Polycaprolactone scaffold and reduced rhBMP-7 dose for the regeneration of critical-sized defects in sheep tibiae

The transplantation of autologous bone graft as a treatment for large bone defects has the limitation of harvesting co-morbidity and limited availability. This drives the orthopaedic research community to develop bone graft substitutes. Routinely, supra-physiological doses of bone morphogenetic proteins (BMPs) are applied perpetuating concerns over undesired side effects and cost of BMPs. We therefore aimed to design a composite scaffold that allows maintenance of protein bioactivity and enhances growth factor retention at the implantation site. Critical-sized defects in sheep tibiae were treated with the autograft and with two dosages of rhBMP-7, 3.5 mg and 1.75 mg, embedded in a slowly degradable medical grade poly(ε-caprolactone) (PCL) scaffold with β-tricalcium phosphate microparticles (mPCL–TCP). Specimens were characterised by biomechanical testing, microcomputed tomography and histology. Bridging was observed within 3 months for the autograft and both rhBMP-7 treatments. No significant difference was observed between the low and high rhBMP-7 dosages or between any of the rhBMP-7 groups and autograft implantation. Scaffolds alone did not induce comparable levels of bone formation compared to the autograft and rhBMP-7 groups. In summary, the mPCL–TCP scaffold with the lower rhBMP-7 dose led to equivalent results to autograft transplantation or the high BMP dosage. Our data suggest a promising clinical future for BMP application in scaffold-based bone tissue engineering, lowering and optimising the amount of required BMP.     

内皮祖细胞促进血管发生及新骨生成辅助治疗骨缺损

文题释义：内皮祖细胞：是血管内皮细胞的前体细胞，可在生理或病理因素刺激下，从骨髓动员到外周血参与损伤血管的修复，在血管内皮再生中发挥着重要作用。血管发生：在胚胎发育时从中胚层起始，由成血管细胞发育成血管内皮细胞并最终形成血管的过程，这是血管“从无到有”的一个生物学过程。  摘要背景：骨折是临床常见的骨科疾病，虽然大多数骨折可以通过坚强内固定等手术治疗实现一期愈合，但仍有相当比例的骨折愈合不良，最终导致骨缺损，而骨缺损部位的血管新生对骨缺损的修复起到至关重要的作用。基于内皮祖细胞促进组织血管发生的能力，其对骨再生和修复的辅助作用逐渐成为学界关注的焦点。目的：综述骨缺损疾病中使用内皮祖细胞促进血管发生及新骨生成的研究进展。方法：遵循PRISMA指南，检索CNKI、万方数据库和PubMed数据库1986至2019年期间关于内皮祖细胞辅助治疗骨缺损的动物实验、临床试验及其机制的文章，检索词分别为“内皮祖细胞，血管生成，血管发生，治疗，骨缺损”“endothelial progenitor cells (EPCs)，angiogenesis，vasculogenesis，therapy/treatment，bone defect”，最后选择58篇文章纳入结果分析。结果与结论：①骨缺损时可以促进内皮祖细胞的激活与归巢；②内皮祖细胞可以促进血管发生；③内皮祖细胞是通过促进血管发生进而促进骨再生的；④将内皮祖细胞辅助治疗骨缺损推广至临床应用目前尚存在一些问题有待解决；⑤需要通过进行更多的临床试验，并且进一步深入研究内皮祖细胞参与血管发生的确切机制，为将来的临床应用提供数据支持，给大量骨缺损致残患者带来更好的治疗。ORCID: 0000-0001-5481-3865(冯源)中国组织工程研究杂志出版内容重点：干细胞；骨髓干细胞；造血干细胞；脂肪干细胞；肿瘤干细胞；胚胎干细胞；脐带脐血干细胞；干细胞诱导；干细胞分化；组织工程     

