODrug therapy by using traditional herbs holds promise in treatment of peripheral nerve injury based on the minimum adverse effects. Derived from Rhodiola rosea L. which is a popular plant in Eastern Europe and Asia, salidroside have pharmacological properties including antiviral, anticancer, hep atoprotective, antidiabetic, and antioxidative effects. Recent studies showed that salidroside has neurotrophic and neuroprotective effects. However, the underlying mechanisms of the salidroside-induced nerve regeneration are still unknown and the effect of salidroside on Schwann cells (SCs) has seldom been studied. In this study, the effect of Salidroside on the attachment, proliferation and gene expressions of SCs lineage (RSC96) was studied though the examination of the cell proliferation, morphology, viability and expression of neurotrophic factor related genes. The results showed that salidroside significantly enhanced survival and migration of SCs. The underlying mechanism might involve salidroside affects on SCs growth through the modulation of several neurotrophic factors including brain derived neurotrophic factor (BDNF), glial cell-derived neurotrophic factor (GDNF), and cerebral dopamine neurotrophic factor (CDNF). As for the concentration,0.4mM,0.2mM and 0.1 mM of salidroside were recommended, especially 0.2mM. This investigation indicates that salidroside is capable of enhancing SCs survival and function in vitro, which highlights the possibility of promoting nerve regeneration in cellular nerve grafts through salidroside-increased neurotrophin secretion in SCs.PartCONSTRUCTION OF SCHWANN CELLS IN VITRO MODELS AND THE EFFECT OF SALIDROSIDE TO THE MODELObjective:To build the culture model of Schwann cells in vitro and observe the effect of Salidroside to the model.Methods:Sciatic nerves were aseptically removed from 8 neonatal (1-2d) SD rats under a dissecting microscope. After cutting into pieces, Schwann cells were extracted by mixing enzyme. Schwann cells were purified and passage following by conventional media, antimitotic media, promoting growth media and enhanced cell culture medium. Schwann cells of the second passage were taken to identify purity, through the expression of mouse anti-human polyclonal antibody(S-100 protein). In vitro model was built by culturing Schwann cells with 0.2mM of Salidroside and Non-Salidroside media respectively. The tests including cell proliferation, viability, morphology and expression of specific protein was taken after cultured of 3,6,9 days respectively.Result:Schwann cells adhered after 12h culturing. Cell bodies were arranged in parallel side by side at the 3rd day. At the 5th day, cells presented an "end to end, side by side" and other laws of mesh or spiral-shaped arrangement,shaped like a"carpet". Immunohistochemistry showed that cultured sciatic nerve Schwann cell purity of 98%.0.2mM concentration of salidroside can enhance Schwann cell proliferation, improve cell viability, and enhanced expression of specific proteins but had no effect on cell morphology in vitro model.Conclusion:Sciatic nerve in vitro model was successfully constructed. Salidroside can promote nerve repair based on in vitro models.PartEFFECT OF TISSUE ENGINEERING REPAIR TECHNIQUE COMBINED WITH SALIIDROSIDE TO SCIATIC NERVE INJURYObjective:Research using tissue engineering repair technologies and Salidroside to repair sciatic nerve injury.Methods:The weight is 200-250mg SD rats were randomly divided into three groups. Group A Injuries were directly sutured after cutting the left sciatic nerve; Group B After cutting off the sciatic nerve in rats utilize PLGA bridge and inject a mixture of Schwann cells and collagen. Group C Based on Group B, Salidroside was injected at post-op day 3, and continuously injected of 21 days. General morphology, Sciatic fuction index(SFI), histology test, specific proteins and sciatic electricity was measured at 4w,8w,12w respectively.Result:After operation, rat wounds healed well, did not want to touch the ground with left low limp claudication, left foot flexion shamed together. Mild symptoms showed in drug group. SFI test results indicated that drug relieved sciatic nerve injury than other two groups. Histology test presented that drug promoted sciatic nerve injury repairing than other two groups. Electrophysiological results suggest that the drug group sciatic nerve conduction velocity was significantly faster than the control group and the material group.Conclusion:Salidroside could protect peripheral nerve injury in rats, and accelerate the progress of nerve repair. Salidroside can be used for clinical treatment of peripheral nerve injury, with the value of further exploitation.