bFGF增强rhBMP-2诱导成骨中Ⅰ、Ⅱ型胶原及碱性磷酸酶的表达

目的：对bFGF增强rhBMP-2诱导成骨中CollagenⅠ、Ⅱ及碱性磷酸酶（ALP）的表达进行研究。方法：110只BALB/c小鼠随机分为2组，每组55只，rhBMP-2/bFGF为实验组，rhBMP-2为对照组，分别于术后3-21d8个时间点取材，用免疫组化法对新生骨组织中的Ⅰ、Ⅱ胶原进行检测；对ALP活性进行定量分析，观察2组在诱导成骨中CollagenⅠ、Ⅱ及ALP的表达情况。结果：⑴Ⅱ型胶原和成软骨、软骨细胞的出现相伴随，但肥大、变性的软骨细胞并不表达Ⅱ型胶原。⑵作为成骨细胞成熟标志物的Ⅰ型胶原，ALP在骨形成期即有表达，但随着成骨细胞的出现，骨组织的形成Ⅰ型胶原表现为高表达，而ALP的表达则呈下降趋势。⑶实验组CollagenⅠ、Ⅱ及ALP的表达早于对照组。结论：bFGF增强了rhBMP-2诱导成骨中CollanenⅠ、Ⅱ及ALP的表达。     

rhBMP-2在体内诱导成骨中Ⅰ、Ⅱ型胶原mRNA及碱性磷酸酶的表达

目的：研究rhBMP-2在体内诱导成骨中CollagenⅠ、ⅡmRNA及碱性磷酸酶（ALP）的表达。方法：将含rhBMP-2 0.5mg的松质骨载体植入BALB/c小鼠的右股部肌袋内，于术后3-21d间8个时间点取材，用原位杂交法对新生骨组织中的Ⅰ、Ⅱ型胶原mRNA进行检测；定量分析ALP活性，观察rhBMP-2在诱导成骨中CollagenⅠ、ⅡmRNA及ALP的表达。结果：⑴Ⅱ型胶原mRNA的出现是和成软骨、软骨细胞的出现相伴随。肥大、变性的软骨细胞并不表达Ⅱ型胶原mRNA。⑵作为成骨细胞成熟标志物的Ⅰ型胶原mRNA、ALP在软骨形成期即有表达，随着成骨细胞的出现，骨组织的形成，Ⅰ型胶原mRNA仍表现为高表达，而ALP的表达则呈下降趋势。结论：在体内诱导成骨中rhBMP-2促进了CollagenⅠ、ⅡmRNA及ALP的表达。     

rhBMP-2对不同培养时间骨髓基质干细胞成骨能力的影响

目的：探讨不同培养阶段骨髓基质干细胞成骨能力的变化及BMP-2对其成骨能力的影响。方法：培养兔骨髓基质干细胞，测定第3代和第18代细胞碱性磷酸酶及骨钙素活性；测定BMP-2对不同培养时间骨髓基质干细胞成骨能力的影响；测定rhBMP-2对细胞增殖的影响。结果：细胞传至第18代后，分泌的骨钙素（OC）水平及ALP活力明显降低，与第3代细胞相比，差异显著（P〈0．05）。第3代细胞在rhBMP-2的诱导下，分泌的OC水平及ALP活力在原基础上进一步升高，与对照组相比，差异显著（P〈0.05）。结第18代细胞在rhBMP-2的诱导下，分泌的OC水平及ALP活力在原基础上升高，与对照组相比，差异不显著（P〉0．05）；随培养时间的延长，各组细胞数量均有所增加，rhBMP-2诱导组与对照组细胞无显著性差异（P〉0．05）。细胞的传代次数对细胞增殖无明显影响（P〉0．05）。结论：rhBMP-2对细胞增殖无影响。随着传代次数的增加，骨髓基质干细胞的成骨能力下降，rhBMP-2促进其成骨的能力亦下降。     

