Regenerative effect of adipose tissue‐derived stem cells transplantation using nerve conduit therapy on sciatic nerve injury in rats

This study proposed a biodegradable GGT nerve conduit containing genipin crosslinked gelatin annexed with tricalcium phosphate (TCP) ceramic particles for the regeneration of peripheral nerves. Cytotoxicity tests revealed that GGT‐extracts were non‐toxic and promoted proliferation and neuronal differentiation in the induction of stem cells (i‐ASCs) derived from adipose tissue. Furthermore, the study confirmed the effectiveness of a GGT/i‐ASCs nerve conduit as a guidance channel in the repair of a 10‐mm gap in the sciatic nerve of rats. At eight weeks post‐implantation, walking track analysis showed a significantly higher sciatic function index (SFI) (P < 0.05) in the GGT/i‐ASC group than in the autograft group. Furthermore, the mean recovery index of compound muscle action potential (CMAP) differed significantly between GGT/i‐ASCs and autograft groups (P < 0.05), both of which were significantly superior to the GGT group (P < 0.05). No severe inflammatory reaction in the peripheral nerve tissue at the site of implantation was observed in either group. Histological observation and immunohistochemistry revealed that the morphology and distribution patterns of nerve fibers in the GGT/i‐ASCs nerve conduits were similar to those of the autografts. These promising results achieved through a combination of regenerative cells and GGT nerve conduits suggest the potential value in the future development of clinical applications for the treatment of peripheral nerve injury. Copyright © 2012 John Wiley & Sons, Ltd.     

Nanofibrous nerve conduit‐enhanced peripheral nerve regeneration

Fibre structures represent a potential class of materials for the formation of synthetic nerve conduits due to their biomimicking architecture. Although the advantages of fibres in enhancing nerve regeneration have been demonstrated, in vivo evaluation of fibre size effect on nerve regeneration remains limited. In this study, we analyzed the effects of fibre diameter of electrospun conduits on peripheral nerve regeneration across a 15‐mm critical defect gap in a rat sciatic nerve injury model. By using an electrospinning technique, fibrous conduits comprised of aligned electrospun poly (ε‐caprolactone) (PCL) microfibers (981 ± 83 nm, Microfiber) or nanofibers (251 ± 32 nm, Nanofiber) were obtained. At three months post implantation, axons regenerated across the defect gap in all animals that received fibrous conduits. In contrast, complete nerve regeneration was not observed in the control group that received empty, non‐porous PCL film conduits (Film). Nanofiber conduits resulted in significantly higher total number of myelinated axons and thicker myelin sheaths compared to Microfiber and Film conduits. Retrograde labeling revealed a significant increase in number of regenerated dorsal root ganglion sensory neurons in the presence of Nanofiber conduits (1.93 ± 0.71 × 10³ vs. 0.98 ± 0.30 × 10³ in Microfiber, p < 0.01). In addition, the compound muscle action potential (CMAP) amplitudes were higher and distal motor latency values were lower in the Nanofiber conduit group compared to the Microfiber group. This study demonstrated the impact of fibre size on peripheral nerve regeneration. These results could provide useful insights for future nerve guide designs. Copyright © 2012 John Wiley & Sons, Ltd.     

Stem cells treatment for sciatic nerve injury

Introduction: Sciatic nerve injury is common and usually results in degeneration of the distal axons and muscle denervation. Chronic muscle atrophy and fibrosis limit the recovery of muscle function and severely compromises efforts to restore muscle function. Despite early diagnosis and modern surgical techniques there is still poor functional recovery.

Areas covered: Stem cell transplantation has been investigated as a promising treatment strategy for peripheral nerve injury, and has demonstrated utility in limiting neuronal damage. The focus has been on the isolation of stem cells from bone-marrow and adipose tissue in addition to embryonic and neuronal stem cells. Transplantation of these cells into transected sciatic nerve in animal models demonstrates clinical improvement, inducing vigorous nerve regeneration accompanied by myelin synthesis. Cell replacement, trophic factor production, extracellular matrix molecule synthesis, guidance, remyelination, microenvironmental stabilization and immune modulation have been postulated as possible mechanisms for stem cell implantation.

