基于氧化铁纳米颗粒增强MRI的小型猪软骨缺损干细胞移植示踪技术的研究

正摘要基质相关干细胞移植(MASI)在治疗软骨缺损病人中预后差异极大,常规MR成像方式无法帮助早期判断干细胞移植修复软骨缺损是否成功。目的与常规MRI比较,     

培养自体软骨细胞移植修复软骨缺损的分子生物学基础

创伤等原因所致的关节软骨缺损可引起患者疼痛,并导致滑膜炎和关节变性等,而软骨组织的自身修复能力又很差,缺损往往不能自行修复。目前临床上修复关节软骨缺损主要是自体软骨植入及软骨代用品植入,效果均不理想。近期研究表明,培养自体软骨细胞移植治疗软骨缺损取得了满意的疗效,这种方法还可在培养软骨细胞增殖和再分化的过程中调节基因表达[1]。笔者就自体软骨细胞移植治疗软骨缺损的分子生物学基础进行综述。一、关节软骨的分子生物学组成关节软骨(也称透明软骨)是覆盖在运动关节骨末端的一层质地坚韧的半透明组织,在膝关节厚度为1～5ｍ…     

异种脐血干细胞移植修复兔全层关节软骨缺损的初步研究

目的 :探讨人脐血干细胞对兔全层关节软骨缺损的修复作用及免疫反应。材料和方法 :取人脐带血中脐血干细胞及幼兔的骨髓基质细胞 ,体外分离培养 ;以聚乳酸 (PLA)为载体 ,将培养的原代细胞植入PLA支架上 ,形成细胞 -PLA复合物。于 2 0只成年新西兰大白兔的股骨滑车关节面上造成直径 4.5mm深 3 .0mm的全层关节软骨缺损 ,将两种细胞 -PLA复合物分别植入关节软骨缺损处。植入异种脐血干细胞 -PLA复合物为实验组 ,植入同种异体骨髓基质细胞 -PLA复合物为阳性对照组 ,缺损不处理为阴性对照组。术后 6周、1 2周观察缺损修复情况、新生组织类型及有无免疫反应。结果 :脐血干细胞组 6周时标本为纤维组织修复 ,内有少量软骨细胞 ;1 2周时 40 %标本为软骨样组织修复 ,较薄 ;60 %标本为纤维组织修复。移植物周围无明显淋巴细胞聚集 ,部分滑膜有炎症反应。骨髓基质细胞组(阳性对照)为软骨样组织修复 ;滑膜无明显炎症反应。阴性对照组为纤维组织修复 ,无软骨形成。结论 :异种脐血干细胞移植修复软骨缺损优于缺损不处理组 (阴性对照) ,但明显差于同种骨髓基质细胞组 (阳性对照 )。脐血干细胞有可能成为软骨修复的新的种子细胞。由于种属差异的影响 ,脐血干细胞组可能存在免疫反应 ,结果需进一步研究     

周围神经损伤的磁共振成像研究进展

周围神经损伤的早期、无创及准确诊断一直是放射医生所要解决的难题。常规MRI检查只能显示粗大周围神经干的大体解剖形态,而难以显示神经的细微结构。近年来,随着MRI软硬件技术的迅速发展,MR功能成像已成功应用于外周神经损伤中,在检测神经损伤修复及再生中有重要价值,为临床早期及直观检测神经损伤部位、判断损伤程度、评价修复可能性及选择治疗方案提供理论依据。     

聚乙醇酸负载同种异体软骨细胞移植修复兔关节软骨缺损

目的：应用聚乙醇酸（ＰＧＡ）负载的兔软骨细胞培养移植修复同种异体关节软骨缺损．方法：应用在生物体内可降解吸收、纤维状多孔态的ＰＧＡ作为支架行兔软骨细胞培养．培养１４天后，软骨细胞在ＰＧＡ提供的三维空间中大量分裂、增殖并合成大量软骨基质，形成ＰＧＡ－软骨细胞复合体，然后利用该复合体移植修复同种异体兔膝关节全层软骨缺损，对侧膝关节作对照．术后行大体、组织学、电镜动态观察及修复组织厚度测定．结果：ＰＧＡ在术后８周完全降解吸收，实验侧与对照侧修复组织的厚度有显著性差异（Ｐ＜０．０１）；术后１６周在实验侧可见典型的软骨组织，电镜下为成熟的软骨细胞，而对照侧为纤维组织修复．结论：应用ＰＧＡ－软骨细胞复合体移植，可修复同种异体的兔关节软骨缺损，为临床治疗关节软骨缺损奠定了基础．     

