生物吸收性多孔碳酸化羟基磷灰石支架的骨传导性体外研究

目的:通过体外实验对新型生物吸收性多孔碳酸化羟基磷灰石(CAP)支架材料的骨传导性进行评价。方法:体外分离培养大鼠骨髓间充质干细胞,向成骨诱导后,定植于不同孔隙率及不同碳酸根含量的CAP支架材料上共同培养,通过扫描电镜、细胞黏附及增殖检测(MTT法)、碱性磷酸酶(ALP)定量检测、骨钙素(OCN)定量检测,评价成骨细胞在支架材料上的附着、增殖和分化情况。结果:成骨细胞定植于不同孔隙率及碳酸根含量的支架材料上,4 h均已开始黏附、且增殖情况良好。分化实验中,ALP和OCN在各组支架材料分化良好。不同孔隙率支架材料组间比较,40%孔隙率的实验组对ALP分化的促进作用有明显优势。结论:CAP支架材料有良好的生物相容性和骨传导性,是一种良好的组织工程支架材料。     

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。     

载辛伐他汀纳米羟基磷灰石支架材料对兔下颌骨缺损修复的影响

目的:采用骨髓间充质干细胞(BMSCs)复合辛伐他汀支架材料修复兔下颌骨局部缺损,观察辛伐他汀对BMSCs复合支架材料修复兔骨缺损的影响。方法:24只新西兰大白兔随机分为2组,每组12只,制备下颌骨缺损模型。A组为实验组,在缺损区植入复合BMSCs的载辛伐他汀纳米羟基磷灰石支架材料;B组为对照组,植入BMSCs复合羟基磷灰石材料。分别于术后2、4、8、12周处死各组动物,行影像学分析、HE染色、扫描电镜观察等检查。结果:影像学检查及组织学染色结果显示,A组骨缺损处愈合程度、成骨速度及骨质量明显优于B组。扫描电镜显示,A组复合材料与组织相容性好,材料吸收优于B组。统计各组各期牙CT分析数据的骨密度值,结果表明A组的骨密度值明显高于B组(P<0.05)。结论:实验表明经BMSCs复合的辛伐他汀支架材料具有明显的促进成骨能力,可加速骨缺损的修复效果,提高修复质量。     

应用生长因子-支架构建方式的组织工程方法再生牙周组织的实验研究

目的：观察评价生长因子-支架构建方式的组织工程方法对牙周组织再生修复的影响和意义，探讨纳米羟基磷灰石材料(nHAC)和重组人骨形成蛋白-2(rhBMP-2)用于牙周组织工程的可行性。方法：将rhBMP-2与nHAC复合植入动物人工牙周组织缺损，表面覆盖聚四氟乙烯(e-PTFE)膜，以卒白对照组和单纯GTR组作为对照。术后8周进行组织学观察和测量，分析评价其牙周组织的再生情况。结果：rhBMP-2-nHAC-膜复合植入组较空白对照组和单纯GTR组有更多的新生牙槽骨、新生牙周膜和新生牙骨质生成，且未见上皮长入。结论：应用生长因子-支架构建方式的牙周组织工程方法能更有效地促进牙周组织再生和重建，而rhBMP-2和nHAC有望用作牙周组织工程的生长因子和支架材料。     

BMSC-HA/TCP修复羟基磷灰石种植体周围骨缺损的实验研究

目的:探讨应用小型猪BMSC为种子细胞,HA-TCP为支架修复种植体周围骨缺损的可行性。方法:将8只小型猪,随机分为实验组及对照组。在两组种植体周围骨缺损区分别植入细胞-支架材料,单纯支架材料,于种植体植入后1个月,3个月取材,进行观察。结果:细胞-支架组1个月骨缺损区可见新生编织骨包绕支架材料,3个月可见支架材料降解,密质骨形成。支架组1个月骨缺损区纤维组织包裹支架材料,3个月支架材料部分降解。结论:细胞-支架构建方式可作为修复羟基磷灰石种植体周围骨缺损的方法之一。     

生物性多孔碳酸化羟基磷灰石支架的制备

目的:研发新型生物吸收性碳酸化羟基磷灰石(CHA)支架材料.方法:Ca(OH)<'2>粉末与不同质量比水溶性造孔剂(NaCl颗粒)充分混合,模具压缩成型,经二氧化碳气体碳酸化10 d,蒸馏水浸泡去除水溶性填料后置磷酸钠缓冲溶液磷酸化2周,得到多孔性材料.对其以扫描电镜(SEM)、X线衍射仪(XRD)、傅立叶变换红外光谱...     

