rhBMP-2/PLA复合涂层种植体骨内诱导成骨的实验研究

目的：观察基因重组人骨形成蛋白-（recombinanthuman bone morphogenetic protein-2，rhBMP-2）和聚乳酸（polylactic acid，PLA）复合形成的活性涂层种植体骨内诱导成骨活性。方法：将rhBMP-2与聚乳酸复合构建活性涂层种植体，植入兔股骨内，分别于4，8，12，16周处死动物，进行组织学及扫描电镜及组织化学观察，检测其成骨活性。结果：构建的活性涂层种植体具有骨诱导能力，PLA为rhBMP-2的良好控释载体。结论：rhBMP-2/PLA涂层具有良好的生物相容性和骨诱导活性，是一种理想的种植体形式。     

基因重组人骨形成蛋白—2与珊瑚／聚乳酸复合异位诱导成骨的实验研究

目的：观察基因重组人骨形成-2(rhBMP-2)和珊瑚／聚乳酸形成复合人工骨的异位诱导成骨活性。方法：把rhBMP-2和珊瑚／聚乳酸形成复合人工骨。进行小鼠肌内种植1，3，6周后，组织学观察其异位诱导成骨活性。结果：rhBMP-2赋予珊瑚／聚乳酸骨诱导能力，珊瑚／聚乳酸则充当rhBMP-2的载体和释放系统，对BMP的活性未不利影响。与单纯的珊瑚／聚乳酸相比，这种复合人工骨以软骨内成骨的方式诱导成骨。结论：rhBMP-2／珊瑚／聚乳酸复合人工骨具有良好的生物相容性和骨诱导活性，是一种较理想的骨移植替代材料。     

基因重组人骨形成蛋白-2和牛骨形成蛋白异位诱导成骨的比较

目的：观察基因重组人骨形成蛋白-2（rhBMP-2)和牛骨形成蛋白（bBMP)分别与珊瑚/聚乳酸形成复合人工骨的异位诱导成骨活性，同时比较两种骨形成蛋白的成骨效率，方法：把rhBMP-2和bBMP分别与珊瑚/聚乳酸形成复合人工骨，进行小鼠肌内种植1、3、6周后，组织学观察和组织形态测量，比较其异位诱导成骨活性。结果：rhBMP-2和bBMP存在骨诱导差异，rhBMP-2诱导成骨量相对较少但血管，骨髓含量丰富，bBMP则相反，结论：两种BMP都具有良好的诱骨活性，但在居骨量和血管，骨髓样组织的形成量上有明显不同。     

活性纳米羟基磷灰石复合胶原聚乳酸材料异位成骨性能研究

目的：探讨既具有骨引导性又具有骨诱导性的活性纳米羟基磷灰石复合胶原/聚乳酸（AnHAC/PLA）材料的异位成骨能力,为该材料作为植骨材料应用于临床打下实验基础。方法：通过扫描电镜观察rhBMP-2与nHAC/PLA材料的复合情况,并将nHAC/PLA、rhBMP-2、AnHAC/PLA材料分别植入小鼠股后肌袋内,术后2周、6周通过X线片、组织学观察、成骨量测定来研究AnHAC/PLA的异位成骨能力。结果：rhBMP-2在nHAC/PLA孔隙中均匀分布,6周时AnHAC/PLA组诱导形成的骨量是rhBMP-2组的10.5倍。结论：AnHAC/PLA材料具有良好成骨能力,nHAC/PLA是rhBMP-2理想的缓释载体。     

基因重组人骨形成蛋白-2与珊瑚/聚乳酸复合异位诱导成骨的实验研究

目的 :观察基因重组人骨形成蛋白 - 2 (rhBMP - 2 )和珊瑚 /聚乳酸形成复合人工骨的异位诱导成骨活性。方法 :把rhBMP - 2和珊瑚 /聚乳酸形成复合人工骨。进行小鼠肌内种植 1、3、6周后 ,组织学观察其异位诱导成骨活性。结果 :rhBMP - 2赋予珊瑚 /聚乳酸骨诱导能力 ,珊瑚 /聚乳酸则充当rhBMP - 2的载体和释放系统 ,对BMP的活性未产生不利影响。与单纯的珊瑚 /聚乳酸相比 ,这种复合人工骨以软骨内成骨的方式诱导成骨。结论 :rhBMP - 2 /珊瑚 /聚乳酸复合人工骨具有良好的生物相容性和骨诱导活性 ,是一种较理想的骨移植替代材料     

