体外诱导猕猴骨髓基质干细胞向雪旺细胞分化

目的探讨体外诱导猕猴骨髓基质干细胞向雪旺细胞分化的实验方法。方法采用BME、b-FGF、ATRA、BDNF、heregulin、Forskolin、PDGF依次联合诱导,倒置相差显微镜观察细胞形态学变化,免疫细胞化学鉴定S-100蛋白、GFAP和P75受体的表达率。结果诱导后的猕猴骨髓基质干细胞具有类似雪旺细胞的形态,免疫细胞化学结果显示S-100蛋白、GFAP和P75受体的表达率分别为(66.8±4.6)%、(57.3±5.4)%和(72.4±5.9)%。结论采用BME、ATRA、BDNF、heregulin、Forskolin、b-FGF、PDGF依次联合诱导,可使猕猴骨髓基质干细胞在体外向雪旺样细胞分化。     

骨髓基质干细胞作软骨组织工程种子细胞研究

目的　综述近年来骨髓基质干细胞体外培养、定向分化为软骨细胞的条件及相关研究进展。方法　广泛查阅相关文献 ,对上述研究进展进行整理、综合和分析。结果　骨髓基质干细胞易于分离培养 ,体外增殖能力强 ,传代多次后仍保持有多分化潜能 ;体内成软骨能力明确 ;但骨髓基质干细胞定向分化的软骨细胞 ,不是终末分化阶段 ,而只是一个中间阶段。结论　骨髓基质干细胞以其自身多方面的特点已成为软骨组织工程的另一种可选择的种子细胞 ,但其进一步分化为成熟软骨细胞的条件尚需进一步研究。     

人骨髓基质干细胞构建组织工程心脏瓣膜的研究

目的探讨人骨髓基质干细胞种植在去细胞猪主动脉瓣叶上体外构建组织工程心脏瓣膜的可行性。方法经1%TritonX100、0.01%胰酶0.02%EDTA、DNaseI及RNaseI处理制备去细胞猪主动脉瓣叶支架,测定瓣叶去细胞前、后的生物力学特性;人骨髓基质干细胞体外分离、培养、扩增后种植在去细胞瓣叶表面,观察细胞生长情况。结果猪主动脉瓣叶去细胞后获得完整无细胞的纤维网状支架,瓣叶去细胞前、后的断裂强度和断裂伸长率差异无统计学意义(P>0.05);体外培养的人骨髓基质干细胞(MSCs)在去细胞瓣叶表面形成一层基本连续的细胞层。结论去除细胞成分的猪主动脉瓣叶组织是一种良好的纤维支架,可以用于构建组织工程心脏瓣膜;人骨髓基质干细胞种植在去细胞猪主动脉瓣叶上构建组织工程心脏瓣膜是可行的。     

骨髓诱导分化内皮细胞构建组织工程心脏瓣膜的实验研究

骨髓基质干细胞（BMSCs）在特定培养条件下能够诱导分化为内皮细胞,是构建组织工程心脏瓣膜（TEHV）较有前景的种子细胞来源.我们研究探讨应用BMSCs诱导分化的内皮细胞和猪去细胞瓣膜支架体外构建TEHV的可行性.     

兔骨髓间质干细胞用于构建组织工程软骨组织的初步报告

目的 采用组织工程方法,以培养后的兔骨髓间质干细胞（MSC）制成人工软骨培养物,经体内外培养后发育出成活的软骨组织。方法 抽取兔人经密度梯度离心得到单个核细胞,再经体外分离、培养获得兔骨髓MSC。向MSC培养液内加入地塞米松、转化生长因子－β1（TGF－β1）和维生素C进行软骨起源诱导培养3周,部分细胞开始转变为圆形并分泌基质。将诱导后的细胞与牛Ⅰ型胶原及人纤维蛋白按一定的比例混合,制成软骨样的培养物并分别做体内外培养。结果 体外培养2周后,培养物内大部分细胞已萎缩消失。但剩余的少量细胞成活,形成类似的软骨陷窝并分泌甲苯胺蓝异染的软骨基质。体内移植培养3周后,培养物已发育成颗粒状成熟的软骨组织。结论 骨髓间质干细胞可用于组织工程软骨组织的构建,是一种非常有前途的人工软骨组织构建中的功能细胞。     

