Use of recombinant human bone morphogenetic protein-2 in spine surgery

Bone morphogenetic proteins are osteoinductive factors which have gained popularity in orthopaedicsurgery and especially in spine surgery. The use of recombinant human bone morphogenetic protein-2 has been officially approved by the United States Food and Drug Administration only for single level anterior lumbar interbody fusion, nevertheless it is widely used by many surgeons with off-label indications. Despite advantages in bone formation, its use still remains a controversial issue and several complications have been described by authors who oppose their wide use.

Implantation of xenogeneic bone combined with recombinant human bone morphogenetic protein-2 into bone defect—An scanning electron microscopic study

To determine the ability of a new type of composite xenogeneic bone grafting to repair bone defect. Methods: The new type of composite xenogeneic bone was obtained by combining the chemically treated cance1lous bone with recombinant human bone morphogenetic protein-2 (rhBMP-2). It was implanted on the bone defect of rabbit. Results: There was a large amount of new bone formation within the combined material and the amount was increasing as the time elapsed. In contrast, there was a lot of fibrous tissue with a little new bone formed on the area of the bone defect when the treated cancellous bone was implanted alone. Conclusion: The results imply that the rhBMP-2 plays a very important role in new bone formation and the composite xenogeneic bone appear to be an ideal material for repair of bone defect.

CORAL AS A CARRIER FOR RECOMBINANT HUMAN BONE MORPHOGENETIC PROTEIN-2

By combining coral with recombinant human bone morphogenetic protein-2 (rhBMP-2), rhBMP-2/coral composite was obtained in this study. Following implantation of the composite into the muscle pouches of mice, cartilage growth was induced in the pores or on the surface of the implants at one week, woven bone at three week and lamellar bone with bone marrow at six week, and coral was absorbed partially. The induced formation of endochondral bone was time-related and rhBMP-2 dose-related. The results of this study indicate that the composite possesses a superior ability of osteogenesis, and coral acts as one of the most suitable rhBMP-2 slowrelease carriers currently available. The composite will be a new type of bone substitute to be used in orthopaedics and maxillofacial surgery.

Heterotopic ossification after the use of recombinant human bone morphogenetic protein-7

AIM To present the incidence of heterotopic ossification after the use of recombinant human bone morphogenetic protein-7(rhB MP-7) for the treatment of nonunions.METHODS Bone morphogenetic proteins(BMPs) promote bone formation by auto-induction. Recombinant human BMP-7 in combination with bone grafts was used in 84 patients for the treatment of long bone nonunions. All patients were evaluated radiographicaly for the development of heterotopic ossification during the standard assessment for the nonunion healing. In all patients(80.9%) with radiographic signs of heterotopic ossification, a CT scan was performed. Nonunion site palpation and ROM evaluation of the adjacent jointswere also carried out. Factors related to the patient(age, gender), the nonunion(location, size, chronicity, number of previous procedures, infection, surrounding tissues condition) and the surgical procedure(graft and fixation type, amount of rhB MP-7) were correlated with the development of heterotopic ossification and statistical analysis with Pearsons χ~2 test was performed.RESULTS Eighty point nine percent of the nonunions treated with rh BMP-7, healed with no need for further procedures. Heterotopic bone formation occurred in 15 of 84 patients(17.8%) and it was apparent in the routine radiologi-cal evaluation of the nonunion site, in a mean time of 5.5 mo after the rh BMP-7 application(range 3-12). The heterotopic ossification was located at the femur in 8 cases, at the tibia in 6, and at the humerus in οne patient. In 4 patients a palpable mass was present and only in one patient, with a para-articular knee nonunion treated with rhB MP-7, the size of heterotopic ossification affected the knee range of motion. All the patients with heterotopic ossification were male. Statistical analysis proved that patient's gender was the only important factor for the development of heterotopic ossification(P = 0.007). CONCLUSION Heterotopic ossification after the use of rh BMP-7 in nonunions was common but it did not compromise the final clinical outcome in most cases, and affected only male patients.