新型种植体涂层材料rhBMP-2/PDLLA诱导成骨作用的观察

目的：观察rhBMP-2/PDLLA涂层诱导钛种植体周围新骨形成情况。方法：选取8只比格犬,在其双侧胫骨随机植入PDLLA/rhBMP-2、PDLLA、rhBMP-2涂层和空白种植体,术后2、4、8、12周进行生物力学测定和骨形态计量学分析,比较各组新骨形成和骨结合情况。结果：rhBMP-2/PDLLA涂层种植体周围新骨形成早于其他组;4周时rhBMP-2/PDLLA涂层种植体骨结合明显优于PDLLA组、空白组（P〈0.05）,8周和12周时PDLLA/rhBMP-2涂层种植体骨结合优于PDLLA组,并有大于其他两组的趋势。结论：新型涂层材料PDLLA/rhBMP-2具有促进新骨形成和提高骨结合率的双重作用。     

消旋聚乳酸复合rhBMP-2/hTGF-β1诱导小鼠成骨及其机制的研究

目的:评价消旋聚乳酸(PDLLA)载体材料复合重组rhBMP-2和hTGF-β1诱导小鼠体内异位成骨的能力,初步探讨其作用机制。方法:建立诱导RCI小鼠股部肌内异位成骨的18只动物模型,实验组(各6只)分别植入PDLLA/rhBMP-2/hTGF-β1和PDLLA/rhBMP-2复合材料,对照组(6只)植入PDLLA材料。采用图像处理技术、组织病理学和RT-PCR等分子生物学方法,对消旋聚乳酸载体材料复合2种细胞因子诱导小鼠体内异位成骨能力进行评价;并对其诱导异位成骨过程中,II型胶原蛋白、骨桥蛋白和骨钙蛋白等骨基质蛋白基因表达进行检测。结果:PDLLA/rhBMP-2/hTGF-β1和PDLLA/rhBMP-2组复合材料均具有明显的诱导小鼠肌内异位成骨能力,而单纯PDLLA载体材料无诱导异位成骨能力,表现为小鼠股部复合材料植入区的相对密度指数存在显著性差异。II胶原、骨桥蛋白和骨钙蛋白及其基因在2种细胞因子复合材料植入组中均有较高表达,而在单纯PDLLA组则无表达。结论:PDLLA复合rhBMP-2/hTGF-β1具有诱导异位成骨作用,软骨内成骨是其诱导小鼠体内异位成骨的主要方式。     

复合膜异位诱导成骨研究

目的将基因重组人骨形态发生蛋白-2（rhBMP-2）与胶原、聚乳酸/聚羟基乙酸共聚体（PLGA）复合,制成rhBMP-2/Co/PLGA复合膜,观察其异位诱导成骨情况,评价其生物特性。方法取雄性昆明小鼠48只,随机分成Co/PLGA复合膜组与rhBMP-2/Co/PLGA复合膜组。在小鼠右后肢大腿肌间隙内分别植入2种复合膜材料。术后7、14、28 d,各组分别处死8只动物,标本行肉眼、软X线照相和组织学观察。结果2组动物术后情况良好。Co/PLGA复合膜组术后7 d复合膜开始溶解,14 d膜结构不连续,28 d大部分溶解;软X线和组织学观察未见异位骨生成。rhBMP-2/Co/PLGA复合膜组软X线和组织学观察均有骨样结构形成,与Co/PLGA复合膜组相比复合膜降解速度缓慢。结论Co/PLGA是rhBMP-2的良好载体,参与rhBMP-2诱导成骨活性的表达,使其在局部发挥更持久的生物活性。     

新型骨组织工程支架复合BMP-2体内异位成骨的研究

目的 评价新型骨组织工程支架聚消旋乳酸与聚乳酸-聚乙二醇-聚乳酸共混物复合rhBMP-2作为组织因子载体的体内异位成骨的能力.方法 在12只成年新西兰兔背部两侧骶棘肌内各制作互不相通的2个肌袋.然后将复合rhBMP-2的材料植入一侧肌袋为实验组,未复合rhBMP-2的材料作为对照组植入另一侧肌袋.术后2、 4、 8周取材行大体标本观察、组织学观察,观察体内异位成骨情况.结果 植入体内8周,实验组见成熟骨组织形成,对照组无骨组织形成.结论 新型骨组织工程支架复合rhBMP-2后植入动物体内有较强的异位成骨能力,是BMP的良好载体.     