骨形态发生蛋白复合HA/TCP修复去势大鼠骨缺损的研究

目的研究羟基磷灰石/磷酸三钙（hydroxyapatite/tricalcium phosphate,HA/TCP）双相生物陶瓷与重组人骨形态发生蛋白-2（recombinant human bone morphogentic protein-2,rhBMP-2）的复合材料对骨质疏松骨缺损的修复作用。方法选用30只8个月龄雌性SD大鼠,随机分为两组。实验组（20只）行双侧卵巢摘除术,对照组（10只）行假手术。术后12周确定实验组骨质疏松模型建立成功,两组大鼠双侧股骨外侧髁上造成直径3 mm骨缺损。同时实验组随机植骨分为两组：单纯HA/TCP组和rhBMP-2/HA-TCP复合材料组;对照组全部植入rhBMP-2/HA-TCP复合材料。植骨术后4、8和12周取双侧股骨标本,进行组织学、X射线、骨密度及生物力学检测。结果实验HA/TCP组4周时材料周围存在密度减低区,缺损部位新生骨量明显低于实验复合材料组,12周时新生骨板界面可见类骨质,材料吸收较快;实验复合材料组12周时材料大部分降解转化为新骨,可见成熟的骨小梁和骨髓组织,有编织骨形成。与单纯HA/TCP组相比,4、8周时实验复合材料组缺损部位X射线、骨密度以及生物力学值明显提高（P〈0.05）,与对照复合材料组比较差异无显著性（P〉0.05）。结论HA/TCP双相生物陶瓷是rhBMP-2较理想的载体材料,复合后具有良好的骨诱导作用,能够明显促进骨质疏松骨缺损的修复。     

透明质酸对BMP-2转染的羊BMSCs增殖、分化的影响

目的观察透明质酸（HA）对携带人骨形态发生蛋白-2的腺病毒（Adv-BMP-2）转染的羊骨髓基质干细胞（BMSCs）体外增殖、分化的影响。方法将羊骨髓体外分离、扩增BMSCs,分成5组：转染Adv-BMP-2的BMSCs＋HA组（Ⅰ组）,转染Adv-BMP-2的BMSCs组（2组）,BMSCs＋HA组（3组）,BMSCs组（4组）,转染携带β半乳糖苷酶的腺病毒（Adv-β-gal）的BMSCs组（5组）。采用细胞计数、绘制细胞生长曲线和流式细胞分析观测细胞增殖;采用碱性磷酸酶（ALP）检测以及RT-PCR检测Ⅰ型胶原（Col-Ⅰ）、骨连接素（ON）和骨涎蛋白（BSP）的mRNA表达。结果①细胞增殖：3 d后各组细胞增殖无显著差异,1周后第1组和第3组的细胞增殖明显高于其他组。②ALP活性：3 d后第3组ALP活性明显低于第4、5组,而第1、2组则显著高于第4、5组;7 d后前3组ALP活性较后两组均显著增加,而第1、2组ALP活性增加更为显著。③Col-Ⅰ、ON和BSP的mRNA表达：3 d和7 d后前3组较后两组均有不同程度的增多。结论HA与BMSCs体外复合培养后可促进BMSCs的增殖、增加ALP的活性以及Col-Ⅰ、ON和BSP基因的表达。     

TGF-β增强rhBMP-2诱导成骨中Ⅰ、Ⅱ型胶原mRNA及碱性磷酸酶的表达

目的：对TGF-β增强rhBMP-2诱导成骨中Collagen Ⅰ、ⅡmRNA及碱性磷酸酶(ALP)的表达进行研究。方法：BALB／c小鼠110只随机分2组，每组55只。rhBMP-2／TGF-β为实验组，rhBMP-2为对照组，于术后3～21d 8个时间点取材，用原位杂交方法对新生骨组织中的Ⅰ、Ⅱ型胶原mRNA进行检测；对ALP活性进行定量分析，观察2组在诱导成骨中CollageⅠ、ⅡmRNA及ALP的表达情况。结果：(1)Ⅱ型胶原mRNA的出现是和成软骨、软骨细胞的出现相伴随的；(2)做为成骨细胞成熟标志物的I型胶原mRNA、ALP在软骨形成期即有表达，随着成骨细胞的出现，骨组织的形成Ⅰ型胶原mRNA仍表现为高表达，而ALP的表达则呈下降趋势；(3)实验组CollagenⅠ、ⅡmRNA及ALP的表达早于对照组。结论：TGF-β增强了rhBMP-2诱导成骨中CollagenⅠ、ⅡmRNA及ALP的表达。     