Expert opinion: Although further research is still needed, this therapeutic approach will probably become a routine treatment technique in the coming years, especially with bone marrow mesenchymal stem cells. We believe that the most promising results were noted for the use of stem cells of this origin in the treatment of sciatic nerve injury.     

Facial nerve regeneration using basic fibroblast growth factor‐impregnated gelatin microspheres in a rat model

Basic fibroblast growth factor (bFGF) plays a crucial role in the regeneration of peripheral nerve defects by affecting nerve cells, Schwann cells and fibroblasts, and by promoting axon outgrowth from the proximal nerve stump. However, the use of exogenous bFGF for in vivo regeneration of the peripheral nerves is limited by its short in vivo half‐life. In this study, a drug delivery system for bFGF was developed that uses acidic gelatin hydrogel, which sustainably released bFGF in vivo over several weeks; its ability to promote peripheral nerve regeneration was also examined. In 8‐week‐old Lewis rats, 7‐mm gaps were made in the buccal branch of the left facial nerve. Acidic gelatin hydrogel microspheres (10 µl) with or without bFGF (50 µg) were infused into a 10 mm silicone tube using a micropipette, and the silicone tube was then implanted into the gap. A 1‐mm long nerve stump was inserted into each end of the tube. Histological examination at 7 weeks after implantation revealed (1) a significantly increased rate of nerve regeneration, (2) inducement of a number of regenerating nerve axons, and (3) a better degree of maturation of nerve axons in the bFGF microsphere group than that in the bFGF‐free microsphere group. Copyright © 2014 John Wiley & Sons, Ltd.     

雷公藤甲素在羊膜复合异体神经移植治疗坐骨神经损伤中的应用

目的：探讨雷公藤甲素对羊膜复合异体神经移植促神经再生和功能恢复的作用。方法：成年SD雄性大鼠30只,随机分3组,切除10mm坐骨神经造模,造模后3组分别采用自体神经移植、异体神经移植加雷公藤药物、异体神经移植。移植术后第24周,观察移植段神经形态学、坐骨神经指数（SFI,术后第8周开始）、胫前肌湿重、单位面积移植神经中段轴突数量和髓鞘厚度。结果：移植术后第24周自体神经移植组和异体神经移植加雷公藤药物组的坐骨神经指数、单位面积移植神经中段轴突数量和髓鞘厚度、胫前肌湿重各项检测指标无显著差异（P>0.05）, 但再生神经形态和功能恢复良好,检测的各项指标明显优于异体神经移植组（P<0.05）。结论：雷公藤甲素可促进同种异体神经移植神经再生和功能恢复治疗坐骨神经损伤。     

Functional recovery of denervated muscle by neurotization using nerve guidance channels

Tissue‐engineered muscle has been proposed as a means of repairing volumetric muscle defects to restore anatomical and functional recovery. We have previously demonstrated that denervated muscle, which is analogous to engineered muscle construct, can be reinnervated by direct transplantation of host nerve (neurotization) in a rat model. However, the use of this approach is not possible if the length of host nerve is inadequate and cannot be mobilized to the insertion site of the engineered muscle. In this study we investigated whether neurotization coupled with nerve guidance channels would increase the regeneration of neuromuscular junctions (NMJs) in completely denervated muscle and encourage neurofunctional recovery. Seventy‐two Lewis rats were evaluated in three groups, a normal control group (n = 8), a denervated group (n = 32) and a neurotization coupled with nerve guidance group (n = 32). Neurofunctional behaviour and histological evaluations were performed at 4, 8, 12 and 20 weeks postoperatively. Extensor postural thrust (EPT) and compound muscle action potential (CMAP) amplitude were significantly improved in the nerve guidance group when compared with the denervated group, even though these values were different from those of the normal control group at 20 weeks postoperation. Regeneration of axons and NMJs was demonstrated histologically in the nerve guidance group. Neurotization coupled with nerve guidance channels leads to regeneration of axons and NMJs in completely denervated muscle. To our knowledge, this is the first report to show that nerve guidance can allow re‐innervation in denervated muscle containing long‐gap nerve injuries. Copyright © 2013 John Wiley & Sons, Ltd.     

