人工组织神经移植物辅加神经再生素修复大鼠周围神经缺损的实验研究

目的　用人工组织神经移植物辅加神经再生素 (NRF)桥接修复大鼠周围神经缺损。　方法　用壳聚糖套管和聚乙醇酸纤维制成人工组织神经移植物 ,辅加促神经生长的中药有效组分NRF ,桥接大鼠坐骨神经缺损10mm。术后作足迹试验 ;2 4周时对再生神经进行电生理学测试、形态学观察和计量学统计。　结果　术后 2 4周内 ,动物未见炎症及排斥反应。实验组的再生神经在足迹试验、电生理学、形态学及计量学上优于硅胶管桥接组。结论　人工组织神经移植物辅加NRF与周围神经组织具有良好的生物相容性 ;它对缺损的神经修复有较好的桥梁和促进作用     

甲壳素神经导管修复大鼠坐骨神经10mm缺损的实验研究

探讨壳聚糖导管乙酰化反应而成的甲壳素神经导管修复周围神经缺损的效果.先将脱乙酰度92.5%的壳聚糖经溶解、冷冻、成形、中和、干燥等步骤制成壳聚糖导管,再经乙酰化反应制备成甲壳素神经导管.以该神经导管桥接大鼠坐骨神经10mm缺损.术后16周,通过电生理、组织形态学等方法评价神经导管修复坐骨神经缺损的效果.结果显示,术后16周再生神经已通过甲壳素神经导管长入远端.坐骨神经干重新恢复连续性,再生神经具有电传导功能,并实现对靶肌肉的再支配.缺损组则未观察到神经再生.实验表明,壳聚糖导管乙酰化而成的甲壳素神经导管能有效修复周围神经缺损.     

脱细胞同种异体神经移植物修复大鼠坐骨神经缺损的实验研究

目的 观察脱细胞处理的同种异体神经移植物修复大鼠坐骨神经缺损的作用。方法 用组织工程学方法制备的大鼠同种异体神经移植物桥接大鼠坐骨神经缺损，并对再生神经进行电生理学功能测试，光镜、电镜观察移植物内的再生神经，并进行统计分析。结果 术后13周内，动物未见炎症及排斥反应。用脱细胞处理的同种异体神经移植物修复神经缺损，再生神经的传导功能、纤维数量、轴突直径、有髓纤维占有的面积与自体神经移植对照及计量学上统计分析均无显著性差异。结论 脱细胞处理的同种异体神经移植物具有良好的组织相容性，它对缺损的坐骨神经再生有促进作用。     

大鼠坐骨神经缺损半个月后人工组织神经移植物修复的实验研究

为了观察人工组织神经移植物对大鼠坐骨神经非新鲜损伤的修复作用。我们在成年SD大鼠左侧股中部切除部分坐骨神经制造神经缺损模型。15d后,实验组(9只)用人工组织神经移植物修复神经缺损,自体神经修复作为阳性对照(6只),保持神经缺损为阴性对照(6只)。第二次手术后3个月,电生理学、形态学结果显示实验组的再生神经虽略差于自体对照组,但明显优于缺损对照组,腓肠肌的萎缩形态学指标变化则较接近自体对照组。实验结果表明人工组织神经移植物对已缺损15d的大鼠周围神经具有较好修复作用。     

应用胶原-壳聚糖桥接管引导大鼠坐骨神经再生

目的:观察胶原-壳聚糖桥接管促进大鼠坐骨神经损伤后再生与修复的作用。方法:用壳聚糖和胶原蛋白按1∶3的比例采用冷冻干燥法制成胶原-壳聚糖复合导管;将20只雄性Wistar大鼠随机分为2组,胶原-壳聚糖导管组和硅胶管组,切断坐骨神经,建立10mm的缺损动物模型;分别用胶原-壳聚糖导管和硅胶管进行桥接。于术后不同时间对2组动物进行大体观察,并于术后14周进行电生理、组织学及逆行示踪检测,比较2组大鼠坐骨神经的再生和功能恢复情况。结果:术后14周2组动物坐骨神经再生和功能恢复情况的各项检测指标显示,胶原-壳聚糖桥接组明显优于硅胶管桥接组。结论:胶原-壳聚糖导管可用来桥接损伤神经,在周围神经缺损修复方面具有良好的应用前景。     