自体镶嵌式骨软骨移植修复膝关节软骨缺损

目的 探讨膝关节软骨缺损的修复方法。方法 6例膝关节软骨缺损患者，关节镜下在其非负重区的软骨面上，用专用器械凿取圆柱状的骨软骨，并移植至软骨缺损部位，用于修复缺损。结果 随访2～24个月，患者的临床症状消失，关节活动度正常，MRI显示原软骨缺损区软骨表面平整，移植的骨软骨柱位置良好。结论 自体镶嵌式骨软骨移植术创伤小、操作简单、能保持关节面的曲度，是较为实用的手术。     

脑神经干细胞移植的磁共振活体成像研究进展

随着对干细胞的深入研究,已有明确的证据表明神经干细胞能促进神经元和胶质细胞的再生及脑组织的修复.MRI在无创性、活体研究移植神经干细胞在宿主体内的分布、存活、分化、移行等功能状态以及评价治疗效果等方面具有独特的价值.就MRI在脑神经干细胞移植的示踪研究中的进展作一综述.     

脑神经干细胞移植的磁共振活体成像研究进展

随着对干细胞的深入研究，已有明确的证据表明神经干细胞能促进神经元和胶质细胞的再生及脑组织的修复。MRI在无创性、活体研究移植神经干细胞在宿主体内的分布、存活、分化、移行等功能状态以及评价治疗效果等方面具有独特的价值。就MRI在脑神经干细胞移植的示踪研究中的进展作一综述。     

间充质干细胞外泌体修复骨缺损的机制及作用研究进展

骨缺损是由于严重的创伤、感染、肿瘤切除、先天性畸形等引起的骨质丧失, 难以自然修复的骨缺损需要通过骨移植技术、膜诱导技术或干细胞骨组织工程技术修复。骨移植相关技术存在应用范围局限、操作复杂等缺点;膜诱导技术存在骨水泥降解速率不可控制, 需要二次手术等缺点;干细胞骨组织工程技术仍存在干细胞不定向分化等不稳定因素。外泌体是细胞之间通信的关键脂质体, 而工程化外泌体相较于天然干细胞外泌体有产量大、免疫原性低的优势, 有望代替干细胞应用于临床。笔者就间充质干细胞(MSC)外泌体修复骨缺损的机制及基于MSC的工程化外泌体修复骨缺损的作用研究进展进行综述, 为骨缺损的基础研究及临床治疗提供新思路。     

自体MSCs/Chondro-Gide工程化软骨再生修复技术的大动物实验

目的探索自体MSCs/Chondro-Gide工程化软骨修复技术用于软骨再生治疗的可行性。方法 12只山羊随机分为实验组、自体基质诱导软骨再生（autologous matrix-induced chondrogenesis,AMIC）治疗组及空白对照组,实验组采用自体MSCs/Chondro-Gide工程化软骨修复技术修复软骨缺损;AMIC治疗组采用AMIC技术,空白对照组不植入任何材料。术后8周行大体观察、关节镜检查、影像学检测、组织学检测、改良Wakitani法评分,评价其对关节软骨缺损的再生修复效果。结果 8周大体观察实验组软骨缺损的修复及整合良好;MRI及关节镜提示软骨缺损修复表面光滑,弹性可;组织学检测修复区域有较多幼稚软骨细胞;AMIC组可见修复区为纤维组织修复;空白组为少量纤维组织覆盖缺损底面。8周及16周改良Wakitani评分示：实验组修复效果优于AMIC组及空白对照组。结论自体MSCs/Chondro-Gide工程化软骨修复技术创伤小,操作简便,能显著促进关节软骨缺损的再生修复,具有较高的科学价值及临床应用前景。     