骨髓基质干细胞复合纳米羟基磷灰石/聚乳酸构建组织工程骨

目的：了解骨髓基质干细胞（MSCs）复合纳米羟基磷灰石／聚乳酸（n-HA／PLA）构建组织工程骨的异位成骨作用。方法：选择6只新西兰白兔，实验组于动物脊柱左侧肌肉内植入MSCs复合n-HA／PLA构建的组织工程骨，对照组于右侧植入n-HA／PLA生物材料。术后4、8周取材，行溴脱氧尿嘧啶（Brdu）标记细胞检测和组织学观察。结果：术后4周，实验组材料边缘均可检测到Brdu标记的MSCs。术后4、8周，实验组材料内部有新骨形成，随着时间推移，新骨量增多，编织骨向板层骨过渡。对照组材料未见新骨形成。结论：MSCs复合n-HA／PLA构建的组织工程骨具有很好的异位成骨作用。     

利用人骨髓基质干细胞异位构建组织工程化骨的实验研究

目的 探讨以人骨髓基质干细胞为种子细胞、以部分脱钙骨为支架材料在体内构建组织工程化骨的可行性及其成骨机制。方法 培养、扩增人骨髓基质干细胞，将第4代hBMSCs接种于部分脱钙骨支架上，通过扫描电镜观察其生长和粘附情况，并测量粘附率。于裸鼠皮下植入人骨髓基质干细胞和部分脱钙骨复合物，以无细胞部分脱钙骨作对照。8及12周取材观察。结果 8及12周复合物植入组均见新骨形成，多数骨小梁表面衬有一层成骨细胞样细胞，提示可能存在膜内成骨。单纯部分脱钙骨植入组未见新骨形成。结论 人骨髓基质干细胞与部分脱钙骨复合可以在体内构建组织工程化骨；其成骨机制可能为膜内成骨。     

组织工程神经在修复周围神经缺损中的应用

周围神经缺损的修复与重建是当前神经领域的一大难题。目前，国内外学者已着力研究雪旺细胞和生物材料复合构建组织工程化人工神经，并将其与日益完善的显微外科技术结合起来，提高周围神经损伤的修复水平。本文结合国内外研究成果，对周围神经损伤修复的研究进行回顾，着重从组织工程方面阐述周围神经修复方法的现状与前景。     

组织工程心脏瓣膜的初步构建

目的探讨用体外培养的犬骨髓基质干细胞（MSC）和由聚4-羟基丁酸酯（P4HB）制作的心脏瓣膜支架构建组织工程心脏瓣膜（TEHv）的可行性。方法取年轻健康犬髂前上嵴的骨髓，分离培养出骨髓基质干细胞，通过苏木素-伊红（HE）染色、Mallory染色、Masson染色及免疫组织化学鉴定细胞，取第3代细胞种植在P4HB构建的心脏瓣膜支架上，培养2周后，用扫描电镜观察。结果MSCs经20～25d的培养后，梭形细胞已达到90％以上融合；经HE染色、Mallory染色、Masson染色及免疫组织化学证实培养出来的细胞为MSCs。扫描电镜下，未种植细胞的瓣膜呈蜂窝状，孔径在89～150btm之间，适宜MSCs的爬行；种植细胞后，瓣膜表面有大量MSCs黏附，且爬行长入蜂窝状孔径内。结论MSCs和以P4HB为材料的瓣膜支架构建TEHV具有可行性。     

骨髓间充质干细胞复合脱细胞血管基质构建组织工程血管的初步研究

目的：探讨骨髓间充质干细胞复合脱细胞血管基质构建组织工程血管的可行性。方法：采用胰蛋白酶、乙二胺四乙酸和曲拉通X-100对兔主动脉进行脱细胞处理，制备成脱细胞血管基质；体外分离和扩增人骨髓间充质千细胞，并将其作为种子细胞种植于脱细胞血管基质上，复合构建组织工程化人工血管。结果：制备的脱细胞血管基质由胶原、弹力纤维等组成，未见细胞成分残留；体外扩增的人骨髓间充质干细胞种植于脱细胞血管基质上可生长增殖。结论：骨髓间充质干细胞与脱细胞血管基质支架材料复合可成功构建组织工程血管，有望为血管缺损的修复提供一种全新的技术方法和手段。     