NPHA/BMP应用于根管充填的动物实验及临床研究

目的:研制一种理想的根充剂并观察其临床疗效.方法;采用天然型网孔羟基磷灰石(NPHA)与骨形成蛋白(BMP)复合物进行家兔肌内植入实验,以及羟基磷灰石(HA)、NPHA 家兔胫骨内植入实验.同时选择口腔门诊需进行根管治疗的患者随机分为实验组(NPHA/BMP)99例,99个牙;对照组(氢氧化钙)93例,95个牙,进行根充治疗.结果:NPHA植入肌肉未见诱导幼稚间充质细胞的增殖、分化及成骨作用,但该材料不引起组织排斥反应,生物相容性好.NPHA/BMP复合物植入肌内,可见明显新生骨形成,新生骨成长活跃且与材料呈直接界面.NPHA植入胫骨内无免疫排斥反应,其生物相容性良好,其成骨量明显多于致密性羟基磷灰石.1年随访观察:NPHA/BMP复合物的根充明显优于氢氧化钙.结论:NPHA有利传导成骨,NPHA/BMP复合物,具有诱导成骨活性的作用.该材料生物相容性良好,是目前根管充填术中理想的充填剂.     

可吸收型羟基磷灰石生物陶瓷的临床应用评估

目的：观察可吸收型羟基磷灰石生物陶瓷临床应用中的疗效和安全性,旨在为临床提供一种新型植骨材料。方法：60例口腔骨缺损患者分为两组：实验组植入可吸收型羟基磷灰石生物陶瓷,对照组植入牛无机骨Bio-Oss颗粒。通过术前术后对体温、血常规、血沉（ESR）、C-反应蛋白（CRP）、肝肾功能（ALT、AST、Bun、Cr）,以及伤口愈合、骨愈合情况等指标的监测,对实验用植骨材料进行临床评价。结果：实验组植入材料后6个月,无1例全身性异常反应,仅1例伤口有红肿,渗液,3周内伤口愈合。骨愈合情况：植入区的骨密度增高,骨愈合良好,实验组与对照组无明显差异。结论：可吸收型羟基磷灰石可用于拔牙创及牙种植周围骨缺损修复,该材料无不良反应,无毒副作用,能加速骨缺损的修复。     

壳聚糖/β-磷酸三钙支架复合骨形态发生蛋白后成骨效能研究

目的通过壳聚糖（CS）/β-磷酸三钙（TCP）复合重组人骨形态发生蛋白（rhBMP）-2修复兔下颌骨缺损,探索CS/β-TCP作为可注射性人工骨支架材料的可行性。方法24只新西兰大白兔共48侧骨缺损随机分为4组：实验组1植入CS/β-TCP/rhBMP-2、实验组2植入CS/β-TCP、对照组1植入自体骨、对照组2不植入任何材料。于术后2、4、8周分批处死动物,通过苏木精-伊红染色和荧光染料标记组织切片观察新骨形成情况,骨密度仪测量骨密度值。结果术后2、4、8周,不同组间的新生骨面积百分比有显著差异,实验组1明显优于实验组2,并随着观察时间的延长,成骨面积的比例也不断增高。荧光观察示实验组1黄色标记面积较大,红色标记面积较小。实验组1术后各时间点的骨密度值明显优于实验组2和对照组2,而与对照组1间无明显差异。结论CS/β-TCP/rhBMP-2复合体具有良好的生物相容性、降解性、骨引导及骨诱导能力,CS/β-TCP可作为rhBMP-2良好的注射性载体,对于颌骨缺损的修复具有一定的临床价值。     

新型复合骨植入材料的体内成骨性能研究

目的 研究新型复合材料3-羟基丁酸-co-3-羟基戊酸共聚物/溶胶-凝胶生物活性玻璃[poly(3-bydroxybutyrate-co-3-bydroxyvalerate)/sol-gel bioactive glass,PHBV/SGBG]的体内成骨效能.方法 制备犬胫骨骨缺损模型,实验组在骨缺损区植入PHBV/SGBG材料,对照组不作处理,分别于术后2、4、8、12周取材,大体标本及组织学切片观察该材料的体内成骨效能.结果 实验组骨再生过程中,软骨成骨明显,术后2周骨缺损区软骨样组织较丰富;术后12周时,植入材料PHBV/SGBG基本完全降解,骨缺损区充填新生的成熟骨组织.对照组的骨修复不全,骨痂中可见纤维组织形成.结论 复合材料PHBV/SGBG具有很好的骨传导性和骨再生能力,有望成为新型的骨组织工程材料.     

