骨髓基质干细胞成骨的研究进展

组织工程学是生命科学中新兴学科，是生物医学工程领域的一个快速发展的新方向。骨组织工程学是骨外科学主要发展方向之一。骨髓基质干细胞有明确的成骨作用，其特点为来源丰富、提取方便、体外扩增迅速、易于成骨诱导、可导入标记性或治疗性基因，因此认为骨髓基质干细胞是骨组织工程学中理想的种子细胞。本文就骨髓基质干细胞成骨进展作一综述。     

骨组织工程学种子细胞研究与应用现状

近 2 0年来 ,随着组织培养、生物材料技术的发展 ,对成骨细胞的来源、培养条件及生物材料进行了大量的研究。1977年Ｇｒｅｅｎ进行了将活细胞种植到人工材料上并将此复合物植入动物体内的试验。在此基础上Ｏｈｇｕｓｈｉ等[1 ] 及Ｂｒｅｉｔ ｂａｒｔ等[2 ] 开始应用含有活细胞的异体植入物来修复实验性骨缺损 ,取得了成功的经验。 1995年Ｖａｃａｎｔｉ等[3] 正式将组织工程学定义为应用工程学和生命科学原理将经体外分离、培养的高浓度的功能相关的活细胞种植于天然的或人工合成的支架上 ,使之植入人体后能够形成新的有功能的组织 ,来制造…     

骨髓基质细胞与骨缺损的修复

目的综述骨髓基质细胞(marrow stromal cells，MSCs)与骨缺损修复的发展近况。方法广泛查阅近年来有关MSCs的生物学特性及其在骨缺损中的应用文献，并作综合分析。结果在适当条件下，MSCs可诱导为成骨细胞，在体内具有成骨性能。以MSCs为种子细胞的骨组织工程学方法和以其为靶细胞的基因治疗方法都可应用于骨缺损的修复。结论MSCs在骨缺损的修复中具有良好的应用前景。     

人骨髓基质细胞接种珊瑚构建组织工程骨

目的：观察体外培养的人骨髓基质细胞与珊瑚复合物植入体内后的成骨能力。方法：穿刺抽吸入髂骨区骨髓基质细胞，体外培养扩增、诱导，将其与珊瑚复合后植入裸鼠体内，以单纯珊瑚作为对照。术后4、8周取材，通过大体、组织学、扫描电镜观察植入物体内成骨情况。结果：术后4周，复合物中有少量新骨形成；术后8周，复合物中出现大量成熟骨组织。而对照组无骨组织形成。结论：人骨髓基质细胞复合珊瑚在无免疫动物体内具有成骨能力，穿刺抽吸的人骨髓基质细胞可作为骨组织工程的种子细胞。     

人脱细胞骨复合骨髓基质细胞成骨活性的实验研究

目的 研究人脱细胞骨(HAB)复合经诱导的骨髓基质细胞的实验效果,观察细胞的黏附和生长情况,并对其成骨活性进行检测。方法 用15％的过氧化氢和乙醚去除人髂骨块内的结缔组织和细胞成分,消毒后制备人脱细胞骨。取材活体或新鲜尸体的骨髓行骨髓基质细胞培养,细胞纯化后加入β-甘油酸钠,地塞米松和抗坏血酸等向成骨方向诱导,并进行对照培养。通过碱性磷酸酶(ALP)和骨钙素(OCN)检测来确定骨髓基质细胞的增殖和分化情况,将诱导的骨髓基质细胞浓缩后复合到制备好的脱细胞骨块内进行复合培养。8d后通过光镜和电镜等形态学观察以及生化指标检测来确定细胞的成骨活性。结果 人髂骨块内细胞清除干净,骨基质保存良好;诱导后的骨髓基质细胞ALP和OCN水平明显高于对照组(P<0.05);复合后的人脱细胞骨培养液中ALP和OCN检测呈阳性;骨髓基质细胞在HAB支架内附着紧密,生长良好。结论 人脱细胞骨复合经诱导的骨髓基质细胞在体外具有有效的成骨功能,是一种较为理想的骨组织工程材料。     