Repairing peripheral nerve defects with tissue engineered artificial nerves in rats

Objective： To observe the effect of tissue engineered nerves in repairing peripheral nerve defects （ about 1. 5 cm in length） in rats to provide data for clinical application.
Methods： Glycerinated sciatic nerves （2 cm in length） from 10 Sprague Dawiey （SD） rats （aged 4 months） were used to prepare homologous dermal acellular matrix. Other 10 neonate SD rats （aged 5-7 days） were killed by neck dislocation. After removing the epineurium, the separated sciatic nerve tracts were cut into small pieces, then digested by 2.5 g/L trypsin and 625 U/nd collagenase and cultured in Dulbecco＇ s modified Eagle＇ s medium （DMEM） for 3 weeks. After proliferation, the Schwann cells （SCs） were identified and prepared for use. And other 40 female adult SD rats （ weighing 200 g and aged 3 months） with sciatic nerve defects of 1.5 cm in length were randomly divided into four groups： the defects of 10 rats bridged with proliferated SCs and homologous dermal acellular matrix （the tissue engineered nerve group, Group A）, 10 rats with no SCs but homologous dermal acellular matrix with internal scaffolds （Group B ）, 10 with autologous nerves （Group C ）, and the other 10 with nothing （the blank control group, Group D）. The general status of the rats was observed, the wet weight of triceps muscle of calf was monitored, and the histological observation of the regenerated nerves were made at 12 weeks after operation.
Results： The wounds of all 40 rats healed after operation and no death was found. No foot ulceration was found in Groups A, B and C, but 7 rats suffered from foot ulceration in Group D. The triceps muscles of calf were depauperated in the experimental sides in all the groups compared with the uninjured sides, which was much more obvious in Group D. The wet weight of triceps muscle of calf and nerve electrophysiologic monitoring showed no statistical difference between Group A and Group C, but statistical difference was found between Groups A and B and Groups B and     

Cranial repair using BMP-2 gene engineered bone marrow stromal cells

BACKGROUND: Bone grafts, allografts, and biocompatible artificial bone substitutes all have their shortcomings when used for the repair of cranial bone defects. Tissue engineered bone shows promise as an alternative for the repair of these defects. MATERIALS AND METHODS: Rabbit bone marrow mesenchymal stromal cells (MSCs) were separated from iliac crest aspirates and expanded in a monolayer culture 1 month before implantation. These MSCs were then infected with replication-defective adenovirus-human BMP-2 genes 1 week before implantation. Bilateral critical-size cranial defects were created in the animal with removal of osteoinductive periosteum and dura. MSCs were mixed with alginate UP (ultrapure) to form MSC/polymer construct. MSCs used for the control site were infected with adenovirus beta-galactosidase (beta-gal). After 1 week, 6 weeks, and 3 months, five rabbits from each experimental group were sacrificed and the cranial defect site was examined by histology study. RESULTS: Near-complete repair of the large size cranial defects using the tissue engineered MSC/alginate construct was observed. The H&E stain and von Kossa's staining should better regenerate bone at the experiment site. A statistically significant difference in bone formation was noted by 3D CT imaging at 3 months post-BMP-2 treatment of the cranial defects (0.79 +/- 0.06 versus 0.47 +/- 0.05 cm(2), P < 0.001) but not at 6 weeks (0.36 +/- 0.04 versus 0.33 +/- 0.03 cm(2), P = 0.347). CONCLUSIONS: Near-complete repair of large cranial defects can be achieved using tissue engineered bone. The use of newly developed polymers as well as the integration of the stem cell concept with gene medicine is necessary to attain this goal.     

