Repair of rat calvarial bone defects by controlled release of rhBMP-2 from an injectable bone regeneration composite

The objective of the present study was to enhance the regeneration ability of an injectable bone regeneration composite (IBRC) by the controlled release of recombinant human bone morphogenetic protein-2 (rhBMP-2). The IBRC comprised nano-hydroxyapatite/collagen (nHAC) particles in an alginate hydrogel carrier. First, bovine serum albumin (BSA) as a model protein was released from IBRC to evaluate its release rules. The results suggested that IBRC is a good controlled release carrier for BSA in the range 5-75 μg/ml. In the in vitro study the rhBMP-2 released from IBRC was determined by an enzyme-linked immunosorbent assay specific for rhBMP-2. The bioactivity of the released rhBMP-2 was evaluated through differentiated function of marrow mesenchymal stem cells (MSCs), as measured by alkaline phosphatase activity. The results of an in vitro study confirmed that rhBMP-2 released continuously for 21 days, and its bioactivity was well preserved during this period. The bone formation ability was assessed using a rat calvarial defect model of critical size. Micro-computed tomography (micro-CT) and histological analysis demonstrated that the IBRC had good bone formation ability, which was promoted through rhBMP-2 released from IBRC/rhBMP-2. In vitro and in vivo studies suggested that the present system is a potential bone critical defect repair material for clinical applications.     

Bone regeneration in minipigs via calcium phosphate cement scaffold delivering autologous bone marrow mesenchymal stem cells and platelet‐rich plasma

Macroporous calcium phosphate cement (CPC) with stem cell seeding is promising for bone regeneration. The objective of this study was to investigate the effects of co‐delivering autologous bone marrow mesenchymal stem cells (BMSCs) and autologous platelet‐rich plasma (PRP) in CPC scaffold for bone regeneration in minipigs for the first time. Twelve female adult Tibet minipigs (12–18 months old) were used. A cylindrical defect with 10 mm height and 8 mm diameter was prepared at the femoral condyle. Two bone defects were created in each minipig, one at each side of the femoral condyle. Three constructs were tested: (1) CPC scaffold (CPC control); (2) CPC seeded with BMSCs (CPC‐BMSC); (3) CPC seeded with BMSCs and PRP (CPC‐BMSC‐PRP). Two time points were tested: 6 and 12 weeks (n = 4). Good integration of implant with surrounding tissues was observed in all groups. At 12 weeks, the CPC‐BMSC‐PRP group had significantly less residual CPC remaining in the defect than the CPC‐BMSC group and the CPC control (p < 0.05). The residual CPC volume for the CPC‐BMSC‐PRP group was half that of the CPC control. New bone formation for CPC‐BMSC‐PRP was more than two‐fold that of the CPC control (p < 0.05). CPC‐BMSC‐PRP had new blood vessel density that was nearly two‐fold that of the CPC control (p < 0.05). In conclusion, CPC scaffold with autologous BMSC‐PRP doubled the new bone regeneration and blood vessel density in minipigs compared with the CPC control. In the present study, the new macroporous CPC system with co‐delivered BMSC‐PRP has been shown to promote scaffold resorption and bone regeneration in large defects. Copyright © 2017 John Wiley & Sons, Ltd.     

脂肪干细胞成骨分化及与复合支架结合：在修复骨质疏松症骨缺损中的应用

背景：针对骨质疏松症伴发骨缺损疾病的传统治疗方法,诸如自体骨移植、异体骨移植、生物材料植入均有明显的局限性。以脂肪干细胞为种子细胞,采用再生医学的方法,为骨质疏松症骨缺损的修复提供了一种新的途径。
　　目的：就骨质疏松症的发病机制及其对骨缺损修复的影响、信号通路对脂肪干细胞成骨分化的调控、脂肪干细胞修复骨质疏松症骨缺损的可行性等方面作一总结。
　　方法：应用计算机检索中国期刊全文数据库(CNKI)和PubMed数据库中1998年1月至2014年9月相关文献。在标题和中以“脂肪干细胞,骨质疏松症,骨缺损,成骨分化,骨再生”或“adipose-derived stem cel s, osteoporosis, bone defect, osteogenic differentiation, bone regeneration”为检索词进行检索,重点对77篇文章进行分析。
　　结果与结论：近年来,脂肪干细胞已广泛应用于再生医学的研究。随着有关学科如再生医学、组织工程学、分子生物学、材料学的发展,对脂肪干细胞成骨分化调控机制的研究不断深入,脂肪干细胞复合生物支架构建组织工程骨为解决骨质疏松症骨缺损修复难题,提供了一种新的思路和方法,具有良好的发展前景。     

