rhBMP-2增强腱骨界面愈合的生物力学研究

目的:探讨rhBMP-2增强移植腱骨隧道界面愈合能力。方法:取成年新西兰兔同侧半腱肌肌腱作为自体移植材料,建立70只新西兰兔双侧前交叉韧带重建动物模型。实验组在移植腱-骨隧道界面注射填充以纤维蛋白胶作为载体的rhBMP-2,对照组仅填充纤维蛋白胶,完全空白对照组则不作任何填充。分别于术后第2、4和8周取材,进行生物力学检测。结果:实验组最大载荷在2、4、8周较对照组分别增强13.53%、82.13%、93.23%。实验组刚度在4、8周较对照组分别增强71.91%、121.99%,差异在统计学上显著(P<0.05)。结论:rhBMP-2可以在术后早期提高腱骨界面的最大载荷和刚度,增强了腱骨界面的结合力,促进腱骨界面愈合。     

复合rhBMP-2的注射型成骨材料修复犬桡骨骨缺损的实验研究

探讨以纤维蛋白胶(fibrin sealant,FS)为载体,复合rhBMP-2\bFGF的注射型骨修复材料,修复犬桡骨节段性缺损的作用,为其临床应用提供实验依据.实验分为:实验组(FS bFGF rhBMP-2)、对照组(FS).于12只成年健康家犬右侧桡骨中上段造成2cm缺损,制成犬桡骨2cm骨缺损实验模型,然后严密缝合皮下组织及皮肤,将实验材料经伤口周围正常皮肤注射到骨缺损处,术后4、8、16、24w进行放射学检查,术后24w,标本进行组织学和骨密度检查,研究其成骨效应.结果表明:实验组骨缺损区在成骨活跃程度、骨密度和再生髓腔结构等方面均显著优于对照组,使骨缺损得到了成功的修复(P＜0.01).以纤维蛋白胶为载体复合rhBMP-2和bFGF的注射型骨修复材料,具有高效的骨修复能力,对犬的骨缺损有很好的修复效果.     

磷酸钙活性人工骨与自体骨颗粒环抱式植骨治疗四肢骨不连#br#

目的　探讨固化型磷酸钙活性人工骨(CPC/rhBMP-2)与自体骨颗粒环抱式植骨治疗四肢非感染性萎缩型骨不连的临床疗效。 方法　对2013年9月至2017年9月年间治疗的16例四肢非感染性萎缩型骨不连患者进行回顾性分析,其中男12例,女4例;年龄（37.06±16.31）岁（16~67岁）。骨不连部位：下肢11例（胫骨6例、股骨3例、跟骨1例、腓骨1例）,上肢5例（桡骨3例、锁骨1例、手舟骨1例）,所有患者均行断端新鲜化,骨缺损中央植入自体骨颗粒,外周植入CPC/rhBMP-2形成环抱式植骨。术后复查X线片观察骨折愈合情况,记录并发症发生情况,随访患者直到骨折愈合。采用上肢功能障碍评定量表（DASH）、下肢功能量表(LEFS)和SF-12生活质量量表对治疗前、后进行疗效评定。 结果　本组16例均获随访,随访时间（16.93±4.06）月（12~26月）。X片显示全部病例均获得骨性愈合,愈合时间（5.43±2.25）月（3~10月）;术后DASH、LEFS和SF-12评分与术前比较均有统计学差异(P<0.05)。 结论　固化型磷酸钙活性人工骨(CPC/rhBMP-2)和自体骨颗粒环抱式植骨治疗四肢萎缩型骨不连的愈合率及安全性高,疗效可靠。     

凝胶型E基质在大鼠脊柱后外侧融合中的应用

背景：重组人骨形态发生蛋白(recombinant human bone morphogenetic protein,rhBMP)的骨诱导能力已在各种动物模型和临床试验中得到验证。 目的：利用大鼠脊柱后外侧融合模型,分析凝胶型E基质作为rhBMP-2的新型载体在脊柱后外侧融合中的作用。 方法：建立大鼠后外侧融合模型,105只Lewis雄性大鼠在相同条件下分别在L4-5横突间植入可吸收明胶海绵复合不同质量的rhBMP-2,对加或不加凝胶型E基质进行分组观察。 结果及结论：10 μg和3 μg rhBMP-2两组融合率100%,1,0.5,0.1 μg rhBMP-2组的融合率分别是40%,10%,0%。加E基质的0.5 μg以上的rhBMP-2组全部融合,而0.1,0.05 μg rhBMP-2组未发现融合迹象。Micro-CT扫描提示3 μg rhBMP-2复合明胶海绵加E基质与10 μg rhBMP-2复合明胶海绵组融合节段形成的新生骨骨量相似,而0.1,0.05 μg rhBMP-2不管有无E基质,都无新骨形成。说明应用E基质作为载体能明显提高rhBMP-2在脊柱后外侧的融合成功率,但当rhBMP-2的剂量过小时,使用E基质做载体也不能达到预期的脊柱融合。     

