珍珠层人工骨促进成骨细胞的体外成骨能力

目的:研究珍珠层人工骨对人成骨细胞体外成骨能力的影响.方法:将珍珠层人工骨、聚乳酸(对照组)与人成骨细胞共同培养,观察细胞形态、细胞活性、碱性磷酸酶(ALP)活性和基质钙化情况.结果:实验组在细胞形态、细胞活性等指标与对照组相比差异无显著性;实验组在培养7d及14d后ALP阳性细胞数多于对照组;培养21d后可观察到骨结节,对照组没有骨结节产生.结论:珍珠层人工骨可促进成骨细胞的体外成骨能力.     

珍珠层人工骨促进成骨细胞的体外成骨能力

目的：研究珍珠层人工骨对人成骨细胞体外成骨能力的影响。方法：将珍珠层人工骨、聚乳酸（对照组）与人成骨细胞共同培养，观察细胞形态、细胞活性、碱性磷酸酶（ALP）活性和基质钙化情况。结果：实验组在细胞形态、细胞活性等指标与对照组相比差异无显著性；实验组在培养7d及14d后ALP阳性细胞数多于对照组；培养21d后可观察到骨结节，对照组没有骨结节产生。结论：珍珠层人工骨可促进成骨细胞的体外成骨能力。     

成骨细胞在珍珠层复合人工骨表面的粘附和增殖

目的 评价人成骨细胞在珍珠层聚乳酸人工骨上的粘附能力。方法 将珍珠层聚乳酸人工骨与人成骨细胞体外复合培养，采用倒置相差显微镜、扫描电镜、透射电镜及流式细胞仪检测，观察人成骨细胞在珍珠层聚乳酸人工骨上的粘附能力。结果 珍珠层聚乳酸人工骨与人成骨细胞体外复合培养1周后，细胞通过伪足贴附于人工骨表面。透射电镜下成骨细胞形态正常，胞浆内有丰富的粗面内质网和线粒体，并可观察到细胞之间形成的连接。流式细胞仪检测结果显示，附着在珍珠层复合人工骨的成骨细胞增殖指数增高。结论 珍珠层复合人工骨材料有利于成骨细胞的粘附、增殖和分化。     

成骨细胞在珍珠层复合人工骨表面的粘附和增殖

目的　评价人成骨细胞在珍珠层聚乳酸人工骨上的粘附能力。方法　将珍珠层聚乳酸人工骨与人成骨细胞体外复合培养 ,采用倒置相差显微镜、扫描电镜、透射电镜及流式细胞仪检测 ,观察人成骨细胞在珍珠层聚乳酸人工骨上的粘附能力。结果　珍珠层聚乳酸人工骨与人成骨细胞体外复合培养 1周后 ,细胞通过伪足贴附于人工骨表面。透射电镜下成骨细胞形态正常 ,胞浆内有丰富的粗面内质网和线粒体 ,并可观察到细胞之间形成的连接。流式细胞仪检测结果显示 ,附着在珍珠层复合人工骨的成骨细胞增殖指数增高。结论　珍珠层复合人工骨材料有利于成骨细胞的粘附、增殖和分化     

成骨因子BMP7在骨膜细胞体外培养中的作用

目的 探讨成骨因子骨形态发生蛋白(BMP7)在骨膜细胞体外培养中的诱导分化作用.方法取材于成人胫骨骨膜,常规细胞培养法行骨膜细胞体外培养,分为实验组和对照组,分别加入BMP7加成骨细胞培养辅助剂和单纯成骨细胞培养辅助剂,相差显微镜观察骨膜细胞形态特征.每组分别在第5、10、15、20天设3个样本,采用ALP试剂盒法及钙结节Von Kossa染色法分别检测成骨细胞特异性标志物ALP和钙结节的表达情况.结果 骨膜细胞在体外生长良好,实验组和对照组形成的成骨细胞增殖良好,形态一致.细胞早期呈梭形,饱满透明,立体感强;分裂期呈立方形或短柱状;后期由长梭形逐渐变成宽梭和不规则形.由BMP7诱导的骨膜细胞的成骨标志物ALP和钙结节染色阳性率明显高于对照组,有统计学意义(P＜0.01).结论 骨膜细胞具有良好的成骨和再生能力,BMP7在体外培养中具有明显增强骨膜细胞分化为成骨细胞的作用.     