Bioactive injectable aggregates with nanofibrous microspheres and human dental pulp stem cells: A translational strategy in dental endodontics

Regeneration of the pulp–dentin complex with stem cells is a potential alternative to conventional root canal treatments. Human dental pulp stem cells (hDPSCs) have been extensively studied because of their ability to proliferate and differentiate into mineralized dental and non‐dental tissues. Here we combined hDPSCs with two types of injectable poly‐l ‐lactic acid (PLLA) microsphere with a nanofibrous or smooth surface to form bioactive injectable aggregates, and examined their ability to promote pulp regeneration in the root canal in an in vivo model. We investigated the biocompatibility, biosafety and odontogenic potential of fibrous (F‐BIM) and smooth bioactive injectable microspheres (S‐BIM) in vitro and in vivo. Our results demonstrated that PLLA microspheres and hDPSCs were able to form bioactive injectable aggregates that promoted dentin regeneration in both in vitro and in vivo models. Our results suggest that F‐BIM and S‐BIM may induce dentinogenesis upon in vivo grafting, and propose that the potential usefulness of the microsphere–hDPSC aggregates described here should be evaluated in clinical settings. Copyright © 2017 John Wiley & Sons, Ltd.     

骨髓间充质干细胞复合异体骨修复松质骨缺损*

背景：有研究表明骨髓间充质干细胞及异体骨可促进骨缺损的修复,但骨髓间充质干细胞复合异体骨对于松质骨缺损的修复效果至今少有报道。目的：观察骨髓间充质干细胞复合异体骨修复兔松质骨缺损效果。方法：在新西兰大白兔双侧股骨外侧髁造成0.6 cm×1.2 cm 的松质骨缺损,一侧设为模型组,骨缺损处植入复合骨髓间充质干细胞的异体骨,另一侧设为对照组,单纯植入异体骨。结果与结论：植入后4,8,12周,大体观察、X 射线检查和苏木精-伊红染色观察结果显示,模型组在新骨成长方面,缺损区修复方面均优于对照组。植入后12周,模型组骨缺损区可见大量骨小梁形成及成熟的板层骨组织,骨缺损基本修复。对照组骨缺损区仅可见大量编织骨形成,骨缺损尚未得到有效修复。模型组Lane-Sandhu 法 X 射线结合组织学观察评分高于对照组(P <0.05)。生物力学检测结果显示,植入后12周,模型组股骨髁最大压力载荷、载荷/应变比值均高于对照组(P <0.05),最大应变位移较对照组低(P <0.05)。结果证实,骨髓间充质干细胞复合异体骨可有效修复兔股骨髁松质骨缺损,且修复效果明显优于单纯异体骨移植。     

骨髓间充质干细胞复合温敏水凝胶支架的制备

背景：壳聚糖及其衍生物制备的支架对细胞迁移和神经轴突再生有重要作用。壳聚糖及其衍生物的组织相容性好,易使干细胞在其表面附着生长,在神经组织工程具有较为广阔的应用前景。
　　目的：制备适宜骨髓间充质干细胞生长的壳聚糖/壳聚糖季铵盐/甘油磷酸钠温敏性水凝胶细胞支架,观察骨髓间充质干细胞在细胞支架中的生长情况。
　　方法：将壳聚糖进行季铵盐化改性处理,通过傅里叶变换红外光谱分析谱检测确定其生成。实验以壳聚糖与壳聚糖季铵盐配比为8∶1成功制备出较为稳定的壳聚糖/壳聚糖季铵盐/甘油磷酸钠温敏性温敏水凝胶细胞支架,观察成胶情况,并进行生物安全性检测。
　　结果与结论：实验在傅里叶变换红外光图谱上发现了季铵基基团的特征峰。细胞毒性实验显示,水凝胶浸提液干预的大鼠骨髓间充质干细胞无毒性。急性全身毒性实验显示,浸提液对大鼠体质量增加无明显影响,支架生物安全性较好。扫描电镜观察显示,骨髓间充质干细胞在细胞支架中能正常的生长和增殖。结果证实,实验成功制备了壳聚糖/壳聚糖季铵盐/甘油磷酸钠温敏性水凝胶细胞支架,适合骨髓间充质干细胞生长和增殖。     