纳米羟基磷灰石/重组人骨形成蛋白-2复合人工骨的实验研究

目的：探讨纳米羟基磷灰石复合重组人骨形成蛋白-2人工骨（Nano-HA／rhBMP-2）的骨缺损修复能力，为临床骨缺损修复提供依据。方法：采用新西兰大白兔75只，单侧桡骨制备骨缺损动物模型，以Nano-HA／rhBMP-2复合人工骨植入骨缺损处进行修复作为实验组（A组），以Nano-HA人工骨（B组）及空白组（C组）作为对照组；术后4周、8周、12周分别行大体标本观察、X线、扫描电镜（SEM）、放射性核素骨扫描（ECT）及生物力学测试，综合评价Nano-HA／rhBMP-2复合人工骨对骨缺损的修复能力及对机体的影响。结果：Nano-HA／rhBMP-2复合人工骨、Nano-HA人工骨均可促进新骨形成，前者新骨形成量大，骨缺损修复能力明显优于后者，差异有统计学意义（P〈0．05）。结论：Nano-HA／rhBMP-2复合人工骨具有良好的骨缺损修复能力，可望成为一种理想的骨缺损修复材料。     

注射型rhBMP-2骨修复材料对兔桡骨骨缺损修复的实验研究

探讨以纤维蛋白胶(fibrin sealant,FS)为载体,复合重组BMP-2(rhBMP-2)的注射型骨修复材料,修复兔桡骨节段性骨缺损的能力,为其临床应用提供实验依据。将实验动物分为:实验组(FS rhBMP-2)、对照组(FS)。于28只新西兰白兔右侧桡骨干处造成1.5cm缺损,然后严密缝合皮下组织及皮肤,将各组材料经正常皮肤注射骨缺损处,术后4、8、16、24周进行放射学、组织学和骨密度等方法检查,对其成骨效应进行研究。结果表明:实验组(FS rhBMP-2)骨缺损区在成骨活跃程度、骨密度和再生髓腔结构等方面均显著优于对照组(FS),使骨缺损得到了彻底修复(P<0.01);对照组不能产生骨性愈合。由此说明以纤维蛋白胶为载体复合rhBMP-2的注射型骨修复材料具有高效的骨修复能力。     

基因转染间充质干细胞修复大鼠骨缺损及其生物力学研究

目的评价腺病毒介导的人BMP-2基因转染的间充质干细胞对长骨骨干节段性骨缺损的修复效果。方法:36只雄性Wistar大鼠随机分为3组,每组12只,采用单侧股骨缺损模型,分别植入下列同系细胞与胶原的复合物:(1)Adv-hBMP-2转染的间充质干细胞;(2)Adv-βgal转染的间充质干细胞;(3)未转染细胞。于术后2、4、6、8周行放射学检查,术后8周的标本行组织学检查及生物力学测试。结果放射学检查显示,Adv-hBMP-2转染组术后2周有明显骨痂形成,术后8周12例骨缺损中有10例愈合,其他2组骨缺损均未愈合,放射学评分低于Adv-hBMP-2转染组,差异有统计学意义。组织学分析表明,Adv-hBMP-2转染组术后8周骨缺损内有丰富的编织骨和板层骨,其他2组无明显骨痂或仅有少量骨形成。生物力学测试显示,Adv-hBMP-2转染组手术侧股骨的弯曲强度是对侧未手术股骨的85%±8%。结论Adv-hBMP-2基因转染的同系大鼠间充质干细胞可修复长骨干节段性骨缺损。     