Regulating the bioactivity of non-glycosylated recombinant human bone morphogenetic protein-2 to enhance bone regeneration

Recombinant human bone morphogenetic protein-2(rhBMP-2)is the predominant growth factor that effectively induces osteogenic differentiation in orthopedic procedures.However,the bioactivity and stability of rhBMP-2 are intrinsically associated with its sequence,structure,and storage conditions.In this study,we successfully determined the amino acid sequence and protein secondary structure model of non-glycosylated rhBMP-2 expressed by an E.coli expression system through X-ray crystal structure analysis.Furthermore,we observed that acidic storage conditions enhanced the proliferative and osteoinductive activity of rhBMP-2.Although the osteogenic activity of non-glycosylated rhBMP-2 is relatively weaker compared to glycosylated rhBMP-2;however,this discrepancy can be mitigated by incorporating exogenous chaperone molecules.Overall,such information is crucial for rationalizing the design of stabilization methods and enhancing the bioactivity of rhBMP-2,which may also be applicable to other growth factors.

Expression of mature peptide of human bone morphogenetic protein-2 in Escherichia coli

To express die mature peptide of human bone morphogenetic protein-2 in Escherichia coil. Methods: TheDNA fragment encoding the mature peptide of human bone morphogenetic protein-2 (hBMP-2m) was inserted into expression vectorpDH in which foreign gene was controlled by PRPL promoters. E. coli DH5a transformed with recombinant plasmid pDHB2m wasinduced at 42℃to express the target protein. The expressed product was partially purified and refolded, and then implanted intorat thigh muscles to assay its bone inductive activity. Results: After induction, a protein band on SDS-PAGE gel with an apparentmol. wt. of 13kD was observed to anticipate in the strain carrying pDHB2m, but not in the control. The expressed hBMP-2m accounted for 45%-60% of the total bacterial protein. The expressed product existed in a form of inclusion body. After partially purified and refolded, rhBMP-2m could induce the formation of cartilage and bone tissue heterotopically. Conclusion: The maturepeptide of human bone morphogenetic protein-2 has ben successfully expressed in E. coli and the product has ectopic bone inductive activity.

含重组人碱性成纤维细胞生长因子和重组人骨形态发生蛋白-2骨水泥在骨质疏松性腰椎压缩性骨折治疗的应用价值

目的:探讨含重组人碱性成纤维细胞生长因子(recombinant human basic fibroblast growth factor,rhbFGF)和重组人骨形态发生蛋白-2(recombinant human bone morphogenetic protein-2,rhBMP-2)骨水泥在骨质疏松性腰椎压缩性骨折(osteoporotic vertebral compression fracture,OVCF)患者经皮椎体后凸成形术(percutaneous kyphoplasty,PKP)治疗的应用价值。方法:回顾性分析2018年1月至2021年1月收治的103例行PKP手术治疗的OVCF患者,男40例,女63例;年龄61~78(65.72±3.29)岁。受伤原因:滑倒33例,跌倒42例,提重物受伤28例。根据填充骨水泥不同分为3组:磷酸钙组34例,男14例,女20例,年龄(65.1±3.3)岁,填充磷酸钙骨水泥;rhBMP-2组34例,男12例,女22例,年龄(64.8±3.2)岁,填充含rhBMP-2的骨水泥;rhbFGF+rhBMP-2组35例,男14例,女21例,年龄(65.1±3.6)岁,填充含rhbFGF和rhBMP-2的骨水泥。比较3组Oswestry功能障碍指数(Oswestry dysfunction index,ODI)、骨密度、椎体前缘丢失高度、伤椎前缘压缩率、疼痛视觉模拟评分(visual simulation score,VAS)及再骨折发生率。结果:所有患者获得12个月随访。3组术后ODI、VAS呈下降(P<0.001),骨密度增高(P<0.001),椎体前缘丢失高度、伤椎前缘压缩率呈先下降后缓慢上升趋势(P<0.001),rhbFGF+rhBMP-2组术后第1、6、12个月ODI、VAS均低于rhBMP-2组和磷酸钙组(P<0.05),术后第6、12个月骨密度大于rhBMP-2组和磷酸钙组(P<0.05)。rhbFGF+rhBMP-2组术后第6、12个月椎体前缘丢失高度、伤椎前缘压缩率均低于rhBMP-2组和磷酸钙组(P<0.05)。3组再骨折发生率比较差异无统计学意义(P>0.05)。结论:含rhbFGF和rhBMP-2骨水泥可更有效地增加OVCF患者骨密度,获得术后满意的临床和放射学效果,显著改善临床症状。