丝素蛋白复合骨髓间充质干细胞构建组织工程化骨修复节段性骨缺损的实验研究

目的 探讨丝素蛋白材料复合骨髓间充质干细胞构建组织工程化骨组织修复兔桡骨的节段性骨缺损的可行性.方法 分离培养兔骨髓间充质干细胞,与丝素蛋白膜材料复合培养,扫描电镜观察细胞在材料上的生长情况.将24只新西兰大白兔制成桡骨中段1.5cm长的骨缺损模型,随机分为3组:实验组(植入细胞材料复合物)、对照组(单纯植入丝素蛋白材料)、空白组(不植入修复材料).术后2,4,8,12周分别行大体观察、组织学观察和X线观察,比较3组骨缺损修复的情况.结果 骨髓间充质干细胞在丝素蛋白膜材料上生长情况良好.术后2,4,8,12周放射学检查新骨生成以及组织学检查新骨生成情况,实验组均优于对照组,空白组各时点均无新骨形成.结论 丝素蛋白材料与骨髓间充质干细胞体外复合培养构建的组织工程化骨能够修复兔桡骨缺损,可以作为组织工程骨的支架材料的全新来源. Abstract： Objective To investigate the possibility of adopting the silk fibroin biomaterial as the scaf-fold for bone marrow mesechymal stem cells(BMSCs) in the repair of rabbit radial defects. Methods BMSCs were isolated and co-cultured with the silk fibroin biomaterial in vitro. The growth condition of these cells on the scaffold was observed under electronic microscope. Bone defect models were made by removing 15 mm length of midshaft radial bone in 24 New Zealand rabbits. Animals were randomly devided into the experimental group in which the BMSCs seeded silk fibroin scaffold were transplanted, control group in which simple silk fibroin bioma-terial scaffold was adopted and blank group in which rabbits were left untreated. The repair of the defects was observed at 2, 4, 8, 12 weeks after operation, respectively. Results The rabbits BMSCs grew well on the material and the animals treated with grafts exhibited new bone formation. Result from experimental group was apparently superior to that of the control group at 2, 4, 8, 12 we     

The effect of mesenchymal stem cell sheets on structural allograft healing of critical sized femoral defects in mice

Structural bone allografts are widely used in the clinic to treat critical sized bone defects, despite lacking the osteoinductive characteristics of live autografts. To address this, we generated revitalized structural allografts wrapped with mesenchymal stem/progenitor cell (MSC) sheets, which were produced by expanding primary syngenic bone marrow derived cells on temperature-responsive plates, as a tissue-engineered periosteum. In vitro assays demonstrated maintenance of the MSC phenotype in the sheets, suggesting that short-term culturing of MSC sheets is not detrimental. To test their efficacy in vivo, allografts wrapped with MSC sheets were transplanted into 4-mm murine femoral defects and compared to allografts with direct seeding of MSCs and allografts without cells. Evaluations consisted of X-ray plain radiography, 3D microCT, histology, and biomechanical testing at 4- and 6-weeks post-surgery. Our findings demonstrate that MSC sheets induce prolonged cartilage formation at the graft-host junction and enhanced bone callus formation, as well as graft-host osteointegration. Moreover, a large periosteal callus was observed spanning the allografts with MSC sheets, which partially mimics live autograft healing. Finally, biomechanical testing showed a significant increase in the structural and functional properties of MSC sheet grafted femurs. Taken together, MSC sheets exhibit enhanced osteogenicity during critical sized bone defect repair, demonstrating the feasibility of this tissue engineering solution for massive allograft healing.     

