骨髓干细胞诱导分化构建组织工程神经

目的]探讨组织工程化神经修复周围神经缺损的作用。方法]以DMEM为培养基体外诱导人骨髓基质干细胞分化为雪旺细胞，与细胞外基质及可降解聚乳酸导管构建组织工程化神经；建立坐骨神经缺损10mm的Wistar大鼠动物模型，A组：经诱导骨髓基质干细胞分化雪旺细胞与天然细胞外基质（extra cellular matrix，ECM）凝胶及可降解聚乳酸导管构建组织工程化神经桥接神经缺损；B组：单纯将ECM凝胶注入可降解聚乳酸导管桥接神经缺损；C组：自体神经移植组。术后12周进行神经电生理检测、新生神经组织学观察和轴突计数等检测坐骨神经功能恢复情况。结果]1．诱导后骨髓基质干细胞呈梭形、胞核大、周围有光晕、突起细长呈纵形排列，GAFP及S-100免疫组织化学染色阳性。动物模型各组经移植术后12周，再生神经已通过缺损区长至神经远端。A组、C组组织学及电生理检测指标均优于B组（PAB=0．021，PBC=0．001），A组与C组无显著性差异（PAC=0．065）；A、B组聚乳酸导管降解吸收明显。结论]骨髓基质干细胞在体外可诱导分化为雪旺氏细胞，利用其与细胞外基质及可降解聚乳酸导管构建组织工程化神经可以修复周围神经缺损。

Repairing peripheral nerve defect by tissue engineered nerve

Objective]To evaluate the effect of the tissue engineered nerve for bridging and repairing verve defect.Method]Human bone marrow stromal cells(hBMSCs) were purified with centrifugate method,cultured in DMEM,induced with ATRA,BDGF and affected by heregulin,forsholin,bFGF(basic fibroblast growth factor),and PDGF(platelet-derived growth factor) of hBMSCs).The protein positive rate of S100 and GFAP of hBMSCs were determined by immunohistochmical staining.The tissue engineered nerves were constructed with hBMSCs mixed with extra-cellular matrix(ECM) and polylactic acid(PLA) tube.A 10mm defect of sciatic nerve was created in 24 Wistar mouse right limbs and ramdonly divided into three groups: group A(n=8),nerve defects bridged with polylactic acid(PLA) tube containing induced Schwann cells mixed with ECM,group B(n=8),with PLA tube containing ECM,group C(n=8) with autologous nerve graft.Functional recovery of nerve was examined by electrophysiological method and histological changes were examined with histological stainning of nerve and measurement quantity of new axon.Result]The Schwann cells were presented at 12 wks after operation.The histologic and functional recovery of nerves of group A and group C were better than those of group B.the showed significant difference between group A or group C and group B and no significant difference between group A and group C.(PAB=0.021,PBC=0.001,PAC=0.065).Degradation of PLA tubes showed in group A and group B.Conclusion]Schwann cells could be induced from hBMSCs,and the tissue engineered nerves,which were contructed by induced Schwann cells mixed with ECM and PLA tube,could be used to bridged and repair the peripheral nerve defect.