| ObjectiveThe trauma of peripheral nerves is the familiar clinical disease, most of which are caused by force, whatever in war or in common. According the trauma statistical information in Word War II , the number of trauma of peripheral nerves is 10% of all trauma. There are 60% of fracture by weapons, associated with trauma of peripheral. It always happens in ulnaris nerve, medianus nerve, radiulis nerve, sciatic nerve and peroneus communis nerve. It will cause serious disable of limbs, if it is treated irrelevant. The major therapy is auto nerve repla-ntment. However , because the nerve which can be replanted is finite , these operations are limited. In recent years ,with the development of tissue engineering , multiple repairment of Schwann cells and biomaterial is extensive used experiment method . Schwann cells is important structure and functional cells. And it is main role in regeneration of peripheral nerves, but for the difficulty of source and cultivation in vitro,the usage of it is limited.The success of isolation , purification, amplification and biological character of mesenchymal stem cells ( MSCs) from rabbit bone marrow offer a new seed sells of tissue engineering for repairment of peripheral nerves.The whole experiment of consisits isolation, purification, amplification and inducement into Schwann cells in vivo to promote the regeneration of rabbits sciatic nerve, so at to provide the parameter and evidence for clinical application of mesenchymal stem cells in the future.MethodsThe original isolation, cultivation, identify and plant into the rabbit model of cut sciatic nerve by expecting the in vivo inducement. Including therafter the mesenchmal stem cells were isolated from the thighbone of a rabbit of 2 months under axenic condition, being isolated by Percoll , so as to obtain one certain kind of simplex cells, according to the ability of affixing, filtrating the cells which were easy to affix and fall off to propagate . The original cells were culture in DMEM containing 15% fetal bovine serum. We observed the growth status of , and identify the phenotype of cells by immunocytochemistry of CD45 and CD90. 16 adult rabbits were divided into two equal teams at random. All of their left sciatic nerve were sharply transected and immediately repaired with 7/0 nylon sutures. MSCs of passage 3 with 50 ul culture fluid was pushed into distal stump of MSCs - treated group;50 ul pure culture fluid was pushed into distal stump of control group. Gross observation , electrophysiological examination and immuhis-tochemistry were carried out at 5 weeks post - operation.ResultWe cultivated the mesenchymal stem cells of passage one and the followed passage successfully, the mesenchymal stem cells of passage one were oval, short spindle - shaped, or polygonal under the light microscope . After purification and amplification ,they were uniform long spindl — shaped morphology. The cells of passage one welted on the 2n day , becoming collection between the 5' day, 90% overspread on the 14th day .The special mark antigen of CD45 is negative , CD90 were detected and op-sitive express by immunocytochemistry.5 weeks later,in gross observation,there were slight ulcer on control team rabbits"treated feet ,but nothing on the feet of MSCs -treated team. Under low narcotics , with stimulation the treated legs with needle , the rabbits in treated team reflected firmly,but ones in the control team reflect infirmly. Observatingthe distal stump with unaided eyes, there were muscle fibre aroud the nerve, after clearing the fibre ,the good repaired distal stump can be saw. Through electro-physiological examination , the electromyograms of rabbits "gastocnemius muscles in treated team were complicated potential, but the ones of the control team is appear the nerve - fibre - losing potential. The speed of conduction of nerves in the treated team is faster than the one of control team obviously ( p < 0. 05). Through the immuhistochemistry method it proved that the MSCs becomed the SchwamTs cells.ConclusionThe mesenchymal stem cells could be deduced into Schwannvs cells in vivo condition. And them can promote the regeneration of peripheral nerve.
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