利用重组人骨形态发生蛋白-2诱导椎间盘成骨的实验研究

目的确定在兔子的椎间盘内注射重组人骨形态发生蛋白-2（recombinant human bone morphogenetic protein-2，rhBMP-2）诱导椎体间融合的可行性。方法将24只成年新西兰大白兔，随机分为2组，每组12只。用微量注样器将含有rhBMP-2200μg的生理盐水溶液20μl和等量的生理盐水分别注射到成年新西兰大白兔的L4～5椎间盘的髓核内。术后10、30、60及90天进行X线照相和组织学检查。结果注射椎间盘未见免疫排斥反应。实验组可见纤维环和软骨终板成骨并在相邻椎体间形成骨桥。对照组的椎间盘内未见骨形成。结论利用注射的方法，rhBMP-2可诱导椎间盘成骨，达到椎体间融合的目的。     

重组人骨形成蛋白-2对细胞成骨分化的作用

目的 进一步探讨rhBMP-2的促细胞成骨分化作用，以期找到合适的成骨分化标志作为rhBMP-2的定量活性测定指标。方法 首先表达制备rhBMP-2，用小鼠股部肌袋包埋法进行诱骨活性实验，然后检测rhBMP-2作用后的骨髓基质细胞（MSC）、NIH3T3和C2C12等3种细胞的碱性磷酸酶（ALP）和骨钙素（OC）、细胞总蛋白合成量以及细胞增殖的变化。结果 rhBMP-2具有良好的诱导骨形成的活性，可增加3种细胞的OC含量和蛋白合成量，对MSC的ALP活性变化影响明显，且可促进MSC的增殖，抑制NIH3T3细胞的生长。结论 rhBMP-2具有促进上述细胞向成骨细胞分化的作用；在一定剂量范围内，rhBMP-2的作用与细胞骨钙素合成量的增加呈线性正相关，故定量测定OC的含量基本可反映rhBMP-2的活性。     

两种壳聚糖载rhBMP-2纳米微球对SD大鼠体内异位成骨的影响

目的　通过SD大鼠异位成骨实验来探究重组人骨形态发生蛋白-2/壳聚糖/硫酸葡聚糖(rhBMP-2/CS/DS) 复合微球和重组人骨形态发生蛋白-2/壳聚糖 (rhBMP-2/CS) 微球对SD大鼠体内异位成骨的影响。 方法　随机将36只SD大鼠平均分为三组（n=12）,分别为A组 (rhBMP-2), B组(rhBMP-2/CS), C组(rhBMP-2/CS/DS)。制备股四头肌肌袋模型后,分别将三种材料植入股四头肌肌袋肌间隙中。分别在4,8和12周时大体观察植入区组织硬度,每组处死4只大鼠后取出异位骨块,并切取异位骨化的组织行micro-CT扫描及 Mimics软件三维重建;检测各组织块骨体积分数（bone volume fraction,BVF）、骨小梁厚度（trabecular thichness,Tb.Th）、骨密度（bone mineral density,BMD）;并行组织学观察和ALP活性、钙含量检测。 结果 4周时,A、B、C三组植入区周围组织质地均稍硬,三者并无明显区别;8周和12周时,三组植入区硬度明显增加,且C组比A、B组质地更硬。4周时,HE染色可见三组有少量骨组织形成,但不明显;B、C两组BVF、Tb.Th、BMD,碱性磷酸酶（ALP）活性、钙含量均高于A组;B、C两组以上指标差异无统计学意义。8、12周时,HE染色可见到三组骨组织逐渐增多,并逐渐成熟,且B、C两组可见到比A组更成熟的骨组织,C组骨组织比B组更成熟;B、C两组BVF、Tb.Th、BMD,ALP活性、钙含量均高于A组,C组以上指标均高于B组。 结论　rhBMP-2/CS/DS纳米缓释微球的成骨效果明显强于rhBMP-2/CS纳米微球和单独rhBMP-2,其可能在骨组织工程领域有较好的运用前景。     

The effect of a fibrin-fibronectin/beta-tricalcium phosphate/recombinant human bone morphogenetic protein-2 system on bone formation in rat calvarial defects