Accelerating bone defects healing in calvarial defect model using 3D cultured bone marrow‐derived mesenchymal stem cells on demineralized bone particle scaffold

Bone defects are usually difficult to be regenerated due to pathological states or the size of the injury. Researchers are focusing on tissue engineering approaches in order to drive the regenerative events, using stem cells to regenerate bone. The purpose of this study is to evaluate the osteogenic differentiation of bone marrow‐derived mesenchymal stem cells (BMSCs) on biologically derived Gallus gallus domesticus‐derived demineralized bone particle (GDD) sponge. The sponges were prepared by freeze‐drying method using 1, 2, and 3 wt% GDD and cross‐linked with glutaraldehyde. The GDD sponge was characterized using scanning electron microscopy, compressive strength, porosity, and Fourier transform infrared. The potential bioactivity of the sponge was evaluated by osteogenic differentiation of BMSCs using 3(4, dimethylthiazol‐2‐yl)‐2, 5‐diphenyltetrazolium bromide assay and quantifying alkaline phosphatase (ALP) activity. in vivo experiments were evaluated through a micro‐computerized tomography (μ ‐CT) and histological assays. The analysis confirmed that an increase in the concentration of the GDD in the sponge leads to a higher bone formation and deposition in rat calvarial defects. Histological assay results were in line with μ ‐CT. The results reported in this study demonstrated the potential application of GDD sponges as osteoinductor in bone tissue engineering in pathological or nonunion bone defects.     

Mannitol-containing macroporous calcium phosphate cement encapsulating human umbilical cord stem cells

Stem cell-based tissue engineering offers immense promise for bone regeneration. The objective of this study was to develop a self-setting, mannitol-containing calcium phosphate cement (CPC) encapsulating human umbilical cord mesenchymal stem cells (hUCMSCs) for bone tissue engineering. hUCMSCs could be an inexhaustible and low-cost alternative to the gold-standard bone marrow MSCs, which require an invasive procedure to harvest. hUCMSCs were encapsulated in alginate beads and mixed into the CPC paste. Water-soluble mannitol porogen was incorporated into CPC to create macropores. The porosity was increased from 49% for the hUCMSC-encapsulating CPC to 64% after adding mannitol and absorbable-fibres (p < 0.05). Flexural strength of the construct was increased from 0.3 MPa to 2.0 MPa via fibres. Live cell percentage was > 80% for all constructs. The ALP and OC gene expressions were low at 1 day and greatly increased at 14 days. The constructs that contained mannitol had significantly higher ALP and OC expressions than that without mannitol. ALP activity of hUCMSCs inside CPC with mannitol and fibre was significantly higher than that without mannitol. At 14 days, mineralization by the encapsulated hUCMSCs was eight-fold higher than that at 1 day. In conclusion, a novel mannitol-containing porous CPC-hUCMSC construct was developed for bone tissue engineering. Its advantages include cell delivery inside a load-bearing CPC that has injectable and in situ setting capabilities. hUCMSCs inside CPC had good viability and successfully osteodifferentiated. The self-setting and strong hUCMSC-encapsulating CPC scaffold is promising for bone tissue engineering in a wide range of orthopaedic and craniofacial applications.     