新型骨替代材料-珍珠层的生物相容性研究

[目的]研究珍珠层的生物相容性。[方法]在体外培养的第3代成骨细胞中分别加入珍珠层（实验组）、橡胶（对照组）的材料浸提液，观察细胞形态、细胞膜和超微结构的变化；通过BrdU核掺入法检测细胞增殖情况、通过MTT法检测成骨细胞代谢活性。[结果]实验组细胞形态及细胞结构良好、细胞膜完整；对照组中细胞形态发生改变，细胞膜及胞浆内细胞器均有破坏；BrdU及MTT检测结果显示珍珠层对人成骨细胞的增殖和代谢活性无阻滞作用。[结论]珍珠层具有良好的生物相容性，可作为骨替代材料应用于骨缺损修复。     

人骨膜细胞体外成骨分化的基因表达和功能检测

目的 探讨并鉴定骨膜细胞经骨形成蛋白7(BMP7)诱导分化为成骨细胞的基因表达和细胞功能.方法 成人胫骨骨膜常规体外细胞培养法,分实验组和对照组,分别加入BMP7加成骨辅助剂和单纯成骨辅助剂进行体外培养.CCK-8法检测细胞增殖活性,第5、10、15和20天分别采用Real Time-PCR检测骨钙素基因表达,ELISA法检测上清液碱性磷酸酶(alkaline phosphatase,ALP)、骨钙素(osteocalcin,OCN)及骨桥蛋白(osteopontin,OPN)的水平,甲苯胺蓝染色检测糖胺聚糖(GAG),Real Time-PCR检测Ⅱ型胶原基因,比色法检测细胞ALP活性,ALP染色法检测ALP,Yon Kossa染色法检测钙结节.结果 两组骨钙素基因表达及上清液ALP、骨钙素、骨桥蛋白的含量均增高,实验组与对照组差异有统计学意义(P＜0.05).两组细胞的ALP和钙结节染色阳性率增高,实验组与对照组差异有统计学意义(P＜0.05).甲苯胺蓝染色阳性率及Ⅱ型胶原基因表达表现为先高后低,实验组与对照组差异有统计学意义(P＜0.05).结论 骨膜细胞在BMP7诱导下体外大量增殖和分化成骨,表达出明显的成骨特异基因,并具有合成分泌成骨特异蛋白的功能;成骨化过程中,除直接分化成骨外,还存在部分细胞先经软骨形成再钙化成骨的现象;经骨膜细胞-BMP7途径在体外获取大量成骨细胞可用于组织工程的体外构骨及临床应用.     

珍珠层/聚乳酸人工骨的生物相容性研究

目的：研究珍珠层／聚乳酸人工骨在体内外的生物相容性。方法：将珍珠层／聚乳酸人工骨在体外与兔成骨细胞复合培养作实验组，以脱钙骨／聚乳酸人工骨作对照，行MTT法、组织学和扫描电镜检测，观察成骨细胞在材料表面的粘附、生长和增殖情况；将同种异体成骨细胞—珍珠层／聚乳酸人工骨复合植入体内，观察机体对细胞与材料的排斥反应。结果：肌法显示随培养时间的延长，细胞在材料表面不断增殖；组织学及电镜显示，在体外细胞于材料表面及孔隙中附着、生长良好，存在接触抑制现象；细胞与材料复合植入体内，珍珠层／聚乳酸组的炎性反应明显比对照组轻。结论：珍珠层／聚乳酸人工骨在体内外有良好的生物相容性。     

重组骨生长肽对组织工程性骨肌皮瓣影响的实验研究

目的探讨重组骨生长肽对组织工程性骨肌皮瓣的影响。方法自2004年12月至2005年5月,采用新西兰大耳白兔36只,在其髂后上棘抽取骨髓基质干细胞进行体外培养,诱导分化为成骨细胞。然后将第3代细胞与羟基磷灰石/磷酸三钙(HA/TCP)、重组骨生长肽结合,共同培养14d后,经相差显微镜、扫描电镜观察体外细胞的生长情况,最后分别将72块复合物植入36只白兔的双侧背阔肌中,构成组织工程骨肌皮瓣。含重组骨生长肽的一侧为实验组;含成骨细胞的一侧为对照组。术后6周,进行大体解剖观察,行HE染色,观察骨肌皮瓣的生长情况。结果骨髓基质干细胞可以诱导分化为成骨细胞,钙盐沉积,可形成不透光的矿化结节。在不同时间的骨髓基质干细胞,实验组ALP活性较对照组高(P<0.05),并表现为时间依赖性。扫描电镜显示:支架材料表面和孔隙内均有成骨细胞生长,有良好的增殖活动。两组均可形成肌骨瓣,但实验组在成骨速度、成骨质量、血管化程度等方面均优于对照组。结论应用重组骨生长肽可成功地构建组织工程性骨肌皮瓣。     