Mesenchymal stem cell-based therapy for cartilage repair: a review

Articular cartilage injury remains one of the major concerns in orthopaedic surgery. Mesenchymal stem cell (MSC) transplantation has been introduced to avoid some of the side effects and complications of current techniques. The purpose of this paper is to review the literature on MSC-based cell therapy for articular cartilage repair to determine if it can be an alternative treatment for cartilage injury. MSCs retain both high proliferative potential and multipotentiality, including chondrogenic differentiation potential, and a number of successful results in transplantation of MSCs into cartilage defects have been reported in animal studies. However, the use of MSCs for cartilage repair is still at the stage of preclinical and phase I studies, and no comparative clinical studies have been reported. Therefore, it is difficult to make conclusions in human studies. This requires randomized clinical trials to evaluate the effectiveness of MSC-based cell therapy for cartilage repair.     

Autologe Chondrozytentransplantation zur Behandlung von Knorpeldefekten des Kniegelenks

BACKGROUND: Currently the use of autologous chondrocytes as a cartilage-repair procedure for the repair of injured articular cartilage of the knee joint, is recommended. METHODS: This review presents the technique of autologous chondrocyte transplantation (ACT) and their modifications as matrix-associated autologous chondrocyte transplantation (MACT). Beside the surgical procedure the experimental and clinical results are discussed. Furthermore the major complications and the indication guidelines are presented. RESULTS: Articular cartilage in adults has a poor ability to self-repair after a substantial injury. Surgical therapeutic efforts in treating cartilage defects have focused on bringing new cells capable of chondrogenesis into the lesions. With ACT good to excellent clinical results are seen in isolated posttraumatic lesions of the knee joint in the younger patient with the formation of hyaline-like repair tissue. The major complications are periosteal hypertrophy, delamination of the transplant, arthrofibrosis and transplant failure. The current limitations include osteoarthritic defects and higher patient age. CONCLUSION: With the right indication and operative technique ACT is an effective and save option for the treatment of large full thickness cartilage defect of the knee joint.     

不同细胞移植修复兔全层关节软骨缺损的比较研究

目的 :比较软骨细胞、骨髓基质细胞及成纤维细胞对全层关节软骨缺损的修复作用。材料和方法 :取幼兔的软骨细胞、骨髓基质细胞及成纤维细胞 ,共 3种有生成软骨潜力的细胞进行体外分离培养 ;以聚乳酸 (PLA)为载体 ,将培养的原代细胞植入PLA支架上 ,形成细胞 -PLA复合物。于 2 8只成年新西兰大白兔的股骨滑车关节面上造成直径 4 5mm、深 3 0mm的全层关节软骨缺损 ,将 3种细胞 -PLA复合物分别植入关节软骨缺损处。植入细胞 -PLA复合物为实验组 ,单纯植入PLA支架为对照组。术后 6周、12周观察缺损修复情况及新生组织类型。结果 :软骨细胞移植组为软骨样组织修复 ,分界明显 ,甲苯胺兰及Ⅱ型胶原染色阳性 ;软骨下骨部分重建 ;细胞排列紊乱。骨髓基质细胞移植组为软骨样组织修复 ,分界不明显 ,甲苯胺兰及Ⅱ型胶原染色阳性 ;软骨下骨重建良好 ,软骨下潮线恢复 ;细胞排列趋于正常。成纤维细胞移植组为纤维组织修复 ,甲苯胺兰及Ⅱ型胶原染色阴性 ;软骨下潮线消失。对照组为纤维组织修复。结论 :软骨细胞、骨髓基质细胞移植修复软骨缺损明显优于成纤维细胞及对照组。骨髓基质细胞与软骨细胞移植组的修复结果无统计学差异 ,但骨髓基质细胞修复组织的细胞排列有序 ,软骨下骨重建良好 ,与周围组织融合密切 ,更接近正?     

