聚乳酸与重组人骨形成蛋白—2复合植入块修复兔下颌骨缺损…

采用冷冻干燥法，将聚乳酸（ＰＬＡ）制成多孔成形块状，并将ＰＬＡ与重组人骨形成蛋白－２（ｒｈＢＭＰ－２）有效的复合，植入兔下颌骨缺损动物模型，在术后２，４周通过Ｘ线片、组织学观察缺损部位的骨生成情况。结果表明：ＰＬＡ－ｒｈＢＭＰ－２植入组术后２周就有部分新骨形成，术后４周骨生成明显；而单独植入ＰＬＡ组术后４周仅有少量新骨生成。钙含量测定显示ＰＬＡ－ｒｈＢＭＰ－２组高于ＰＬＡ组。结果提示：ＰＬＡ为ＢＭ     

聚乳酸与重组人骨形成蛋白-2复合植入块修复兔下颌骨缺损的早期观察

采用冷冻干燥法，将聚乳酸（ＰＬＡ）制成多孔成形块状，并将ＰＬＡ与重组人骨形成蛋白－２（ｒｈＢＭＰ－２）有效的复合，植入兔下颌骨缺损动物模型，在术后２，４周通过Ｘ线片、组织学观察缺损部位的骨生成情况。结果表明：ＰＬＡ－ｒｈＢＭＰ－２植入组术后２周就有部分新骨形成，术后４周骨生成明显；而单独植入ＰＬＡ组术后４周仅有少量新骨生成。钙含量测定显示ＰＬＡ－ｒｈＢＭＰ－２组高于ＰＬＡ组。结果提示：ＰＬＡ为ＢＭＰ的有效传递系统，ＰＬＡ－ｒｈＢＭＰ－２复合植入块是一种有应用潜能的人工骨替代物。     

聚乳酸及其复合物修复下颌骨缺损的实验研究

目的　聚乳酸与骨形成蛋白复合 ,研究该材料修复颌骨缺损的能力 ,探讨聚乳酸作为骨形成蛋白载体的有效性。方法　 18只日本大耳白兔 ,随机分组 ,在双侧下颌骨体部形成 12 m m× 6 mm的缺损 ,分别植入聚乳酸 -人骨形成蛋白 - 2复合物 (PL A- rh BMP- 2 )、单纯聚乳酸 (PL A) ,于 2、4、8、12周分批处死。通过 X线、组织学染色等方法进行观察。结果　 PL A- rh BMP- 2植入组于术后 2周 ,缺损区部分新骨形成 ;术后 8周 ,大片新骨形成并开始改建 ,术后 12周 ,PL A大部分降解 ,由骨组织修复。结果优于对照组。结论　 PL A可作为 BMP的有效载体 ,PL A-rh BMP- 2是良好的颌骨缺损修复材料     

聚乳酸-脱钙冻干胚胎骨修复下颌骨缺损的实验研究

胚胎骨移植免疫原性低 ,爬行替代快 ,兼备骨诱导活性 ;聚乳酸 (ｐｏｌｙｌａｃｔｉｃａｃｉｄ ,ＰＬＡ)膜可体内降解 ,骨引导活性可靠 ,但单独应用均存在一定不足。我们将ＰＬＡ膜和脱钙冻干胚胎骨 (ｄｅｍｉｎｅｒａｌｉｚｅｄｆｒｅｅｚｅ ｄｒｉｅｄｆｅｔａｌｂｏｎｅ ,ＤＦＤＦＢ)复合修复兔下颌骨缺损 ,探讨ＰＬＡ ＤＦＤＦＢ的骨修复效果。1.材料和方法 :(1)ＰＬＡ膜 :分子量 190 0 0 ,厚 2 0 0 μｍ ,孔径 <5 μｍ。(2 )ＤＦＤＦＢ制备 :取孕 2 8ｄ胎兔四肢骨 ,剪成 1～ 2ｍｍ骨粒。 2 5℃下 1∶1氯仿 甲醇脱脂 ,浸入 2℃ 2ｍｏｌ/…     