神经细胞外基质材料制备及修复周围神经缺损的实验研究

目的 :制备一种新型天然神经细胞外基质材料 ,通过动物实验研究 ,探讨其修复周围神经干节段性缺损的可行性。方法 :采用NaOH消蚀法 ,制备家兔坐骨神经细胞外基质材料 ,行扫描电镜观察及生物相容性实验 ,用于桥接修复家兔坐骨神经节段性缺损并以自体神经修复作为对照 ,术后通过肌电图检测、再生神经纤维组织学观察等方法 ,证实该支架可有效地引导和促进神经纤维再生。结果 :(1)经NaOH消蚀处理的坐骨神经组织 ,其细胞成分被完全消蚀掉 ,神经膜管保持原有的构筑特征 ;无明显排异反应并可降解吸收。 (2 )该材料和自体神经移植修复周围神经干节段性缺损在电生理和组织结构的恢复方面经统计学处理无显著性差异 (P >0 .0 5 )。结论 :此方法制备的细胞外基质材料可有效地桥接修复周围神经干节段性缺损 ,为其临床应用奠定实验基础。     

几丁糖与聚乳酸合成生物材料修复周围神经缺损

背景：单纯几丁糖材料制成的神经导管机械强度较差,易于塌陷,不利于再生神经的生长。 目的：观察几丁糖与聚乳酸复合物修复大鼠周围神经缺损的可行性。 方法：取30只SD大鼠,制作单侧坐骨神经缺损模型,随机均分为3组,分别采用自体神经、硅胶导管及几丁糖与聚乳酸复合导管修复神经缺损,修复后12周,观察桥接神经外观、表面粘连情况及有无神经瘤生成等,检测大鼠神经传导速度、动作电位波幅及潜伏期,苏木精-伊红染色观察坐骨神经桥接物中段神经再生轴突数量及再生神经横截面积,称量大鼠完整小腿三头肌湿质量。 结果与结论：修复后12周,3组再生神经均通过5 mm神经缺损间隙,硅胶管组形成神经瘤,其余两组均未出现神经瘤;自体神经组再生神经直径大于几丁糖-聚乳酸组、硅胶管组(P < 0.05),几丁糖-聚乳酸组再生神经直径大于硅胶管组(P < 0.05);几丁糖-聚乳酸组、自体神经组可见排列整齐的高密度再生轴突,再生轴突数量多于硅胶管组(P < 0.05),且神经传导速度、动作电位波幅、小腿三头肌湿质量显著大于硅胶管组(P < 0.05),潜伏期低于硅胶管组(P < 0.05)。表明几丁糖-聚乳酸复合导管可促进缺损周围神经的再生。  中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程     

外源性神经生长因子诱导下自体静脉桥接修复神经缺损

背景:采用自体神经游离移植修复神经缺损效果比较理想,但有其弊端。为此寻求一种更佳修复神经缺损的治疗方法。目的:验证及外源性神经生长因子诱导下自体静脉桥接神经缺损对神经再生的影响。方法:采用Wistar大鼠建立周围神经缺损模型。随机将大鼠分为3组。实验组采用自体静脉桥接并注入神经生长因子;对照组采用自体静脉桥接并注入生理盐水;标准组采用自体神经桥接。分别于术后1,3个月,对实验动物进行活体观察,电生理检测及组织学检测。结果与结论:3组实验动物均有神经再生及修复表现,但程度不同。实验组失神经表现恢复的较对照组早,电生理检测运动神经传导速度快,组织学检查再生神经纤维数量及质量明显高于对照组(P0.05);与"金标准"的自体神经桥接组比较无显著性意义(P0.05)。结果提示采用自体静脉桥接+神经生长因子诱导对周围神经缺损后的再生、修复具有有促进作用,可以使再生神经纤维的数量增加并显著提高再生神经纤维质量。     

带血管蒂筋膜瓣(管)桥接周围神经缺损的实验研究

对20只大鼠坐骨神经缺损用邻近的带血管蒂筋膜瓣作了管状桥接。不同存活期组织学检查发现,管桥中及神经远侧残端均有再生纤维。逆行追踪和电生理学方法对再生纤维的功能检测证实,手术45天以后确有再生纤维通过管桥到达坐骨神经远端。荧光染料包埋于管桥远侧的神经断端后,相应脊髓节段的灰质前角及脊神经节中均发现有标记细胞。电生理测试再生纤维动作电位阳性;神经传导速度部分恢复。以上结果提示,带血管蒂筋膜瓣(管)有可能作为一种新型的自体非神经桥接物供修复周围神经缺损之用,临床应用尚需进一步探讨。     

无细胞神经支架复合骨髓间充质干细胞构建组织工程人工神经修复坐骨神经缺损

背景：作者已经成功制备了无细胞神经移植物,并且复合骨髓间充质干细胞构建组织工程人工神经桥接大鼠坐骨神经缺损。 目的：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后运动功能的恢复。 方法：成年雄性SD大鼠构建大鼠坐骨神经15 mm缺损模型,分别应用组织工程人工神经、组织工程神经支架或自行神经桥接坐骨神经缺损。桥接后20周再生神经电生理学测定,手术侧胫骨前肌湿质量、腓肠肌组织学及透视电镜分析。 结果与结论：桥接20周后,组织工程人工神经与自体神经移植组胫骨前肌湿质量比较,差异无显著性意义(P > 0.05),神经干传导速度为(30.56±2.15)m/s。结果提示,无细胞神经移植物复合骨髓间充质干细胞构建的组织工程人工神经桥接大鼠坐骨神经缺损后,可以促进再生神经运动功能的恢复。     

