Animal model

Male Sprague–Dawley rats (180–200 g) were provided by the Experimental Animal Center of Nantong University. The rats were randomly divided into eight groups (six rats per group) and underwent sciatic neurectomy. All animal tests were conducted in accordance with the US National Institutes of Health’s Guide for the Care and Use of Laboratory Animals and by the Key Laboratory of Neuroregeneration Guidelines for the Care and Use of Laboratory Animals. The Institutional Animal Care and Use Committee of Nantong University approved all protocols used in this study.

The rats were anesthetized using an injection of complex narcotics (85 mg/kg trichloroacetaldehyde monohydrate, 42 mg/kg magnesium sulfate, and 17 mg/kg sodium pentobarbital), and the sciatic nerve was identified and lifted through an incision on the lateral aspect of the mid-thigh of the right hind limb. The sciatic nerve was cut, and a 1-cm segment was excised. One group of rats was immediately used in experiments (0 h), and the other groups were used 6, 12, and 24 h as well as 1, 2, 3, and 4 weeks after the surgery. The 0-h animals received sham operations.