新型聚乳酸共聚物修复兔下颌骨缺损的实验研究

目的:研究一种新型的聚乳酸鄄聚乙二醇(PLA鄄PEG)共聚物作为细胞因子的载体修复兔下颌骨缺损。方法:新型聚乳酸共聚物(孔隙率为88.7%左右,孔径150～250μm,分子量35973u)和细胞因子(骨形成蛋白、碱性成纤维细胞生长因子)复合后,分为实验组Ⅰ(PLA鄄PEG/BMP)、实验组Ⅱ(PLA鄄PEG/BMP/bFGF)和对照组(PLA鄄PEG)三组,分别植入27只雌性新西兰白兔的右侧下颌体部预制直径5mm,深3mm的骨缺损。术后2周、4周和8周,对实验标本进行大体、X线、组织学观察及计算机图像分析观察。结果:实验期间各组实验位点均未发生炎症和排异反应,各组创口愈合均良好,成骨活跃。2周时实验组Ⅱ成骨量最多,实验组Ⅰ其次,对照组最少,差异在统计学上有显著性意义;4周时实验组Ⅱ成骨量最多,其余两组成骨量差异不大;8周时各组的成骨量的差异在统计学上无显著性意义。结论:新型的PLA鄄PEG共聚物呈现良好的生物相容性和骨引导性,复合BMP后早期通过BMP骨诱导作用对骨再生具有较明显的促进作用,bFGF在与PLA鄄PEG和BMP复合后通过其促进毛细血管增殖的效应而对PLA鄄PEG和BMP有协同增强作用。     

聚乳酸膜复合脱钙冻干异体骨修复下颌骨缺损

目的　探讨聚乳酸 (polylactic acid,PL A)膜复合脱钙冻干异体骨 (demineralized freeze- dried bone,DFDB)修复下颌骨缺损的可行性 ,比较单纯 PL A膜和 PL A膜复合 DFDB的骨修复能力。方法　在 2 4只日本大耳白兔双侧下颌骨下缘中份形成 1.0 cm× 0 .6 cm× 0 .4cm的矩形缺损。左侧缺损覆以 PL A膜 ,右侧缺损植入 DFDB后表面覆盖 PL A膜。术后 4、8、12周分期处死动物 ,取双侧下颌骨标本作大体观察 ,组织学观察 ,以及 X线片计算机灰度值分析。结果　 PL A膜复合 DFDB侧成骨活跃 ,成骨量高 ,计算机灰度值分析表明 ,术后 4、8周两侧缺损区内骨密度差异有显著性 (P<0 .0 1) ,复合材料侧骨密度较高。结论　 PL A/ DFDB复合材料是一种较理想的骨修复材料。     

聚乳酸聚乙二醇复合骨形成蛋白修复下颌骨缺损

目的:探讨聚乳酸聚乙二醇嵌段共聚物作为人工骨支架材料的可行性。方法:制备聚乳酸聚乙二醇嵌段共聚物/重组人骨形成蛋白2多孔复合材料,测定其压缩强度和压缩模量;人为制造兔下颌骨缺损模型,分别植入该材料(实验组)和不含骨形成蛋白的聚乳酸聚乙二醇多孔材料(对照组),于2、4、8、16周处死动物,通过组织病理学观察和光密度分析来评价该材料的成骨效果以及制备方法是否合理。结果:复合材料的压缩强度为(30.05±3.12)MPa,压缩模量为(371.67±12.37)MPa;实验组在各个时期均可见到新生骨形成,且新生骨逐渐向材料内部生长,对照组仅在初期有少量新生骨出现;实验组各个时段的光密度明显高于对照组,在16周时实验组缺损区同周围骨组织密度近似(P>0.5)。结论:多孔材料的制备方法未破坏骨形成蛋白活性,复合材料具有较好的体内成骨能力,聚乳酸聚乙二醇嵌段共聚物可作为人工骨支架材料。     