胶原与骨形成蛋白复合物在大鼠皮下的骨诱导活性

目的 评价Ⅰ型胶原与rhBMP-2复合物在大鼠皮下骨诱导活性。方法 将150mg牛皮来源的Ⅰ型胶原与1mg的rhBMP-2相复合，冻干压成圆盘状，同时制备单纯胶原作为对照。将rhBMP-2/胶原，胶原及1mg的rhBMP-2植于大鼠背部皮下，于术后1、2及4周处死动物，常规组织学观察。结果 rhBMP-2/胶原复合物在大鼠皮下术后1周可诱导骨形成：术后4周，已完全由骨所代替，较单纯BMP植入组成骨时间早且致密。结论 Ⅰ型胶原可作为rhBMP-2的良好载体。可增强rhBMP-2的诱导活性。     

Ectopic bone formation after implantation of a slow release system of polylactid acid and rhBMP-2

Objectives: The present study was conducted to test the hypothesis that preshaped polylactic acid (PLA) implants loaded with recombinant human bone morphogenic protein 2 (rhBMP-2) can induce bone formation in a rat ectopic model.
Materials and methods: Two groups of porous cylindrical poly- dl -lactic acid implants of 8-mm diameter were produced by gas foaming with CO₂, incorporating 48 and 96 μg rhBMP-2, respectively, into each implant. Blank PLA implants were used as controls. The release of BMPs and the induction of alkaline phosphatase were assessed in vitro . Osteoinduction in vivo was tested by insertion of 15 implants from each group into the gluteal muscles of Wistar rats. Five implants from each group were retrieved after 6, 13 and 26 weeks and assessed using flat panel volume detector computed tomography and light microscopy.
Results: Both groups of implants showed increased release of rhBMP-2 during the first 24–48 h, with a slightly higher amount being released from the implants with 48 μg. Release during subsequent intervals was <100 ng/72 h in the low-concentration group and >100 ng in the group with 96 μg rhBMP-2. Implants with 95 μg rhBMP-2 exhibited bone formation in vivo on the outside of the implants across the observation period of 26 weeks with invasion of bone into the pores, whereas implants with 48 μg rhBMP-2 failed to induce the formation of bone tissue. No bone formation was found in the control implants.
Conclusions: The results suggest that release rates of rhBMP-2 for ectopic bone induction have to be >100 ng/72 h to maintain the osteoinductive activity of the tested porous PLA implants. This slow release system may have impact on alveolar bone augmentation procedures when used as individually preformed osteoinductive implants.     

Bone formation at rhBMP-2-coated titanium implants in the rat ectopic model

BACKGROUND: The objective of this study was to evaluate local bone formation at titanium porous oxide (TPO) implant surfaces adsorbed with recombinant human bone morphogenetic protein-2 (rhBMP-2). METHODS: In vitro studies were used to estimate the kinetics of I125-labeled rhBMP-2 released from TPO surfaces with narrow (N) or open (O) pores. Machined/turned titanium (MT) surfaces served as control. The rat ectopic model was used to assess local bone formation. Briefly, TPO-N, TPO-O, and MT disc implants adsorbed with 5, 10, or 20 microg rhBMP-2, respectively, were implanted subcutaneously into the ventral thoracic region in 5-week-old male Long Evans rats. The animals were euthanized at day 14 postsurgery when implants with surrounding tissues were removed, radiographed, and gross observations recorded. The specimens were processed for histologic evaluation using conventional cut-and-grind techniques. TPO implants without rhBMP-2 included in a preliminary evaluation revealed no evidence of bone formation, tissue encapsulation, or vascularity, thus such controls were not further used. RESULTS: TPO and MT implant surfaces adsorbed with 5 microg rhBMP-2 retained 2.3-5.4% rhBMP-2 following immersion and rinse in buffer, and 1.1-2.2% rhBMP-2 following repeated immersions and rinses over 27 days. TPO implants retained the most rhBMP-2 and MT implants retained the least. Explants revealed increased hard tissue formation, tissue encapsulation, and vascularity at TPO compared with MT implants. Radiographic observations were consistent with the explant observations. The histologic analysis showed greater amounts of bone formation, osteoblastic cells, osteoid, marrow, tissue encapsulation, vascularity, and bone voids for implants adsorbed with 10 and 20 microg rhBMP-2, and for TPO implants at the 5-microg rhBMP-2 dose. The histometric analysis revealed significantly greater bone formation at TPO-O than at MT implants at the 5-microg rhBMP-2 dose. All surfaces showed significant bone formation at the 10- and 20-microg dose. CONCLUSIONS: rhBMP-2 adsorbed onto TPO implant surfaces executes an osteoinductive effect including bone contacting the implant surface. This effect is surface- and dose-dependent; the TPO-O surface yielding the most bone at the low discriminating rhBMP-2 dose.     

