Recellularized neural complex for repair of sciatic nerve gap and nerve-muscle construction as well as functional rehabilitation in rabbits / 中国组织工程研究

ABSTRACT

BACKGROUND: Previous studies has explored the effects of nerve growth factor (NGF) on cultured rabbit Schwann cells as well as preparation of acellular nerve allografts, in addition, the neural complex was prepared in vitro.OBJECTIVE: To investigate the effect of acellular nerve allografts on the functional recovery and reconstruction of the nerve-muscle structure of the sciatic nerve defect in rabbits.DESIGN, TIME AND SETTING: The randomized controlled animal experiment was performed at the Center Laboratory of Third Hospital of Hebei Medical University from March 2006 to June 2007.MATERIALS Totally 37 healthy, adult, New Zealand, white rabbits were selected. One rabbit was prepared for extracted nerve bridge, and the others were randomly divided into the experimental and control groups, with 18 animals in each group.METHODS: The double sides of sciatic nerve were removed, divested surrounding tissues, and cut into 3 cm segments, then placed in TdtonX-100 solution for 12 hours, washing with distilled water. The procedure was repeated, and TritonX-100 totally used for 96 hours. Then the extracted nerve bridge was conserved in Hank's solution at temperature of 4 ℃. The concentration of 2~(nd) passage Schwann cell was regulated to 1 ×10~(11)/L, and injected to extracted nerve bridge, followed by DMEM culture, to obtain neural complex. Rabbits in the experimental group were prepared a 20 m defects above knee joints, and the recellularized neural complex were transplanted into the defective sciatic nerve. Rabbits in the control group were prepared by transplanting extracted nerve bridge without Schwann cells.MAIN OUTCOME MEASURES: The elcosis and healing of feet were observed at weeks 4, 8, and 16 after operation, meantime,the recovery of axon of distal end peroneal nerves, myelin sheath, tibialis anterior, as well as motor end plate were detected by electromyogram, light microscope and transmission electron microscope.RESULTS: At weeks 4, 8 and 16 after operation, the rejection was not found in the operating field. The experimental group was better than the control group in healing of ulcers, the number of nerve fibres, the ultramicrostructure of medullary sheaths, the regeneration nerve, the structure of the motor end plate and muscle. At 4 weeks after operation, no nerve conduction was found in 2 groups, but at weeks 8 and 16 after operation, the experimental group was better than the control group in wet weight of tibialis anterior muscle and nerve conduction velocity (P < 0.05).CONCLUSION: The recellularized neural complex can significantly promote the reconstruction of the nerve-muscle structure and functional recovery of injured sciatic nerve.