Experimental study on autologous injectable platelets rich fibrin combined with bone mesenchymal stem cells in treating sciatic nerve injury in rats

Objective: To investigate the effectiveness of autologous injectable platelet rich fibrin (i-PRF) combined with bone marrow mesenchymal stem cells (BMSCs) for sciatic nerve injury in rats. 方法: 取 10～15 日龄 SD 乳鼠胫骨骨髓分离培养 BMSCs 至第 4 代备用。取 24 只成年 SD 大鼠眶后静脉血采用改良低速离心法制备 i-PRF 后，采用改良挤压损伤法制作坐骨神经Ⅲ度损伤模型后随机分为 4 组，每组 6 只。A、B、C、D 组分别于损伤部位鞘膜内注射 BMSCs 悬液+自体 i-PRF、自体 i-PRF、BMSCs 悬液、生理盐水。术后 1～8 周每周采用 BBB 评分法评价大鼠患肢神经功能恢复情况；术后 2 个月处死各组大鼠取材，行 HE 染色观察坐骨神经组织结构变化，透射电镜观察神经纤维、髓鞘、细胞核等细微结构改变，Western blot 检测 N-cadherin、巢蛋白（Nestin）、胶质纤维酸性蛋白（glial fibrillary acidic protein，GFAP）表达。. Results: No immune rejection or death occurred in the rats after operation. There was no significant difference in BBB scores between groups at 1 week after operation ( P>0.05); at 2-8 weeks after operation, BBB scores in group A were significantly higher than those in groups B, C, and D, and in groups B, C than in group D ( P 0.05). HE staining showed that the nerve fibers in group A arranged in order, without defect or demyelination; the nerve fibers in group B were not clear and slightly swollen; some of the nerve fibers in group C were disordered and demyelinated; the nerve fibers in group D were not continuous, obviously demyelinated, and some of the nerve adventitia damaged. Transmission electron microscope showed that the structure of nerve fibers in group A was clear, myelin sheath was complete, and nucleus was dense; group B was slightly less than group A; group C had fuzzy structure, demyelination, and hollowing out; group D had disorder structure, demyelination, and hollowing out, and the middle part of nerve adventitia continuity. Western blot detection results showed that there was no significant difference in the relative expression of Nestin between groups ( P>0.05). The relative expression of N-cadherin was significantly lower in groups B, C, and D than in group A, in groups C and D than in group B, and in group D than in group C ( P 0.05). Conclusion: Autologous i-PRF combined with BMSCs can effectively treat sciatic nerve tissue injury in rats.