骨相关生长因子对兔骨髓基质干细胞生长及分化的量效作用

目的研究地塞米松、重组人成纤维细胞生长因子（recombinant human fibroblast growth factor，rhFGF）及重组人骨形成蛋白2（recombinant human bone morphogenetic protein 2，rhBMP-2）对兔骨髓基质干细胞（marrow slromal stem cells，MSCs）生长及分化的量效作用，为其在骨组织上程中的应用提供实验基础。方法体外分离培养免MSCs，分为1个空白对照组及9个实验组。实验组分别与终浓度为10^-8、10^-7、10^-6mol／L地塞米松；终浓度为50、200、500ngng/ml FGF；终浓度为50、500、1000ng／ml rhBMP-2培养。于4、7d终止培养并测定细胞总蛋白及碱性磷酸酶（alkaline phosphatase。ALP）活性。结果与空白对照组比较，10mol／L地塞米松显著抑制细胞蛋白合成（P〈0．05），而10^-8、10^-7mol／L地塞米松对细胞蛋白合成无明显影响；10^-6,10^-7mol／L地塞米松刺激MSCs高度表达ALP（P〈0．05）。rhFGF各浓度组显著促进细胞蛋白合成量差异有统计学意义（P〈0．05），表现ALP活性抑制。rhBMP-2符浓度组对细胞蛋白合成九明显影响；50ng／ml rhBMP2不影响MSCs的ALP活性；当浓度增至500ng／ml与1000ng／ml时，ALP活性显苦增加（P〈0．05）。结论10^-7mol／L地塞米松及500、1000ng／ml rhBMP-2在不影响MSCs增殖的前提下，适当浓度能显著促进MSCs向成骨细胞转化，在骨组织工程的研究中有重要的应用价值。     

重组人骨形态发生蛋白-2/万古霉素/硫酸钙药物缓释系统体外释放的实验研究

目的 研究生物可降解材料硫酸钙对万古霉素和重组人骨形态发生蛋白-2( rhBMP-2)体外缓释特性. 方法 利用高效液相色谱分析和抑菌实验检测缓释材料中万古霉素的浓度及活性,利用ELISA试验和ALP实验检测缓释材料中rhBMP-2的浓度及生物活性. 结果 rhBMP-2/万古霉素/硫酸钙药物缓解系统可释放高于55.8 μg/mL万古霉素长达144h,活性达70％以上;可释放活性rhBMP-2长达30d,对骨髓基质干细胞无抑制增殖作用,具有较高的生物安全性. 结论 rhBMP-2/万古霉素／硫酸钙药物缓解系统能缓慢释放活性万古霉素与rhBMP-2,且不会抑制骨髓基质干细胞的增殖,具有较高的临床应用前景.     

血管内皮生长因子和骨形态发生蛋白7在细胞分化中的协同作用

目的：研究rhVEGF和rhBMP-7对成骨细胞分化能力的影响.方法：取大鼠颅盖骨组织块,采用改良组织块混合酶消化法培养成骨细胞,将不同浓度的rhVEGF和rhBMP-7加入第四代成骨细胞的培养基继续进行细胞培养,用碱性磷酸酶试剂盒检测定细胞在第1、3、5天的磷酸酶的活性,分析不同浓度的rhVEGF和rhBMP-7对成骨细胞分化的影响.结果：rhVEGF和rhBMP-7能促进成骨细胞的分化,其中,3.125ng/mlrhVEGF和50.000ng/ml rhBMP-7单独或者两者联合作用并于第3天时,对成骨细胞碱性磷酸酶活性的影响最明显.结论：一定剂量的rhVEGF和rhBMP-7可明显促进成骨细胞的分化.     