同种异体骨髓间充质干细胞在比格犬体内异位构建组织工程骨

BACKGROUND: Allogenic bone marrow mesenchymal stem cells as seed cells for tissue engineering have become the future trend of development. OBJECTIVE: To investigate the osteogenic effects of allogenic bone marrow mesenchymal stem cells and the outcome in vivo. METHODS: Bone marrow mesenchymal stem cells from beagle dogs were marked with chloromethylbenzoyl ammonia fluorescent dye (CM-Dil), and the proliferation of labeled cells was measured using MTT assay in vitro. Autologous or allogenic bone marrow mesenchymal stem cells were inoculated into coral and β-tricalcium phosphate scaffolds for 7 days osteogenic induction and then subcutaneously implanted into the back of beagle dogs. Dogs undergoing blank scaffold implantation served as negative controls. Hematoxylin-eosin staining was used to observe new bone formation at 3 days, 1, 2, 4, 8, 12 weeks after surgery. Bone formation area was statistically analyzed using ipp software. In the CM-Dil group, frozen sections were made to trace the in vivo outcome of bone marrow mesenchymal stem cells under a fluorescence microscope. RESULTS AND CONCLUSION:The osteogenesis speed in the allogenic bone tissue engineering group was faster than that in the autologous bone tissue engineering group at 4-8 weeks after implantation, but no significant difference between the two groups was found beginning at the 12th week. At 4 weeks after implantation, the expression of γ-carboxy glutamic acid protein in the autologous bone tissue engineering group was higher than that in the allogenic bone tissue engineering group, prompting the bone mineralization appeared earlier in the latter group than the former one. ELISA results showed that the expression of alkaline phosphatase and osteocalcin in the autologous bone tissue engineering group was higher than that in the allogenic bone tissue engineering group at 4 weeks after implantation, and then the expression showed no difference at 12 weeks. CM-Dil labeling results showed that the number of allogenic bone marrow mesenchymal stem cells was reduced significantly compared with that of autologous bone marrow mesenchymal stem cells. All these findings indicate that the ectopic osteogenesis of the allogenic tissue-engineered bone in large animals is found within 12 weeks after implantation, but the osteogenesis efficiency at early stage (within 8 weeks) is lower compared with the autologous tissue-engineered bone. This difference may be related to the post-implantation immunoreactions that lead to the reduction in cell number. 中国组织工程研究杂志出版内容重点：组织构建;骨细胞;软骨细胞;细胞培养;成纤维细胞;血管内皮细胞;骨质疏松;组织工程     

脂肪干细胞在骨组织工程中的研究进展

各种原因导致的骨损伤甚至骨缺损会给患者带来较大的经济及社会负担,而骨组织工程研究能为治疗骨损伤提供新的方向。脂肪干细胞因其来源广泛、易于获取等特性在骨组织工程中发挥着重要作用,且脂肪干细胞在生长因子、机械刺激、各种信号通路的适宜刺激下能进行自我增殖并成骨分化,形成骨组织以治疗骨损伤及骨缺损,改善骨损伤带来的一系列症状。     

A comparison of bone regeneration with human mesenchymal stem cells and muscle-derived stem cells and the critical role of BMP

Adult multipotent stem cells have been isolated from a variety of human tissues including human skeletal muscle, which represent an easily accessible source of stem cells. It has been shown that human skeletal muscle-derived stem cells (hMDSCs) are muscle-derived mesenchymal stem cells capable of multipotent differentiation. Although hMDSCs can undergo osteogenic differentiation and form bone when genetically modified to express BMP2; it is still unclear whether hMDSCs are as efficient as human bone marrow mesenchymal stem cells (hBMMSCs) for bone regeneration. The current study aimed to address this question by performing a parallel comparison between hMDSCs and hBMMSCs to evaluate their osteogenic and bone regeneration capacities. Our results demonstrated that hMDSCs and hBMMSCs had similar osteogenic-related gene expression profiles and had similar osteogenic differentiation capacities in vitro when transduced to express BMP2. Both the untransduced hMDSCs and hBMMSCs formed very negligible amounts of bone in the critical sized bone defect model when using a fibrin sealant scaffold; however, when genetically modified with lenti-BMP2, both populations successfully regenerated bone in the defect area. No significant differences were found in the newly formed bone volumes and bone defect coverage between the hMDSC and hBMMSC groups. Although both cell types formed mature bone tissue by 6 weeks post-implantation, the newly formed bone in the hMDSCs group underwent quicker remodelling than the hBMMSCs group. In conclusion, our results demonstrated that hMDSCs are as efficient as hBMMSCs in terms of their bone regeneration capacity; however, both cell types required genetic modification with BMP in order to regenerate bone in vivo.     

