[Repair of facial nerve with bioactive artificial nerve conduit: experiment with rats].

OBJECTIVE

To evaluate the effect of bioactive artificial nerve conduits in the repair of facial nerve defects.

METHODS

Schwann cells (SC) were collected from the sciatic nerve and brachial plexus of a newborn SD rat, cultured, transfected with the plasmid pcDNA3. 1 (+)/GDNF containing glial cell line-derived neurotrophic factor gene, digested by pancreatin to make mixture of cell suspension to be injected into poly (L-lactic-co-glycolic acid) conduits. After injected with SCs, the conduits were cultured in for 2 weeks. Thirty female SD rat underwent buccal branch of facial nerve and then were randomly divided into 3 groups: Group A, undergoing direct anastomosis of the amputated dextral nerve; Group B, in which the 2 sides of amputated nerve were put into the PLGA conduit without transfected GDNF; and Group C in which the 2 sides of amputated nerve were put into the PLGA conduit with transfected GDNF. The motion of the facial muscles and whisker was observed. Two weeks, and 1, 2, and 3 months after the operation electrophysiological study was conducted to measure the action potential of the facial nerve. Then the rata were killed with their bilateral facial nerve and pontes were taken out to undergo histological examination.

RESULTS

Compound action potential could be detected in all groups at any time points except in Groups A and B 2 weeks after the operation. The values of compound action potential of Group C at different time points were all significantly higher than those of Groups A and B (all P < 0.01). However, there were not significant differences in the compound action potential values at any time point between Groups A and B (all P > 0.05). The mean number of myelinated nerve fibers, thickness of myelin sheath, and number of motor neuron of Group C were all significantly higher than those of Groups A and B (all P < 0.05).

CONCLUSION

Conduit with SCs transfected with GDNF gene + PLGA is superior to that with SCs + PLGA and direct anastomosis in repair of facial nerve.