Evaluation of biocompatibility of polypyrrole in vitro and in vivo

In this study, the biocompatibility of the electrically conductive polymer polypyrrole (PPy) with nerve tissue was evaluated in vitro and in vivo. The extraction solution of PPy powder, which was synthesized chemically, was tested for acute toxicity, subacute toxicity, pyretogen, quantitative measure of cell viability, hemolysis, allergen, and micronuclei. The PPy membrane was synthesized electrochemically on the indium tin oxide conductive borosilicate glass. The dorsal root ganglia from 1-3-day-old Sprague-Dawley rats were cultured above PPy membrane and observed by light or scanning electron microscopy. The PPy-silicone tube (PPy membrane on the inner surface of the silicone tube) also synthesized electrochemically was used to bridge across 10-mm sciatic nerve gap in rats. Twenty-four weeks after the operation to rats, the regenerated tissues were observed by electrophysiological and histological techniques. PPy extraction solution showed no evidence of acute and subacute toxicity, pyretogen, hemolysis, allergen, and mutagenesis, and the Schwann cells from the PPy extraction solution group showed better survival rate and proliferation rate as compared with the saline solution control group. The migration of the Schwann cells and the neurite extension from dorsal root ganglia on the surface of PPy membrane-coated glass was better than those of bare glass. There was only lightly inflammation during 6 months of the postoperation, when the PPy-silicone tube bridged across the gap of the transected sciatic nerve. The regeneration of nerve tissue in the PPy-silicone tube was slightly better than that in the plain silicone tube by means of electrophysiological and histological examination. The results of this study indicate that PPy has a good biocompatibility with rat peripheral nerve tissue and that PPy might be a candidate material for bridging the peripheral nerve gap.     

Tubulation with dental pulp cells promotes facial nerve regeneration in rats

Dental pulp is an easily obtainable source of viable cells for potential use in peripheral nerve regeneration. We prepared artificial conditions for nerve regeneration using a silicone tube containing a collagen gel embedded with rat dental pulp cells, and we examined its effectiveness for repairing a gap in the rat facial nerve. Twelve days after transplantation, defective facial nerves connected with silicone tubes containing dental pulp cells were repaired more rapidly than control tubes containing the collagen gel alone. When a tube containing green fluorescent protein (GFP)-positive dental pulp cells was transplanted into a facial nerve gap in a GFP-negative rat, we observed regenerated nerves with GFP-positive cells at 2 weeks posttransplantation. The regenerated nerves included Tuj1-positive axons, RECA1 and GFP double-positive blood vessels, and S100 and GFP double-positive Schwann-like supportive cells. Osmium-toluidine blue staining revealed that the regenerated nerves contained myelinated fibers. Moreover, fluorescent retrograde tracing analysis by application of Fluoro-Gold into the regenerated nerves demonstrated the presence of Fluoro-Gold-positive motor neurons in the facial nucleus of the rat brain. These results suggest that the transplanted dental pulp cells formed blood vessels and myelinating tissue and contributed to the promotion of normal nerve regeneration.     

EXPERIMENTAL IN VIVO REGENERATION OF PERIPHERAL NERVE AXONS and PERINEURIUM GUIDED BY RESORBABLE COLLAGEN FILM

In our previous paper, we reported a marked advantage in using collagen gel matrix available for cell culture in combination with a silicone tube as an effective environment for axonal sprouting during peripheral nerve regeneration. In the present experiment, collagen film was substituted for the silicone tube because of its non-toxicity, biocompatibility and better availability. Also, the surgical procedure was simplified, using a fibrin adhesive system instead of suturing. In the second postoperative week, severed proximal and distal stumps became joined together concomitantly with absorption of the collagen matrix and film. On size-frequency histograms, the diameters of both myelinated and unmyelinated axons at 8 weeks after surgery had recovered to their normal ranges. These findings demonstrate that this procedure of enveloping a collagen matrix and severed nerve stumps in bioresorbable collagen film would be an ideal way of forming a perfect perineurium. The regeneration of peripheral nerve axons resulted in normal thickness of the original nerve bundle without exception, unlike the axons on the control side.     