人工脑膜复合大鼠骨髓间充质干细胞修复心肌梗死

背景：干细胞移植治疗心肌梗死拥有广泛的应用前景,寻求理想的细胞类型和有效的移植方式是提高干细胞治疗效果的关键因素。目的：探讨人工脑膜复合骨髓间充质干细胞修复心肌梗死的安全性及作用。方法：采用全骨髓贴壁筛选法分离培养骨髓间充质干细胞,取培养良好的第3代骨髓间充质干细胞经DAPI标记后接种于人工脑膜制备细胞人工脑膜复合物。构建SD大鼠心肌梗死模型,60只大鼠随机数字表法均分为假手术组、心肌梗死组、人工脑膜组、细胞脑膜复合物组。移植4周后检测心功能参数,Westernblot检测心肌组织缝隙连接蛋白43的表达,计算心肌梗死后生存率。结果与结论：构建心肌梗死模型并移植后4周,细胞脑膜复合物组心脏组织冰冻切片于荧光显微镜下可观察到心肌内少量核蓝染的细胞,表明骨髓间充质干细胞得以存活;细胞脑膜复合物组与心肌梗死组和人工脑膜组相比,左心室功能明显改善,Cx43蛋白的表达上调,生存率增加（P〈0．05）。说明人工脑膜复合骨髓间充质干细胞移植可提高心肌梗死大鼠心脏功能及生存率。     

壳聚糖复合导管与人脐带间充质干细胞对神经侧芽分化生长的作用

背景：人脐带间充质干细胞与骨髓间充质干细胞相类似,在特定环境下可以定向分化成神经样细胞,可以按需分泌各种因子,提供神经再生的基质和基础细胞。 目的：研究桥接人脐带间充质干细胞壳聚糖复合神经导管在神经端侧吻合中的作用。 方法：将30只大耳白兔随机均分为3组,切断右后侧腓总神经中部分支,近端结扎,翻转缝合于肌肉内,对照组将腓总神经远断端与胫神经以30°-45°夹角行传统端侧吻合,支架组以同等间隙及夹角桥接壳聚糖导管于胫神经-腓总神经端侧吻合口间,细胞-支架组以同等间隙及夹角桥接填充人脐带间充质干细胞的壳聚糖复合导管于胫神经-腓总神经端侧吻合口间。术后12周行大体观察、神经电生理和抗S-100免疫组织化学检测。 结果与结论：术后12周,细胞-支架组壳聚糖复合神经导管完全降解,神经直径接近正常腓神经,运动神经传导速度快于对照组与支架组（P ＜0.01）;抗S-100免疫组织化学显示,细胞-支架组可见大量棕红色增殖的许旺细胞排列在再生神经纤维周围,支架组与对照组棕红色物质少而稀疏,许旺细胞生长情况较差。表明人脐带间充质干细胞在神经端侧吻合中对神经再生有明显促进作用,对诱导轴芽生长,加快再生纤维生长速度,促进许旺细胞生长及成熟有显著意义。     

自组装纳米多肽水凝胶负载干细胞对软骨损伤修复的研究

目的探讨自组装纳米多肽水凝胶负载干细胞对新西兰兔软骨缺损的修复作用。方法构建自组装纳米多肽水凝胶,利用扫描电镜技术检测丝素蛋白支架的结构,培养兔源性骨髓间充质干细胞(BMSC),流式细胞仪检测第2代BMSC表面蛋白CD34、CD45、CD90和CD105表达,活细胞/死细胞双重染色检测水凝胶与BMSC的生物相容性,CCK-8法检测BMSC增殖情况检测,实时定量PCR检测水凝胶对BMSC的蛋白聚糖(AGN)、Ⅱ型胶原a1(COL2a1)、成软骨分化调控基因Sox-9 mRNA的表达,分析水凝胶对BMSC成软骨分化的影响,并利用甲苯胺蓝染色评估水凝胶对兔软骨缺损的修复效果。结果原子力显微镜观察功能化自组装多肽可以形成纳米纤维网状结构;第2代BMSC表面蛋白结果显示CD105阳性和CD45阴性的比例为91.22%,而CD90阳性和CD34阴性的比例为95.10%。生物相容性检测示兔BMSC在自组装水凝胶中生长状态稳定,以绿染的活细胞为主。CCK-8法检测示BMSC复合水凝胶组在培养3 d时增殖能力高于BMSC组(P <0.001)。PCR检测示空白组、水凝胶、诱导液组和水凝胶与诱导液混...     