改良差时贴壁法分离培养鉴定小鼠骨髓间充质干细胞和内皮前体细胞

目的 探索同时从小鼠骨髓分离培养间充质干细胞(MSCs)与内皮前体细胞(EPCs)及对其鉴定的方法。方法 小鼠骨髓细胞经改良差时贴壁法分离,以48h为时间点,48h内贴壁细胞传至3代后行成骨、成软骨、成脂分化诱导实验,流式细胞术（FCM）检测其表面标记;48h后收集未贴壁细胞,传至3代后行血管形成实验,传至5代后行CD31免疫荧光细胞染色实验,FCM检测其表面标记。 结果 第3代48h内贴壁细胞可诱导分化为骨、软骨和脂肪细胞,FCM 检测Sca-1、CD29、CD45、CD11b 阳性率分别为（98.30±0.75）%,（97.47±1.32）%,（1.87±0.15）%,（1.03±0.71）%;第3代48h后贴壁细胞在基质胶上可形成血管样结构,第5代48h后贴壁细胞特异性表面抗原CD31呈阳性表达,FCM检测CD34、CD133、血管内皮生长因子受体（VEGFR2） 阳性率分别为（88.90±1.18）%,（92.73±2.90）%,（87.63±1.79）%。 结论 采用改良差时贴壁法可同时分离培养扩增小鼠骨髓 MSCs和 EPCs,且简便高效稳定可重复。     

Human bone marrow stromal cells: In vitro expansion and differentiation for bone engineering

Stromal cells from marrow hold a great promise for bone regeneration. Even if they are already being exploited in many clinical settings, the biological basis for the source and maintenance of their proliferation/differentiation potential after in vitro isolation and expansion needs further investigation.

Most studies on osteogenic differentiation of marrow stromal cells (MSC) have been performed using bone marrow from the iliac crest. In this study, MSC were derived from spare femoral bone marrow obtained during hip replacement surgery from 20 adult donors. After in vitro isolation the cells were grown in osteogenic medium, and their proliferation and differentiation analysed during in vitro expansion. We found that MSC isolated from the femur of adult patients consistently maintain an osteogenic potential. Using biochemical signals, these cells turn to fully differentiated osteoblasts with a predictable set of molecular and phenotypic events of in vitro bone deposition. When seeded on polycaprolactone-based scaffold or surfaces, the proliferation and mineralization of femur-derived MSC were modulated by the surface chemistry/topography. Despite remarkable differences between individual colony-forming ability, alkaline phosphatase production, and mineralization ability, these cells are a potential source for bone engineering, either by direct autologous reimplantation or by ex vivo expansion and reimplantation combined to a proper scaffold.     

Degradable hydrogels for spatiotemporal control of mesenchymal stem cells localized at decellularized bone allografts

The transplantation of cells, such as mesenchymal stem cells (MSCs), has numerous applications in the field of regenerative medicine. For cell transplantation strategies to be successful therapeutically, cellular localization and persistence must be controlled to maximize cell-mediated contributions to healing. Herein, we demonstrate that hydrolytic degradation of poly(ethylene glycol) (PEG) hydrogels can be used to spatiotemporally control encapsulated MSC localization to decellularized bone allografts, both in vitro and in vivo. By altering the number of hydrolytically degradable lactide repeat units within PEG-d,l-lactide-methacrylate macromers, a series of hydrogels was synthesized that degraded over ∼1, 2 and 3 weeks. MSCs were encapsulated within these hydrogels formed around decellularized bone allografts, and non-invasive, longitudinal fluorescence imaging was used to track cell persistence both in vitro and in vivo. Spatiotemporal localization of MSCs to the exterior of bone allograft surfaces was similar to in vitro hydrogel degradation kinetics despite hydrogel mesh sizes being ∼2–3 orders of magnitude smaller than MSC size throughout the degradation process. Thus, localized, cell-mediated degradation and MSC migration from the hydrogels are suspected, particularly as ∼10% of the total transplanted MSC population was shown to persist in close proximity (within ∼650 μm) to grafts 7 weeks after complete hydrogel degradation. This work demonstrates the therapeutic utility of PEG-based hydrogels for controlling spatiotemporal cell transplantation for a myriad of regenerative medicine strategies.     

