填充结构对3D打印聚己内酯支架力学性能的影响

背景:3D打印聚己内酯组织工程支架是近些年来研究的热点之一,选择合适的材料制备力学性能优良的多孔支架是当前研究的难点。目的:制备不同填充结构的三维多孔聚己内酯支架,研究其机械性能。方法:设计0°/90°、0°/60°、0°/60°/120°、0°/45°和0°/45°/90°/135°5种填充结构,采用生物3D打印机打印三维多孔聚己内酯支架,测试支架的孔隙率及压缩和拉伸性能。结果与结论:(1)5种支架的孔隙率比较差异无显著性意义(P> 0.05);(2)从Z方向压缩时,不同填充结构聚己内酯支架的压缩性能差异很小;(3)从Y方向压缩时,0°/45°、0°/60°、0°/90°三种支架的压缩性能随填充角度增加而增强,0°/45°/90°/135°支架的压缩模量和强度比0°/45°支架高,0°/60°/120°支架的压缩模量和强度比0°/60°支架强;(4)从X方向压缩时,支架压缩模量和强度的规律与Y方向压缩相反;在5种支架中,0°/45°/90°/135°支架的拉伸模量和强度最大,0°/90°支架的拉伸模量和强度最小,0°/45°、0°/60°、0°/90°支架的拉伸强度和模量随角度...     

3D打印成型纳米羟基磷灰石/壳聚糖/聚己内酯三元复合支架材料的构建及表征

文题释义： 组织工程骨：将体外培养的功能相关的种子细胞种植于天然的或人工合成的支架材料内,加入生长因子体外培养一段时间,将他们移植到体内,促进组织修复和骨再生的人工骨。组织工程骨形成的3要素为：支架材料、成骨细胞、生长因子。 生物陶瓷：生物表面活性陶瓷通常含有羟基,还可做成多孔性,生物组织可长入并同其表面发生牢固的键合;生物吸收性陶瓷的特点是能部分吸收或者全部吸收,在生物体内能诱发新生骨的生长。生物活性陶瓷具有骨传导性,它作为一个支架,成骨在其表面进行;还可作为多种物质的外壳或填充骨缺损。生物陶瓷有羟基磷灰石陶瓷、磷酸三钙陶瓷等。  背景：目前常用的骨缺损修复支架材料种类较多,但单一类型材料难以满足骨组织工程支架材料的要求,通过合适的方法将几种单一材料组合形成复合型材料,综合考虑各种材料优缺点,是近年来学者们的研究重点。 目的：构建纳米羟基磷灰石/壳聚糖/聚己内酯三元复合支架材料,并作表征分析研究。 方法：采用3D打印成型技术制备纳米羟基磷灰石/壳聚糖/聚己内酯多孔三元复合支架材料,从X射线衍射分析、吸水率、抗压强度、体外降解性能、孔径分析、扫描电镜分析等多个维度对支架材料进行表征研究。 结果与结论：①X射线衍射分析显示,纳米羟基磷灰石/壳聚糖/聚己内酯多孔三元复合支架的晶型峰图与羟基磷灰石粉末衍射标准卡片类似,表明该三元复合支架是通过物理作用相互结合的,不影响羟基磷灰石的生物学功能;②三元复合支架的吸水率为18.28%,亲水性好,支架可承受的最大压力为1 415 N,其体外降解速率与成骨速率相当;③显微镜下可见三元复合支架的内孔为方形,孔径250 µm,孔径大小均匀、分布有致;④扫描电镜下三元复合支架可见,壳聚糖和聚己内酯组成的纤维排列整齐有序,成网格状, 羟基磷灰石呈颗粒状在纤维表面均匀分布,三元复合材料呈现均匀、疏松的微孔结构;⑤结果表明,通过3D打印成型技术可成功制备纳米羟基磷灰石/壳聚糖/聚己内酯三元复合支架材料,其具有适度的抗压强度、一定的孔隙率、适宜的降解速度和吸水率,能为修复骨缺损的奠定基础。 ORCID: 0000-0002-6321-9160(余和东) 中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程       