骨形态发生蛋白-2释放系统的研究进展

骨形态发生蛋白（BMP）-2是体内成骨重要的促进因子，能诱导未分化间充质干细胞向成骨细胞方向分化。BMP-2释放系统的建立与应用是目前研究关注的重点，建立一个稳定的局部释放系统是治疗性的策略，可优化骨的愈合和降低并发症的发生。本文就BMP-2释放系统建立的必要性、构建材料种类、性能要求、研究趋势等进行综述。     

糖尿病对大鼠牙槽骨缺损修复中骨形态发生蛋白-2表达影响的研究

目的 观察糖尿病(diabetes mellitus,DM)对实验性大鼠牙槽骨缺损修复过程中不同时期骨形态发生蛋白-2(bonemorphogenetic protein-2,BMP-2)表达的影响。方法 将48只雄性SD大鼠随机分为DM组和对照组,每组24只,DM组大鼠经腹腔注射链脲佐菌素造成DM大鼠模型,建模成功后行大鼠牙槽骨骨缺损制备,2组均分别于骨缺损制备后1、2、4、8周各取6只大鼠处死,取术区组织。苏木精-伊红染色(hematoxylin-eosin staining,HE染色)镜下观察缺损区内新生骨样组织形成情况;用免疫组化法检测术后1、2、4、8周缺损区内BMP-2的表达情况,比较各组的平均光密度。结果 HE染色观察显示DM组成骨较对照组减少。术后1周、2周免疫组化观察对照组新骨BMP-2的表达强于DM组,二者之间差异有统计学意义(P<0.05),术后4周、8周对照组BMP-2表达较之前弱,但与DM组二者之间差异无统计学意义(P>0.05)。结论 DM影响了大鼠牙槽骨缺损的修复,可能是DM使BMP-2形成减少,从而抑制了未分化间充质向成骨细胞的转化,从而影响种植体骨结合,降低种植初期稳定性。?     

Comparison of BMP-2 and -4 for rat mandibular bone regeneration at various doses

OBJECTIVE: To compare mandibular bone regeneration with bone morphogenetic proteins-2 and -4 (BMP-2 and -4) at varying doses. STUDY DESIGN: Defects were created in the left hemi-mandibles of 82 Sprague-Dawley rats. The defects were filled with a hyaluronic acid polymer loaded with 0.01, 0.1, 1, or 10 microg of BMP-2 or -4. Control groups consisted of animals with unfilled defects, or with defects filled with the hyaluronic acid sponges loaded with growth factor dilution buffer. Animals were killed after 8 weeks, and the hemi-mandibles were analyzed histologically using stereologic techniques. RESULTS: Mandibles implanted with carriers containing 10 microg of BMP-2 or -4 differed significantly from controls in terms of new bone area (p = 0.01 and p = 0.0001, respectively). Marrow space development occurred in a dose-dependent fashion (p < 0.0001 for both growth factors), and this effect was more pronounced for BMP-2 at larger doses (p < 0.0001 at 1 and 10 microg doses). New bone areas and volumes did not differ significantly between the growth factors. While defects implanted with BMP-4 tended to have thicker cortical bone and more trabecular bone, at least partial defect bridging was achieved in a greater number of defects implanted with BMP-2 (47%) than with BMP-4 (35%). CONCLUSION: Although similar areas and volumes of new bone were induced with BMP-2 and -4, differences were noted in the quality of bone generated with each growth factor. The results indicate a threshold dose for acute administration between 1 and 10 mug BMP-2 for bony union in this model, and > or =10 microg for BMP-4. SIGNIFICANCE: These findings suggest that differences in bone growth factor osteogenic potential deserve further study and may have an impact on the translation of osteoinductive protein therapy into clinical practice.     