体外负压培养对hBMSCs成骨活性影响的初步研究

[目的]探讨体外负压培养对hBMSCs成骨活性的影响.[方法]取第3代hBMSCs分为实验组和对照组,实验组进行间歇性负压培养,设置压力为17 kPa,30 min/次,4次/d,干预2周;对照组于普通CO,培养箱中常规培养.倒置显微镜下观察细胞形态,MTT法和流式细胞仪检测细胞增殖和凋亡,检测ALP活性,茜素红染色观察钙节结形成,免疫组织化学检测Ⅰ型胶原和VEGF的表达.[结果]诱导2周,实验组细胞增殖能力下降,S期细胞百分比为(5.14±1.56)%,较对照组(13.45±3.51)%约下降62.4%,细胞凋亡增加.实验组ALP活性为(15.68±1.97)mU/mg,对照组为(6.344±1.21)mU/mg,两组比较差异有统计学意义(P<0.05);与对照组比较,实验组钙结节形成增多,VEGF表达较对照组显著提高;实验组Ⅰ型胶原表达呈阳性,对照组呈阴性反应.[结论]负压能抑制hBMSCs增殖,促进细胞凋亡,但可以提高细胞成骨活性.     

Nacre initiates biomineralization by human osteoblasts maintained In Vitro

Summary When nacreous shell produced by the marine oyster Pinctada maxima, used as a biomaterial in oral surgery, is implanted in human bone, new bone formation occurs, resulting in a tight welding of the bone to the nacre [16]. These findings are consistent with the possibility that nacre adjacent to bone can locally stimulate osteogenic activity. To test this hypothesis, we have evaluated the effect of the simultaneous presence of bone and nacre on human osteoblasts in vitro. Nacre chips (1 mm³) were placed at 1 mm distance from a similarly sized bone chip on a layer of first passage human osteoblasts. None of the chemical inducers generally required to obtain bone mineralization in vitro (in particular, -glycerophosphate) was added to the cultures. Mineralized sections of the cultures were evaluated by light and electron microscopy, contact microradiography, and Laser Raman Spectroscopy. The results demonstrated that nacre has strong osteogenic effects on human osteoblasts when placed in proximity to bone in vitro. New bone formation occurred by both appositional growth on the existing bone and by the formation of mineralized nodules within the matrix adjacent to the bone explant. Electron microscopic evaluation of these sites demonstrated findings typical of those described in the course of bone formation in vivo, and no evidence of toxicity was observed. In addition, under the conditions of culture used, nacre can also promote the formation by osteoblasts of a structure with characteristics similar to nacre (e.g., lamellar organic matrix mineralized with aragonite, as demonstrated by Laser Raman Spectroscopy). Given the unusual capacity of nacre in the presence of human osteoblasts in vitro to induce different types of mineralization, this model should provide insights into the specific interactions between matrix proteins and minerals that control the type of mineral produced in the course of biomineralization.     

Bioglass ®45S5 Stimulates Osteoblast Turnover and Enhances Bone Formation In Vitro: Implications and Applications for Bone Tissue Engineering

We investigated the concept of using bioactive substrates as templates for in vitro synthesis of bone tissue for transplantation by assessing the osteogenic potential of a melt-derived bioactive glass ceramic (Bioglass 45S5) in vitro. Bioactive glass ceramic and bioinert (plastic) substrates were seeded with human primary osteoblasts and evaluated after 2, 6, and 12 days. Flow cytometric analysis of the cell cycle suggested that the bioactive glass-ceramic substrate induced osteoblast proliferation, as indicated by increased cell populations in both S (DNA synthesis) and G2/M (mitosis) phases of the cell cycle. Biochemical analysis of the osteoblast differentiation markers alkaline phosphatase (ALP) and osteocalcin indicated that the bioactive glass-ceramic substrate augmented osteoblast commitment and selection of a mature osteoblastic phenotype. Scanning electron microscopic observations of discrete bone nodules over the surface of the bioactive material, from day 6 onward, further supported this notion. A combination of fluorescence, confocal, transmission electron microscopy, and X-ray microprobe (SEM-EDAX) examinations revealed that the nodules were made of cell aggregates which produced mineralized collagenous matrix. Control substrates did not exhibit mineralized nodule formation at any point studied up to 12 days. In conclusion, this study shows that Bioglass 45S5 has the ability to stimulate the growth and osteogenic differentiation of human primary osteoblasts. These findings have potential applications for tissue engineering where this bioactive glass substrate could be used as a template for the formation of bioengineered bone tissue.     