骨髓间充质干细胞与脱细胞脑组织支架的生物相容性

背景：骨髓间充质干细胞与细胞载体联合移植治疗中枢神经系统损伤还处于实验研究阶段。目的：评价大鼠骨髓间充质干细胞与脱细胞脑组织支架的生物相容性,探讨脱细胞脑组织支架作为中枢神经系统组织工程材料的可行性。方法：以全骨髓法分离纯化大鼠骨髓间充质干细胞,通过物理及化学方法相结合制各脱细胞脑组织支架。将转染携带绿色荧光蛋白基因的骨髓间充质干细胞种植到支架材料上共培养,通过倒置相差显微镜、扫描电镜、激光共聚焦显微镜等方法观察脱细胞脑组织支架的内部结构及复合支架上细胞的生长状况。结果与结论：制备的脱细胞脑组织支架材料呈三维立体网状结构。骨髓间充质干细胞可在支架上黏附生长,形态良好。大鼠骨髓间充质干细胞与脱细胞脑组织支架具有良好的生物相容性,有望作为中枢神经系统组织工程的载体材料。     

微骨折与自体骨髓间充质干细胞外基质支架修复猪膝关节软骨缺损

背景：微骨折术方法简单,操作方便,是治疗关节软骨缺损有效的方法之一,但仍然存在再生软骨为纤维软骨、再生软骨退化等问题。现在学者们主要致力于使用各种方法改良微骨折修复软骨缺损的效果。 目的：探索微骨折处理软骨缺损区域后植入自体骨髓间充质干细胞外基质支架治疗猪膝关节软骨缺损的疗效。 方法：分离并原代培养猪骨髓间充质干细胞,收集其分泌的细胞外基质膜,采用交联、冻干技术将收集的基质膜制备成三维多孔支架。选取小型成年猪,制备双膝股骨髁、股骨滑车部全层软骨缺损模型,深2 mm,直径6 mm;采用自体左右对照模式,右膝作为对照组,使用单纯微骨折治疗软骨缺损,左膝作为实验组,采用微骨折处理软骨缺损区域后,植入预先制备的支架。术后6个月使用番红固绿染色、Masson 染色等评价软骨再生情况,使用Wakitani评分整体评估再生软骨,并测定再生组织糖胺聚糖、DNA含量。 结果与结论：术后6个月,实验组股骨滑车和股骨髁处均可见软骨修复,表面光滑,对照组股骨滑车修复组织表面较平整,股骨髁未见明显修复。实验组股骨滑车和股骨髁再生软骨经番红固绿染色、Masson染色均显示软骨层基质含量丰富,软骨下骨骨小梁密集,对照组软骨层染色不明显,软骨下骨修复欠佳。实验组Wakitani评分、糖胺聚糖含量高于对照组,DNA含量低于对照组（P＆lt;0.05）。结果可见微骨折结合自体骨髓间充质干细胞外基质支架修复软骨效果良好,股骨滑车和股骨髁治疗效果无显著差异。     

脂肪间充质干细胞复合骨诱导性磷酸钙陶瓷支架的异位成骨☆

背景：生物材料的骨诱导现象已经在多种动物实验中被证实。目的：考察磷酸钙陶瓷自身固有的诱导骨生成能力在其作为骨组织工程支架时的表现。方法：取健康家犬10只,在每只的背部肌肉内分别植入骨诱导性磷酸钙陶瓷与自体脂肪间充质干细胞复合物、非骨诱导性磷酸钙陶瓷与自体脂肪间充质干细胞复合物、骨诱导性磷酸钙陶瓷及非骨诱导性磷酸钙陶瓷,植入后8,12周,取出植入材料及其周围组织进行Micro-CT检测和组织形态学检测,评价成骨情况。结果与结论：组织学观察结果显示,骨诱导性磷酸钙陶瓷组及骨诱导性磷酸钙陶瓷与自体脂肪间充质干细胞复合物组均有有异位骨生成,并且骨诱导性磷酸钙陶瓷与自体脂肪间充质干细胞复合物组的成骨量显著大于骨诱导性磷酸钙陶瓷组(P<0.05);其余两组均无异位成骨。Micro-CT检测结果与组织形态学检测结果一致。结果表明骨诱导性磷酸钙陶瓷作为骨组织工程支架材料有明显的成骨优势,而脂肪间充质干细胞作为种子细胞对异位成骨有明显的促进作用。     

