Synergistic effects of G‐CSF and bone marrow stromal cells on nerve regeneration with acellular nerve xenografts

Peripheral nerve defects result in severe denervation presenting sensory and motor functional incapacitation. Currently, a satisfactory therapeutic treatment promoting the repair of injured nerves is not available. As shown in our previous study, acellular nerve xenografts (ANX) implanted with bone marrow stromal cells (BMSCs) replaced allografts and promoted nerve regeneration. Additionally, granulocyte‐colony stimulating factor (G‐CSF) has been proven to mobilize supplemental cells and enhance vascularization in the niche. Thus, the study aimed to explore whether the combination of G‐CSF and BMSC‐laden ANX exhibited a synergistic effect. Adult Sprague‐Dawley (SD) rats were randomly divided into five groups: ANX group, ANX combined with G‐CSF group, BMSCs‐laden ANX group, BMSCs‐laden ANX combined with G‐CSF group and autograft group. Electrophysiological parameters and weight ratios of tibialis anterior muscles were detected at 8 weeks post‐transplantation. The morphology of the regenerated nerves was assayed, and growth‐promoting factors present in the nerve grafts following G‐CSF administration or BMSCs seeding were also investigated. Nerve regeneration and functional rehabilitation induced by the combination therapy were significantly advanced, and the rehabilitation efficacy was comparable with autografting. Moreover, the expression of Schwann cell markers, neurotrophic factors and neovessel markers in the nerve grafts was substantially increased. In conclusion, G‐CSF administration and BMSCs transplantation synergistically promoted the regeneration of ANX‐bridged nerves, which offers a superior strategy to replace autografts in repairing peripheral nerve injuries.     

Sciatic nerve repair by acellular nerve xenografts implanted with BMSCs in rats xenograft combined with BMSCs

Acellular nerves possess the structural and biochemical features similar to those of naive endoneurial tubes, and have been proved bioactive for allogeneil graft in nerve tissue engineering. However, the source of allogenic donators is restricted in clinical treatment. To explore sufficient substitutes for acellular nerve allografts (ANA), we investigated the effectiveness of acellular nerve xenografts (ANX) combined with bone marrow stromal cells (BMSCs) on repairing peripheral nerve injuries. The acellular nerves derived from Sprague-Dawley rats and New Zealand rabbits were prepared, respectively, and BMSCs were implanted into the nerve scaffolds and cultured in vitro. All the grafts were employed to bridge 1 cm rat sciatic nerve gaps. Fifty Wistar rats were randomly divided into five groups (n = 10 per group): ANA group, ANX group, BMSCs-laden ANA group, BMSCs-laden ANX group, and autologous nerve graft group. At 8 weeks post-transplantation, electrophysiological study was performed and the regenerated nerves were assayed morphologically. Besides, growth-promoting factors in the regenerated tissues following the BMSCs integration were detected. The results indicated that compared with the acellular nerve control groups, nerve regeneration and functional rehabilitation for the xenogenic nerve transplantation integrated with BMSCs were advanced significantly, and the rehabilitation efficacy was comparable with that of the autografting. The expression of neurotrophic factors in the regenerated nerves, together with that of brain-derived neurotrophic factor (BDNF) in the spinal cord and muscles were elevated largely. In conclusion, ANX implanted with BMSCs could replace allografts to promote nerve regeneration effectively, which offers a reliable approach for repairing peripheral nerve defects.     

Synergistic effects of ultrashort wave and bone marrow stromal cells on nerve regeneration with acellular nerve allografts