Enhanced in vivo survival of Schwann cells by a synthetic oxygen carrier promotes sciatic nerve regeneration and functional recovery

Local hypoxia in the early stages of peripheral nerve injury is a challenge for axonal regeneration. To address this issue, perfluorotributylamine (PFTBA)‐based oxygen carrying fibrin hydrogel was prepared and injected into Schwann cell (SC)‐seeded collagen‐chitosan conduits to increase oxygen supply to SCs within the conduits. The conduit containing PFTBA‐SC gel was then applied to bridge a 15‐mm sciatic nerve defect in rats. It was observed that most of the GFP‐labeled SCs initially seeded in the PFTBA hydrogel remained alive for approximately 28 days after their in vivo implantation. The number of SCs was significantly higher in the PFTBA‐SC scaffold than that in the SC scaffold without PFTBA. In addition, nerve regeneration and functional recovery were examined after nerve injury repair. We found that the PFTBA‐SC scaffold was capable of promoting axonal regeneration and remyelination of the regenerated axons. Further studies showed the PFTBA‐SC scaffold was able to accelerate the recovery of motor and sensory function of the regenerating nerves. Electrophysiological analysis showed area under the curve of compound muscle action potential and nerve conduction velocity were also improved, and gastrocnemius muscle atrophy was partially reversed by PFTBA‐SC scaffold. Furthermore, microvessel density analysis showed PFTBA‐SC composites were beneficial for microvascular growth, which provided sustained oxygen for regenerating nerve in the later stages of nerve regeneration. In conclusion, enhanced survival of SCs by PFTBA is capable of promoting sciatic nerve regeneration and functional recovery, which provides a new avenue for achieving better functional recovery in the treatment of peripheral nerve injuries. Copyright © 2016 John Wiley & Sons, Ltd.     

Cell‐free artificial implants of electrospun fibres in a three‐dimensional gelatin matrix support sciatic nerve regeneration in vivo

Surgical repair of larger peripheral nerve lesions requires the use of autologous nerve grafts. At present, clinical alternatives to avoid nerve transplantation consist of empty tubes, which are only suitable for the repair over short distances and have limited success. We developed a cell‐free, three‐dimensional scaffold for axonal guidance in long‐distance nerve repair. Sub‐micron scale fibres of biodegradable poly‐ε‐caprolactone (PCL) and collagen/PCL (c/PCL) blends were incorporated in a gelatin matrix and inserted in collagen tubes. The conduits were tested by replacing 15‐mm‐long segments of rat sciatic nerves in vivo. Biocompatibility of the implants and nerve regeneration were assessed histologically, with electromyography and with behavioural tests for motor functions. Functional repair was achieved in all animals with autologous transplants, in 12 of 13 rats that received artificial implants with an internal structure and in half of the animals with empty nerve conduits. In rats with implants containing c/PCL fibres, the extent of recovery (compound muscle action potentials, motor functions of the hind limbs) was superior to animals that had received empty implants, but not as good as with autologous nerve transplantation. Schwann cell migration and axonal regeneration were observed in all artificial implants, and muscular atrophy was reduced in comparison with animals that had received no implants. The present design represents a significant step towards cell‐free, artificial nerve bridges that can replace autologous nerve transplants in the clinic. Copyright © 2017 John Wiley & Sons, Ltd.     