骨髓间充质干细胞与复合I型胶原和骨形态发生蛋白2的聚乳酸乙醇酸构建组织工程骨

目的探讨骨髓间充质干细胞(BMSC)体外分离培养后种植到复合Ⅰ型胶原和重组人类骨形态发生蛋白2(rhBMP-2)的聚乳酸乙醇酸(PLGA)生物支架上,构建组织工程骨的可行性.方法密度梯度离心法提取分离BMSC,倒置显微镜观察细胞形态,流式细胞分析法对细胞表面抗原进行鉴定.相分离法制备多孔三维PLGA生物支架,支架材料上复合Ⅰ型胶原和rhBMP-2,扫描电镜观察其超微结构.将第3代的BMSC接种于复合支架上,扫描电镜观察材料的细胞黏附性,将培养6 h 后的细胞-支架复合体植入SD大鼠肌袋内,于2个月后取材进行HE染色,观察其构建组织工程骨的情况.结果 BMSC可在体外分离扩增,表达CD29、CD44,不表达CD34和CD45.制备的PLGA支架孔隙率为90%,平均孔径为100 μm,与BMSC有较好的黏附性.2个月后动物体内细胞-支架复合体的大体观察和HE染色显示,BMSC种植到复合Ⅰ型胶原和rhBMP-2的PLGA生物支架上可构建骨组织.结论 BMSC可在体外长期、稳定培养,是理想的组织工程种子细胞.PLGA与干细胞有较好的黏附性,可用来做组织工程生物材料.BMSC种植到复合Ⅰ型胶原和rhBMP-2的PLGA生物支架上后,在动物体内可构建组织工程骨.     

骨髓间充质干细胞对致敏小鼠造血干/祖细胞移植植入的影响

目的: 前期的研究已经证实致敏小鼠造血干/祖细胞移植植入失败率高。本研究拟通过骨髓间充质干细胞(MSCs)进行干预,观察能否提高造血干、祖细胞移植的植入率。方法: 应用贴壁培养法体外培养正常小鼠骨髓MSCs,并分为6个实验组,包括实验组1:d11 MSCs干预的致敏组;实验组2: d0 MSCs干预的致敏组;实验组3:d11和d0 2次MSCs干预的致敏组;实验组4: 无MSCs干预的致敏小鼠对照组;实验组5:无MSCs干预的正常小鼠(非致敏小鼠)移植对照组;实验组6:无MSCs干预的正常小鼠不移植对照组。观察指标包括生存分析、移植效果分析(血象改变、骨髓细胞恢复及嵌合分析等)和移植物抗宿主病(GVHD)检测,最终评估MSCs干预对各实验组异基因造血干/祖细胞移植植入率的影响效果。结果: 与对照组(实验组4、5、6)比较,MSCs干预(实验组1、2、3)在2次异基因脾细胞注射法致敏的动物模型进行异基因造血干/祖细胞移植时,未能促进骨髓造血干/祖细胞移植的植入,也未能延长致敏动物移植后的生存时间。结论: 体内应用1×10⁶ MSCs干预,未能促进2次异基因1×10⁶ C57BL/6小鼠脾细胞输注法建立的重度致敏模型异基因造血干/祖细胞移植的植入。     

