Effect of local administration of cyclosporine A on peripheral nerve regeneration in a rat sciatic nerve transection model

ObjectiveTo assess the effect of cyclosporine A (CsA) loaded in chitosan conduit on bridging the sciatic nerve defects in a rat model.MethodsA 10 mm sciatic nerve defect was bridged using a chitosan conduit filled with 10 μl carrier-drug dilution (10 μg/L CsA). In control group, the conduit was filled with the same volume of carrier dilution alone. The regenerated fibers were studied 4, 8 and 12 weeks after surgery.ResultsThe functional study confirmed faster recovery of the regenerated axons in treatment group than control group (P < 0.05). There was statistically significant difference of the gastrocnemius muscle weight ratios between treatment and control groups (P < 0.05). Morphometric indices of regenerated fibers showed that the number and diameter of the myelinated fibers in CsA-treated animals were significantly higher than those in control group. In immunohistochemistry, the location of reactions to S-100 in CsA group was clearly more positive than control group.ConclusionCsA loaded in a chitosan conduit results in improvement of functional recovery and quantitative morphometric indices of sciatic nerve. It is easily available without any complications compared with its systemic administration.