新型神经支架材料的构建及其与骨髓基质干细胞复合的实验研究

[目的]研制出一种可用于修复周围神经缺损的组织工程支架材料,并观察体外培养的骨髓基质干细胞在支架材料中的生长情况。[方法]以I型胶原蛋白和明胶通过冷冻干燥技术制备胶原蛋白支架材料。扫描电镜观察内部结构的排列规律及走行,测量其孔径大小、孔隙率等指标。将骨髓基质干细胞复合到胶原蛋白支架材料中共培养5 d后,扫描电镜下观察其在材料内部的生长情况。[结果]构建的材料均为圆柱状,内部为孔径均匀且平行排列的微管结构,体外培养的骨髓基质干细胞成功种植在支架材料上,在材料内部生长良好。[结论]构建的支架材料具有良好的三维空间构形和生物相容性,为神经损伤的修复提供了一种新型的支架材料。     

组织工程骨软骨复合物的构建与形态学观察

目的探讨采用组织工程技术构建骨软骨复合物的可行性。方法将骨髓基质细胞(BMSCs)成诱导软骨后接种于快速成形的三维支架材料聚乳酸／聚羟乙酸共聚物(PLGA)构建组织工程软骨，经成骨诱导的BMSCs接种于聚乳酸／聚羟乙酸共聚物／磷酸三钙(PLGA／TCP)构建组织工程骨，在体外分别培养2周后，将两种工程化组织及两者以无损伤线缝合形成的组织工程骨软复合体分别植入自体股部肌袋，术后8周取材，行组织学观察。结果术后组织学观察表明。组织工程软骨在体内可形成软骨组织组织工程骨在体内可形成骨组织，两者的复合体在体内可形成骨软骨复合物。结论以骨髓基质细胞为种子细胞、以快速成形的生物降解材料为支架体外构建的组织工程骨软骨复合物，可在体内形成骨软骨组织，有望用于骨软骨缺损的修复。     

Engineering scaffold‐free bone tissue using bone marrow stromal cell sheets

The use of exogenous scaffolds to engineer bone tissue faces several drawbacks including insufficient biological activity, potential immunogenicity, elevated inflammatory reaction, fluctuating degradation rate, and low cell‐attachment efficiency. To circumvent these limitations, we sought to engineer large scaffold‐free bone tissue using cell sheets. We harvested intact cell sheets from bone marrow stromal cells using a continuous culture method and a scraping technique. The cell sheets were then rolled and fabricated into large constructs. Finally, the constructs were implanted into the subcutaneous pockets of nude mice. The cells within the sheet maintained in vitro osteogenic potential after osteoblast differentiation. Computed tomography scans and histological examination confirmed new bone formation in vivo. Additionally, the engineered bone exhibited enhanced compressive strength. Our results indicate that the BMSC sheets can facilitate the formation of functional three‐dimensional bone tissue without the use of exogenous scaffolds. Hence, the study provides an intriguing alternative strategy for bone repair. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:697–702, 2010     

基因强化组织工程骨联合显微外科方法修复长段骨缺损的实验研究

目的评价骨形态发生蛋白2（BMP-2）基因强化的组织工程骨联合显微外科方法修复长段骨缺损的效果。方法分离培养兔骨髓基质干细胞，经BMP-2基因转染后复合异种骨支架体外构建基因强化的组织工程骨（GEB）。建立兔双侧桡骨缺损（2．5cm长）模型，采用5种方法修复。A：GEB加带血管蒂骨膜移植；B：GEB加血管束植入；C：GEB加游离骨膜移植；D：GEB；E：单纯支架。术后4、8、12周行X线、组织学、生物力学测定和微血管墨汁灌注等观察血管形成及成骨情况。结果A组血运建立最快，B组血管束早期即发出分支向移植骨内长入，C组4周时游离骨膜成活并发出微小血管，D组在BMP-2基因诱导下成骨速度和质量优于E组，12周时骨缺损部分修复，但中央区成骨不良，而E组12周时形成骨不连，缺损区内被纤维组织填充。在细胞成活率、生物力学性能、VEGF表达水平等方面，均表现为A〉B〉C〉D〉E，差异有统计学意义（P〈0．05）。结论BMP-2基因强化的组织工程骨联合显微外科方法修复长段骨缺损，既提供了血运，又提供了有效的成骨诱导因子，是治疗长段骨缺损较为理想的方法。其中，带血管蒂骨膜联合移植修复效果最佳；血管束植入法血供重建较快，方便临床应用。     