煅烧骨与诱导的MSCs复合的实验研究

目的：观察大鼠骨髓基质干细胞（MSCs）与经胶原涂层处理的煅烧骨（CCB）复合行体外培养时贴附、增殖能力的变化,探讨构建组织工程骨体外培养的最适时间。方法：制备鼠尾胶原（I型胶原）,无菌条件下,将煅烧骨置于胶原液中,2h后取出骨块,置滤网中将孔内外的胶原溶液沥干。体外培养的大鼠MSCs经矿化液诱导向成骨细胞分化。将分化后的成骨细胞滴加到涂胶原的煅烧骨块上,同时以未涂胶原的煅烧骨块为对照组。3天,7天时取材,扫描电镜下观察实验组与对照组成骨细胞在煅烧骨表面的贴附数量及形态,用细胞计数法测定细胞在两组材料的生长曲线,组织化学方法检测成骨细胞的ALP活性。结果：扫描电镜发现实验组成骨细胞的贴附数量显著高于对照组（P〈0．01）。细胞计数认为实验组细胞在材料上粘附数量多,增殖速度快。实验组ALP活性明显高于对照组（P〈0．01）。结论：胶原修饰的煅烧骨具有良好的组织相容性,能明显提高成骨细胞的贴附,并且促进成骨细胞活性维持,体外培养7～8天时,材料上的细胞数达到最大,应尽快植入体内。     

补肾健骨方含药血清对ROBs和rBMSCs增殖、分化和矿化的影响

目的观察补肾健骨方含药血清对大鼠颅骨成骨细胞(rat calvarial osteoblasts,ROBs)和大鼠骨髓间充质干细胞(rat bone marrow mesenchymal stem cells,r BMSCs)细胞活性及分化、矿化的影响。方法制备补肾健骨方含药血清,将ROBs和r BMSCs分为5%、10%、15%、20%、25%浓度含药血清组、无药血清组及传统诱导组,分别对各组ROBs和r BMSCs进行成骨诱导。MTT法检测ROBs和r BMSCs细胞的增殖情况;用试剂盒检测ROBs和r BMSCs的碱性磷酸酶(ALP)活性;茜素红染色法检测矿化结节形成。结果不同浓度含药血清组与空白无药血清组、传统诱导组相比,均不同程度地促进ROBs和r BMSCs的增殖,使ALP活性提高,增加钙化结节数量和面积。其中含药血清浓度为20%时促进ROBs增殖分化作用最佳,浓度为10%时促进r BMSCs增殖分化效果最为显著。结论不同浓度补肾健骨方含药血清均能够促进ROBs和r BMSCs的成骨增殖、分化和矿化,分别在浓度为20%和10%时最佳。     

正弦电磁场对高糖环境下大鼠骨髓间充质干细胞分化的影响

目的探讨正弦电磁场对高糖环境下大鼠BMSCs分化的影响,并探讨其中可能的分子机制。方法贴壁筛选法分离、培养大鼠BMSCs,将第三代细胞分为暴磁组、高糖组、高糖暴磁组及对照组。高糖组采用高糖培养基(葡萄糖浓度为15 mmol/L),电磁场组每天给予1 mT、50 Hz正弦电磁场刺激2 h。刺激21 d后采用茜素红染色、油红O染色观察各组在成骨和成脂分化上的差异,刺激7 d后Real-time PCR检测成骨/成脂相关基因Runx2、ALP、Id4、PPARγ、aP2的表达变化。结果暴磁组钙结节形成能力较对照组增强、成骨相关基因表达增高,高糖组形成脂滴能力增强、成脂相关基因表达增高,高糖暴磁组成骨和成脂基因表达均有增高,但前者更为明显。结论正弦电磁场对高糖环境下的大鼠骨髓间充质干细胞有促进成骨、间接抑制成脂分化的作用,其机制可能与通过上调关键分子Id4有关。     