兔骨髓基质细胞的分离培养

目的 为骨组织工程寻找一种理想的种子细胞。方法 采取兔骨髓组织，应用梯度离心获取骨髓基质细胞，体外培养传代，通过光镜、透射电镜及成骨特性的鉴定，观察细胞的形态、生长特点及成骨特性。结果 培养的骨髓基质细胞形态多为三角形或梭形，生长增殖迅速，具有成骨能力，易于定向分化为成骨细胞。结论 自骨髓获得的骨髓基质细胞具有明显的增殖能力和成骨活性，可以做为骨组织工程中比较理想的种子细胞。     

骨髓基质细胞成骨作用的研究进展

骨髓基质中存在确定性骨祖细胞成分,分体外分化受多种因素影响。在骨组织工程学院研究中骨髓基质细胞作为新生骨组织的细胞来源,日益引起重视。     

骨髓基质细胞促进引导性骨再生的研究

目的观察骨髓基质细胞增强引导性骨再生（GBR）修复骨缺损的能力。方法30只兔造成双桡骨干15mm骨缺损，以硅胶管桥接骨断端，实验组在硅胶管内注射自体骨髓基质细胞（MSC）1ml；对照组注射等量生理盐水。在不同时间内作X线片、大体、组织学观察及生化捡测。结果实验组成骨活跃，10周骨缺损完全修复，对照组各时间点骨修复均较实验组差，10周时仍无1只兔骨性愈合。术后4周实验组钙及碱性磷酸酶含量明显高于对照组（P〈0．01），术后8及10周实验组骨缺损区新生骨骨痂密度与相邻尺骨密度比值亦明显高于对照组（P〈0．01）。结论自体骨髓基质细胞可明显增强GBR修复骨缺损的能力。     

骨髓基质干细胞及其在骨组织工程中的应用

骨髓基质干细胞（BMSCs）是一群存在于骨髓中的非造血干细胞,具有较强的自我更新能力和多向分化潜能,在体外不同的诱导条件下可分化为骨细胞、软骨细胞、肌腱细胞、脂肪细胞、神经细胞、平滑肌细胞等多种细胞.BMSCs的应用是目前国际上骨组织工程领域的重要研究内容,具有广泛的临床应用前景.近年来,许多实验室从分子、生化、物理等水平对其成骨分化调控进行了深入研究,取得了较大的进展.     

骨髓基质细胞成骨作用研究进展

18 67年 ,德国病理学家Ｃｏｈｎｈｅｉｍ在研究伤口愈合过程时 ,提出骨髓中有骨髓基质细胞 (ＭａｒｒｏｗＳｔｏｍａｌＣｅｌｌ,ＭＳＣ)存在的观点。 1974年Ｆｒｉｅｄｅｎｓｔｅｉｎ等[1] 发现 ,骨髓标本中小部分贴附细胞在培养过程中能够分化形成类似骨或软骨的集落。 1988年Ｍａｍｉａｔｏｐｏｕｌｏｓ等[2 ] 首次报道鼠骨髓基质细胞在体外培养能形成钙化的骨样组织 ,经Ｘ线衍射分析确定形成的钙化物具有羟基磷灰石结构 ,证明体外培养骨髓基质具有成骨能力。Ｂｅｎａｋｙａｈｕ等[3 ] 将骨髓基质细胞体外培养获得具有典型的成骨细胞 (Ｏ…     

转染BMP-2基因的兔BMSCs种植PLA/PCL支架体外构建组织工程骨

目的:用腺病毒载体将人骨形态发生蛋白-2(BMP-2)基因导入兔骨髓基质干细胞(BMSCs),种植PLA/PCL(聚乳酸/聚己内酯)支架体外构建组织工程骨.方法:蛋白印迹法检测转染后细胞BMP-2的表达,流式细胞仪和ALP活性检测分析基因转染对细胞增殖分化的影响.然后将转染后细胞接种到PLA/PCL支架上,扫描电镜观察细胞贴附、生长状况.结果:转染后,BMSCs表达BMP-2,S期细胞比例和ALP活性明显增高.扫描电镜见转染细胞分布均匀,伸展良好.结论:BMP-2基因转染BMSCs,可促进细胞增殖分化.转染后细胞在PLA/PCL支架上生长良好,BMP-2基因治疗的组织工程骨构建成功.     