Effects of sintering temperature over 1,300 degrees C on the physical and compositional properties of porous hydroxyapatite foam

Porous hydroxyapatite (HAP) foam permits three-dimensional (3D) structure with fully interconnecting pores as well as excellent tissue response and good osteoconductivity. It is therefore thought to be a good candidate as scaffold material for bone regeneration and as a synthetic bone substitute material. To fabricate better porous HAP foam, improved physical and structural properties as well as higher osteoconductivity are desired. In the present study, the effects of sintering temperature on the physical and compositional properties of porous HAP foam were evaluated by employing high sintering temperature starting at 1,300 degrees C up to 1,550 degrees C. The mechanical strength of porous HAP foam increased with sintering temperature to reach the maximum value at 1,525 degrees C, then decreased slightly when sintering temperature was further increased to 1,550 degrees C. Alpha tricalcium phosphate (alpha-TCP) was formed, and thus the porous HAP foam became biphasic calcium phosphate. Biphasic calcium phosphate consisting of both alpha-TCP and HAP had been reported to show higher osteoconductivity than HAP alone. We therefore recommend 1,500-1,550 degrees C as the sintering temperature for porous HAP foam since this condition provided the most desirable physical properties with biphasic calcium phosphate composition.     

Functional reconstruction of the non-human primate mandible using recombinant human bone morphogenetic protein-2

The purpose of this study was to evaluate the long-term functional properties of regenerated bone induced by recombinant human bone morphogenetic protein-2 (rhBMP-2) in segmental bone defects of primate mandibles. The 30-mm defects were created in the mandibles of six young monkeys and the mandibles were fixed with titanium plates. Then 9 mg of rhBMP-2 permeating a poly-D, L-lactic-co-glycolic acid-coated gelatin sponge (PGS) was implanted into the bone defect. Dental implants were placed into the regenerated mandible 20 weeks after surgery, then suprastructures were placed and masticatory force loading was begun 8 weeks after the insertion of the dental implants. Bone formation and the quality of new bone were evaluated radiologically and histologically at 15 and 30 weeks after surgery, and 4 and 24 weeks after masticatory force loading. The resected mandibles were completely regenerated with the rhBMP-2-induced bone. Excellent remodelling and consolidation of new bone were observed after loading. This study demonstrated that the new bone induced by rhBMP-2 in large segmental defects was maintained and functional for at least 1 year. Bone regeneration induced by rhBMP-2 holds promise as a future therapy and may be an effective alternative to autogenous bone grafts for implant dentistry and reconstructive surgery.     

Experimental study of secondary bone graft of alveolar clefts using bone morphogenetic protein (BMP)

The purpose of this study was to evaluate the utility of recombinant human bone morphogenetic protein-2 (rhBMP-2) as a bone substitute on artificial alveolar clefts of adult Macaca fuscata monkeys. First, we created simulated alveolar clefts to represent human bilateral alveolar clefts, and then we implanted a mixture of rhBMP-2 and autogeneous particulate marrow cancellous bone (PMCB) into these models, as experimental groups. The mixture ratio was varied as follows (mixture ratio = rhBMP-2: PMCB). Group 1: rhBMP-2 alone. Group 2: Mixture of rhBMP-2 and PMCB (1:1). Group 3: Mixture of rhBMP-2 and PMCB (3:1). Group 4: Mixture of rhBMP-2 and PMCB (4:1). Positive control group: PMCB alone. Negative control group: PLGA (poly[L-lactide-co-glycolide] copolymer/gelatin sponge complex (PGS) alone. All animals were sacrificed 12 weeks after implantation and evaluated radiographically and histologically. The results were as follows. Bone bridge formation was not observed in Group 1, using rhBMP-2 alone, but it was observed in Groups 2, 3, and 4 using mixture of rhBMP-2 and PMCB. The vertical height of bone bridge formation in Group 4 was equal to that in the positive control group, roughly. The histological finding showed that the bone density of Group 4 was higher than in the positive control group, and the structure of cancellous bone turned into mature type. Bone formation and remodeling was active in Group 4. These results indicated that rhBMP-2 may be an effective substitute for autogenous PMCB in bone grafting into alveolar clefts.     