RGD多肽表面修饰生物陶瓷修复骨缺损BMP-2的表达

目的：了解精氨酸-甘氨酸-天冬氨酸（Arg-Gly-Asp,RGD）多肽表面修饰的羟基磷灰石-磷酸三钙（hydroxyapatite-tricalcium phosphate,HA-TCP）修复节段性骨缺损局部骨形态发生蛋白-2（bone morphogenetic protein-2,BMP-2）的表达。方法：以骨髓基质干细胞（marrow stromal cells,MSCs）复合RGD多肽表面修饰的HA-TCP或单纯材料培养制备组织工程骨,选择60只新西兰白兔,制作15mm长的桡骨节段性骨缺损模型,实验根据植入不同的材料分为A、B、C和D组,A组：骨缺损区植入MSCs复合RGD多肽表面修饰的HA-TCP培养制备的组织工程骨;B组：骨缺损区植入MSCs复合HA-TCP培养制备的组织工程骨;C组：骨缺损区植入RGD多肽表面修饰的HA-TCP;D组：骨缺损区植入HA-TCP。术后4周取材,行修复区局部BMP-2免疫组化分析。结果：术后4周各组骨缺损区均有新骨生成,修复区局部BMP-2表达水平依次为：A〉B〉C〉D（P〈0.001,P〈0.05）。结论：RGD多肽表面修饰对以HA-TCP为支架材料组织工程骨的修复作用有明显优化作用。     

组织工程化人工神经修复长段神经缺损实验的初步报告

目的 研究组织化人工神经修复大鼠2．5cm长坐骨神经缺损的效果。方法 90只2个月月龄的Lewis1W雌性大鼠,按手术先后顺序随机分成3个神经移植组,每组30只。A组：用种植同源雪旺细胞并具有内部支架结构的胶原神经管桥接,即组织工程化人工神经组。B组：用无雪旺细胞但具有内部支架结构的胶原神经管桥接,即对照组。C组：自体神经移植组。术后6月,进行神经电生理监测,神经肌肉组织学观察;用S－100和神经微丝蛋白免疫组化染色后,行轴突计数等检测。结果 完成对21只大鼠（每组7只）的实验评估。从A组和C组的胫前肌中均能诱发出波幅明显的神经肌肉复合动作电位（CMAP）,再生轴突已通过移植段神经全长,远端肌肉轻度萎缩。B组中则没有或仅记录到波幅很低的CMAP,移植神经远端结缔纤维组织增生,再生轴突罕见,所支配肌肉明显萎缩。结论 组织工程化人工神经可用来修复大鼠长段神经缺损。     

Repair of mandible defect with tissue engineering bone in rabbits

BACKGROUND: The aim of the present study was to investigate the effect of tissue engineering bone composed of bone marrow-derived osteoblasts and demineralized bone in repairing mandible defect. METHODS: Bone marrow-derived osteoblasts of 20 rabbits were cultured and seeded into scaffold of allogeneic demineralized bone to construct tissue engineering bone graft in vitro, which was used to repair the 10 x 5-mm bone defect made in the same rabbit mandible edge. Implant of demineralized bone alone was as the control. Rabbits were killed according to the schedule: five after 2 weeks, five after 4 weeks, five after 8 weeks, five after 12 weeks, and the implants were harvested for gross, radiographic, and histological observation. RESULTS: New bone formation at the margin region of defect and osteogenesis at the centre were observed in the implant of tissue engineering bone, and the bone formation pattern included osteogenesis, osteoconduction, and osteoinduction. In the implant of demineralized bone alone, the major bone formation pattern was 'creeping substitute'. CONCLUSIONS: The tissue engineering bone graft constructed by autogenous bone marrow-derived osteoblasts and allogeneic demineralized bone was better than demineralized bone alone in bone formation capability, which might be an ideal graft for bone defect repair.