A new source for cardiovascular tissue engineering: human bone marrow stromal cells

Objective: Vascular-derived cells represent an established cell source for tissue engineering of cardiovascular constructs. Previously, cell isolation was performed by harvesting of vascular structures prior to scaffold seeding. Marrow stromal cells (MSC) demonstrate the ability to differentiate into multiple mesenchymal cell lineages and would offer an alternative cell source for tissue engineering involving a less invasive harvesting technique. We studied the feasibility of using MSC as an alternative cell source for cardiovascular tissue engineering. Methods: Human MSC were isolated from bone marrow and expanded in culture. Subsequently MSC were seeded on bioabsorbable polymers and grown in vitro. Cultivated cells and seeded polymers were studied for cell characterization and tissue formation including extracellular matrix production. Applied methods comprised flow cytometry, histology, immunohistochemistry, transmission (TEM) and scanning electron microscopy (SEM), and biochemical assays. Results: Isolated MSC demonstrated fibroblast-like morphology. Phenotype analysis revealed positive signals for alpha-smooth muscle actin and vimentin. Histology and SEM of seeded polymers showed layered tissue formation. TEM demonstrated formation of extracellular matrix with deposition of collagen fibrils. Matrix protein analysis showed production of collagen I and III. In comparison to vascular-derived cell constructs quantitative analysis demonstrated comparable amounts of extracellular matrix proteins in the tissue engineered constructs. Conclusions: Isolated MSC demonstrated myofibroblast-like characteristics. Tissue formation on bioabsorbable scaffolds was feasible with extracellular matrix production comparable to vascular-cell derived tissue engineered constructs. It appears that MSC represent a promising cell source for cardiovascular tissue engineering.     

聚乳酸-聚羟基乙酸神经导管和骨髓间充质干细胞构建组织工程神经

[目的]用聚乳酸-聚羟基乙酸共聚物(poly lactide-co-glycolide acid,PLGA)为原料制备新型神经导管,同时对兔骨髓间充质干细胞与PLGA构建组织工程神经的可行性进行观察.[方法]以聚乳酸-聚羟基乙酸共聚物和壳寡糖为原料,采用静电纺丝工艺制备中空的PLGA神经导管.通过扫描电镜观察材料的微观结构,排水法测定材料的孔隙率.将兔的骨髓间充质干细胞(BMSCs)分离培养后与导管共培养,扫描电镜观察细胞在材料上的生长粘附情况,MTT方法检测细胞在材料上的增殖活性.[结果]PLGA神经导管管壁具有疏松多孔结构,管壁纤维直径为18 μm左右,孔隙率为85.4%±1.6%,MTT结果显示导管无细胞毒性.兔骨髓间充质干细胞在导管表面生长良好.[结论]PLGA神经导管具有良好的孔隙率,生物相容性好,是构建组织工程神经的良好材料.     

Bone marrow stem cells for urologic tissue engineering

OBJECTIVES: Experiments in rats and dogs have demonstrated the potential of bone marrow-derived mesenchymal stem cells (MSCs) for urinary tract tissue engineering. However, the small graft size in rats and a failure to identify the MSCs in engineered tissues made it difficult to assess the true potential of these cells. Our goals were to characterize MSCs from pigs, determine their ability to differentiate into smooth muscle cells (SMCs) and use them in an autologous augmentation cystoplasty. METHODS: MSCs were isolated from pigs and analyzed for common markers of MSCs by flow cytometry. SMC differentiation was determined by immunoblotting. MSCs were isolated, genetically labeled, expanded in vitro, seeded onto small intestinal submucosa (SIS) and used for autologous bladder augmentation. RESULTS: Porcine MSCs are morphologically and immunophenotypically similar to human MSCs. Culturing MSCs at low density enhances proliferation rates. MSCs consistently differentiate into mature SMCs in vitro when maintained at confluence. Labeled MSCs grew on SIS over one week in vitro and survived a 2-week implantation as an autologous bladder augment in vivo. Some label-positive cells with SMC morphology were detected, but most SMCs were negative. Notably, many cells with a urothelial morphology stained positively. CONCLUSIONS: Porcine MSCs have similar properties to MSCs from other species and consistently undergo differentiation into mature SMC in vitro under specific culture conditions. Labeled MSCs within SIS may assist tissue regeneration in augmentation cystoplasty but may not significantly incorporate into smooth muscle bundles.     