人脐血源性MSCs的免疫调节作用

目的 从人脐血中分离、培养间充质干细胞(MSCs)并探讨其对淋巴细胞的免疫调节作用.方法 淋巴细胞分离液分离人脐血单个核细胞,利用贴壁筛选法通过多次传代得到MSCs,流式细胞仪测定细胞表型;将获得的MSCs分别以不同数量加入到外周血混合淋巴细胞培养体系和植物血凝素(PHA)刺激的外周血淋巴细胞转化体系中,用H3-TdR标记β液体闪烁计数仪检测细胞增殖,观察脐血来源的MSCs对混合淋巴细胞反应和淋巴细胞转化的影响.结果 从人脐血中分离获得的贴壁细胞,呈成纤维样的细胞形态,CD29、CD105和CD166表达阳性,CD14、CD34和CD45表达阴性;人脐血源性MSCs在体外对混合淋巴细胞反应和PHA诱导的淋巴细胞转化均具有明显的抑制作用,抑制作用与细胞数量呈正相关.结论 从人脐血中可以成功地分离出MSCs,其对同种异体淋巴细胞具有免疫调节作用,为其作为骨组织工程异基因种子细胞来源打下基础.     

The potential of human fetal mesenchymal stem cells for off-the-shelf bone tissue engineering application

Mesenchymal stem cells (MSCs) have become one of the most promising cell sources for bone tissue engineering (BTE) applications. In this review, we first highlight recent progress in the understanding of MSC biology, their in vivo niche, multi-faceted contribution to fracture healing and bone re-modelling, and their role in BTE. A literature review from clinicaltrials.gov and Pubmed on clinical usage of MSC for both orthopedic and non-orthopedic indications suggests that translational use of MSC for BTE indications is likely to bear fruit in the ensuing decade. Last, we disscuss the profound influence of ontological and antomical origins of MSC on their proliferation and osteogenesis and demonstrated human fetal MSC (hfMSC) as a superior cellular candidate for off-the-shelf BTE applications. This relates to their superior proliferation capacity, more robust osteogenic potential and lower immunogenecity, as compared to MSC from perinatal and postnatal sources. Furthermore, we discuss our experience in developing a hfMSC based BTE strategy with the integrated use of bioreactor-based dynamic priming within macroporous scaffolds, now ready for evaluation in clinical trials. In conclusion, hfMSC is likely the most promising cell source for allogeneic based BTE application, with proven advantages compared to other MSC based ones.     

以转染CDMP1基因的BMSCs修复软骨缺损

 目的 探讨CDMP1基因转染的骨髓间充质干细胞（BMSCs）负载于聚乳酸-羟基乙酸（PLGA）支架上修复喉软骨缺损的能力,并对其修复效果做出初步评估。方法 用反转录聚合酶链式反应（RT-PCR）和免疫印迹法(Western blot)检测hCDMP1mRNA和蛋白的表达;用免疫组织化学方法检测Ⅱ型胶原蛋白(ColⅡ)以及糖胺聚糖(GAG)的表达;将转染前后的细胞支架培养体系移植入兔甲状软骨全层缺损处,从大体、组织学方面观察其对软骨缺损的修复作用。结果 腺病毒感染方法可以将外源hCDMP1基因成功转入BMSCs,并使其获得稳定表达;和对照组比较,转染hCDMP1基因的BMSCs分泌ColⅡ、GAG等软骨特异性基质的能力增强,有促进软骨分化趋势;转染细胞支架复合物可更加有效地修复喉软骨缺损。结论 转染hCDMP1基因的BMSCs/PLGA三维生物支架复合物移植动物体内可修复喉软骨缺损。     

硼酸盐生物玻璃和自体髂骨移植对新西兰兔桡骨大段骨缺损修复的对比研究

目的比较硼酸盐生物玻璃和自体髂骨移植对新西兰兔桡骨大段骨缺损的修复效果。方法取38只新西兰兔,制作桡骨干15 mm骨缺损动物模型,并将其随机分为空白组(8只)、对照组(15只)和实验组(15只),对照组和实验组分别植入自体髂骨和硼酸盐生物玻璃(borate glass, BG)。术后4、8和12周行X线检查,观察材料的降解和新生骨生成情况。术后6周和9周分别腹腔注射茜素红和钙黄绿素。术后12周取材行组织学和Micro-CT检查。结果影像学和组织学结果显示对照组和实验组新骨生成明显优于空白组,12周后对照组和实验组新骨完全修复缺损;实验组材料降解与新骨生成协调进行;术后12周缺损处组织学切片显示,对照组和实验组缺损处有大量的新生骨组织。结论硼酸盐生物玻璃可完全修复兔桡骨干大段骨缺损,其修复效果与自体髂骨移植接近,在骨组织工程领域有广阔的应用前景。     

