Bridging of peripheral nerve defects with exogenous laminin-fibrin matrix in silicone tubes in a rat model

Fibrin matrix (FM) is a biological substance involved in the comprehensive wound healing process, and has been used in local applications as a carrier of nerve growth factor (NGF) to achieve an effective local neurotrophic concentration by slow release of the factor. In the present experiment, an exogenous fibrin matrix enriched with laminin (LM) and tubulized by a silicone conduit was used to improve the bridging effect of a peripheral nerve defect in a rat model. A 10 mm nerve defect was bridged with a 14 mm silicone conduit which was prefilled either with 25 μl fibrin matrix enriched without or with laminin (0.1 μg/ml), serving as groups FM and LM-FM, or with the same amount of saline solution for control (CTR group) (n = 10). After 12 weeks, the nerve conduction velocity and the distal latency were calculated from the electromyographic recordings. In addition, morphological semi-quantitative evaluations in longitudinal and transversal sections were carried out by immuno-histochemical staining with a monoclonal antibody against neurofilament. An improvement in nerve conduction velocity and distal latency, and a better orientation of the regenerated nerve fibers in the gap area were achieved in the LM-FM group than in the CTR and FM groups. These results indicate that the bridging of peripheral nerve defect in a rat model may be improved by the use of exogenous fibrin matrix enriched with laminin (as a filling material) in a silicone conduit.