应用珊瑚作为重组人骨形成蛋白-2缓释载体的动物实验研究

将大肠杆菌表达的重组人骨形成蛋白-2（rhBMP－2）和珊瑚（coral）复合，制成rhBMP－2／coral复合人工骨，将其植入小鼠股部肌肉内，并以单纯珊瑚植入作对照，术后1、3、6周取材，组织学观察。结果显示：rhBMP－2／coral复合人工骨在植入局部诱导形成骨和软骨，表现出良好的异位诱导成骨能力；珊瑚对rhBMP－2的活性未产生不利影响，是rhBMP－2的良好缓释载体。此复合人工骨可望作为一种新型生物性植骨材料而应用于骨科和颌面外科。     

重组人骨形成蛋白-2/珊瑚复合人工骨的动物实验研究

本研究将重组人骨形成蛋白－２（ｒｈＢＭＰ－２）和珊瑚以一定的方式复合后,植入小鼠股部肌袋和兔颅骨标准大小缺损,以单纯珊瑚植入作对照,术后不同时间取材,通过组织学方法检测其骨诱导活性和骨修复能力．结果显示：ｒｈＢＭＰ－２／珊瑚复合人工骨植入小鼠肌袋１周,诱导软骨形成,３周,形成编织骨,６周,形成含骨髓的板层骨,同时,珊瑚被部分降解吸收;复合人工骨植入兔颅骨缺损后,以引导成骨和诱导成骨双重机制完成骨修复过程,术后１２周,植入物完全被成熟的骨组织取代,其骨修复效果明显优于单纯的珊瑚．此复合人工骨具有骨传导和骨诱导活性,骨修复能力较强,是一种较理想的新型生物性植骨材料     

Exogenous recombinant human BMP-2 has little initial effects on human osteoblastic cells cultured on collagen type I coated/noncoated hydroxyapatite ceramic granules.

PURPOSE: Tissue engineering of bone entails the successful interplay between osteoinductive factors, osteogenic cells, their extracellular environment, and an osteoconductive biomaterial scaffold. Naturally produced ceramics, like hydroxyapatite (HA) calcified from red algae, are the most promising materials for use as scaffolds in this field. We hypothesized that extracellular matrix compartments and osteoinductive factors could further ameliorate the bioactivity of the scaffold. MATERIALS AND METHODS: Osteosarcoma cells with proven osteogenic phenotype (SaOS-2) were cultured onto type I collagen coated (Coll I/HA) and noncollagen coated HA granules (NC/HA) gained from red algae (C GRAFT/Algipore). Cells grown on tissue culture polystyrene dishes (TCPS) were used as controls. Second, SaOS-2 cells cultured on Coll I/HA, NC/HA, and TCPS were treated with recombinant human bone morphogenetic protein-2 (rhBMP-2) in different concentrations (10, 100, and 500 ng/mL). Non rhBMP-2-treated cultures were used as controls. Cultures of both experiments were grown under osteogenic differentiation conditions and after 24, 48, and 72 hours assays for cell viability, apoptosis, alkaline phosphatase activity (ALP), and osteocalcin (OC) secretion were done. RESULTS: Coating of HA granules with type I collagen showed higher cell viability in rhBMP-2-treated and nontreated cells. Supplementation of cultured cells with exogenous rhBMP-2 showed a dose-dependent effect only in the TCPS group. No alterations of the apoptotic rate within 1 investigation group were found. Addition of rhBMP-2 did not significantly alter the specific OC secretion of cells grown on Coll I/HA and TCPS. CONCLUSION: These in vitro findings show that in the initial period of cultivation and up to 72 hours, the coating of HA granules with collagen type I had positive effects on cell viability and osteoblastic characteristics of osteoblastic cells. In contrast, the supplementation with exogenous rhBMP-2 shows no dose-dependent effects. The combination of collagen type I and exogenous rhBMP-2 did not ameliorate the bioactivity of hydroxyapatite calcified from red algae in the initial period of cultivation.