三种钙磷陶瓷材料复合重组人骨形成蛋白-2体内成骨的研究

目的 探讨和比较3种钙磷陶瓷材料HA、TCP、HA／TCP复合重组入骨形成蛋白。2(rhBMP—2)体内异位成骨效果，为临床应用提供依据。方法 取35只3月龄Wistar大鼠，将复合rhBMP—2的3种钙磷陶瓷材料(1：1)植于鼠背部肌袋内，未复合rhBMP-2的上述3种单纯陶瓷材料为对照组。术后2、4和8周取材，测定植入物碱性磷酸酶(ALP)活性，通过HE染色和计算机图像分析进行组织学和组织计量学观察，比较新生骨组织的形成。结果 术后2、4周复合植入物ALP活性测定从高到低依次为HA、HA／TCP、TCP，但在相同rhBMP—2剂量下，其差异无统计学意义(P＞0．05)，与相对应单纯支架材料比较有统计学意义(P＜0．05)；组织学和组织计量学检测结果显示各复合材料组均有新骨形成，成骨量随时间推移而增加，2周时以HA/rhBMP—2成骨量较多，但3组间差异无统计学意义(P＞0．05)；8周时新骨形成以双相陶瓷HA／TCP最佳，相关参数和图像分析有统计学意义(P＜0．05)，成骨量8周较2、4周多，有统计学意义(P＜0．01)；3种单纯支架材料各观察期均无骨样组织形成。结论 双相陶瓷材料HA／TCP是携带rhBMP—2的钙磷陶瓷良好支架材料。     

Development of a hydroxyapatite/collagen nanocomposite as a medical device

The effect of cross-linking of a hydroxyapatite/collagen (HA/Col) nanocomposite, in which HA nanocrystals and collagen fibers are aligned like natural bone by a self-organization mechanism between HA and collagen in vitro, on mechanical properties was examined. The influence of degree of cross-linking, as well as rhBMP-2 preadsorption to the composite on the substitution pattern and rate with bone, was examined. In Experiment 1, anterior fusion was carried out at the C3-C4 vertebrae on 10 dogs and they were implanted as follows: without cross-linking and without adsorbed rhBMP-2 (three dogs), with cross-linking and without adsorbed rhBMP-2 (three dogs), without cross-linking and with adsorbed rhBMP-2 (two dogs), and with cross-linking and adsorbed rhBMP-2 (two dogs). Implants were removed from each dog for histology determinations after 12, 16, and 24 weeks in the non-rhBMP-treated groups, and after 16 and 24 weeks in the rhBMP-treated groups. In Experiment 2, the HA/Col composites with cross-linking and both with and without rhBMP-2 pretreatment were implanted into a bone defect of 20 mm made in the central part of tibiae in dogs (N = 3 in each group). As a control, bone defects of 20 mm remained without implantation (N = 3). The dogs were allowed to walk using an Ilizarov extra skeletal fixator. The implants were removed after 12, 16, and 24 weeks from one dog in each group. The cross-linking of the HA/Col composite was effective in controlling both the mechanical strength and bioresorbability. A "self-organization process" on the HA/Col implant surface resulted in the formation of bone remodeling units in and around the implant. Radiographic and histological findings suggest that a combined treatment of cross-linking of the HA/Col composite with preadsorption of rhBMP-2 molecules may be a very suitable replacement of existing ceramic systems in the anterior fusion of the cervical spine, as well as inlay grafting of bone defects in weight-bearing sites.     