Enhanced vertical alveolar bone augmentation by recombinant human bone morphogenetic protein-2 with a carrier in rats

This study aimed to evaluate the effect of recombinant human bone morphogenetic protein-2 (rhBMP-2) on vertical bone regeneration of edentulous ridge. Bilateral upper first and second molars of 8-week-old Wistar rats were extracted and the ridges were allowed to heal for 3 weeks. Compressed poly(lactic-co-glycolic acid) copolymer/gelatin sponge (PGS) was used as a carrier of rhBMP-2. PGS alone (control group) or PGS with 5 mug rhBMP-2 (test group) was implanted at the top part of alveolar ridge. The sham group received no implantation. The rats were killed at 1, 2, 4, 8 and 12 weeks after implantation and examined histologically and histomorphometrically. In the test group, significant bone augmentation was evident on the alveolar ridge throughout the experimental period. Histomorphometric analysis revealed greater tissue volume and height of alveolar bone in the test group compared with the control and sham groups (P < 0.05) from 4 weeks onward and the augmented tissues (5 mm3 in tissue volume and 1.5 mm in bone height) were maintained until 12 weeks. Osteoblast surface increased at 2 and 4 weeks and osteoid thickness reached a peak (25 microm) at 2 weeks. Dynamic variables, which represented calcification, were higher in the test group than the control and sham groups at 4 and 8 weeks (P < 0.05). These results suggest that use of rhBMP-2/PGS may achieve vertical bone augmentation, and stabilizes denture prosthesis or makes up for inadequate bone mass for implant prosthesis.     

纳米壳聚糖骨形成蛋白水凝胶修复下颌骨缺损实验研究

目的：观察可注射性纳米壳聚糖骨形成蛋白水凝胶修复颌骨缺损的效果。方法：以纳米壳聚糖为载体,加入重组人骨形成蛋白-2制备成可注射性纳米壳聚糖骨形成蛋白水凝胶（NCS／BMP-2 Gel）。取9只SD大鼠,在双侧背部皮下分别注射200μl（100μg／ml）NCS／BMP-2 Gel及单纯纳米壳聚糖水凝胶（NCS Gel）。于术后10、20、30 d分别处死3只,取材进行大体及常规病理学观察;选取54只SD大鼠,随机均分为3组（n＝18）制备下颌骨缺损模型,实验组骨缺损中注入NCS／BMP-2 Gel、对照组注入NCS Gel、空白组不注射。术后3、6、9周各组处死6只大鼠。分离下颌骨,用钼靶扫描图像,Image Pro-Plus软件比较其颌骨缺损面积;常规病理观察颌骨成骨情况。结果：实验侧、对照侧均形成皮下结节,实验侧30 d结节内可见类骨样结构;钼靶扫描检查：植入后3、6、9周时,实验组剩余骨缺损面积均低于对照组及空白组（P＜0．05）;组织学观察显示,实验组下颌骨成骨情况优于对照组及空白组。结论：NCS／BMP-2水凝胶有良好的生物相容性,能促进颌骨缺损修复。     

rhBMP-2、PRF和自体骨分别复合珊瑚羟基磷灰石成骨效能的比较研究

目的：通过建立动物骨缺损模型,比较重组人骨形成蛋白-2（rhBMP-2）与珊瑚羟基磷灰石（CHA）复合物、富血小板纤维蛋白（PRF）与珊瑚羟基磷灰石复合物、自体骨与珊瑚羟基磷灰石复合物以及单纯珊瑚羟基磷灰石这四种骨移植材料在骨缺损中的成骨效能。方法：在比格犬双侧胫骨干骺端制备四个相同的骨缺损区,在缺损区分别植入rhBMP-2/CHA、 PRF/CHA、自体骨/CHA及CHA （对照）;3个月后处死动物,行大体标本观察;拍牙科CT,观察各植骨区骨密度情况;制作石蜡切片、 HE染色,比较各植骨区骨组织学特点及新骨形成量。结果：大体标本见四组骨缺损间隙均完全关闭。 X线示自体骨/CHA组和PRF/CHA组骨密度较致密, rhBMP-2/CHA组致密性低于前两者, CHA组未见明显骨致密影。 HE切片见四组新生骨与宿主骨连接紧密,新生骨小梁不规则,粗细不一,排列无序;复合型骨移植材料的新生骨小梁比对照组更密集、粗大,连续性更好;四组植骨区成骨量比较：自体骨/CHA组〉PRF/CHA组〉rhBMP-2/CHA组〉CHA组。结论：复合型骨移植材料成骨效应明显优于单纯珊瑚羟基磷灰石;三种复合型材料中自体骨/CHA成骨效应最好,其次为PRF/CHA, rhBMP-2/CHA最差。     