组织工程软骨移植物修复兔关节软骨缺损

目的　观察组织工程软骨移植物修复兔关节软骨缺损的效果。　方法　经软骨起源诱导后的兔骨髓间质干细胞(mesenchymalstemcells,MSCs),与牛Ⅰ型胶原及人纤维蛋白相混合制成组织工程软骨移植物。60只5个月龄的日本大耳白兔均分为软骨移植物组、单纯载体对照组和空白对照组,观察各组修复兔股骨髁关节软骨全层缺损的效果。　结果　软骨移植物组12周时已形成正常厚度的软骨层及完整的软骨下骨板,O'drilscoll组织学评分18.22±2.45,Ⅱ型胶原含量97.9%,甲苯胺蓝变色反应表明其与周围正常软骨无明显区别,为透明软骨组织修复。而对照组12周时为纤维软骨修复,后期为纤维组织和板层骨修复。　结论　该组织工程软骨移植物作为软骨移植的替代物是可行的。     

MR imaging of autologous chondrocyte implantation of the knee

Autologous chondrocyte implantation (ACI) is a surgical technique that is increasingly being used in the treatment of full-thickness defects of articular cartilage in the knee. It involves the arthroscopic harvesting and in vitro culture of chondrocytes that are subsequently implanted into a previously identified chondral defect. The aim is to produce a repair tissue that closely resembles hyaline articular cartilage that gradually becomes incorporated, restoring joint congruity. Over the long term, it is hoped that this will prevent the progression of full-thickness articular cartilage defects to osteoarthritis. This article reviews the indications and operative procedure performed in ACI. Magnetic resonance imaging (MRI) sequences that provide optimal visualization of articular cartilage in the post-operative period are discussed. Normal appearances of ACI on MRI are presented along with common complications that are encountered with this technique.     

Radiologische Bildgebung der Kniegelenkarthrose

Clinical/methodical issue

Osteoarthritis is the most common degenerative age-related joint disease leading to typical degradation of articular cartilage with severe pain and limitation of joint motion.

Standard radiological methods

Although knee radiographs are widely considered as the gold standard for the assessment of knee osteoarthritis in clinical and scientific settings they increasingly have significant limitations in situations when resolution and assessment of cartilage is required.

Methodical innovations

Analysis of osteoarthritis of the knee with conventional x-ray is associated with many technical limitations and is increasingly being replaced by high-quality assessment using magnetic resonance imaging (MRI) or sonography both in the clinical routine and scientific studies.

Performance

Novel imaging modalities such as MRI or ultrasound enable in vivo visualization of the quality of the cartilaginous structure and bone as well as all articular and periarticular tissue. Therefore, the limitations of radiographs in assessment of knee osteoarthritis could be overcome by these techniques. This review article aims to provide insights into the most important radiological features of knee osteoarthritis and systematic visualization with different imaging approaches.

Practical recommendations

The demographic development in western industrialized countries predicts an increase of ageing-related osteoarthritis of the knee for the next decades. A systematic radiological evaluation of patients with knee osteoarthritis includes the assessment of the periarticular soft tissue, cartilaginous thickness, cartilage volume, possible cartilage defects, the macromodular network of hyaline cartilage, bone marrow edema, menisci and articular ligaments. Modern imaging modalities, such as MRI and sonography allow the limitations of conventional radiography to be overcome and to visualize the knee structures in great detail to quantitatively assess the severity of knee osteoarthritis.     

Mesenchymal stem cells for the treatment of cartilage lesions: from preclinical findings to clinical application in orthopaedics

Purpose

The aim of this systematic review is to examine the available clinical evidence in the literature to support mesenchymal stem cell (MSC) treatment strategies in orthopaedics for cartilage defect regeneration.

Methods

The research was performed on the PubMed database considering the English literature from 2002 and using the following key words: cartilage, cartilage repair, mesenchymal stem cells, MSCs, bone marrow concentrate (BMC), bone marrow-derived mesenchymal stem cells, bone marrow stromal cells, adipose-derived mesenchymal stem cells, and synovial-derived mesenchymal stem cells.

