The Experiment Study Of Bone Marrow Mesenchymal Stem Cells With Support Of Ultrasound-mediated Microbubbles To Repair Peripheral Nerves

Objective:In this study,BMSCs were transplanted into the tail vein of rats with peripheral nerve injury.To study the feasibility of BMSCs homing to the site of peripheral nerve injury and repair of peripheral nerve injury which was induced by ultrasound-mediated microbubbles.In order to provide new strategies and ideas for the repair of peripheral nerve injury.Methods:Eight four-weeks old male Sprague-Dawley rats were chosen.Using whole bone marrow and adherent separation to get and label bone marrow mesenchymal stem cells.Sixty two-months old male Sprague-Dawley rats were chosen and separated into two groups randomly after establishing the rat models of peripheral nerve injury.All these rats were transplanted BMSCs into the tail vein 24 hours after the neurorrhaphy.The experimental group was intervented by ultrasound-mediated microbubbles While the control group was not intervented.Evaluating the healing of neurological function between the two groups through the general obeservation,sciatic nerve functional index,motor nerve conductive velocity,histological and immunohistochemical and the ultrastructure with transmission electron microscopy.Results:1.General obeservation:In the two groups of rats,the right lower extremity was completely paralyzed and the toes were together.The right lower extremity skid the ground while walking,and the ankles and toes prolapsed.The control group had three animals in the first and second weeks after operation,heel ulcers appeared and healed in 4-5 weeks.Heel ulcers did not appear in the experimental group,and no autophagy occurred in both groups.The recovery of sensory and autonomous movement was greatly faster in the experimental group than in the control group.2.Sciatic nerve functional index(SFI):SFI in both groups recovered slowly from four to twelve weeks after operation,and the recovery of the experimental group was greatly better than that of the control group after statistical analysis(P<0.05).3.Motor nerve conductive velocity(MNCV):The motor nerve conduction velocity and amplitude of the control group were greatly lower than those of the experimental group after statistical analysis(P<0.05).4.HE staining and immunohistochemical observation:HE staining:Nerve fibers can be seen growing to the distal end in both groups,but the experimental group has better nerve fiber arrangement and nerve regeneration per unit area than the control group.Immunohistochemical observation:The positive rate of S-100 in the experimental group was greatly higher than that in the control group,and the proliferation of Schwann cells in the peripheral nerve injury site of the experimental group was greatly better than that in the control group.5.The ultrastructure with transmission electron microscopy(TEM):In each high-power field of view,the number of nerve fibers,axon diameter,nerve fiber structure,and myelin thickness of the experimental group were better than those of the control group.Conclusion:ultrasound-mediated microbubbles can obviously promote the homing of BMSCs to peripheral nerve injury in rats,and improve the regeneration of peripheral nerve injury.However,the specific mechanism of this influence needs further study.