In spite of good prospects for bone morphogenetic proteins (BMP) applications, an ideal carrier system for BMPs has not yet been identified. The purpose of this study was to evaluate the osteogenic effect of a fibrin-fibronectin sealing system (FFSS) combined with beta-tricalcium phosphate (beta-TCP) as a carrier system for recombinant human bone morphogenetic proteins (rhBMP-2) in the rat calvarial defect model. Eight-millimeter critical-size calvarial defects were created in 100 male Sprague-Dawley rats. The animals were divided into five groups of 20 animals each. The defects were treated with rhBMP-2/FFSS, rhBMP-2/FFSS/beta-TCP, FFSS and FFSS/beta-TCP carrier control or were left untreated as a sham-surgery control. Defects were evaluated by histologic and histometric parameters following a 2- and 8-week healing interval (10 animals/group/healing intervals). The FFSS/beta-TCP carrier group was significantly greater in new bone area at 2 weeks (p<0.05) and new tissue area at 2 and 8 weeks (p<0.01) relative to the FFSS carrier group. New bone and new tissue area in the rhBMP-2/FFSS/beta-TCP group were significantly greater than in the rhBMP-2/FFSS group at 8 weeks (p<0.01). On histologic observation, FFSS remnants were observed at 2 weeks, but by 8 weeks, the FFSS appeared to be completely resorbed. rhBMP-2 combined with FFSS/beta-TCP produced significantly more new bone and new tissue formation in this calvarial defect model. In conclusion, FFSS/beta-TCP may be considered as an available carrier for rhBMP-2.     

Three-dimensionally presented anti-fouling zwitterionic motifs sequester and enable high-efficiency delivery of therapeutic proteins

Zwitterions are well known for their anti-biofouling properties. Past investigations of zwitterionic materials for biomedical uses have been centered on exploiting their ability to inhibit non-specific adsorption of proteins. Here, we report that zwitterionic motifs, when presented in three dimensions (e.g. in crosslinked hydrogels), could effectively sequester osteogenic bone morphogenetic protein-2 (rhBMP-2). The ionic interactions between rhBMP-2 and the 3-D zwitterionic network enabled dynamic sequestering and sustained release of the protein with preserved bioactivity. We further demonstrated that the zwitterionic hydrogel confers high-efficiency in vivo local delivery of rhBMP-2. It can template the functional healing of critical-size femoral segmental defects in rats with rhBMP-2 at a loading dose substantially lower than those required for current natural or synthetic polymeric carriers. These findings reveal a novel function of zwitterionic materials beyond their commonly perceived anti-biofouling property, and may establish 3-D zwitterionic matrices as novel high-efficiency vehicles for protein/ionic drug therapeutic delivery.     

The kinetic and biological activity of different loaded rhBMP-2 calcium phosphate cement implants in rats

The healing of large bone defects can be improved by osteogenic bone graft substitutes, due to growth factor inclusion. A sustained release of these growth factors provides more efficient bioactivity when compared with burst release and might reduce the dose required for bone regeneration, which is desirable for socioeconomical and safety reasons. In this study, we compared different rhBMP-2 loadings in a sustained release system of CaP cement and PLGA-microparticles and were able to couple kinetic to biological activity data. Fifty-two rats received a critical-size cranial defect, which was left open or filled with the cement composites. The implants consisted of plain, high, and five-fold lower dose rhBMP-2 groups. Implantation time was 4 and 12 weeks. Longitudinal in vivo release was monitored by scintigraphic imaging of (131)I-labeled rhBMP-2. Quantitative analysis of the scintigraphic images revealed a sustained release of (131)I-rhBMP-2 for both doses, with different release profiles between the two loadings. However, around 70% of the initial dose was retained in both implant formulations. Although low amounts of rhBMP-2 were released (2.4 +/- 0.8 mug in 5 weeks), histology showed defect bridging in the high-dose implants. Release out of the low-dose implants was not sufficient to enhance bone formation. Implant degradation was limited in all formulations, but was mainly seen in the high-dose group. Low amounts of sustained released rhBMP-2 were sufficient to bridge critically sized defects. A substantial amount of rhBMP-2 was retained in the implants because of the slow release rate and the limited degradation.     