提取并部分纯化bBMP促进节段性骨缺损愈合的定量组织学研究

目的　从小牛骨基质中提取并部分纯化bBMP ,以促进节段性骨缺损的愈合。方法　通过SDS PAGE电泳及生物活性鉴定实验 ,证实bBMP保留了其活性蛋白成分 ,具有良好的骨诱导活性。在此基础上 ,合成一种新型复合人工骨材料即HA bBMP Co ,用以整复家兔尺骨中段 1.5cm节段性骨缺损 ,并对缺损区新骨生长量进行定量组织学测定。结果　HA bBMP Co复合人工骨植入整复节段性骨缺损 ,其新骨生长量明显高于同期HA Co复合人工骨组 (P <0 .0 1)。结论　HA bBMP Co复合人工骨能有效地促进节段性骨缺损的愈合 ,是一种具有良好应用前景的骨替代材料     

The use of tissue-engineered bone with human bone morphogenetic protein-4-modified bone-marrow stromal cells in repairing mandibular defects in rabbits

In this study, the capacity of hBMP-4 gene therapy combined with tissue-engineering techniques to improve the repair of mandibular osseous defects in rabbits was explored. A mammalian plasmid vector expressing enhanced green fluorescent protein-human bone morphogenetic protein-4 (pEGFP-hBMP-4) was initially constructed through subcloning techniques. Bone-marrow stromal cells (bMSCs) from New Zealand White rabbits were cultured and either transfected with pEGFP-hBMP-4 or pEGFP, or left untransfected in vitro. Once the transfer efficiency was determined through the expression of EGFP, cells from the three groups were combined with natural non-organic bone (NNB) at a concentration of 50 x 10(6)cells/ml and placed in 15 mm x 6 mm bilateral, full-thickness, mandibular defects surgically made in 12 rabbits. Together with NNB control, there were six samples per group. Four weeks after surgery, the implants were harvested and evaluated histomorphologically. Under optimal experimental conditions, gene transfer efficiency reached a maximum of 38.2+/-9.4%. While the percentage of new bone area in the NNB control group was 8.8+/-3.1%, in the untransfected bMSC group 22.5+/-8.2%, and in the pEGFP group 18.1+/-9.0%, a significantly higher amount of 32.5+/-6.1% was observed in the pEGFP-hBMP-4 group. These results suggest that transfection of bMSCs with hBMP-4 enhances their inherent osteogenic capacity for maxillofacial bone tissue-engineering applications.     

Effects of bone morphogenetic protein-6 on periodontal wound healing in a fenestration defect of rats