Acellular nerve allografts (ANA) possess bioactivity and neurite promoting factors in nerve tissue engineering. Previously we reported that low dose ultrashort wave (USW) radiation could enhance the rate and quality of peripheral nerve regeneration with ANA repairing sciatic nerve defects. Meanwhile, ANA implanted with bone marrow stromal cells (BMSCs) exhibited a similar result. Thus, it is interesting to know whether it might yield a synergistic effect when USW radiation is combined with BMSCs‐laden ANA. Here we investigated the effectiveness of ANA seeded with BMSCs, combined with USW therapy on repairing peripheral nerve injuries. Adult male Wistar rats were randomly divided into four groups: Dulbecco's modified Eagle's medium (DMEM) control group, BMSCs‐laden group, ultrashort wave (USW) group and BMSC + USW group. The regenerated nerves were assayed morphologically and functionally, and growth‐promoting factors in the regenerated tissues following USW administration or BMSCs integration were also detected. The results indicated that the combination therapy caused much better beneficial effects evidenced by increased myelinated nerve fiber number, myelin sheath thickness, axon diameter, sciatic function index, nerve conduction velocity, and restoration rate of tibialis anterior wet weight. Moreover, the mRNA levels of brain‐derived neurotrophic factor (BDNF) and vascular endothelial growth factor (VEGF) in the spinal cord and muscles were elevated significantly. In conclusion, we found a synergistic effect of USW radiation and BMSCs treatment on peripheral nerve regeneration, which may help establish novel strategies for repairing peripheral nerve defects. Synapse 67:637–647, 2013 . © 2013 Wiley Periodicals, Inc.     

A simple model of radial nerve injury in the rhesus monkey to evaluate peripheral nerve repair

Current research on bone marrow stem cell transplantation and autologous or xenogenic nerve transplantation for peripheral nerve regeneration has mainly focused on the repair of peripher-al nerve defects in rodents. In this study, we established a standardized experimental model of radial nerve defects in primates and evaluated the effect of repair on peripheral nerve injury. We repaired 2.5-cm lesions in the radial nerve of rhesus monkeys by transplantation of autografts, acellular allografts, or acellular allografts seeded with autologous bone marrow stem cells. Five months after surgery, regenerated nerve tissue was assessed for function, electrophysiology, and histomorphometry. Postoperative functional recovery was evaluated by the wrist-extension test. Compared with the simple autografts, the acellular allografts and allografts seeded with bone marrow stem cells facilitated remarkable recovery of the wrist-extension functions in the rhesus monkeys. This functional improvement was coupled with radial nerve distal axon growth, a higher percentage of neuron survival, increased nerve fiber density and diameter, increased myelin sheath thickness, and increased nerve conduction velocities and peak amplitudes of compound motor action potentials. Furthermore, the quality of nerve regeneration in the bone marrow stem cells-laden allografts group was comparable to that achieved with autografts. The wrist-extension test is a simple behavioral method for objective quantification of peripheral nerve regeneration.     

富血小板血浆诱导骨髓间充质干细胞结合化学萃取去细胞神经修复坐骨神经缺损

背景：周围神经损伤早期许旺细胞尚未大量分裂增殖,此时由于解剖连续性的中断,通过轴浆逆向运输提供的营养因子骤减,缺乏神经营养因子支持的神经元有可能死亡,从而使周围神经不能再生或再生乏力。 目的：观察植入经富血小板血浆诱导的骨髓间充质干细胞结合去细胞神经修复坐骨神经缺损的效果。 方法：取新西兰大耳白兔制备坐骨神经缺损模型,随机抽签法分成4组：去细胞神经组,移植同种异体去细胞神经;骨髓间充质干细胞组,移植同种异体骨髓间充质干细胞结合化学萃取的同种异体去细胞神经：经诱导骨髓间充质干细胞组,移植经富血小板血浆诱导的同种异体骨髓间充质干细胞结合化学萃取的同种异体去细胞神经;自体神经组,移植自体神经。术后进行形态学观察与靶肌肉肌湿质量恢复率、运动神经传导速度、轴突直径和髓鞘厚度的检测。 结果与结论：经富血小板血浆诱导的骨髓间充质干细胞结合化学萃取的去细胞神经移植修复神经的靶肌肉肌湿质量恢复率、运动神经传导速度、轴突直径和髓鞘厚度及形态学观察明显优于移植单纯化学萃取的去细胞神经与骨髓间充质干细胞结合化学萃取的去细胞神经的效果,而与移植自体神经修复结果相似。说明经诱导后的骨髓间充质干细胞在体内具有许旺细胞的部分功能,可作为组织工程化外周神经的种子细胞,用于周围神经缺损的修复。     