重组人骨形态发生蛋白-2用于骨壁缺损拔牙位点保存的效果

目的:评价重组人骨形态发生蛋白-2(recombinant bone morphogenetic proteinrh-2,rhBMP-2)用于骨壁缺损拔牙位点保存的临床效果。方法:2019年2月~2023年1月将符合条件的142例患者随机分组,A组使用rhBMP-2+胶原蛋白海绵填充拔牙窝,B组使用胶原蛋白海绵,C组不使用移植物。于拔牙后18周、24周开展种植手术,并编为A1、A2;B1、B2;C1、C2组,种植术中发现有牙槽嵴顶骨缺损的病例测量牙槽嵴缺损的最大近远中径(L)、颊舌径(W)及深度(H),计算体积(V)值(V=L×W×H);无牙槽骨顶骨缺损的病例取种植窝骨块进行组织学分析。结果:A1、A2组牙槽嵴顶骨缺损的发生频率分别为:0.32、0.14;B1、B2组分别为:0.75、0.43;C1、C2组分别为:0.72、0.37。A1B1组间、A2B2组间、A1C1组间及A2C2组间V值差异有统计学意义(P<0.05)。A1B1组间及A1C1组间新生骨占比差异有统计学意义(P<0.05)。结论:rhBMP-2用于骨壁缺损的拔牙位点保存可缩短成骨时间(18周),减少不良愈合的发生,为后期种植手术的开展创造更有利的骨条件。

Reconstruction of orbital defect in rabbits with composite of calcium phosphate cement and recombinant human bone morphogenetic protein-2

Background Calcium phosphate cement （CPC） is a biocompatible and osteoconductive bone substitute, and recombinant human bone morphogenetic protein-2 （rhBMP-2） has strong osteoinductibility, therefore we developed a composite bone substitute with CPC and rhBMP-2 and evaluate its reconstruction effect in rabbit orbital defect.Methods Thirty-six rabbits were randomly divided into two groups and a 5 mmx5 mmx2 mm bone defect in the infraorbital rim was induced by surgery in each orbit （72 orbits in all）. The orbital defects were treated with pure CPC or composite of CPC and rhBMP-2. The osteogenesis ability of different bone substitute was evaluated by gross observation, histological examination, histomorphometrical evaluation, compressive load-to-failure testing, and scanning electron microscope （SEM）.Results Gross observation showed that both bone substitutes were safe and effective for reconstruction of orbital defect. However, histological examination, histomorphometrical evaluation and SEM showed that CPC/rhBMP-2 group had faster speed in new bone formation and degradation of substitute material than CPC group. Compressive load-to-failure testing showed that CPC/rhBMP-2 group had stronger compressive strength than CPC group at every stage with significant difference （P ＜0.05）.Conclusion Composite of CPC/rhBMP-2 is an ideal bioactive material for repairing orbital defect, with good osteoconductibility and osteoinductibility.

The use of recombinant human bone morphogenetic protein-2 （rhBMP-2） in maxillofacial trauma

In recent years, recombinant human bone morphogenetic protein-2 （rhBMP-2） has been introduced as a therapeutic option in the treatment of several congenital and acquired craniofacial defects. Although there have been promising clinical results, the international literature still lacks complete guidelines, including limits and indications for the use of rhBMP-2. The possible indications for rhBMP-2 in patients undergoing facial trauma are discussed in this article.