Recombinant human bone morphogenetic protein-7 expressed from CHO cells possessing the activity of bone-induced in vitro

Bone morphogenetic protein-7(BMP-7),amember of transforming growth factor-βgene super-family,is originally isolated from bone and involved inthe growth,differentiation and repair of a wide varietyof tissues[1].For the reason that there is few BMP-7in nat…     

联合rhBMP-2与成骨细胞诱导骨髓基质细胞成骨分化的实验研究

目的探讨rhBMP-2和成骨细胞联合诱导骨髓基质细胞(BMSCs)的成骨分化能力。方法应用全骨髓贴壁法分离培养4周龄SD大鼠的BMSCs,通过改进酶消化法结合反复贴壁法培养1日龄SD乳鼠成骨细胞。实验分为4组:rhBMP-2诱导组、成骨细胞诱导组、rhBMP-2+成骨细胞诱导组、单纯培养液组。倒置相差显微镜及扫描电镜观察细胞生长情况;分别收集第3、6、9天细胞培养液上清液定性及定量测定碱性磷酸酶并进行统计学分析。结果 rhBMP-2诱导组、成骨细胞诱导组、rhBMP-2+成骨细胞诱导组均检测出成骨细胞生成,其中,rhBMP-2+成骨细胞诱导组碱性磷酸酶含量明显大于前两组,差异有统计学意义(P0.05)。结论rhBMP-2、成骨细胞、rhBMP-2联合成骨细胞均能提供成骨微环境,并在体外诱导BMSCs向成骨细胞分化,rhBMP-2联合成骨细胞对BMSCs的成骨分化具有更优的诱导能力。     

The effect of recombinant human bone morphogenetic protein-2 on the osteogenic potential of rat mesenchymal stem cells after several passages

Background Since the osteogenic potential of bone marrow derived mesenchymal stem cells (BMSCs) becomes reduced with passage, establishment of culture condition that permit the rapid expansion of BMSCs while retaining their potential for differentiation is needed for clinical application. Bone morphogenetic proteins stimulate osteogenic differentiation in mesenchymal progenitor cells as well as increase stem cell numbers. Thus, we analyzed the effect of recombinant human bone morphogenetic protein-2 (rhBMP-2) on the osteogenic potential of rat BMSCs over several passages.

Material and methods Osteogenic differentiation in vitro was evaluated in terms of the alkaline phosphatase (ALP) activity and the osteocalcin (OC) concentration in the supernatants, and the expression of ALP and OC mRNA in the cultured cells. For in-vivo osteogenesis, BMSCs cultured with and without rhBMP-2 through all passages were implanted into athymic mice.

Results  The levels of osteogenic markers were significantly higher in the cells of the BMP(+) group than in the cells of the BMP(-) group, although they decreased with passage irrespective of whether or not rhBMP-2 was added. Similar to the in-vitro experiments, there was a greater degree of bone and cartilage tissue formation in the BMP(+) group over all passages.

Interpretation  From our results, osteogenic potential can be maintained even in BMSCs that have been passaged several times in the presence of rhBMP-2. These cells are capable of inducing and participating in bone formation and can be used for clinical applications.     

Comparative study of fusion rate induced by different dosages of Escherichia coli-derived recombinant human bone morphogenetic protein-2 using hydroxyapatite carrier

Background contextHydroxyapatite (HA) is considered to be useful because of its high affinity for recombinant human bone morphogenetic protein (rhBMP), mechanical resistance to compressive force, and possible reduction of rhBMP dose.PurposeTo evaluate the osteoinductivity of Escherichia coli–derived rhBMP-2 and the suitability of porous HA as an rhBMP-2 carrier.Study designIn vivo study using microcomputerized tomography (micro-CT) scanning.Patient sampleSeventy-six New Zealand white male rabbits were randomized into a single control group (n=14) without rhBMP-2 and four experimental groups (10 μg, 50 μg, 200 μg, and 500 μg of rhBMP-2; n=14 in each group). The subjects were divided into 3- and 6-week groups.Outcome measuresOutcome was evaluated by radiography, bending test, three-dimensional micro-CT, and histologic examinations.MethodsBilateral posterolateral fusion was carried out, and rhBMP-2 (0, 10, 50, 200, 500, 1,000, and 2,000 μg) was implanted into the bilateral transverse processes using HA as a carrier.ResultsThe fusion rates of the 3-week group were 83.3% for 50 and 200 μg of rhBMP-2 and 100% for 500 μg. The improved fusion rates of the 50 μg or higher groups compared with those of control were statistically significant. The fusion rates of the 6-week group were 75% for 10 μg of rhBMP-2 and 100% for 50 μg or higher. Similarly, the improved fusion rates of the 10 μg or higher groups compared with those of control were statistically significant. Significantly higher percent volumes were observed in the 3-week 200 μg of rhBMP-2 group and 6-week 200 μg of rhBMP-2 group than the 3-week HA group and 6-week HA group, respectively. Trabecular thickness was significantly higher in the 3-week 200 μg of rhBMP-2 group than the 3-week HA group. Histologic analysis of the 10 μg group showed bone tissues within the pores from 3 weeks, and this was observed more vividly in the 50, 200, and 500 μg groups. The 6-week 10 μg and 50 μg of rhBMP-2 groups had lower amounts of new tissue but higher portions of complete bone tissue within the HA specimen, along with higher formation of completely reconstituted bone tissues outside HA.ConclusionsInjection of 50 μg or more of E. coli–derived rhBMP-2 into a HA carrier induced earlier bone fusion in the intertransverse process of rabbits, which confirms the excellent bone forming ability of E. coli–derived rhBMP-2 and the suitability of HA as a carrier of rhBMP-2.     

