Topically-administered acetyl-L-carnitine increases sciatic nerve regeneration and improves functional recovery after tubulization of transected short nerve gaps

BACKGROUND: Peripheral nerve injuries repair is still among the most challenging and concern-raising tasks in neurosurgery. The effect of an acetyl-L-carnitin-loaded silicone tube as an in-situ delivery system in defects bridging was studied using a rat sciatic nerve regeneration model. METHODS: A 10-mm sciatic nerve defect was bridged using a silicone tube (SIL/ALC) filled with 10 mu L acetyl-L-carnitine (100 ng/mL). In the control group (SIL), the tube was filled with the same volume of the phosphate-buffered solution. The regenerated fibers were studied 4, 8, 12 and 16 weeks after surgery. RESULTS: The functional study confirmed faster recovery of the regenerated axons in acetyl-L-carnitine treated than control group (P<0.05). The mean ratios of gastrocnemius muscles weight were measured. There was a statistically significant difference between the muscle weight ratios of SIL/ALC and SIL groups (P<0.05). Morphometric indices of regenerated fibers showed that the number and diameter of the myelinated fibers in SIL/ALC were significantly higher than in the control group. In immuohistochemistry, the location of reactions to S-100 in the SIL/ALC group was clearly more positive than in the SIL group. CONCLUSIONS: Acetyl-L-carnitine, when loaded in a silicone tube, can bring to an improvement in functional recovery and quantitative morphometric indices of sciatic nerve.