Injectable magnetic liposomes as a novel carrier of recombinant human BMP-2 for bone formation in a rat bone-defect model

Small-sized magnetic liposomes with incorporated recombinant human bone morphogenetic protein-2 (rhBMP-2) were prepared, and the efficiency for bone formation after topical injection was evaluated in a rat bone-defect model. A critical-sized segmental bone defect was created in the mid-part of the femoral shaft, and a permanent magnet was attached. Topical injection onto the defects was performed with different liposomal preparations (nonmagnetic and magnetic liposomes) using different treatment modalities (different doses and different treatment timing of rhBMP-2). Weekly evaluations were made radiographically and microcomputed tomographically, histologically, and/or by mechanical testing at 9 weeks after surgery. A single topical application of magnetic liposomes with an appropriate amount of rhBMP-2 (approximately 3 microg) incorporated under magnetic induction immediately after surgery was effective for new bone formation. The combined treatment of topical magnetic rhBMP-2 liposomes and magnetic implantation at the injury site was effective for the treatment of bone defects. This injectable carrier for BMP is expected to have many advantages over solid carriers because it can be prepared easily and can be less invasively applied to the injured site at any time after surgery.     

Restoration of segmental bone defects in rabbit radius by biodegradable capsules containing recombinant human bone morphogenetic protein-2

Recombinant human bone morphogenetic protein-2 (rhBMP-2) was encapsulated in biodegradable poly(DL-lactide-co-glycolide) (PLGA) capsules to regenerate bone by controlling the release rate of rhBMP-2. The rhBMP-2/PLGA capsules containing 12 microg of rhBMP-2 were implanted in seven 15-mm segmental defects of rabbits radii to examine the healing capacity of the rhBMP-2/PLGA capsules. For the control group, four segmental defects were left empty and two were implanted with ghost PLGA capsules. Healing of the defects was followed for 24 weeks and periodically evaluated by radiographs and histological examination. Mechanical testing was applied to three regenerated bone samples at 24 weeks postoperatively when the mature cortex was observed. Mechanical properties of regenerated bone were not significantly different from normal intact bone statistically. Histologically, the rhBMP-2/PLGA capsules disappeared completely during the process of bone regeneration. These results increased possibilities for clinical application of rhBMP-2/PLGA capsules.     

Fibroblast Growth Factor-2 Augments Recombinant Human Bone Morphogenetic Protein-2-Induced Osteoinductive Activity

The osteoinductive activity induced by recombinant human BMP-2 (rhBMP-2) blunts proportionately as the recipient ages. In order to compensate for this bluntness administration of fibroblast growth factor-2 (FGF-2) has been considered. The aim of this study was to determine whether FGF-2 administration augments osteoinductive activity caused by rhBMP-2 and to evaluate the effect of aging on bone formation induced by coadministration of rhBMP-2 and FGF-2. Sixty-four Wistar strain male rats of 8-week-old (prepubertal) and 16-week-old (postpubertal) received bone defects bilaterally in the parietal bone and the defects were filled by a polylactic acid polyglycolic acid copolymer/gelatin sponge (PGS) impregnated with rhBMP-2 plus 0 ng, 25 ng, and 250 ng FGF-2 (n=10 in each). At 2 weeks after grafting, the new bone volume seemed to be larger in the rhBMP-2+FGF-2 groups than in the rhBMP-2 alone group. At 4 weeks, the new bone formation was linked to the adjacent original bone. In the prepubertal rats, all newly formed bone was similarly calcified. In the postpubertal rats, only the rhBMP-2+25 ng FGF-2 group showed this higher degree of calcification. At 2 weeks, alkaline phosphatase (ALP) activity in the rhBMP-2+25 ng FGF-2 group was significantly (p<0.05) larger than that in the rhBMP-2 group in both prepubertal and postpubertal rats. This result shows that low-dose administration of FGF-2 enhanced the degree of calcification and ALP activity in the rhBMP-2 grafting site especially in the postpubertal rats. Therefore, FGF-2 would be a candidate to compensate for the reduction of osteoinductive activity of rhBMP-2 with aging.     

Bone regeneration by recombinant human bone morphogenetic protein-2 and a novel biodegradable carrier in a rabbit ulnar defect model

The effects of recombinant human bone morphogenetic protein (rhBMP)-2 and a novel carrier, PLGA-coated gelatin sponge (PGS), on bone defect repair was examined. A 1.5 cm unilateral segmental bone defect was created in the ulnar diaphysis of a Japanese white rabbit. In an initial study, defects were either treated with PGS impregnated with various concentrations of rhBMP-2 (0, 0.1, 0.4 and 1 mg/cm(3)) or left untreated. Defect healing was assessed by radiographic union rate, and biomechanical properties of regenerated bones were determined at 16 weeks postoperatively. In a second study, defects were implanted with PGS with or without rhBMP-2, and histologically observed at postoperative weeks 8 and 16. Radiographic union rate increased the dose-dependently at an early time point. All defects treated with rhBMP-2 (0.4 and 1 mg/cm(3)) were radiographically repaired. Mechanical properties of regenerated bones were restored in a dose-dependent manner. Neither ulnae left untreated nor implanted PGS alone showed radiographic union. Longitudinal alignment of lamellar structure was observed histologically at 16 weeks, indicating that remodeling of regenerated bone was complete. Implanted PGS was almost completely resorbed by 8 weeks, and no abnormalities were observed in the surrounding soft tissue. These results suggest that PGS is a promising carrier for rhBMP-2.     

