The optimal diameter of microfilaments in polylactic polyglycolic polymer three-dimensional conduit in repairing peripheral nerve defects

Abstract

Objective To studythe optimal diameter of microfilaments in polylactic polyglycolic polymer(PLGA)three-dimensional nerve conduit in repairing peripheral nerve defects of rats.Methods Sixty adult SD rats(weighing 300-350 g)were randomly divided into 6 groups(n=10),and their sciatic nerves(length:12 mm)were resected.In all groups except F group nerve defects were repaired using the PLGA nerve conduit containing 20 microfilaments with different diameters(60,80,100,120,and 140μm).The nerve conduits of all groups were filled with 0.3 ml laminin and never growth factor.The rats in group F were subjected to nerve autograft(control group).The left-behind legs served as experiment sides,and the right ones as control sides.To evaluate the repairing outcome,special assessments were performed including EMG testing,immunohistochemisty to test the number of regeneration nerves 12 weeks after operation.Results Twelve weeks after operation,compared to groups A and E,the conducting velocity and the weight of triceps muscle of calf were increased in groups B,C,D and F(P 0.05).Under light microscope and electron microscope,it waft,found there was significant difference in nerve fiber diameter,thickness of myelin sheath,and fiber density between groups B,C or D and groups A or C(P<0.05).Furthermore,image analysis suggested in the groups F,C,B,and D the nerve regeneration was better than in groups A and E in quantity of nerve fiber,thickness of myelin sheath,and nerve fiber diameter(P<0.05).Conclusion The diameters of microfilaments in three-dimensional nerve conduit can influence the regeneration of sciatic nerves,and the optimal diameter range is 80-120μm. Key words: Peripheral nerve; Nerve conduit; Tissue engineering