分米波促周围神经再生机制的实验研究

目的:研究分米波对周围神经损伤后再生的影响。方法:构建大鼠坐骨神经再生的模型,实验组对受损神经局部进行分米波辐射,对照组空白对照。术后7、14、30、60和90天取材,行大体、光镜、电镜超微结构观察。术后90天行轴突图像分析及电生理检测。术后30、60和90天行坐骨神经功能指数(SFI)测定。结果:与对照组相比,实验组再生有髓神经纤维数目较多、轴突较粗且髓鞘较成熟,复合肌肉动作电位的潜伏期短、神经传导速度快且波幅较高,SFI的恢复率明显高于对照组,差异有显著性意义(P<0.01)。结论:分米波能促进周围神经的再生和功能恢复。     

不同浓度许旺细胞与聚乳酸-聚羟基乙酸共聚物修复损伤周围神经的比较

背景：有研究表明,许旺细胞神经移植复合体具有极强修复自体神经缺损作用,并且许旺细胞在神经再生过程中发挥至关重要的作用。目的：比较不同浓度许旺细胞神经移植复合体修复自体神经缺损时周围神经的再生效果。方法：建立坐骨神经缺损模型大鼠。原代培养大鼠许旺细胞,构建聚乳酸-聚羟基乙酸共聚物管-细胞外基质凝胶-许旺细胞神经移植复合体修复坐骨神经缺损模型大鼠。按许旺细胞浓度的不同分为105,106,107,108,109 L-1结果与结论：建模后3,6和12周,含许旺细胞各浓度的神经移植复合体组各时间点神经传导速率均高于对照组（P 〈0.01）,其中10浓度组,对照组不含许旺细胞。分别于建模后3,6和12周,行运动神经传导速度的测定。建模后12周各组胫骨前肌湿质量测量和组织学观察。8 L-1组运动神经传导速度优于其他各浓度组（P 〈0.05）。建模后12周,大鼠胫骨前肌苏木精-伊红染色显示,各浓度许旺细胞神经移植复合体组正常肌纤维数均多于对照组（P 〈0.05）。其中许旺细胞浓度108,109 L-1浓度组胫骨前肌形态恢复较好,肌纤维细条样、波浪状,同向而行,长短、粗细及疏密大致一致。结果证实,108 L-1许旺细胞神经聚乳酸-聚羟基乙酸共聚物移植复合体对缺损坐骨神经再生的促进作用较好。     

Ultrasound‐guided plasma rich in growth factors injections and scaffolds hasten motor nerve functional recovery in an ovine model of nerve crush injury

In the present study we evaluated the motor recovery process of peripheral nerve injury (PNI), based on electrophysiological and histomorphometric criteria, after treatment with plasma rich in growth factors (PRGF) injections and scaffolds in an ovine model. Three groups of sheep underwent a nerve crush lesion: the first group (n = 3) was left to recover spontaneously (SR); the second group was administered saline injections (SI; n = 5) and a third group (n = 6) received PRGF injections and scaffolds immediately after the crush injury. At post‐intervention week 8, 70% of sheep in the PRGF group were CMAP‐positive, with no electrophysiological response in the rest of the groups. Histomorphometric analysis 12 weeks after the surgical intervention revealed that the average axonal density of the SR (1184 ± 864 axons/µm²) and SI (3109 ± 2450 axons/µm²) groups was significantly inferior to the control (8427 ± 2433 axons/µm²) and also inferior to the PRGF group (5276 ± 4148 axons/µm²), showing no significant differences between the control and PRGF groups. The axonal size of the SR and SI groups was significantly smaller compared with the control group (18 ± 4 µm²), whereas the axonal size of the PRGF group (6 ± 5 µm²) did not show statistical differences from the control. Morphometry of the target muscles indicated that the PRGF group had the lowest percentage volume reduction 12 weeks after the crush injury. The PRGF group had larger muscle fibre areas than the SI and SR groups, although the differences did not reach statistical significance. Overall, these data suggest that the PRGF injections and scaffolds hastened functional axon recovery and dampened atrophy of the target muscles in an ovine model. Copyright © 2015 John Wiley & Sons, Ltd.     