Etifoxine provides benefits in nerve repair with acellular nerve grafts

Introduction: Acellular nerve grafts are good candidates for nerve repair, but the clinical outcome of grafting is not always satisfactory. We investigated whether etifoxine could enhance nerve regeneration. Methods: Seventy‐two Sprague‐Dawley rats were divided into 3 groups: (1) autograft; (2) acellular nerve graft; and (3) acellular nerve graft plus etifoxine. Histological and electrophysiological examinations were performed to evaluate the efficacy of nerve regeneration. Walking‐track analysis was used to examine functional recovery. Quantitative polymerase chain reaction was used to evaluate changes in mRNA level. Results: Etifoxine: (i) increased expression of neurofilaments in regenerated axons; (ii) improved sciatic nerve regeneration measured by histological examination; (iii) increased nerve conduction velocity; (iv) improved walking behavior as measured by footprint analysis; and (v) boosted expression of neurotrophins. Conclusions: These results show that etifoxine can enhance peripheral nerve regeneration across large nerve gaps repaired by acellular nerve grafts by increasing expression of neurotrophins. Muscle Nerve 50:235–243, 2014     

Effects of 660‐nm gallium–aluminum–arsenide low‐energy laser on nerve regeneration after acellular nerve allograft in rats

Purpose : The purpose of this study was to explore and discuss the effects of 660‐nm gallium–aluminum–arsenide low‐energy laser (GaAlAs LEL) irradiation on neural regeneration after acellular nerve allograft repair of the sciatic nerve gap in rats. Methods : Eight male and female Sprague–Dawley rats were used as nerve donors, and 32 healthy Wistar rats were randomly divided into four groups: normal control group, acellular rat sciatic nerve (ARSN) group, laser group, and autograft group. Twelve weeks after surgery, nerve conduction velocity, restoration rate of tibialis anterior wet muscle weight, myelinated nerve number, and calcitonin gene‐related peptide (CGRP) protein and mRNA expression of the spinal cord and muscle at the injury site were quantified and statistically analyzed. Results : Compared with the ARSN group, laser therapy significantly increased nerve conduction velocity, restoration rate of tibialis anterior wet muscle weight, myelinated nerve number, and CGRP protein and mRNA expression of the L₄ spinal cord at the injury site. Conclusions : These findings demonstrate that 660‐nm GaAlAs LEL therapy upregulates CGRP protein and mRNA expression of the L₄ spinal cord at the injury site and increases the rate of regeneration and target reinnervation after acellular nerve allograft repair of the sciatic nerve gap in rats. Low‐energy laser irradiation may be a useful, noninvasive adjunct for promoting nerve regeneration in surgically induced defects repaired with ARSN. Synapse 64:152–160, 2010. © 2009 Wiley‐Liss, Inc.     

Effects of local release of hepatocyte growth factor on peripheral nerve regeneration in acellular nerve grafts

Options for reconstructing peripheral nerve gaps after trauma are limited. The acellular nerve is a new kind of biomaterial used to reconstruct the peripheral nerve defect, but its use could be improved upon. We aimed to investigate the effect of adenoviral transfection with hepatocyte growth factor (HGF) on the functional recovery of transected sciatic nerves repaired by acellular nerve grafting. 30 Rats were divided into three groups (10/group) for autografting and acellular grafting, as well as acellular grafting with adenovirus transfection of HGF (1 × 10⁸ pfu) injected in muscles around the proximal and distal allograft coapation. Sciatic functional index (SFI) was evaluated every 4 weeks to week 16 by measuring rat footprints on walking-track testing. The three groups presented initial complete functional loss, followed by slow but steady recovery, with final similar SFIs. Weight of the gastrocnemius and soleus muscles, histologic and morphometric study and neovascularization in the nerve grafts were evaluated at week 16. Autografting gave the best functional recovery, but HGF-treated acellular grafting gave better recovery than acellular grafting alone. Neovascularization was greater with HGF-treated acellular grafting than with autografting and acellular grafting alone. Axonal regeneration distance of autografting on the 20th postoperative day was the longest in the three groups,while that of acellular grafting alone was the smallest. Acellular nerve grafting may be useful for functional peripheral nerve regeneration, and with human HGF gene transfection may improve on acellular grafting alone in functional recovery.     