Results

The systematic research showed an increasing number of published studies on this topic over time and identified 72 preclinical papers and 18 clinical trials. Among the 18 clinical trials identified focusing on cartilage regeneration, none were randomized, five were comparative, six were case series, and seven were case reports; two concerned the use of adipose-derived MSCs, five the use of BMC, and 11 the use of bone marrow-derived MSCs, with preliminary interesting findings ranging from focal chondral defects to articular osteoarthritis degeneration.

Conclusions

Despite the growing interest in this biological approach for cartilage regeneration, knowledge on this topic is still preliminary, as shown by the prevalence of preclinical studies and the presence of low-quality clinical studies. Many aspects have to be optimized, and randomized controlled trials are needed to support the potential of this biological treatment for cartilage repair and to evaluate advantages and disadvantages with respect to the available treatments.

Level of evidence

IV.     

Disease-specific clinical problems associated with the subchondral bone

The subchondral bone is involved in a variety of diseases affecting both the articular cartilage and bone. Osteochondral defects in distinct locations and of variable sizes are the final results of different etiologies. These include traumatic osteochondral defects, osteochondritis dissecans, osteonecrosis, and osteoarthritis. Traumatic osteochondral defects are caused by osteochondral fractures, separating an osteochondral fragment that includes articular cartilage and both subchondral and trabecular bone from the joint surface. In osteochondritis dissecans, the disease originates in the subchondral bone and secondarily affects the articular cartilage. Location, stage, size, and depth of osteochondral lesions play a role in the treatment of traumatic osteochondral defects and osteochondritis dissecans. Surgical options include fragment refixation, transplantation of osteochondral autografts, or bone restoration by impacted cancellous bone grafts combined with autologous chondrocyte transplantation. An insufficiency fracture of the subchondral bone may be the initiating factor of what was formerly believed to be a spontaneous osteonecrosis of the knee (SPONK). Recent histopathological studies suggest that each stage of SPONK reflects different types of bone repair reactions following a fracture of the subchondral bone plate. Osteoarthritis is a disease that does affect not only the articular cartilage, but also the subchondral bone. Reconstructive surgical techniques aim at preserving joint function, inducing fibrocartilaginous repair, and at correcting malalignment. This review summarizes the current status of the clinical treatment of traumatic osteochondral defects, osteochondritis dissecans, osteonecrosis, and osteoarthritis as they affect the subchondral bone region and its adjacent structures.     

肾功能衰竭大鼠超顺磁性氧化铁标记骨髓间充质干细胞肾脏移植MR活体示踪的研究

目的应用磁性氧化铁纳米粒子和多聚左旋赖氨酸（poly-L-lysine，PLL）的偶联物Fe2O3-PLL标记大鼠骨髓间充质干细胞（MSCs），MR活体示踪经肾动脉移植入肾功能衰竭（简称肾衰）大鼠肾脏的标记细胞。方法制备Fe2O3-PLL，分离、纯化并培养大鼠骨髓MSCs，Fe2O3-PLL标记细胞，普鲁士蓝染色显示细胞内铁。肌内注射甘油所致肾衰的大鼠分为2组，分别经左肾动脉移植入标记细胞（6只）和未标记细胞（5只），移植后即刻及第1、3、5、8天应用MRI对移植细胞进行活体示踪，并与肾脏组织切片普鲁士蓝染色和HE染色对照。结果MSCs的Fe2O3-PLL标记率近100％，普鲁士蓝染色显示蓝色铁颗粒位于MSCs胞质内。标记细胞移植后肾衰大鼠肾脏皮质区信号强度明显下降，T2＊WI信号改变最明显，而肾髓质及肾盂信号较细胞移植前无明显变化，信号改变随着时间的延长逐渐减轻一直持续到移植后第8天。组织学分析见绝大多数标记细胞分布于肾皮质肾小球内，与MRI信号改变区域基本一致。未标记细胞移植后未见肾脏信号改变。结论Fe2O3-PLL可以有效标记大鼠骨髓MSCs，临床应用型1．5T磁共振仪可对经肾动脉移植入肾衰大鼠肾脏的标记细胞进行初步活体示踪。