脂肪干细胞复合明胶海绵修复兔桡骨缺损

背景：脂肪干细胞是近年来新发现的一种成体干细胞,有很强的多向分化能力,但其在体内成骨分化的能力研究较少。
　　目的：考察脂肪组织来源间充质干细胞复合明胶海绵修复骨缺损的效果。
　　方法：从兔腹股沟脂肪垫分离和培养脂肪干细胞,用含骨形态发生蛋白2的成骨诱导培养液进行培养,然后注入明胶海绵继续培养。制作兔桡骨缺损模型,将脂肪干细胞-明胶海绵复合体植入实验侧兔桡骨缺损区,对照侧植入明胶海绵。于骨缺损修复后第6,12周处死动物,取标本进行X射线、CT扫描、苏木精-伊红染色作放射学和组织学评价。
　　结果与结论：兔桡骨缺损修复后6,12周,植入明胶海绵-脂肪干细胞复合体的实验侧的Lane-Sandhu X射线评分和 Lane-Sandhu 组织学评分均比对照侧显著升高,说明实验侧骨缺损修复更好。结果表明脂肪干细胞-明胶海绵复合体对兔长骨骨缺损修复有促进作用,具有较明显的体内诱导成骨作用。     

Tubular scaffold with microchannels and an H‐shaped lumen loaded with bone marrow stromal cells promotes neuroregeneration and inhibits apoptosis after spinal cord injury

As a result of its complex histological structure, regeneration patterns of grey and white matter are quite different in the spinal cord. Therefore, tissue engineering scaffolds for repairing spinal cord injury must be able to adapt to varying neural regeneration patterns. The aim of the present study was to improve a previously reported spinal cord‐mimicking partition‐type scaffold by adding microchannels on a single tubular wall along its longitudinal axis, thus integrating the two architectures of a single H‐shaped central tube and many microchannels. Next, the integrated scaffold was loaded with bone marrow stromal cells (BMSCs) and transplanted to bridge the 5‐mm defect of a complete transverse lesion in the thoracic spinal cord of rats. Subsequently, effects on nerve regeneration, locomotion function recovery, and early neuroprotection were observed. After 1 year of repair, the integrated scaffold could guide the regeneration of axons appearing in the debris of degraded microchannels, especially serotonin receptor 1A receptor‐positive axonal tracts, which were relatively orderly arranged. Moreover, a network of nerve fibres was present, and a few BMSCs expressed neuronal markers in tubular lumens. Functionally, electrophysiological and locomotor functions of rats were partially recovered. In addition, we found that BMSCs could protect neurons and oligodendrocytes from apoptosis during the early stage of implantation. Taken together, our results demonstrate the potential of this novel integrated scaffold loaded with BMSCs to promote spinal cord regeneration through mechanical guidance and neuroprotective mechanisms.     

体外培养骨髓干细胞及趋化因子受体CXCR4的表达

背景：有实验证明骨髓间充质干细胞表面CXCR4的表达水平决定了细胞向靶组织归巢及随后血管生成的效率.目的：分析骨髓间充质干细胞的分离、培养、鉴定及多向分化潜能,探讨细胞表面CXCR4的表达在促血管再生作用领域的意义.方法：无菌条件下骨穿针垂直穿刺髂后上棘处抽取猪骨髓,并行分离及培养,得到传代的骨髓间充质干细胞,并行体外细胞凋亡检测,骨髓间充质干细胞表面蛋白CXCR4的检测：并行骨髓间充质干细胞的凋亡周期检测.结果与结论：实验分离骨髓间充质干细胞的细胞形态比较均一.传代培养后,细胞不再以集落方式生长,而呈分布均匀的纺锤形.细胞在4 d左右开始快速增长,1周后细胞生长进入稳定期.流式细胞仪检测发现细胞表面CXCR4的表达较多.证明实验成功分离骨髓干细胞,CXCR4蛋白在细胞体外培养中明显高表达,提高CXCR4的表达将为骨髓间充质干细胞移植促进血管再生、治疗下肢缺血性疾病提供临床治疗依据.     