组织工程骨技术治疗骨缺损的优越性

文题释义：骨缺损：是部分骨骼的缺失,小部分骨缺损机体可以自我修复,但当缺损长度超过缺损骨横径的1.5倍时,则会造成缺损处迁延不愈的情况,是临床常见病,其中四肢骨缺损最为常见。发病原因主要有高能量直接损伤和感染,以及肿瘤和骨髓炎所致也较为常见,目前对于骨缺损治疗方面有着治疗周期长,成本高,疗效不可控,并有感染、骨不连等并发症。 组织工程骨技术：是将组织工程技术应用到治疗骨缺损上,其方法是从患者自身提取出所需的种子细胞,在体外经过特殊的体外培养技术,使其大量增殖,然后把培养的种子细胞放置在适合缺陷部位形态结构的细胞支架上,接着将植入种子细胞的支架放入到已经清创的骨缺损部位,随着种子细胞的成骨作用,支架材料也开始降解,最终完成骨缺损的治疗。 背景：随着当今社会的不断发展,车祸等所造成的创伤性骨缺损越来越多见,骨缺损范围越来越大,目前骨缺损治疗有着治疗周期长、所需花费高、疗效不可控制的特点,并有感染、骨不连等并发症,给患者身心健康造成了巨大的痛苦,同时对骨科医生来说是难题也是挑战。 目的：分析传统骨缺损治疗方法的优缺点以及其最新进展,着重探究组织工程技术领域治疗骨缺损的研究进展及其优越性,作一综述。 方法：作者以“骨缺损,骨移植,组织工程,诱导膜技术,骨搬移技术,内皮祖细胞,3D打印技术”为中文关键词,以“bone defect,bone transplantation,tissue engineering,induced membrane technology,bone transfer technology,endothelial progenitor cells,3D printing technology”为英文关键词,通过检索CNKI、万方和PubMed数据库归纳总结,检索到120篇相关文献,并通过对于题目、摘要和部分文献内容的阅读,排除了时效性不强、结论模糊、重复的文献,最后纳入符合标准的49篇文献进行综述。 结果与结论：①传统骨缺损治疗方式大都存在一定的缺陷,组织工程骨技术的出现有望成为骨缺损治疗最有效的方式;②种子细胞有着良好的成骨性能并能分泌促进成骨的一些重要因子;③支架材料可为患者早期提供机械强度,有着良好生物相容性、骨诱导性、可控降解性等优势;④迫在眉睫的血管化问题也在逐步解决,能够为骨缺损患者带来福音。 ORCID: 0000-0003-3706-0771(秦宇星) 中国组织工程研究杂志出版内容重点：人工关节;骨植入物;脊柱;骨折;内固定;数字化骨科;组织工程     

Biodegradable composite scaffolds incorporating an intramedullary rod and delivering bone morphogenetic protein-2 for stabilization and bone regeneration in segmental long bone defects

In this study, a two-part bone tissue engineering scaffold was investigated. The scaffold consists of a solid poly(propylene fumarate) (PPF) intramedullary rod for mechanical support surrounded by a porous PPF sleeve for osseointegration and delivery of poly(dl-lactic-co-glycolic acid) (PLGA) microspheres with adsorbed recombinant human bone morphogenetic protein-2 (rhBMP-2). Scaffolds were implanted into critical size rat segmental femoral defects with internal fixation for 12 weeks. Bone formation was assessed throughout the study via radiography, and following euthanasia, via microcomputed tomography and histology. Mechanical stabilization was evaluated further via torsional testing. Experimental implant groups included the PPF rod alone and the rod with a porous PPF sleeve containing PLGA microspheres with 0, 2 or 8 μg of rhBMP-2 adsorbed onto their surface. Results showed that presence of the scaffold increased mechanical stabilization of the defect, as evidenced by the increased torsional stiffness of the femurs by the presence of a rod compared to the empty defect. Although the presence of a rod decreased bone formation, the presence of a sleeve combined with a low or high dose of rhBMP-2 increased the torsional stiffness to 2.06 ± 0.63 and 1.68 ± 0.56 N·mm, respectively, from 0.56 ± 0.24 N·mm for the rod alone. The results indicate that, while scaffolds may provide structural support to regenerating tissues and increase their mechanical properties, the presence of scaffolds within defects may hinder overall bone formation if they interfere with cellular processes.     