Experimental in vivo regeneration of peripheral nerve axons and perineurium guided by resorbable collagen film

In our previous paper, we reported a marked advantage in using collagen gel matrix available for cell culture in combination with a silicone tube as an effective environment for axonal sprouting during peripheral nerve regeneration. In the present experiment, collagen film was substituted for the silicone tube because of its non-toxicity, biocompatibility and better availability. Also, the surgical procedure was simplified, using a fibrin adhesive system instead of suturing. In the second postoperative week, severed proximal and distal stumps became joined together concomitantly with absorption of the collagen matrix and film. On size-frequency histograms, the diameters of both myelinated and unmyelinated axons at 8 weeks after surgery had recovered to their normal ranges. These findings demonstrate that this procedure of enveloping a collagen matrix and severed nerve stumps in bioresorbable collagen film would be an ideal way of forming a perfect perineurium. The regeneration of peripheral nerve axons resulted in normal thickness of the original nerve bundle without exception, unlike the axons on the control side.     

Functional recoveries of sciatic nerve regeneration by combining chitosan-coated conduit and neurosphere cells induced from adipose-derived stem cells

Suboptimal repair occurs in a peripheral nerve gap, which can be partially restored by bridging the gap with various biosynthetic conduits or cell-based therapy. In this study, we developed a combination of chitosan coating approach to induce neurosphere cells from human adipose-derived stem cells (ASCs) on chitosan-coated plate and then applied these cells to the interior of a chitosan-coated silicone tube to bridge a 10-mm gap in a rat sciatic nerve. Myelin sheath degeneration and glial scar formation were discovered in the nerve bridged by the silicone conduit. By using a single treatment of chitosan-coated conduit or neurosphere cell therapy, the nerve gap was partially recovered after 6 weeks of surgery. Substantial improvements in nerve regeneration were achieved by combining neurosphere cells and chitosan-coated conduit based on the increase of myelinated axons density and myelin thickness, gastrocnemius muscle weight and muscle fiber diameter, and step and stride lengths from gait analysis. High expressions of interleukin-1β and leukotriene B4 receptor 1 in the intra-neural scarring caused by using silicone conduits revealed that the inflammatory mechanism can be inhibited when the conduit is coated with chitosan. This study demonstrated that the chitosan-coated surface performs multiple functions that can be used to induce neurosphere cells from ASCs and to facilitate nerve regeneration in combination with a cells-assisted coated conduit.     

三色染色法和免疫细胞化学法显示培养的神经轴索及雪旺细胞

本研究目的在于用三色染色法和免疫细胞化学反应显示培养的周围神经中的轴索及雪旺细胞。将大鼠背根神经节体外培养于聚吡咯膜上 2周 ;用苏木精、固绿 FCF、变色素 2 R及磷钨酸等配制的染色液染色 ;或用抗 S-10 0蛋白和抗神经微丝蛋白抗体进行免疫细胞化学法反应。结果证明 ,在三色染色法中神经节神经元发出的长突起呈蓝绿色 ,细胞核呈红色或紫红色 ,胞质呈浅灰色。免疫细胞化学反应证明神经节发出的长突起为轴索 ,紫红色核和浅灰色胞质的细胞为雪旺细胞。本文结果提示 ,三色染色法能区别显示培养的周围神经组织中的轴索及雪旺细胞。     

Scaffolds from block polyurethanes based on poly(ɛ-caprolactone) (PCL) and poly(ethylene glycol) (PEG) for peripheral nerve regeneration

Nerve guide scaffolds from block polyurethanes without any additional growth factors or protein were prepared using a particle leaching method. The scaffolds of block polyurethanes (abbreviated as PUCL-ran-EG) based on poly(?-caprolactone) (PCL-diol) and poly(ethylene glycol) (PEG) possess highly surface-area porous for cell attachment, and can provide biochemical and topographic cues to enhance tissue regeneration. The nerve guide scaffolds have pore size 1–5 μm and porosity 88%. Mechanical tests showed that the polyurethane nerve guide scaffolds have maximum loads of 4.98 ± 0.35 N and maximum stresses of 6.372 ± 0.5 MPa. The histocompatibility efficacy of these nerve guide scaffolds was tested in a rat model for peripheral nerve injury treatment. Four types of guides including PUCL-ran-EG scaffolds, autograft, PCL scaffolds and silicone tubes were compared in the rat model. After 14 weeks, bridging of a 10 mm defect gap by the regenerated nerve was observed in all rats. The nerve regeneration was systematically characterized by sciatic function index (SFI), histological assessment including HE staining, immunohistochemistry, ammonia silver staining, Masson's trichrome staining and TEM observation. Results revealed that polyurethane nerve guide scaffolds exhibit much better regeneration behavior than PCL, silicone tube groups and comparable to autograft. Electrophysiological recovery was also seen in 36%, 76%, and 87% of rats in the PCL, PUCL-ran-EG, and autograft groups respectively, whilst 29.8% was observed in the silicone tube groups. Biodegradation in vitro and in vivo show proper degradation of the PUCL-ran-EG nerve guide scaffolds. This study has demonstrated that without further modification, plain PUCL-ran-EG nerve guide scaffolds can help peripheral nerve regeneration excellently.