Functional recovery guided by an electrospun silk fibroin conduit after sciatic nerve injury in rats

The aim of this study was to evaluate the regenerative capacity of a newly developed nerve guidance conduit using electrospun silk fibroin (SFNC) implanted in a 10‐mm defect of the sciatic nerve in rats. After evaluating the physical properties and cytocompatibility of SFNC in vitro, rats were randomly allocated into three groups: defect only, autograft and SFNC. To compare motor function and abnormal sensation among groups, ankle stance angle (ASA) and severity of autotomy were observed for 10 weeks after injury. Immunostaining with axonal neurofilament (NF) and myelin basic protein (MBP) antibodies were performed to investigate regenerated nerve fibres inside SFNC. ASA increased significantly in the SFNC group at 1, 7 and 10 weeks after injury compared to the defect only group (p < 0.05). At one week, mean ASA of the SFNC group was significantly higher than that of the autograft group (p < 0.05). Onset and severity of autotomy decreased significantly in the SFNC group compared to other groups (p < 0.05). Autotomy in the SFNC group started at 4 weeks and maximally reached toe level. However, the defect only and autograft groups first showed autotomy at 2 and 1 weeks following injury, respectively, and then reached the sole level. Well myelinated nerve fibres stained with NF and MBP were found inside SFNC. In conclusion, SFNC could be helpful in restoring motor function and preventing abnormal sensations after nerve injury. Copyright © 2012 John Wiley & Sons, Ltd.     

Electrospun silk fibroin‐based neural scaffold for bridging a long sciatic nerve gap in dogs

Silk fibroin (SF)‐derived silkworms represent a type of highly biocompatible biomaterial for tissue engineering. We have previously investigated biocompatibility of SF with neural cells isolated from the central nervous system or peripheral nerve system in vitro, and also developed a SF‐based nerve graft conduit or tissue‐engineered nerve grafts by introducing bone marrow mesenchymal stem cells, as support cells, into SF‐based scaffold and evaluated the outcomes of peripheral nerve repair in a rat model. As an extension of the previous study, the electrospun technique was performed here to fabricate SF‐based neural scaffold inserted with silk fibres for bridging a 30‐mm‐long sciatic nerve gap in dogs. Assessments including functional, histological and morphometrical analyses were applied 12 months after surgery. All the results indicated that the SF‐based neural scaffold group achieved satisfactory regenerative outcomes, which were close to those achieved by autologous nerve grafts as the golden‐standard for peripheral nerve repair. Overall, our results raise a potential possibility for the translation of SF‐based electrospun neural scaffolds as an alternative to nerve autografts into the clinic.     

Regenerated host axons form synapses with neurons derived from neural stem cells transplanted into peripheral nerves

It is reported that neural stem cells (NSC) can arrest denervated muscle atrophy and promote nerve regeneration when transplanted into injured peripheral nerves, and that regenerated host axons can form synapses with transplanted and differentiated NSC. In this study, F344 rat nerve segments and F344 rat NSC were transplanted into host green fluorescence protein (GFP) transgenic F344 rats. This allowed transplanted F344 rat tissue to be used as a nonluminous background for the clear visualization of regenerated host GFP axons. Regenerated host axons grew into the transplanted F344 nerve segment 2 weeks after nerve anastomosis. Immunohistochemical staining and confocal microscope analysis revealed that regenerated host axons formed synapses with NSC-derived neurons. The findings confirmed that regenerated peripheral axons form synapses with neurons in peripheral nerves, possibly forming the basis for clinical application in peripheral nerve injury.     