基于聚己内酯纤维的组织工程支架研究进展

聚己内酯(PCL)是一种生物相容性好、可吸收、易加工改性的聚酯,材料基于PCL纤维的组织工程支架,具有比表面积高、机械性能良好与孔径、孔隙率和纤维取向等结构特征易调控等特点,被广泛应用于组织工程领域。重点综述PCL纤维的组织工程支架的主要应用缺陷(包括细胞亲和力差、降解速度过慢及机械强度低)及改进手段,同时针对基于PCL纤维的组织工程支架在皮肤、血管、神经、肌腱、韧带和软骨等组织再生的最新进展进行归纳总结,发现目前多数研究集中于通过引入生物活性物质或药物以改善细胞-支架相互作用和调控支架降解行为,或通过选取不同的纺丝工艺和参数以改变支架的物理结构,调控支架机械性能与细胞诱导行为。此外,目前多数研究仍停留在实验室阶段,利用基于PCL纤维的组织工程支架低成本、易加工的优势以加快其临床转化是未来重要的发展方向。     

新型聚己内酯/磷酸钙支架的制备及生物相容性研究

探讨新型聚己内酯(PCL)/磷酸钙(CPC)复合材料支架的制备方法及对骨髓基质细胞(BMSCs)的生物相容性。采用溶液共混法,利用可溶盐晶体做造孔剂,制备PCL/CPC复合材料支架,以单纯PCL和CPC支架为对照组,Q800型动态力学分析仪进行动态力学性能试验(DMA),采用排水法测量孔隙率;灭菌后通过与犬BMSCs体外共同培养后细胞形态、生长曲线、碱性磷酸酶(ALP)染色和半定量及骨钙素(OC)半定量等方法检测细胞在支架材料上的黏附、增殖及成骨分化情况,动物体内异位成骨检测其成骨情况。结果显示,复合材料的储能模量在PCL/CPC比例为7:3时达到最大,制得的材料孔径为250～350μm,多孔支架的孔隙率为70%～80%;BMSCs在新型PCL/CPC组、CPC组支架表面分布均匀,生长增殖明显较PCL组活跃(P<0.05);PCL/CPC组、CPC组BMSCs成骨行为与PCL组之间有显著差异(P<0.05)。动物体内异位成骨检测提示,4周时PCL/CPC组为13.78%±1.60%、CPC组BMSCs为15.29%±1.20%,成骨显著强于PCL组BMSCs的7.56%±2.20%(P<0.05),表明PCL和CPC的复合明显改善了两种材料的缺陷,获得的PCL/CPC支架具有良好的生物相容性,可与BMSCs共同构建具有成骨能力的三维立体组织工程化骨。     

构建淫羊藿苷/聚己内酯纳米纤维膜及体外促成骨能力

背景:在骨组织工程中,静电纺丝的应用使得促成骨生长因子能够更长久的发挥作用。研究表明,淫羊藿苷可促进MC3T3-E1细胞的增殖。目的:构建载淫羊藿苷/聚己内酯纳米纤维膜,评估其生物相容性及体外促成骨能力。方法:采用同轴静电纺丝技术制备淫羊藿苷/聚己内酯纳米纤维膜,表征其微观形貌及体外药物释放。体外培养MC3T3-E1细胞,分4组处理:空白组常规培养细胞,纳米纤维膜组加入聚己内酯纳米纤维膜,药物组加入含淫羊藿苷的培养基,实验组加入淫羊藿苷/聚己内酯纳米纤维膜,检测各组细胞骨架形态、增殖、碱性磷酸酶活性及骨钙素m RNA表达。结果与结论:(1)扫描电镜显示,淫羊藿苷/聚己内酯纳米纤维膜具有三维立体的网状交织的结构,相互交错,空隙大小均一,孔径100-200μm,纤维平均分布范围为300-600 nm;(2)观察淫羊藿苷/聚己内酯纳米纤维膜1个月内的药物释放累积量,开始1-5 d药物有突释现象,释药量达45%左右,后期药物呈缓慢持续释放,到30 d时药物释放量达80%以上;(3)培养24 h后激光共聚焦显微镜下可见,细胞黏附于纳米纤维膜生长,细胞肌动蛋白走行及细胞内部结构清晰;(4)CCK-...     