Nerve guides seeded with autologous schwann cells improve nerve regeneration

This study evaluates the ability of Schwann cells (SCs) transplanted into a nerve guide to improve regeneration and reinnervation after sciatic nerve resection and repair, leaving a 6-mm gap, in the mouse. SCs were isolated from predegenerated adult sciatic nerves and expanded in culture using a chemically defined medium. Syngeneic, isogeneic, and autologous SCs were suspended in Matrigel and seeded in resorbable, permeable poly(l-lactide-co-epsilon-caprolactone) guides at 150,000 cells/tube. Guides containing SCs were compared to guides filled with Matrigel alone and with peroneal nerve autografts. Functional reinnervation was assessed by noninvasive methods to determine recovery of sweating, nociceptive, sensory, and motor functions in the hindpaw during 4 months postoperation. Morphological analysis of the regenerated nerves was performed at the end of follow-up. The group with an autograft achieved faster and higher levels of reinnervation and higher number of regenerated myelinated fibers than groups repaired by tubulization. The immunogenicity of transplanted SCs influenced the outcome of nerve regeneration. Transplants of autologous SCs resulted in slightly lower levels of reinnervation than autografts, but higher recovery and number of regenerated fibers reaching the distal nerve than transplants of isologous and syngeneic SCs, although most of the differences were not statistically significant. Syngeneic SCs did not improve regeneration with respect to acellular guides. Prelabeled transplanted SCs were found to survive into the guide 1-3 months after implantation, to a larger number when they were autologous than syngeneic. Cellular prostheses composed of a resorbable guide seeded with autologous SCs appear as an alternative for repairing long gaps in injured nerves, approaching the success of autografts.     

富血小板血浆诱导骨髓间充质干细胞修复坐骨神经缺损：并与自体神经修复的效果相比较

目的：通过植入经PRP诱导的BMSCs结合化学萃取的去细胞神经修复坐骨神经缺损,观察其对周围神经的修复作用。 方法：32只新西兰大耳白兔,随机分成4组,即单纯的化学萃取的去细胞神经、BMSCs结合化学萃取的去细胞神经、经PRP诱导的BMSCs结合化学萃取的去细胞神和自体神经修复坐骨神经缺损,检测指标包括形态学观察、靶肌肉肌湿重恢复率、运动神经传导速度（MNCV）及轴突直径和髓鞘厚度等。 结果：结果显示,靶肌肉肌湿重恢复率、MNCV、轴突直径和髓鞘厚度和形态学观察在经PRP诱导的BMSCs结合化学萃取的去细胞神经组明显优于单纯的化学萃取的去细胞神经组和BMSCs结合化学萃取的去细胞神经组,而与自体神经修复组结果相似。 结论：经诱导后的BMSCs在体内具有SC的部分功能,可作为组织工程化外周神经的种子细胞,用于周围神经缺损的修复。     

同种异体神经复合体修复兔周围神经缺损

背景：应用种植许旺细胞的去细胞同种异体神经复合体修复周围神经缺损,探索其对神经再生及功能恢复有更好的促进作用,并且免疫原性非常小。 目的：用种植胎兔许旺细胞的去细胞同种异体神经复合体修复兔缺损的坐骨神经,观察移植神经周围免疫细胞的变化及功能恢复。 　 方法：48只新西兰白兔随机分成实验组和对照组。两组动物均切除一段坐骨神经,造成2.0 cm长的缺损,实验组用种植胎兔许旺细胞的同种异体神经复合体修复坐骨神经;对照组仅用去细胞同种异体神经修复。移植后1,4,8周光镜观察移植段坐骨神经周围肌肉组织中免疫细胞的浸润情况,计数每个高倍视野免疫细胞的数量。移植后4,8,16周大体观察兔的足部溃疡形成及愈合情况,大体观察神经愈合情况;肌电图检查桥接段坐骨神经的传导速度。 结果与结论：手术区局部均未出现明显的排斥反应,实验组足部溃疡愈合情况优于对照组。移植后1周移植段坐骨神经周围肌肉组织中有大量淋巴细胞及巨噬细胞浸润,实验组明显多于对照组(P < 0.05);移植后4周,浸润的免疫细胞两组均较1周后明显减少,实验组减少更明显。移植后8周,浸润的免疫细胞更加减少,但两组间比较差异无显著性意义(P > 0.05)。移植后4周时,两组均未见明显的神经传导,8,16周神经传导速度实验组均优于对照组(P < 0.05)。提示,种植许旺细胞的去细胞同种异体神经复合体免疫原性非常小,对神经再生及功能恢复有更好的促进作用。     

