Peripheral nerve transplantation with growth factors for acute spinal cord injury / 中国组织工程研究

ABSTRACT

BACKGROUND: At present the strategy of nerve regeneration and repairng are main promoting nerve intrinsic regeneration capacity and improving the micro-environment. Studies have shown a number of combined treatment which could promote the regeneration and growth of nerve axon.OBJECTIVE: To explore the feasibility and effect of rat spinal cord injury repaired by peripheral nerve combined growth factor. METHODS: Sixty healthy adult female SD rats were randomly divided into 4 groups nerve graft group, nerve graft combined growth factor group, spinal cord transaction group and laminectomy group. Taking T_9 as the center, a longitudinal incision was conducted in rat skin, revealing dural sac, spinal cord was transected and removed 3 mm, 2-cm segment of the eighth to tenth intercostal nerve was obtained from nerve graft group and nerve graft combined with growth factor group, autologous intercostal nerve was cross-transplanted into spinal defect (proximal white matter and distal gray matter, distal white matter and proximal gray matter) after pruning appropriately. The transplanted intercostal nerves were fixed with fibrin glue in nerve graft group, while those in nerve graft combined growth factor group were fixed with fibrin glue containing 2.1 mg/L acidic fibroblast growth factor, followed by dural suture～ Stump of broken ends was done in spinal cord transection group, while laminectomy was performed in laminectomy group. RESULTS AND CONCLUSION: At 90 days post-surgery, somatosensory evoked potential (SEP) and motor evoked potential (MEP) were determined, the motor function of hind limbs was evaluated by the Basso. Beattie.Bresnahan (BBB) test at 70 days. Both SEP and MEP were led in the laminectomy group, but not lead in spinal cord transection group; in nerve graft group, 3 rats showed bilateral SEP, 4 led unilateral SEP, 4 led bilateral MEP, 3 led unilateral MEP; in nerve graft combined with growth factor group, 5 led bilateral SEP and 2 led unilateral SEP, 5 led bilateral MEP and 2 led unilateral MEP. The SEP and MEP latency and amplitude in the nerve graft group and nerve graft combined growth factor group were significantly superior to the spinal cord transection group (P < 0.01), autologous rib nerve graft group was better than nerve graft combined growth factor group (P <0.01). In the laminectomy group, awake rats following anesthesia returned to normal exercise, rats in spinal cord transection group continued to extend limbs and rotated within 3 months, rats in other two groups recovered functions obviously 3 weeks post-surgery and gradually restored throughout the entire observation period. Nerve graft group and nerve graft combined growth factor group showed significantly increased BBB score compared with spinal cord transection were (P < 0.01), and the nerve graft combined growth factor group was superior to nerve graft group (P < 0.01). The peripheral nerve graft can promote the spinal function following spinal cord injury, while the nerve combined growth factor can better restore the function.