骨髓间充质干细胞在节段性神经损伤局部微环境中的迁移和转归

背景：面对周围神经损伤修复这一难题,大量研究已证实组织工程干细胞修复方法的可行性,但干细胞的修复作用机制尚不明确。目的：探索骨髓间充质干细胞在损伤神经局部的迁移过程及对损伤神经的修复效果,并着重观察骨髓间充质干细胞在神经局部微环境中的分化及转归。 方法：选取8周龄雄性SD大鼠,使用液氮冰冻坐骨神经,制造节段性神经损伤模型。将36只成功造模的大鼠随机分成3组(n=12),每组按添加细胞的方式不同具体分组如下：单纯冰冻损伤神经组,损伤神经内部注射细胞组,损伤神经周围添加细胞组。造模前及植入细胞后4,8,12周测量坐骨神经功能指数;植入细胞后12周,分别对小腿三头肌进行电生理学、湿重恢复率、收缩力恢复率检测以及Masson染色,损伤段神经组织进行免疫荧光染色,损伤远端神经进行甲苯胺蓝染色。结果与结论：植入细胞后4,8,12周各组坐骨神经功能指数差异无显著性意义,但损伤神经内部注射细胞组和损伤神经周围添加细胞组均高于单纯损伤神经组,并且损伤神经内部注射细胞组略高于损伤神经周围添加细胞组;各组电生理检测结果显示,2个细胞治疗组复合肌肉动作电位的潜伏期和波幅差异无显著性意义,两组的潜伏期均值较单纯损伤神经组缩短、波幅均值较单纯损伤神经组显著升高(P < 0.05);2个细胞治疗组肌纤维横截面积均高于单纯损伤神经组;免疫荧光染色结果显示,在植入细胞12周后,2个细胞治疗组均能观察到Nestin、S100、P0蛋白的表达。结果表明在节段性损伤的神经周围添加骨髓间充质干细胞不仅可以迁移到损伤神经内部参与神经修复,而且能够向许旺细胞和神经干细胞方向分化,达到与直接向神经内部注射干细胞类似的修复效果。 中国组织工程研究杂志出版内容重点：干细胞;骨髓干细胞;造血干细胞;脂肪干细胞;肿瘤干细胞;胚胎干细胞;脐带脐血干细胞;干细胞诱导;干细胞分化;组织工程     

骨髓间充质干细胞联合血管内皮祖细胞修复骨质疏松性牙槽骨缺损

BACKGROUND:Numerous studies have demonstrated that estrogen can regulate the proliferation and migration of endothelial progenitor cells (EPCs), while EPCs can also promote the function and activity of bone marrow mesenchymal stem cells (BMSCs) in vitro. OBJECTIVE:To evaluate the ability of the BMSCs and EPCs which construct the composite cell sheet in the repair of alveolar bone defect in ovariectomized rats. METHODS:BMSCs/EPCs composite sheet, EPCs sheet and BMSCs sheet were respectively implanted into the defects of the alveolar bone in ovariectomized rats. Rats with no implantation served as control group. Repaired alveolar bone was assessed by gross examination, histological observation and micro-CT scan at 2, 4, 8 weeks after operation. RESULTS AND CONCLUSION:BMSCs/EPCs composite sheet has greater osteogensis activity and bone repair capacity than BMSCs or EPCs sheet alone.