去卵巢对大鼠颌骨成骨细胞增殖与成骨分化能力的影响

目的探讨去卵巢对大鼠颌骨成骨细胞增殖与成骨分化能力的影响。方法建立去卵巢大鼠骨质疏松模型,分离培养假手术组和去卵巢组颌骨成骨细胞并进行形态学观察。采用CCK-8法检测假手术组和去卵巢组大鼠颌骨成骨细胞的增殖能力差异。通过碱性磷酸酶染色与活性测定、矿化结节茜素红染色与定量、成骨相关基因及蛋白表达检测,探讨去卵巢对大鼠颌骨成骨细胞增殖及成骨分化能力的影响。结果假手术组和去卵巢组大鼠均可成功分离培养颌骨成骨细胞,两组细胞均可贴壁生长,细胞形态未见显著差异。与假手术组相比,去卵巢大鼠颌骨成骨细胞的增殖能力,碱性磷酸酶染色与活性均显著增高;但去卵巢大鼠颌骨成骨细胞的Runx2和OC在mRNA与蛋白水平的表达上及体外矿化结节形成能力方面皆显著低于假手术组。结论去卵巢可影响大鼠颌骨成骨细胞的增殖与成骨分化能力,研究结果将为探讨颌面部骨组织骨质疏松的发病机制与防治提供实验依据。     

过氧化物酶体增殖物激活受体激动剂罗格列酮对大鼠成骨细胞增殖和分化的影响

目的 观察过氧化物酶体增殖物激活受体PPARγ2的激动剂罗格列酮对大鼠成骨细胞增殖和分化能力的影响。方法 取新生SD大鼠颅骨进行原代培养,经碱性磷酸酶ALP染色和矿化结节检测鉴定为成骨细胞。实验分为6组:取第3代细胞接种至96孔板,根据加入罗格列酮的浓度的不同分为A、B、C、D、E、F组(浓度分别为0、1、2、5、10、20 μmol/L),A组为对照组,B～F组为实验组。每组5个复孔,经罗格列酮作用24h后,应用噻唑蓝(MTT)比色法和PNPP法检测大鼠成骨细胞增殖和ALP活性的变化。结果 作用24h后,6种浓度罗格列酮对大鼠成骨细胞增殖作用均无影响,且组间差异无统计学意义(F=1.335,P＞0.05);但各实验组大鼠成骨细胞ALP活性均较对照组降低,并具浓度依赖性,组间差异有统计学意义(F=82.304,P＜0.01)。结论 一定剂量的罗格列酮对大鼠成骨细胞无明显促增殖作用,但却明显抑制了大鼠成骨细胞的分化,表明罗格列酮可影响成骨活性,提示PPARγ2参与了机体的成骨过程,在骨质疏松的发病中发挥一定了的作用。     

Interconversion potential of cloned human marrow adipocytes in vitro

Information on the interconversion potential of adipocytes and other end cells characteristic of the stromal fibroblastic cell lineages, key in the understanding of bone turnover in metabolic diseases such as osteoporosis, is limited. The object of the present study was: i) to isolate relatively pure populations of adipocytes from human bone marrow; ii) to clone single adipocytes from these populations; and iii) to examine in vitro the interconversion potential of the progeny of these single-cloned adipocytes between the osteogenic and adipogenic phenotypes. Adipogenic colonies were isolated from the low-density floating fraction of normal bone marrow cells cultured in adipogenic media for 4 days. Single adipocytes were isolated and cloned by limiting dilution. Cloned adipocytes were found to dedifferentiate into fibroblast-like cells, and subsequently to differentiate into two morphologically distinct cell types: osteoblasts and adipocytes in appropriate culture systems. The adipocytic phenotype was confirmed by morphology, oil red O staining, and immunocytochemistry using antiserum to aP2. The osteogenic phenotype was confirmed by alkaline phosphatase, osteocalcin immunostaining using specific osteocalcin antiserum, and formation of mineralized cell aggregates. These findings demonstrate the extent of plasticity between the differentiation of adipocytic and osteogenic cells in human bone marrow stromal cell cultures. We have shown the ability of isolated clonal adipogenic cells to redifferentiate into cells of the osteogenic and adipogenic lineage and the interconversion potential of human marrow stromal cells in vitro. These results provide further evidence that the osteogenic and adipogenic cells share a common multipotential precursor.