The impact of motor and sensory nerve architecture on nerve regeneration

Sensory nerve autografting is the standard of care for injuries resulting in a nerve gap. Recent work demonstrates superior regeneration with motor nerve grafts. Improved regeneration with motor grafting may be a result of the nerve's Schwann cell basal lamina tube size. Motor nerves have larger SC basal lamina tubes, which may allow more nerve fibers to cross a nerve graft repair. Architecture may partially explain the suboptimal clinical results seen with sensory nerve grafting techniques. To define the role of nerve architecture, we evaluated regeneration through acellular motor and sensory nerve grafts. Thirty-six Lewis rats underwent tibial nerve repairs with 5 mm double-cable motor or triple-cable sensory nerve isografts. Grafts were harvested and acellularized in University of Wisconsin solution. Control animals received fresh motor or sensory cable isografts. Nerves were harvested after 4 weeks and histomorphometry was performed. In 6 animals per group from the fresh motor and sensory cable graft groups, weekly walking tracks and wet muscle mass ratios were performed at 7 weeks. Histomorphometry revealed more robust nerve regeneration in both acellular and cellular motor grafts. Sensory groups showed poor regeneration with significantly decreased percent nerve, fiber count, and density (p < 0.05). Walking tracks revealed a trend toward improved functional recovery in the motor group. Gastrocnemius wet muscle mass ratios show a significantly greater muscle mass recovery in the motor group (p < 0.05). Nerve architecture (size of SC basal lamina tubes) plays an important role in nerve regeneration in a mixed nerve gap model.     

Acellular spinal cord scaffold seeded with bone marrow stromal cells protects tissue and promotes functional recovery in spinal cord‐injured rats

Therapy using scaffolds seeded with stem cells plays an important role in repair of spinal cord injury (SCI), with the transplanted cells differentiating into nerve cells to replace the lost tissue while releasing neurotrophic factors that contribute to repair following SCI and enhance the function of the damaged nervous system. The present study investigated the ability to extend the survival time of bone marrow stromal cells (BMSCs) to restore the damaged spinal cord and improve functional recovery by grafting acellular spinal cord (ASC) scaffold seeded or not with BMSCs in a rat model of acute hemisected SCI. BBB scores revealed that treatment with BMSCs seeded into ASC scaffold led to an obvious improvement in motor function recovery compared with treatment with ASC scaffold alone or untreated controls. This improvement was evident at 2 and 8 weeks after surgery (P < 0.05). When BMSCs labeled with 5‐bromodeoxyuridine were implanted together with ASC scaffold into the injured sites, they differentiated into glial cells, and some BMSCs could be observed within the graft by immunofluorescent staining at 8 weeks after implantation. Evaluation of caspase‐3 activation suggested that the graft group was able to reduce apoptosis compared with SCI alone at 8 weeks after operation (P < 0.05). This study suggests that ASC scaffolds have the ability to enhance BMSC survival and improve differentiation and could also reduce native damaged nerve tissue apoptosis, thus protecting host tissue as well as improving functional recovery after implantation. © 2013 Wiley Periodicals, Inc.     

Granulocyte‐macrophage colony‐stimulating factor improves mouse peripheral nerve regeneration following sciatic nerve crush

Peripheral nerve injuries severely impair patients’ quality of life as full recovery is seldom achieved. Upon axonal disruption, the distal nerve stump undergoes fragmentation, and myelin breaks down; the subsequent regeneration progression is dependent on cell debris removal. In addition to tissue clearance, macrophages release angiogenic and neurotrophic factors that contribute to axon growth. Based on the importance of macrophages for nerve regeneration, especially during the initial response to injury, we treated mice with granulocyte‐macrophage colony‐stimulating factor (GM‐CSF) at various intervals after sciatic nerve crushing. Sciatic nerves were histologically analyzed at different time intervals after injury for the presence of macrophages and indicators of regeneration. Functional recovery was followed by an automated walking track test. We found that GM‐CSF potentiated early axon growth, as indicated by the enhanced expression of growth‐associated protein at 7 days postinjury. Inducible nitric oxide synthase expression increased at the beginning and at the end of the regenerative process, suggesting that nitric oxide is involved in axon growth and pruning. As expected, GM‐CSF treatment stimulated macrophage infiltration, which increased at 7 and 14 days; however, it did not improve myelin clearance. Instead, GM‐CSF stimulated early brain‐derived neurotrophic factor (BDNF) production, which peaked at 7 days. Locomotor recovery pattern was not improved by GM‐CSF treatment. The present results suggest that GM‐CSF may have beneficial effects on early axonal regeneration.     