个体化钛支架复合珊瑚羟基磷灰石和重组人骨形成蛋白2修复兔下颌骨缺损

目的通过观察个体化钛支架复合珊瑚羟基磷灰石(CHA)和重组人骨形成蛋白2(rhBMP-2)修复兔下颌骨缺损的实验效果,探讨下颌骨个体化修复再生的途径。方法以9只新西兰大白兔为实验对象,采用磨骨术建立兔下颌骨单侧缺损模型,利用计算机辅助设计/制作、快速成型技术等设计制作兔下颌骨个体化钛修复体,再将其与CHA和rhBMP-2复合应用于兔下颌骨标准化缺损修复,通过大体标本观察、骨密度检测、生物力学测试和组织学染色对下颌骨缺损的个体化再生修复效果进行研究。结果兔下颌骨解剖形态恢复理想,生物力学测试、骨密度检测及组织学观察均显示随时间点延长成骨效果呈明显上升趋势(P<0.05),钛支架内具有大量新骨形成,新生骨组织在24周时已明显成熟。结论采用快速成型技术制作的个体化钛支架复合CHA和rhBMP-2,可望通过骨再生途径实现下颌骨缺损的个体化修复重建。     

Influence of bone morphogenetic protein and proportion of hydroxyapatite on new bone formation in biphasic calcium phosphate graft: Two pilot studies in animal bony defect model

PurposeThe purpose of these two pilot studies using animal bony defect models was to evaluate the influence of bone morphogenetic protein (BMP) and proportion of hydroxyapatite (HA)/beta-tricalcium phosphate (β-TCP) in biphasic calcium phosphate (BCP) graft on new bone formation.MethodsIn this study, four kinds of synthetic osteoconductive bone materials known for bone growth scaffold, OSTEON™II(HA:β-TCP 30:70), OSTEON™III (HA:β-TCP 20:80), OSTEON™II Collagen, and OSTEON™III Collagen, were prepared as BCP graft materials. In pilot study 1, three BCP materials (OSTEON™II, OSTEON™III, and OSTEON™II Collagen) were grafted in rabbit calvarial defects after impregnating in rhBMP-2. OSTEON™II without the rhBMP-2 impregnation was included in the study as the control. The amount of new bone was examined and measured histologically at 2, 4, and 8 weeks. In pilot study 2, four BCP materials (OSTEON™II, OSTEON™III, OSTEON™II Collagen, and OSTEON™III Collagen) were grafted in beagle dog mandibular defects after soaking in the rhBMP-2. The amount of total bone and new bone were measured three-dimensionally using microCT and healing process was examined histologically at 2, 4, and 8 weeks.ResultsIn pilot study 1, rhBMP-2 impregnated groups showed more new bone formation than the rhBMP-2 free group. In pilot study 2, increased new bone formation was observed in time-dependent manner after graft of BCP and BCP-collagen (OSTEON™II, OSTEON™III, OSTEON™II Collagen, and OSTEON™III Collagen) impregnated with rhBMP-2. Also, BCP with a higher proportion of HA (30% HA) showed more favorable result in new bone formation and space maintenance, especially at the 8 weeks.ConclusionFrom the results of the pilot studies, rhBMP-2 played positive roles in new bone formation and BCP could become a scaffold candidate for rhBMP-2 impregnation to induce new bone formation. Moreover, BCP with a higher proportion of HA (30% HA) could be considered more appropriate for rhBMP-2 carrier.     