BACKGROUND: Bone morphogenetic proteins (BMPs) may play significant roles in bone formation. The ability of BMP-6 to promote wound healing has been chosen as the subject of this investigation. In this study, a synthetic rat BMP-6 polypeptide was applied to a periodontal fenestration defect in rats to elucidate the effects of BMP-6 on periodontal wound healing. MATERIAL AND METHODS: Following surgery to create a bony window on the buccal aspects of mandibular molar roots, 24 male Sprague Dawley rats were divided into four groups according to BMP application (0, 1, 3 and 10 microg, respectively). Animals were killed after 28 days and the mandible taken for histological examination. Histometric measurements were performed on sections selected from three levels (coronal, middle and apical levels; with 240 microm apart from the central) of the defect. New bone and cementum formation (including area and thickness) were analyzed and compared. RESULTS: In general, minimal new bone was observed on the surgically created defects in the non-BMP group, whereas a complete osseous healing occurred in all BMP-6 treated animals. New bone formation (both in area and thickness) was significantly influenced by both the dosage and the examining level, whereas new cementum formation was affected by dosage only. An increase in bone and cementum formation was noted in all three BMP groups when compared with the control group at all examined levels. Among the BMP groups, greatest new bone and cementum formation were noted in the 3 microg group. New cementum thickness increased on the cementum surfaces of the defects compared with the dentinal surfaces in all study groups. CONCLUSION: An increase in new bone and cementum formation was noted after applying a synthetic BMP-6 polypeptide to a periodontal fenestration defect in rats. Therefore, we suggest that BMP-6 may play a certain role in periodontal regeneration.     

骨缝牵引中联合应用骨形态发生蛋白-2和骨保护素的实验研究

目的探索上颌骨在骨缝牵引时加入缓释骨形态发生蛋白-2（BMP-2）和骨保护素（OPG）对新骨形成的影响。方法以24只杂种犬为研究对象,随机分为A、B、C组。通过手术在上颌骨腭横缝植入自制的新型牵引器。A、C组术后5 d在牵引区附近注射缓释重组人骨形态发生蛋白-2/聚乳酸-羟基乙酸共聚物/纤维蛋白胶（rhBMP-2/PLGA/FS）,B、C组在牵引3周后注射人骨保护素/纤维蛋白胶（rhOPG/FS）。牵引1、2、4、6周后处死动物,采集标本进行组织学染色,并通过组织计量学方法检测腭横缝的组织改建情况。结果A、C组骨缝区成骨细胞功能活跃,透射电镜显示细胞内有大量高尔基复合体、线粒体及粗面内质网。牵引6周时,A、B、C组成骨细胞指数分别为38.5±7.7、35.7±6.5、41.7±11.0,破骨细胞指数分别为5.9±1.0、1.2±0.3、2.8±0.4,骨小梁厚度分别为（38.36±13.28）、（66.20±9.16）、（51.85±9.92）μm;B、C组表现出骨密度增加及破骨细胞指数下降。结论本实验所用牵引器能促进新骨生成;BMP-2与OPG在骨缝牵引过程中有协同作用,可以促进新骨形成及骨改建。     

低强度脉冲超声波联合引导骨组织再生促进牙周骨缺损修复的实验研究

目的探讨低强度脉冲超声波（LIPUS）联合引导骨组织再生（GBR）对Beagle犬尖牙牙周骨缺损的修复效应。方法将8只Beagle犬中每只犬的4颗尖牙随机分配到4组：实验1组（LIPUS处理+GBR+自体骨移植组）,实验2组（LIPUS处理+自体骨移植组）,实验3组（GBR+自体骨移植组）,空白对照组。在犬尖牙颊侧区根中1/3处制备牙周骨缺损模型,根据分组,自体骨移植后,实验1组和2组采用LIPUS处理20 min·d-1,超声强度为30 mW·cm-2,实验1、3组植入Bio-Gide胶原膜。在LIPUS处理6、8周后处死Beagle犬,对各组尖牙牙周骨缺损区进行Micro-CT检测和分析。结果临床观察各组牙周骨缺损面积均不同程度缩小。Micro-CT检测分析表明,各组6周与8周时的骨小梁数目、骨小梁厚度和骨小梁体积均无统计学差异（P＞0.05）,而各组之间的骨组织测量指标均有统计学差异（P＜0.05）,实验1组新生骨量最多。结论LIPUS具有促进牙周骨缺损修复的潜能,LIPUS与GBR结合可能更有利于牙周骨缺损的修复与再生。