地塞米松复合聚己内酯胶原支架材料的构建及性能评价

BACKGROUND: Tissue engineering scaffold materials have been widely used in all kinds of tissue and nerve repair, but there are many limitations and the effect is not good. OBJECTIVE: To construct a kind of tissue engineering scaffold material for the regeneration and repair of spinal cord injury. METHODS: The dexamethasonemicrospheres were prepared by emulsification-solvent evaporation. The comprehensive scores of encapsulation efficiency, drug-loading rate and yield were taken as the indexes. The effect of dosage of dexamethasone and polylactic acid-glycolic acid copolymer and mass fraction of polyvinyl alcohol on formulation process of dexamethasone sustained-release microsphere was inspected by orthogonal experiment. The characterization of microspheres was observed by scanning electron microscope. The nanofiber scaffold of compound dexamethasone microspheres was prepared by taking collagen protein and polycaprolactone as raw materials using electrospinning technology. The mouse bone marrow mesenchymal stem cells were co-cultured with the scaffold for 3 days. Cell morphology was observed by scanning electron microscope. Composite material was implanted into the defect of spinal cord in rats. RESULTS AND CONCLUSION: The optimal preparation process of dexamethasone sustained-release microspheres: dosage of dexamethasone was 10 mg, dosage of poly lactic acid-glycolic acid copolymer was 80%, mass fraction of polyvinyl alcohol was 0.5%. Appearance of dexamethasone microspheres was smooth, with a round surface. The encapsulation efficiency, drug-loading rate and yield of microspheres were (2.26±0.03)%, (83.62±0.21)% and (90.87±2.45)% respectively. The growth of mouse bone marrow mesenchymal stem cells was good on the surface of compound dexamethasone microspheres. There was no immunological reaction between the implant material and host, and the material was degraded gradually with time. These results demonstrate that the compound dexamethasone microsphere scaffold has good biocompatibility, which is a favorable kind of biological scaffold material.        

纳米羟基磷灰石/聚己内酯电纺支架修复种植体周围骨缺损

背景：牙齿缺失导致牙槽嵴骨质的改建和持续吸收,严重影响种植体植入的条件和种植区软硬组织的美观。目的：评价纳米羟基磷灰石/聚己内酯电纺支架促进即刻种植体周围骨缺损的成骨效果。方法：制作犬骨髓间充质干细胞复合纳米羟基磷灰石/聚己内酯电纺支架的组织工程化骨。拔除6只实验犬双侧下颌第二前磨牙,在其近中根牙槽窝处制备种植床,即刻植入种植体,在钛钉颊侧制作三壁骨缺损,两侧骨缺损处分别植入组织工程化骨与Bio-Oss小牛无机骨粉,并在材料表面覆盖Bio-Gide胶原膜。术后即刻、4周、8周、12周X射线测量种植体周围骨灰度值;12周后完整取出下颌骨,甲苯胺蓝染色观察骨缺损区的微观结构,新生骨量、形态结构及种植体-骨结合情况。结果与结论：两组间术后各时间点骨密度变化无明显差异,表明两组材料在促进骨再生过程中的成骨效果基本一致。组织工程化骨组骨缺损区内形成致密板状骨,可见成熟骨细胞,哈弗氏管,新生骨-种植体结合较紧密;Bio-Oss小牛无机骨粉组板层骨致密,新骨中有少量Bio-Oss颗粒分布,成骨细胞较组织工程化骨组少,部分哈弗管结构内可见到毛细血管,新骨与植入材料之间形成桥形连接,与种植体结合紧密。表明纳米羟基磷灰石/聚己内酯支架复合骨髓间充质干细胞、Bio-Gide胶原膜可促进种植体周围牙槽骨再生。中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程全文链接：     

载紫杉醇聚己内酯-聚乙二醇-聚己内酯胶束的制备及药代动力学研究简

目的制备新型可注射用载紫杉醇聚己内酯-聚乙二醇-聚己内酯（PCl-PEG-PCL）胶束,并评价和比较其与市售紫杉醇注射液在大鼠体内的药代动力学性质。方法以PCL-PEG-PCL为载体材料,通过薄膜-水化-超声法制备出载紫杉醇PCl-PEG-PCL胶束,并对其进行表征。以市售紫杉醇注射液为对照．采用SD大鼠尾静脉注射后观察载紫杉醇PCL-PEG-PCL胶束的体内药代动力学．并用DAS2．0药代动力学数据软件计算相关参数。结果载紫杉醇PCL-PEG-PCL胶束呈大小均匀的球形,具有明显的核壳结构;平均粒径为93nm,多分散系数为0．19;载药量为28．98％,药物包封率为94．36％。体外释放研究表明．载紫杉醇PCL-PEG-PCL胶束具有缓释效果。药代动力学研究表明．两种制剂均符合二房室模型．市售紫杉醇注射液和紫杉醇聚合物胶束消除半衰期（t1/2）分别为（1．96±0．27）h和（12．65±1．77）h,平均滞留时间（MRT）分别为（0．93±0．19）h和（11．18±1．41）h,体内总清除率（CL）分别为（0．44±0．05）L·kg／h和（0．10±0．01）L·kg／h,药-时曲线下面积（AUC0-∞）分别为（17．15±2．35）mg·h／L和（73．82±10．38）mg．h／L。结论成功制备了新型可注射用载紫杉醇PCL-PEG-PCL胶束．药代动力学研究表明．所研制的载紫杉醇PCL-PEG-PCL胶束明显延长紫杉醇在血液中的循环时间及消除半衰期．显著提高生物利用度,是一种有潜力的紫杉醇缓控释新剂型。     