rhBMP-2在种植体周围骨缺损修复中应用的组织学观察

目的:研究rhBMP-2及不同载体在种植体周围骨缺损修复中的应用。方法:在beagle犬下颌骨植入种植体,颊侧形成裂开性骨缺损,置入复合了不同浓度rhBMP-2的珊瑚羟基磷灰石人造骨(CHA)或可吸收胶原海绵(ACS)。种植体植入后2、4、8、12周,获取含种植体骨标本,进行组织学观察。结果:2周时,rhBMP-2组可见极少量的新生骨组织。4周时,rhBMP-2/ACS组新骨组织由牙槽骨顶端向缺损区中心方向生长;rhBMP-2/CHA组人造骨颗粒内部和周围出现呈岛状生长的新生骨组织。8周时,rhBMP-2/ACS组的新骨形成大片状结构;rhBMP-2/CHA组人造骨颗粒周围较多骨岛形成。12周时,rhBMP-2组的缺损区内骨量和骨高度进一步增加,与种植体形成骨性结合。浓度为0.05 mg/ml和0.2 mg/ml,载体为CHA或ACS促进骨再生作用差异无统计学意义。结论:以CHA或ACS为载体rhBMP-2能促进种植体周围骨缺损区内的骨组织再生并与种植体表面较好地结合。     

Osteopontin and bone metabolism: a histology and scintigraphy study in rats

Osteopontin (OPN) is one of the major non-collagen proteins in extracellular bone matrix. To elucidate the function of OPN in bone metabolism, a cellular defect was created in parietal bone and tibia of 12 rats. In Group 1, the left defects were filled with OPN-coated hydroxyapatite (OPN-H). In Group 2, the right defects were filled with non-coated hydroxyapatite (N-H). In both groups, the contra lateral defects were used as control defects. In Group 3, OPN-H was inserted in the left defects and N-H in the right defects. Bone metabolism was measured by (45)Ca and technetium-99m methylene diphosphonate scintigraphy for 4 weeks. Scintigraphy did not show any significant differences in bone metabolism between the defects filled with OPN-H and N-H. A higher bone metabolism was measured between the parietal defects filled with OPN-H or N-H in comparison with the parietal control defects. This difference, however, was not significant and was less for tibia defects. Histological observation (7th week) shows less inflammatory cells at the tibia defects filled with OPN-H compared to the tibia defects filled with N-H. This study did not show any acceleration or inhibition of bone metabolism in parietal or tibia bone in rats, but there is some evidence that OPN might influence inflammatory cells in bone matrix.     

Effect of recombinant human bone morphogenetic protein-4 with carriers in rat calvarial defects

BACKGROUND: Bone morphogenetic proteins (BMPs) are being evaluated as candidates for periodontal and bone regenerative therapy. However, the research on recombinant human bone morphogenetic protein-4 (rhBMP-4) has been insufficient to evaluate its capacity to enhance bone formation and its carrier system. The purpose of this study was to evaluate the bone regenerative effect of rhBMP-4 delivered with an absorbable collagen sponge (ACS) or beta-tricalcium phosphate (beta-TCP). We also compared the potential of beta-TCP to that of ACS as a carrier system for rhBMP-4. METHODS: Eight-mm calvarial critical-sized defects were created in 100 male Sprague-Dawley rats. The animals were divided into 5 groups of 20 animals each. The defects were treated with rhBMP-4/ACS (rhBMP-4 at 0.05 mg/ml), rhBMP-4/beta-TCP (rhBMP-4 at 0.05 mg/ml), ACS alone, beta-TCP alone, or left untreated for surgical control. The rats were sacrificed at 2 or 8 weeks postsurgery, and the results were evaluated radiodensitometrically, histologically, and histomorphometrically. RESULTS: The results of radiodensitometric analysis were as follows: the rhBMP-4/ACS and the rhBMP-4/beta-TCP groups were more radiopaque than other groups at both 2 and 8 weeks (P < 0.01). The histologic observations were as follows: in the rhBMP-4/ACS and the rhBMP-4/beta-TCP groups, new bone was evident at the defect sites at 2 weeks and 8 weeks. The results of histomorphometric analysis were as follows: the rhBMP-4/ACS and the rhBMP-4/beta-TCP groups had more bone (%) than other groups at both 2 and 8 weeks (P < 0.01). CONCLUSIONS: Surgical implantation of rhBMP-4/ACS may be used to support bone regeneration in the rat calvarial critical-sized defect, and rhBMP-4/beta-TCP may be able to regenerate bone in the rat calvarial critical-sized defect without complication. In addition, both ACS and beta-TCP may be considered as available carriers for rhBMP-4.