GDNF‐treated acellular nerve graft promotes motoneuron axon regeneration after implantation into cervical root avulsed spinal cord

T‐H. Chu, L. Wang, A. Guo, V. W‐K. Chan, C. W‐M. Wong and W. Wu (2012) Neuropathology and Applied Neurobiology 38, 681–695 GDNF‐treated acellular nerve graft promotes motoneuron axon regeneration after implantation into cervical root avulsed spinal cord It is well known that glial cell line‐derived neurotrophic factor (GDNF) is a potent neurotrophic factor for motoneurons. We have previously shown that it greatly enhanced motoneuron survival and axon regeneration after implantation of peripheral nerve graft following spinal root avulsion. Aims: In the current study, we explore whether injection of GDNF promotes axon regeneration in decellularized nerve induced by repeated freeze‐thaw cycles. Methods: We injected saline or GDNF into the decellularized nerve after root avulsion in adult Sprague–Dawley rats and assessed motoneuron axon regeneration and Schwann cell migration by retrograde labelling and immunohistochemistry. Results: We found that no axons were present in saline‐treated acellular nerve whereas Schwann cells migrated into GDNF‐treated acellular nerve grafts. We also found that Schwann cells migrated into the nerve grafts as early as 4 days after implantation, coinciding with the first appearance of regenerating axons in the grafts. Application of GDNF outside the graft did not induce Schwann cell infiltration nor axon regeneration into the graft. Application of pleiotrophin, a trophic factor which promotes axon regeneration but not Schwann cell migration, did not promote axon infiltration into acellular nerve graft. Conclusions: We conclude that GDNF induced Schwann cell migration and axon regeneration into the acellular nerve graft. Our findings can be of potential clinical value to develop acellular nerve grafting for use in spinal root avulsion injuries.     

Comparison of beneficial effects of undifferentiated cultured bone marrow stromal cells and omental adipose-derived nucleated cell fractions on sciatic nerve regeneration

Adipose tissue is a good source for isolation of cells with stem-cell-like properties. The effects of undifferentiated cultured bone marrow stromal cells (BMSCs) and omental adipose-derived nucleated cells (OADNCs) on peripheral nerve regeneration were compared in a rat nerve regeneration model. A 10-mm sciatic nerve defect was bridged using a vein graft. In one group, the vein was filled with BMSCs and in the other group with OADNCs. Functional study, morphometric indices, and immunohistochemistry indicated there was no significant difference (P > 0.05) between groups in recovery of regenerated axons at 4, 8, and 12 weeks after surgery. OADNCs enhanced regeneration similar to undifferentiated BMSCs. These observations suggest OADNCs represent an effective and cost-saving cell population due to the shortened time interval from tissue collection to cell injection as well as procedural simplicity. This approach is clinically translatable toward new methods for enhanced peripheral nerve repair without the limitations of BMSC.     

Chemically extracted aceUular allogeneic nerve graft combined with ciliary neurotrophic factor promotes sciatic nerve repair

A chemically extracted acellular allogeneic nerve graft can reduce postoperative immune rejection, similar to an autologous nerve graft, and can guide neural regeneration. However, it remains poorly understood whether a chemically extracted acellular allogeneic nerve graft combined with neurotrophic factors provides a good local environment for neural regeneration. This study investigated the repair of injured rat sciatic nerve using a chemically extracted acellular allogeneic nerve graft combined with ciliary neurotrophic factor. An autologous nerve anastomosis group and a chemical acellular allogeneic nerve bridging group were prepared as controls. At 8 weeks after repair, sciatic functional index, evoked potential amplitude of the soleus muscle, triceps wet weight recovery rate, total number of myelinated nerve fibers and myelin sheath thickness were measured. For these indices, values in the three groups showed the autologous nerve anastomosis group 〉 chemically extracted acellular nerve graft ＋ ciliary neurotrophic factor group 〉 chemical acellular allogeneic nerve bridging group. These results suggest that chemically extracted acellular nerve grafts combined with ciliary neurotrophic factor can repair sciatic nerve defects, and that this repair is inferior to autologous nerve anastomosis, but superior to chemically extracted acellular allogeneic nerve bridging alone.     