体外构建组织工程骨-软骨复合组织

背景：设计一体化、具有过渡结构的双层支架材料,复合软骨细胞、骨髓间充质细胞,有利于新生的骨与软骨组织之间形成良好界面。 目的：模仿自然骨-软骨基质构建复合支架,以软骨细胞和骨髓间充质干细胞为种子细胞,体外观察复合组织的成软骨及成骨能力。 方法：制备明胶-硫酸软骨素-透明质酸及明胶-陶瓷化骨多孔复合支架,构建自然骨-软骨基质复合支架,复合兔软骨细胞与骨髓间充质干细胞,分未成骨诱导与成骨诱导两组培养,并进行MTT、糖胺多糖含量、碱性磷酸酶活性检测,以及苏木精-伊红染色检测。 结果与结论：未成骨诱导与成骨诱导两组骨髓间充质干细胞增殖及糖胺多糖含量差异无显著性意义。未成骨诱导组碱性磷酸酶活性缓慢上升,成骨诱导组诱导后碱性磷酸酶活性迅速上升,14 d时达到稳定状态。两组苏木精-伊红染色结果无明显区别,均已形成含有双层组织的类似骨-软骨样组织,其间可见未降解支架形态,但由于基质形成不完善及支架未完全降解,此种结构不成熟,细胞分布不均匀,支架内部可见散在无细胞区域。证实采用两种细胞与双层结构的支架经体外分层复合能够形成组织工程骨软骨复合组织。     

静电纺丝聚己内酯纳米纤维支架支持小鼠诱导多能干细胞表达心肌细胞标志物

目的利用多能干细胞与仿生材料支架构建人工心肌,探讨仿生材料支架本身对多能干细胞心肌特异性分化的直接作用,为构建组织工程心肌提供理论支持。方法采用静电纺丝聚己内酯纳米纤维仿生支架,接种小鼠i PSCs(mi PSCs)细胞培养分化15 d,免疫荧光染色与Western blot法检测多能干细胞与心肌细胞特异性标志物。结果mi PSCs特异性表达多能干性标志物Oct4和Nanog,而且能够在聚己内酯纳米纤维支架上集落样增殖、分化;培养15 d后,mi PSCs在支架上分化出心肌特异性标志物c Tn T和MLC2a双重免疫荧光染色阳性的细胞;心肌细胞特异性结构蛋白c Tn T、α-MHC和MLC2的表达水平,支架组全面高于对照组。结论聚己内酯纳米纤维仿生支架支持mi PSCs生长与心肌细胞特异性分化。     

注射型猪小肠黏膜下层与脂肪间充质干细胞的体外共培养

BACKGROUND: The decellularized porcine small intestinal submucosa is a kind of bioactive extracellular matrix, which is mainly composed of collagen, glycoprotein, proteoglycan and rich in collagen, glycosaminoglycan and various growth factors, and these components play an important role in promoting the differentiation and proliferation of tissue cells. OBJECTIVE: To prepare the injectable small intestinal submucosa and to investigate its co-culture with rat adipose-derived mesenchymal stem cells in vitro. METHODS: The injectable small intestinal submucosa and rat adipose-derived stem cells were prepared. Cell counting kit-8 test for cell proliferation: Passage 3 adipose-derived stem cells were seeded onto the injectable small intestinal submucosa (experimental group) and cells cultured under normal condition as control group. The cell proliferation was observed at 1, 3, 5 and 7 days of incubation. Live/dead staining test for the survival of cells: Passage 3 adipose-derived stem cells were respectively cultured in the injectable small intestinal submucosa extracts (experimental group) and complete culture medium (control group). Cell survival was determined at 1, 3, 5 and 7 days of culture. RESULTS AND CONCLUSION: Scanning electron microscope oval and strip adipose- derived stem cells adhered onto the material. The absorbance values in the experimental group were higher than those in the control group at 1 and 5 days of incubation (P < 0.05). Cell survival: The number of cells appeared to be in a rising trend with time in both two groups; after 1-day co-culture, all cells in the two groups survived. Then dead cells appeared in both two groups, showing no significant difference. These results show that the injectable small intestinal submucosa exhibits a good cytocompatibility.      

