The effects of triptolide on the cellular activity of cryopreserved rat sciatic nerves and nerve regeneration after allotransplantation

Purpose: To investigate the effects of triptolide (T10) on the cellular activity of cryopreserved rat sciatic nerves and nerve regeneration after allotransplantation.Materials and methods: After the optimal T10 concentration was determine, sciatic nerve fragments from Sprague-Dawley (SD) rats were randomly divided into 5 groups: the fresh nerve group (group A), the Dulbecco’s modified Eagle’s medium (DMEM)-preservation group (group B), the T10-preservation group (group C), the T10-pretreatment, DMEM-preservation group (group D), and the T10-pretreatment, T10-preservation group (group E). The nerves in the preservation groups were preserved at 4 °C for 4 w. Then, either cryopreserved or fresh nerves were used to repair 10-mm sciatic nerve defects in Wistar rats (group A′, group B′, group C′, group D′, and group E′, which correspond to the nerve groups described above); in addition, one fresh homologous transplantation group (group F′) was established.Results: Nerve growth factor (NGF) was expressed at significantly higher levels in the groups treated with the T10 solution at 37 °C. After rat sciatic nerves were cryopreserved for 4 w, group E had increased numbers of live nerve cells and increased levels of biological activity (P < 0.001) and reduced levels of immunogenicity (P < 0.001) when compared with those for the other groups. Sixteen weeks after transplantation, recipient nerve regeneration in group E′ was increased compared with that in groups A′, B′, C′, and D′ (P < 0.05).Conclusions: The application of T10 in vitro induced the expression of neurotrophic factors in rat sciatic nerves, increased the biological activity of cryopreserved nerves, reduced immunogenicity, and promoted recipient nerve regeneration after allotransplantation.