Effect of FK506 and basic fibroblast growth factor on nerve regeneration using a polytetrafluoroethylene chamber for nerve repair

Peripheral nerve repair can be accomplished by using a polytetrafluoroethylene tubular chamber to guide nerve healing and regeneration. In this study, we delivered basic fibroblast growth factor (bFGF) into the chamber for sciatic nerve repair in rats. In addition, the animals were given systemically 1 mg/kg/day FK506 (tacrolimus), a potent immunosuppressant with neurotrophic properties. Nerve regeneration was evaluated by means of a nociceptive test and a grasping test starting 2 weeks postoperatively. Animals that received bFGF and FK506 showed a significantly faster recovery from injury than did the control group. Morphometric analysis at 3 months showed no difference between the two groups in total number of axonal fibers, fiber diameter, fiber density, and myelin:axon ratio. We conclude that the combination of bFGF and low dose FK506 enhances nerve healing in this animal model by accelerating early regrowth but has no effect on the final outcome.