骨骼肌卫星细胞异体移植对周围神经缺损后再生的影响

背景：有研究表明肌卫星细胞不仅在体外具有较强的增殖能力及适应能力,而且在异体内免疫原性低,免疫排斥反应低,移植后存活时间长。因此设想肌卫星细胞异体移植在促进缺损神经再生等方面可能具有良好的研究和应用前景。 目的：探讨骨骼肌卫星细胞移植对周围神经缺损后再生修复的影响。 方法：将16只Wistar大鼠随机分成移植组与对照组,每组8只,均切断右后肢坐骨神经,并通过生物可降解膜包裹缺损神经断端形成神经再生室。用微量注射器抽取已配制成的肌干细胞悬液0.2 mL注入移植组的神经再生室内。对照组注入等量的生理盐水。术后4,8和12周进行大鼠行步态测定,并用锇酸染色法制片观察缺损神经再生情况。观测大鼠坐骨神经功能指数、腓肠肌湿质量恢复率、再生的有髓神经纤维数量和直径及髓鞘厚度的变化。 结果与结论：大鼠经肌卫星细胞移植后腓肠肌湿质量残存率、再生的有髓神经纤维数目、直径及髓鞘厚度等项检测指标与对照组相比均差异有显著性意义(P < 0.05)。术后8和12周,移植组坐骨神经功能指数恢复情况明显优于对照组(P < 0.05)。实验结果提示在神经再生室中加入肌卫星细胞能促进缺损神经纤维的再生及其结构的成熟。 关键词：肌卫星细胞;生物可降解膜;异体;细胞移植;周围神经缺损;神经再生     

HRP逆行示踪评价复合骨髓间充质干细胞的无细胞神经移植物

背景：作者前期将无细胞神经移植物与骨髓间充质干细胞复合培养,成功构建了组织工程人工神经。 目的：应用辣根过氧化物酶(HRP)神经逆行示踪技术对无细胞神经移植物复合骨髓间充质干细胞构建的神经移植复合体桥接大鼠坐骨神经缺损后运动神经元的保护作用进行评价。 方法：成年清洁级健康雄性SD大鼠,随机分成3组：①实验组：采用复合骨髓间充质干细胞的无细胞神经移植物桥接大鼠坐骨神经缺损。②空白对照组：采用无细胞神经移植物桥接大鼠坐骨神经缺损。③自体神经对照组：采用自体神经移植桥接大鼠坐骨神经缺损。术后12周应用辣根过氧化物酶神经逆行示踪技术对脊髓前角运动神经元的再生进行评价。 结果与结论：术后12周脊髓前角运动神经元再生评价结果显示：实验组优于无细胞神经移植物组,而与自体神经移植物组相比差异无显著性意义。证实无细胞神经移植物复合骨髓间充质干细胞构建组织工程人工神经修复大鼠坐骨神经缺损,对大鼠脊髓运动神经元具有保护作用,可能达到与自体神经移植相似的效果。 关键词：无细胞神经移植物;骨髓间充质干细胞;辣根过氧化物酶;神经移植;大鼠     

Schwann cells seeded in acellular nerve grafts improve functional recovery

Introduction: This study evaluated whether Schwann cells (SCs) from different nerve sources transplanted into cold‐preserved acellular nerve grafts (CP‐ANGs) would improve functional regeneration compared with nerve isografts. Methods: SCs isolated and expanded from motor and sensory branches of rat femoral and sciatic nerves were seeded into 14mm CP‐ANGs. Growth factor expression, axonal regeneration, and functional recovery were evaluated in a 14‐mm rat sciatic injury model and compared with isografts. Results: At 14 days, motor or sensory‐derived SCs increased expression of growth factors in CP‐ANGs versus isografts. After 42 days, histomorphometric analysis found CP‐ANGs with SCs and isografts had similar numbers of regenerating nerve fibers. At 84 days, muscle force generation was similar for CP‐ANGs with SCs and isografts. SC source did not affect nerve fiber counts or muscle force generation. Conclusions: SCs transplanted into CP‐ANGs increase functional regeneration to isograft levels; however SC nerve source did not have an effect. Muscle Nerve 49 : 267–276, 2014