骨髓基质干细胞在软骨组织工程中的应用

骨髓基质细胞(BMSC)是倍受关注的具有多向分化潜能的干细胞,可在体外大规模扩增而不丢失多分化潜能,异体移植时排斥反应小,是组织工程再生修复应用的重点种子细胞.近年来BMSC在软骨创伤修复中的应用较为广泛,特别是在BMSC诱导后重新分化,软骨缺损植入后刺激软骨修复再生,减缓关节损伤进一步发展,体内外特定环境下复合组织工程材料分化成骨或软骨的相容性、分化度等生物学特性等方面进行了细致研究.该文就BMSC在软骨缺损组织工程修复中应用的现状和发展方向作一综述.     

骨髓来源细胞构建组织工程血管补片

目的探讨组织工程方法构建血管补片的可行性。方法用壳聚糖和透明质酸多孔多聚体支架构建高分子复合材料支架，将犬的骨髓细胞种植其中，并植入自身犬的肺动脉上，观察材料上细胞外基质生成及表面内皮化的情况，分别在术后2周、4周、8周用电镜、组化等方法来进行评价。结果所有动物在实验期问均存活，组织学及免疫组织化学显示，术后补片形成类似血管壁样组织。结论此复合材料和骨髓细胞可用来构建组织工程血管补片，其结构与血管壁类似。     

腺病毒介导BMP-2和EGFP基因转染兔骨髓基质干细胞及种植脱钙骨的体外观察

目的用腺病毒载体介导人骨形态发生蛋白-2及EGFP基因转染兔骨髓基质干细胞(rBMSC),种植DBM(脱钙骨)支架体外构建组织工程骨。方法兔髓基质干细胞(rBMSC)的分离、培养;流式细胞仪检测细胞表面标记;转染后,荧光显微镜观察细胞最适感染复数(MOI)及蛋白印迹检测外源基因的表达情况;采用Urist提供的方法制备脱钙骨(DBM),用细胞计量法测定BMSCs与DBM复合培养的黏附率。然后将转染后细胞接种到DBM支架上,用荧光显微镜观察细胞是否成功粘附于支架材料上,扫描电镜观察细胞贴附、生长状况。结果 BMSCs细胞表型鉴定:CD44表达阳性,CD45表达阴性;转染后,蛋白印迹试验检测到BMP-2表达增高;骨髓间充质干细胞与脱钙骨基质的平均粘附率为(72.74±1.99)%;扫描电镜见转染细胞生长良好,伸出丝状突起,相互连接。结论成功培养及鉴定兔BMSCs,Ad-BMP-2/EGFP可高效转染兔BMSCs,转染后的细胞种植于DBM支架材料后生长状况良好,组织工程骨构建成功。     

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。     

Multilayer tendon slices seeded with bone marrow stromal cells: A novel composite for tendon engineering

The ideal scaffold for tendon engineering would possess the basic structure of the tendon, native extracellular matrix, and capability of cell seeding. The purpose of this study was to assess the tissue engineering potential of a novel composite consisting of a decellularized multilayer sliced tendon (MST) scaffold seeded with bone marrow stromal cells (BMSC). BMSC and infraspinatus tendons were harvested from 20 dogs. The tendons were sectioned in longitudinal slices with a thickness of 50 µm. The slices were decellularized, seeded with BMSC, and then bundled into one composite. The composite was incubated in culture media for 14 days. The resulting BMSC‐seeded MST was evaluated by qRT‐PCR and histology. The BMSC viability was assessed by a fluorescent tracking marker. Histology showed that the seeded cells aligned between the collagen fibers of the tendon slices. Analysis by qRT‐PCR showed higher tenomodulin and MMP13 expression and lower collagen type I expression in the composite than in the BMSC before seeding. BMSC labeled with fluorescent tracking marker were observed in the composite after culture. Mechanical testing showed no differences between scaffolds with or without BMSC. BMSC can survive in a MST scaffold. The increased tenomodulin expression suggests that BMSC might express a tendon phenotype in this environment. This new composite might be useful as a model of tendon tissue engineering. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 27: 937–942, 2009