Healing of segmental bone defects in rats induced by a beta-TCP-MCPM cement combined with rhBMP-2.

A beta-tricalcium phosphate-monocalcium phosphate monohydrate (beta-TCP-MCPM) cement was evaluated as an effective carrier of recombinant human bone morphogenetic protein-2 (rhBMP-2) in rat femoral critical-size defects. Hard cement cylinders (4 x 5 mm) impregnated with two different doses of rhBMP-2 (1.26 or 6.28 microg) were implanted into each defect, and the results were compared with those in rats that had implantations of cylinders only. Implantation of the 6.28 microg dose of rhBMP-2 caused a large bone shell to form around the defect, resulting in osseous union in all cases within 3 weeks. Except for beta-TCP granules, the cement was resorbed and replaced by bone tissue at 6 weeks. A torsion test at 9 weeks showed that the failure torque and bone stiffness had recovered 99% and 141%, respectively, compared with the intact contralateral femur. The defects that received 1.26 microg of rhBMP-2 resulted in 40% union and 41% of the failure torque at 9 weeks. However, no instances of union were observed in the defects implanted with cylinders only. In conclusion, the beta-TCP-MCPM cement was shown to be effective as a rhBMP-2 carrier. Combined with rhBMP-2, this cement was rapidly resorbed and completely healed the defects.     

The inhibitory effect of zoledronate on early-stage osteoinduction by recombinant human bone morphogenetic protein 2 in an osteoporosis model

Abstract

This study evaluated the effect of the combined treatment of intravenous zoledronic acid (ZA, 0.08?mg/kg) and rhBMP-2 (5?µg) on osteogenesis in a calvarial defect model of ovariectomized SD rats. New bone formation was evaluated 4 or 8 weeks after calvarial defect implantation using micro-CT and histology. Micro-CT results revealed that the rhBMP-2 group showed significantly higher calvarial defect coverage ratio compared with the ZA?+?rhBMP-2 group at 4 weeks. In addition, bone formation indices were significantly lower in ZA?+?rhBMP-2 group when compared with the rhBMP-2 group after 4 weeks, which indicates a negative effect of ZA on the initial bone formation and the bone quality. At 8 weeks, the negative effect induced by ZA treatment was alleviated as time passed. Histological examination showed similar results to the micro-CT measurements. In conclusion, although ZA treatment lowered the new bone formation induced by rhBMP-2 initially, as time passed, the negative effect was decreased.     

Osteoinductivity potential of rhBMP-2 associated with two carriers in different dosages

The objective of this study was to evaluate bone formation after application of different doses of recombinant human bone morphogenetic protein-2 (rhBMP-2) combined with monoolein or poloxamer gels, in critical bone defects of rats. Forty-five Wistar rats were divided into nine treatment groups with five animals each: I: application of 1 μg rhBMP-2 + monoolein; II: 3 μg rhBMP-2 + monoolein; III: 7 μg rhBMP-2 + monoolein; IV: 1 μg rhBMP-2 + poloxamer; V: 3 μg rhBMP-2 + poloxamer; VI: 7 μg rhBMP-2 + poloxamer; VII: monoolein only; VIII: poloxamer only; and IX: critical bone defect only. A critical-sized defect of 6 mm diameter was produced in the left parietal bone and it was filled with gels of the above mentioned treatments. After 2 weeks, the calvarial bones were removed for histological processing. Bone formation in the groups that received poloxamer gel and rhBMP-2 was not significantly different from the control group (IX). Groups receiving monoolein and rhBMP-2 (1 and 3 μg) and those that received only the carriers (VII and VIII) had less bone formation in relation to the control. The association of rhBMP-2 to both poloxamer and monoolein did not exhibit any significant differentiation in bone formation in comparison with the control group.