脱细胞基质软骨支架的制备

背景：脱细胞基质材料去除了天然材料中的细胞成分,保留了基质成分,有效降低了天然材料的免疫原性,同时能够保持材料的机械强度。 目的：拟利用洗脱方法去除兔肋软骨中的细胞基质,制备天然生物支架材料。 方法：取新西兰大白兔肋软骨,清除周围组织后随机分组处理,以未经处理的肋软骨作为正常对照组;48 h处理组以去污剂-酶化学消化48 h;96 h处理组以去污剂-酶化学消化96 h,3组均通过苏木精-伊红染色及电镜观察脱细胞效果。同时收集诱导第7天的兔骨髓间充质干细胞3×109 L-1,与同种异体肋软骨脱细胞基质体外复合培养,于第3,7天取复合物行电镜观察细胞在脱细胞基质表面的黏附生长情况。 结果与结论：新鲜肋软骨标本每个软骨陷窝内均有排列紧密的二三个软骨细胞,去污剂-酶化学消化后软骨陷窝内的细胞逐渐脱失,至消化处理96 h后,软骨陷窝内的细胞完全脱失。共培养第3天时,脱细胞基质表面有大量骨髓间充质干细胞分布,细胞为多角形,有伪足伸出,锚定在基质表面,部分区域可见细胞在基质表面增殖分裂;第7天时,脱细胞基质表面大部分均为细胞覆盖,细胞呈扁平状,有多个足突充分伸展,细胞之间互相连接,分泌大量细胞外基质沉积在基质表面,呈冰霜样改变,表明制备的脱细胞基质具有良好的细胞相容性。中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程全文链接：     

脱细胞基质材料体外激活巨噬细胞的作用

背景：因巨噬细胞在机体炎症反应中有着举足轻重的作用,所以检测生物材料对巨噬细胞行为的影响,可评估材料的免疫原性。 目的：分析脱细胞基质材料对巨噬细胞的激活作用。 方法：获取BALB/c小鼠腹腔巨噬细胞,分5组培养：对照组为单纯细胞培养组;实验1组为脱细胞基质膜材料与巨噬细胞直接接触培养,实验2组为新鲜心包膜材料与巨噬细胞直接接触培养,实验3组为脱细胞基质膜材料与巨噬细胞间接接触培养,实验4组为新鲜心包膜材料与巨噬细胞间接接触培养。培养48 h后,MTT法检测各组A值,判定毒性分级;培养24 h后,检测细胞培养上清中一氧化氮及细胞因子的分泌。 结果与结论：实验1-4组毒性分别为2级、4级、0级及2级。实验1组、实验2组一氧化氮水平高于对照组(P < 0.05),并且实验2组高于实验1组(P < 0.05)。5组间白细胞介素2、白细胞介素4、干扰素γ、白细胞介素17A和白细胞介素10水平比较差异无显著性意义;实验2组白细胞介素6水平高于对照组(P < 0.05);实验1组、实验2组、实验4组肿瘤坏死因子水平高于对照组(P < 0.05),并且实验2组高于实验1组(P < 0.05)、实验1组高于实验4组(P < 0.05)。说明脱细胞基质材料可在直接接触时激活巨噬细胞。 中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程     