Mesenchymal stem cell expression of SDF‐1β synergizes with BMP‐2 to augment cell‐mediated healing of critical‐sized mouse calvarial defects

Bone has the potential for spontaneous healing. This process, however, often fails in patients with comorbidities. Tissue engineering combining functional cells, biomaterials and osteoinductive cues may provide alternative treatment strategies. We have recently demonstrated that stromal cell‐derived factor‐1β (SDF‐1β) works in concert with bone morphogenetic protein‐2 (BMP‐2) to potentiate osteogenic differentiation of bone marrow‐derived mesenchymal stem/stromal cells (BMSCs). Here, we test the hypothesis that SDF‐1β overexpressed in Tet‐Off‐SDF‐1β BMSCs, delivered on acellular dermal matrix (ADM), synergistically augments BMP‐2‐induced healing of critical‐sized mouse calvarial defects. BMSC therapies alone showed limited bone healing, which was increased with co‐delivery of BMP‐2. This was further enhanced in Tet‐Off‐SDF‐1β BMSCs + BMP‐2. Only limited BMSC retention on ADM constructs was observed after 4 weeks in vivo, which was increased with BMP‐2 co‐delivery. In vitro cell proliferation studies showed that supplementing BMP‐2 to Tet‐Off BMSCs significantly increased the cell number during the first 24 h. Consequently, the increased cell numbers decreased the detectable BMP‐2 levels in the medium, but increased cell‐associated BMP‐2. The data suggest that SDF‐1β provides synergistic effects supporting BMP‐2‐induced, BMSC‐mediated bone formation and appears suitable for optimization of bone augmentation in combination therapy protocols. Copyright © 2015 John Wiley & Sons, Ltd.     

岩藻糖基化修复脐血造血干细胞归巢缺陷研究的新进展

造血干细胞(HSC)植入延迟是脐血移植(UCBT)面临的主要问题,由于植入延迟导致患者移植后感染发生率高,移植相关死亡率增高,限制了UCBT的进行.脐血HSC存在归巢缺陷是造成植入延迟的原因之一.多项研究发现,岩藻糖基化处理能修复脐血HSC的归巢缺陷,并且其操作简便、快捷、安全、有效,对脐血HSC的自我更新与分化能力无损伤,是解决上述难题的可行方法.笔者拟就岩藻糖基化修复脐血造血干细胞归巢缺陷技术的相关研究与临床应用进展进行回顾与展望.     

Enhanced tissue remodelling efficacy of adipose‐derived mesenchymal stem cells using injectable matrices in radiation‐damaged salivary gland model

The present study was conducted to introduce the use of a delivery carrier for local transplantation of human adipose tissue‐derived mesenchymal stem cells (AdMSCs) into the salivary gland (SG) and analyse its ability to enhance radioprotection of AdMSCs against irradiation (IR)‐induced damage. An injectable porcine small intestinal submucosa (SIS) matrix was used as a cell delivery carrier, and human AdMSCs were contained within SIS hydrogel (AdMSC/SIS). After local injection into SGs of mice following local IR, morphological and functional changes were evaluated in the sham, vehicle [phosphate‐buffered saline (PBS)], SIS, AdMSC and AdMSC/SIS groups. Local transplantation of AdMSC resulted in less fibrosis, regardless of the use of a carrier, but the AdMSC/SIS group showed more mucin‐producing acini relative to those in the PBS group. Functional restoration of salivation capacity and salivary protein synthesis was achieved in AdMSC and AdMSC/SIS groups, with a greater tendency being observed in the AdMSC/SIS group. AdMSC treatment resulted in tissue remodelling with a greater number of salivary epithelial cells (AQP‐5), SG progenitor cells (c‐Kit), endothelial cells (CD31) and myoepithelial cells (α‐SMA), among which endothelial and myoepithelial cells significantly increased in the AdMSC/SIS group relative to the AdMSC group. AdMSC treatment alleviated IR‐induced cell death, and the anti‐apoptotic and anti‐oxidative effects of AdMSC were enhanced in the AdMSC/SIS group relative to the AdMSC group. These results suggest local transplantation of AdMSC improves tissue remodelling following radiation damage in SG tissue, and that use of a carrier enhances the protective effects of AdMSC‐mediated cellular protection against IR via paracrine secretion. Copyright © 2016 John Wiley & Sons, Ltd.