生物活性增强型壳聚糖神经导管修复山羊腓总神经缺损

发布时间：2018-06-14 20:22

本文选题：周围神经修复 + 壳聚糖　；参考：《清华大学》2015年博士论文

【摘要】：对于长段周围神经缺损,导管桥接修复的临床效果仍具很大挑战性。当前研究热点是,研发各种具有生物学活性的神经导管,不断提高神经损伤的修复程度。本课题组经过前期研究,已研制出无抗原性、可控降解的壳聚糖基神经修复导管。本研究立足临床转化的实际需求,选取大型哺乳动物(山羊)的腓总神经作为研究对象,以长节段神经缺损为修复目标,探索两种生物活性增强型导管,即壳聚糖导管种植自体骨髓单个核细胞和壳聚糖神经导管复合神经营养因子(NGF、b FGF)缓释凝胶载体的应用可行性。首次采用3.0 T超导型磁共振扫描仪,应用一种优选扫描序列3D m FFE WATs,联合三维后处理技术,观察山羊腓总神经损伤后再生修复的高场强磁共振影像学表现,探讨其在周围神经损伤再生修复的活体形态显示方面的应用潜力。从动物的行为学、高场强磁共振神经成像、电生理、组织形态学,免疫组织化学等方面,观察神经再生与功能恢复情况。术后1年结果显示:(1)壳聚糖导管+自体骨髓单个核细胞,构建组织工程化人工神经,可以修复山羊腓总神经缺损30 mm,效果与自体神经移植相似:动物行为学改善至接近正常状态;再生神经的传导速度与自体神经移植组相比,无显著性差异;新生神经纤维直径较正常细,髓鞘较正常为薄,密度增大,但再生轴索贯通桥接物全长。而生理盐水对照组未见神经明显再生修复,与骨髓单个核细胞组和自体神经移植组相比具有显著差异(p0.05)。(2)壳聚糖导管+NGF/b FGF/肝素/纤连蛋白/纤维蛋白凝胶,成功修复26 mm神经缺损,动物行为学改善明显,电生理检测显示神经传导改善,组织学及MRI观察到神经再生显著且到达远段。而导管盐水对照组未见神经有效修复,与营养因子凝胶组相比具有显著差异(p0.05)。(3)高场强MRI能够清晰显示周围神经损伤及其修复过程,可以动态观察修复导管局部形态变化状况。本研究结果初步证实,增强型生物活性壳聚糖导管(复合骨髓单个核细胞或NGF/b FGF凝胶),能够促进较长距离神经的再生,并获得功能修复。基于统一标准的高度模拟人类的大动物周围神经缺损模型,建立客观量化功能评价体系,比较各种生物活性导管之间优劣,是下一步研究课题。
[Abstract]:For long peripheral nerve defect, the clinical effect of bridge repair is still very challenging. The current research focus is to develop a variety of biological active nerve conduits to improve the degree of nerve injury repair. After previous research, a non-antigenic and controllable degradation chitosan nerve repair catheter has been developed. In this study, based on the practical needs of clinical transformation, the common peroneal nerve of large mammal (goat) was selected as the research object, and two bioactive enhanced catheters were explored with the long segment nerve defect as the repair target. The feasibility of using chitosan catheter to implant autologous bone marrow mononuclear cells and chitosan nerve conduit combined with NGFGF-FGF-based sustained-release gel carrier was studied. A 3.0T superconducting magnetic resonance scanner was used for the first time to observe the high-field magnetic resonance imaging findings of regeneration and repair of the common peroneal nerve in goats by using a selective 3D FFE WATs and 3D post-processing technique. To explore its application potential in living form display of peripheral nerve regeneration and repair. Nerve regeneration and functional recovery were observed in animal behavior, high field magnetic resonance neurography, electrophysiology, histomorphology and immunohistochemistry. One year after operation, the results showed that the bone marrow mononuclear cells were autologous from the chitosan catheter to construct the tissue engineered artificial nerve. It can repair 30 mm defect of common peroneal nerve in goats, the effect is similar to that of autogenous nerve transplantation, the animal behavior is improved to close to normal state, the conduction velocity of regenerated nerve is not significantly different from that of autogenous nerve transplantation group. The diameter of neonate nerve fibers was finer than that of normal, the myelin sheath was thinner and the density increased, but the regenerated axonal bridging material was full length. There was no obvious nerve regeneration in the saline control group, and there was significant difference between the bone marrow mononuclear cells group and the autologous nerve transplantation group. The chitosan conduit NGF / bFGF- / heparin / fibronectin / fibrin gel was significantly different from that in the bone marrow mononuclear cells group and the autologous nerve transplantation group. The nerve defect of 26 mm was successfully repaired, the animal behavior was improved obviously, the nerve conduction was improved by electrophysiological examination, and the nerve regeneration was observed by histology and MRI. Compared with the nutrition factor gel group, the high field MRI could clearly show the peripheral nerve injury and its repair process, and could dynamically observe the local morphological changes of the repaired ducts. The results showed that the enhanced bioactive chitosan catheter (combined with bone marrow mononuclear cells or NGF / bFGF gel) could promote the regeneration of long distance nerve and obtain functional repair. The next step is to establish an objective quantitative function evaluation system based on the unified standard model which highly simulates the human peripheral nerve defect in large animals and to compare the merits and demerits of various bioactive catheters.
【学位授予单位】：清华大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：R651.3

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