单晶硅材料微型圆柱体直径及其排列间距对神经干细胞分化的影响

BACKGROUND: Different structures of matrix models, such as grating, holes and pillars make different effects on the differentiation of neural stem cells. OBJECTIVE: To explore the effects of the diameter and spacing, known as physical signals of micro pillars on neural stem cell differentiation. METHODS: Micro pillars with different diameters and spacing, both of which had four dimensions of 2.5, 5, 10 and 20 μm, were fabricated on silicon substrates by photolithographic method. Purified primary neural stem cells were incubated on the each micro pillar for 7 days in vitro. Then the differentiation of neural stem cells into neuron-like cells was observed using immunofluorescence staining and quantitative real-time PCR. RESULTS AND CONCLUSION: When the diameters of the micro pillars were constant and the spacing of micro pillars varied in the range of 2.5-10 μm, the differentiation rate of neural stem cells increased with the spacing increase. When the spacing was invariable and the diameters changed in the range of 2.5-20 μm, the differentiation rate of neural stem cells declined with the diameter increase. Especially, the micro pillars with 2.5 μm diameter and 10 μm spacing significantly promoted the differentiation of neural stem cells into neuron-like cells. These results show that specific micro pillars with small diameters and large spacing facilitate the differentiation of neural stem cells, thus providing guidance for developing tissue-engineered scaffolds.      

构建骨组织工程支架中应用的3D打印技术

背景：3D打印技术自20世纪末出现以来逐渐应用在医学领域已成为一种趋势。近年来3D打印技术被广泛用于骨组织工程支架材料的成型,并取得了一些令人惊喜的成果。 目的：文章从骨组织工程支架基本概念、3D打印的基本原理和流程、3D打印应用于构造支架的要求以及不同的粉末材料等方面进行阐述,分析其优势与目前存在的局限性,并对未来3D打印在骨组织工程支架中的应用进行展望。 方法：第一作者应用计算机检索1990年1月至2015年2月MEDLINE数据库、Science Direct全文数据库、中国期刊全文数据库、维普中文期刊网等有关3D打印技术在构建骨组织工程支架中应用的文章,检索词“3D打印,组织工程学,快速成型技术,支架,材料”,排除重复性研究。文章共检索到52篇相关文献,其中33篇文献符合纳入标准。 结果与结论：3D打印技术具有高精度、构建速度快、可按需制造实现个性化定制等优势。3D打印应用于骨组织工程支架构建时,所用的粉末或黏合剂需具备一定的条件,如流动性、稳定性与可湿性等。用于打印的粉末材料可分为人工合成多聚体、天然高分子聚合物、生物陶瓷及它们的混合物。不同粉末材料的粉末各自优缺点不同,且最终成型效果也不尽相同。3D打印技术也存在一些包括费用昂贵、不易大规模生产等方面的局限性。但尽管如此,3D打印的临床应用前景一片光明。 中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程     

基于3D打印技术股骨头减压联合骨髓间充质干细胞移植专用移植器的研制及应用

BACKGROUND: Autologous tissue-engineered bone marrow mesenchymal stem cells (BMSCs) transplantation is one of the most common methods of treating early osteonecrosis of femoral head, but now there is still no any special-purpose grafter available in the market. Such surgical transplantation is a laborious, time-consuming and tedious process, which goes against its clinical promotion.     

硫酸钙人工骨复合培养骨髓间充质干细胞对骨诱导脊柱融合的影响

BACKGROUND: Biodegrable calcium sulfate artificial bone has a good biocompatibility, so it is used as a bone graft substitute in the treatment of spinal fusion. OBJECTIVE: To investigate the osteoinductive effects of the tissue-engineered bone made of bone marrow mesenchymal stem cells and calcium sulfate artificial bone in spinal fusion. METHODS: Bone marrow mesenchymal stem cells were cultured in vitro, and then combined with the calcium sulfate artificial bone. The composite material was observed under electron microscope. Totally 67 patients undergoing spinal fusion were enrolled, who were divided into control group (n=35) and observation group (n=32), receiving autologous iliac bone graft and autologous bone marrow mesenchymal stem cells combined with calcium sulfate transplantation, respectively. Subsequently, spinal fusion Lenke classification and low back outcome score were conducted. RESULTS AND CONCLUSION: Under electron microscope, the visible calcium sulfate artificial bone presented a good porous structure, on which bone marrow mesenchymal stem cells grew and adhered well. Slightly but insignificantly better outcomes in the spinal fusion through the use of the Lenke classification system were obtained in the observation group than the control group after surgery (P > 0.05). Besides, scores on low back outcomes in both two groups were significantly higher than baseline data (P < 0.05). These results suggest that the tissue-engineered bone made of calcium sulfate artificial bone as the scaffold and bone marrow mesenchymal stem cells as seed cells can exert a good osteoinduction in spinal fusion, and obtain ideal effects.     