Hydroxyapatite granule graft combined with recombinant human bone morphogenic protein-2 for solid lumbar fusion

The purpose of this study was to evaluate the availability of recombinant human bone morphogenetic protein-2 (rhBMP-2) combined with hydroxyapatite (HA) and autogenous bone. Posterolateral intertransverse fusion between the fifth and sixth lumbar vertebrae was performed in 27 adult Japanese white rabbits. These 27 rabbits were classified into three groups: the autogenous bone group, the HA group, and the bone morphogenic protein (BMP) group. In the HA group, HA (0.5 g) mixed with iliac bone was grafted. In the BMP group, HA (0.5 g) soaked with rhBMP-2 (100 mg) and iliac bone was grafted. At 6 weeks after the procedure, bone union was evaluated. In the BMP group, all cases showed solid bone union, and fusion masses were stiffer than the masses obtained in the other group. Biomechanically and histologically, grafts of HA soaked with rhBMP-2 and iliac bone was clearly effective in obtaining a solid intertransverse arthrodesis.     

剂量因素对羟基磷灰石/磷酸三钙成骨细胞相容性的影响

目的　检测不同剂量的羟基磷灰石 /磷酸三钙 (HA/ TCP)对兔成骨细胞增殖及碱性磷酸酶(AL P)活性的影响 ,明确材料的剂量因素在研究 HA/ TCP细胞相容性中的作用规律。方法　以兔成骨细胞为正常对照 ,细胞加入钛合金材料组为阴性对照 ,细胞加入聚氯乙烯材料组为阳性对照。选择三种材料剂量 ,以材料占细胞面积的比例表示 ,分别为 10 %、4 0 %和 70 %。将各组材料与兔成骨细胞复合培养 ,MTT法检测不同时间点、不同剂量材料作用下兔成骨细胞增殖的情况 ;偶氮偶联法检测不同时间点、不同剂量材料作用下兔成骨细胞表达 AL P的变化。结果　正常兔成骨细胞的生长呈现时间 -效应关系。与正常对照相比 ,10 % HA/ TCP不会对兔成骨细胞的生长产生影响 (P>0 .0 5 ) ;当 HA/ TCP剂量增大为 4 0 % ,细胞的生长速度明显变缓 (P<0 .0 5 ) ,细胞的生长仍呈现时间 -效应关系 ;70 %的 HA/ TCP使细胞生长趋于停滞 (P<0 .0 1)。 10 % HA/ TCP可造成细胞 AL P活性可逆性损伤 ,HA/ TCP浓度达 4 0 %时 ,AL P活性损伤至共培养 6天不可逆转。相对而言 ,惰性金属硬组织材料钛合金在检测三种剂量下均对细胞生长及细胞 AL P活性不会产生影响。结论　评价材料的细胞相容性应向材料接触剂量个体化、特异化的方向发展 ;除增殖指标之外 ,AL