端侧吻合移植神经重建皮瓣感觉的形态观察

目的:探讨感觉神经端侧吻合重建皮瓣感觉的可能性。方法 :用新西兰兔25只 ,将兔的一条耳大神经作为供神经 ,在另侧耳取耳大神经移植体(受神经) ,与供神经作端侧吻合后埋入失神经皮瓣 ,按神经移植体埋入皮瓣后时间分为1、2、4个月3个实验组 ,另设正常皮肤组和未植神经对照组 ,每组动物5只。用抗神经丝抗体免疫组化技术观察神经再生形态和分布 ;用电镜观察再生神经的超微结构。结果 :(1)感觉神经端侧吻合后1个月 ,供神经的轴突即可长入神经移植体(受神经) ,随时间延长 ,再生轴突数量逐渐增多。(2)再生神经纤维的超微结构基本正常。结论 :兔耳大神经端侧吻合植入失神经皮瓣后 ,供神经的轴突能长入神经移植体 ,并最终形成具有功能的感觉未梢。     

Detergent‐based decellularized peripheral nerve allografts: An in vivo preclinical study in the rat sciatic nerve injury model

Nerve autograft is the gold standard technique to repair critical nerve defects, but efficient alternatives are needed. The present study evaluated the suitability of our novel Roosens‐based (RSN) decellularized peripheral nerve allografts (DPNAs) in the repair of 10‐mm sciatic nerve defect in rats at the functional and histological levels after 12 weeks. These DPNAs were compared with the autograft technique (AUTO) and Sondell (SD) or Hudson (HD) based DPNAs. Clinical and functional assessments demonstrated a partial regeneration in all operated animals. RSN‐based DPNAs results were comparable with SD and HD groups and closely comparable with the AUTO group without significant differences (p > .05). Overall hematological studies confirmed the biocompatibility of grafted DPNAs. In addition, biochemistry revealed some signs of muscle affection in all operated animals. These results were confirmed by the loss of weight and volume of the muscle and by muscle histology, especially in DPNAs. Histology of repaired nerves confirmed an active nerve tissue regeneration and partial myelination along with the implanted grafts, being the results obtained with HD and RSN‐based DPNAs comparable with the AUTO group. Finally, this in vivo study suggests that our novel RSN‐based DPNAs supported a comparable tissue regeneration, along the 10‐mm nerve gap, after 12‐week follow‐up to HD DPNAs, and both were superior to SD group and closely comparable with autograft technique. However, further improvements are needed to overcome the efficacy of the nerve autograft technique.     

A polylactic acid non‐woven nerve conduit for facial nerve regeneration in rats

This study developed a biodegradable nerve conduit with PLA non‐woven fabric and evaluated its nerve regeneration‐promoting effect. The buccal branch of the facial nerve of 8 week‐old Lewis rats was exposed, and a 7 mm nerve defect was created. A nerve conduit made of either PLA non‐woven fabric (mean fibre diameter 460 nm), or silicone tube filled with type I collagen gel, or an autologous nerve, was implanted into the nerve defect, and their nerve regenerative abilities were evaluated 13 weeks after the surgery. The number of myelinated neural fibres in the middle portion of the regenerated nerve was the highest for PLA tubes (mean ± SD, 5051 ± 2335), followed by autologous nerves (4233 ± 590) and silicone tubes (1604 ± 148). Axon diameter was significantly greater in the PLA tube group (5.17 ± 1.69 µm) than in the silicone tube group (4.25 ± 1.60 µm) and no significant difference was found between the PLA tube and autograft (5.53 ± 1.93 µm) groups. Myelin thickness was greatest for the autograft group (0.65 ± 0.24 µm), followed by the PLA tube (0.54 ± 0.18 µm) and silicone tube (0.38 ± 0.12 µm) groups, showing significant differences among the three groups. The PLA non‐woven fabric tube, composed of randomly‐connected PLA fibres, is porous and has a number of advantages, such as sufficient strength to maintain luminal structure. The tube has demonstrated a comparable ability to induce peripheral nerve regeneration following autologous nerve transplantation. Copyright © 2012 John Wiley & Sons, Ltd.     