Nanog慢病毒载体构建及在胚胎干细胞分化调控中的应用

BACKGROUND:There is a lack of safe and effective modular lentivectors in differentiation regulation of embryonic stem cells. OBJECTIVE:To construct a modular lentivector, Puro-Nanog-hrGFP, with Nanog promoter-controlled humanized renilla reniformis green fluorescent protein (hrGFP) and puromycin and to observe the expression of Nanog during the differentiation of Nanog-hrGFP-transfected mouse embryonic stem cell lines. METHODS:After PCR amplification, Nanog, hrGFP and entry vector were recombined into the pDest-puro vectors to generate the lentiviral expression vector, Puro-Nanog-hrGFP, by the LR reaction. Through lentivirus production, transduction and puromycin screening, the transduced cell lines with Nanog-hrGFP gene were generated and identified. Expression of Nanog during the differentiation of transgenic mouse cell lines was detected. RESULTS AND CONCLUSION:The lentiviral expression vectors Puro-Nanog-hrGFP were constructed successfully by Gateway technology, and then the transducted cell lines were obtained by lentiviral infection. The expression of Nanog was gradually decreased during the process of transgenic cell lines differentiation, which provides a new tool for further investigation on regulation of stem cell differentiation.     

人前脑啡肽基因修饰骨髓间充质干细胞系的生物学特性

BACKGROUND:Previous studies have found that the transplantation of modified cell lines exhibit analgesic effect. But little is reported on the biological characteristics of human preproenkephalin gene-modified bone marrow mesenchymal stem cell lines. OBJECTIVE:To observe the biological characteristics of human preproenkephalin gene-modified bone marrow mesenchymal stem cells. METHODS:Bone marrow mesenchymal stem cells were isolated and cultured to establish human preproenkephalin gene-modified bone marrow mesenchymal stem cell lines. RESULTS AND CONCLUSION:After freezing-thawing, passage 4 human bone marrow mesenchymal stem cells, human bone marrow mesenchymal stem cells-pBABE and human bone marrow mesenchymal stem cells-human preproenkephalin exhibited no significant changes in the cell viability (P > 0.05), as well as in the fat cell proportion after adipogenic induction (P > 0.05). Moreover, red calcium deposition was presented in all these cells by alizarin red staining after osteogenic induction. Flow cytometry results showed that passage 4 human bone marrow mesenchymal stem cells, human bone marrow mesenchymal stem cells-pBABE and human bone marrow mesenchymal stem cells-human preproenkephalin could express CD29 and CD44, but not express CD34 and CD45. Human preproenkephalin genes were highly expressed in human bone marrow mesenchymal stem cells-pBABE, but lowly expressed in passage 4 human bone marrow mesenchymal stem cells. Additionally, recombinant plasmid pBABE-preproenkephalin-modified human bone marrow mesenchymal stem cells could express enkephalin protein. In conclusion, human preproenkephalin gene-modified human bone marrow mesenchymal stem cell lines can maintain the pluripotent differentiation or proliferation capacity of bone marrow mesenchymal stem cells, and secrete enkephalin protein.     

三维打印组织工程牙计算机辅助设计建模技术的应用

背景：国内外关于如何成功构建组织工程牙支架材料内部空间构型的文献报道较少。 目的：建立适用于组织工程牙需求的支架材料CAD空间构型及支架结构实体微观模型STL格式文件。 方法：采用MICRO CT对离体大鼠第二磨牙进行连续扫描,将MICRO CT获得的DICOM格式文件导入MIMICS软件,将生成的三维模型导入GEOMAGIC12软件,提取外层轮廓,利用偏移功能模拟得到大鼠磨牙外层轮廓数据。利用CATIA V5R17软件构建支架材料空间内部多孔微观模型单体,在空间合适坐标上阵列得到组织工程牙内部支架整体模型,通过变更单体构型还可快速建立多种整体支架构型。装配大鼠磨牙外层轮廓数据与内部空间支架得到三维打印组织工程牙CAD 模型STL文件。 结果与结论：成功建立了牙体组织支架微观结构CAD模型,该CAD STL模型可直接用于三维打印系统快速成型组织工程牙支架。说明基于结合计算机逆向与正向工程建模技术,可快速建立多种符合组织工程牙要求的支架材料空间构型。中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程