PLGA artificial nerve conduits with dental pulp cells promote facial nerve regeneration

A number of recent studies have shown the effectiveness of tubulation, using neural progenitor cells or Schwann cells, for promoting nerve regeneration. However, the use of neural cells from other neural donor tissues has potentially serious clinical complications. Therefore, we focused on dental pulp as a new cell source for use in such artificial conditions. Previously, we showed that silicone tubes filled with dental pulp cells (DPCs) promoted facial nerve regeneration in rats. However, the use of silicone tubes requires a secondary removal operation because they may give rise to chronic inflammation and pain. Therefore, to avoid this procedure, a new artificial device was prepared from a degradable poly-DL-lactide-co-glycolide (PLGA) tube containing DPCs, and its effectiveness for repairing gaps in the facial nerves of rats was investigated. A PLGA tube containing rat DPCs embedded in a collagen gel was transplanted into a gap in a rat facial nerve. Five days after transplantation, the facial nerves connected by the PLGA tubes containing DPCs were repaired more quickly than the control nerves. The PLGA tubes were resorbed in vivo and nerve regeneration was observed 2 months after the transplantation. Immunostaining showed that Tuj1-positive axons were present in the regenerated nerves 2 months after transplantation, and osmium-toluidine blue staining showed no mineralization of the regenerated nerves in those tubes containing myelinated fibres after 9 weeks. PLGA tubes filled with DPCs promoted nerve regeneration and were readily resorbed in vivo.     

Ultrasound Elastographic Measurement of Sciatic Nerve Displacement and Shear Strain During Active and Passive Knee Extension

There is current need for objective measures of sciatic nerve mobility in patients with sciatic‐type pain. The objective of the study was to assess the feasibility and reliability of ultrasound elastography to quantify sciatic nerve displacement and shear strain at the sciatic nerve–hamstring muscle interface during active and passive knee extension‐flexion exercises performed while sitting in healthy people. Ultrasound elastography showed excellent intrarater within‐session reliability for assessing sciatic nerve displacement and sciatic nerve–hamstring muscle interface shear strain during active knee extension‐flexion exercises. These findings will inform similar future work conducted in patients with sciatic‐type pain.     

Testosterone propionate can promote effects of acellular nerve allograft‐seeded bone marrow mesenchymal stem cells on repairing canine sciatic nerve

Peripheral human nerves fail to regenerate across long tube implants (>2 cm), and tissue‐engineered nerve grafts represent a promising treatment alternative. The present study aims to investigate the testosterone propionate (TP) repair effect of acellular nerve allograft (ANA) seeded with allogeneic bone marrow mesenchymal stem cells (BMSCs) on 3‐cm canine sciatic nerve defect. ANA cellularized with allogeneic BMSCs was implanted to the defect, and TP was injected into the lateral crus of the defected leg. The normal group, the autograft group, the ANA + BMSCs group, the ANA group, and the nongrafted group were used as control. Five months postoperatively, dogs in the TP + ANA + BMSCs group were capable of load bearing, normal walking, and skipping, the autograft group and the ANA + BMSCs group demonstrated nearly the same despite a slight limp. The compound muscle action potentials (CMAPs) on the injured side to the uninjured site in the TP + ANA + BMSCs group were significantly higher than that in the ANA + BMSCs group [CMAPs ratio at A: F(3, 20) = 191.40; 0.02, CMAPs ratio at B: F(3, 20) = 43.27; 0.01]. Masson trichrome staining revealed that in the TP + ANA + BMSCs group, both the diameter ratio of the myelinated nerve and the thickness ratio of regenerated myelin sheath were significantly larger than that in the other groups [the diameter of myelinated nerve fibers: F(3, 56) = 13.45; P < .01, the thickness ratio of regenerated myelin sheath: F(3, 56) = 51.25; P < .01]. In conclusion, TP could significantly increase the repairing effects of the ANA + BMSCs group, and their combination was able to repair 3‐cm canine sciatic nerve defect. It therefore represents a promising therapeutic approach.