Therapeutic effects of human umbilical cord-derived mesenchymal stem cells against acute tubular necrosis quantified through measures of iNOS, BMP-7 and Bcl-2

Introduction: Acute tubular necrosis (ATN) is the most prevalent cause of acute renal failure (ARF). Mesenchymal stem cell transplantation has been studied as a potential treatment for renal dysfunction due to ATN. Inducible nitric oxide synthase (iNOS), bone morphogenetic protein-7 (BMP-7) and B-cell lymphoma 2 (Bcl-2) are surrogate markers of renal tubular epithelial regeneration and subsequent recovery of renal function following ATN. Methods: Serum creatinine (Scr) and blood urea nitrogen (BUN), as well as expression of iNOS, BMP-7 and Bcl-2 in gentamycin-induced ATN rat kidneys was investigated after human umbilical cord-derived mesenchymal stem cell (HUC-MSC) transplantation. Immunohistochemical staining was performed in 3 groups of rats: gentamycin-induced ATN treated with HUC-MSC, gentamycin-induced ATN without HUC-MSC, and untreated rats not receiving any treatments. Results: HUC-MSC transplantation led to a reduction in Scr and BUN in the kidneys of rats with gentamycin-induced ATN. Expression of iNOS in the HUC-MSC treated group occurred later and the expression levels were much lower during gentamycin-induced ATN compared to rats with ATN that were not treated with HUC-MSC. The expression of BMP-7 and Bcl-2 in the MSC-transplanted group was significantly increased compared to both control groups of rats with injured and healthy renal tubules. Conclusions: HUC-MSCs induce renal protection in a rat model of gentamycin-induced ATN, which is associated with reduced iNOS expression and up-regulation of Bcl-2 and BMP-7.

负载rh-BMP2的羟基磷灰石人工骨治疗胫骨平台骨折骨缺损的临床疗效研究

目的通过与羟基磷灰石生物陶瓷人工骨对比,评估负载rh-BMP2的羟基磷灰石人工骨对胫骨平台骨折骨缺损修复的临床疗效。方法回顾性分析2014年10月至2019年9月中国人民解放军联勤保障部队第九二〇医院骨科收治的53例SchatzkerⅤ、Ⅵ型胫骨平台骨折骨缺损患者,所有患者均进行骨折切开复位内固定术并予术中植骨,其中27例患者术中予负载rh-BMP2的羟基磷灰石人工骨植骨(研究组),另26例患者予羟基磷灰石生物陶瓷人工骨植骨(对照组)。对比两组患者骨折愈合时间、膝关节HSS功能评分、Rasmussen影像学评分及术后并发症发生情况。结果所有患者获得随访,平均随访时间为(10.45±2.31)个月,所有患者最终均骨性愈合。研究组的骨折愈合时间[(13.46±3.38)周]明显短于对照组[(16.67±6.51)周](P<0.05);术后6个月时研究组HSS评分[(85.53±5.30)分]优于对照组[(80.58±6.40)分](P<0.05)。术后6个月时两组的Rasmussen影像学评分比较,差异无统计学意义(P>0.05),同时两组患者随访期间出现并发症情况比较,差异无统计学意义(P>0.05)。结论相较于羟基磷灰石人工骨治疗胫骨平台骨折骨缺损,负载rh-BMP2的羟基磷灰石人工骨植入后骨折愈合时间更短,膝关节功能恢复更佳,同时未增加并发症发生风险。其可视为一种良好的人工骨修复材料。

重组人骨形态发生蛋白-2联合股骨近端髓内钉内固定术治疗老年骨质疏松股骨粗隆间骨折的效果

目的:观察骨质疏松性粗隆间骨折术中于骨折局部植入重组人骨形态发生蛋白-2(rhBMP-2)治疗的效果。方法:选择2020年至2022年包头医学院第一附属医院创伤二科接收的144例患者,均为骨质疏松性粗隆间骨折,采用随机数字表法分为两组,每组72例。对照组给予单纯骨折复位[股骨近端髓内钉系统(PFNa)内固定术],观察组在对照组采用相同手术方式基础上联合术中局部植入rhBMP-2,通过分析两组患者随访期6个月内骨折愈合时间、骨折愈合率、疼痛数字评分(NRS评分)、髋关节功能评分(Harris评分)、死亡率、住院时间等变量数据对比观察患者术前后并发症、不良反应及治疗效果。结果:观察组骨折愈合率,髋关节功能评分均较对照组有所提升(P<0.05);观察组骨折愈合时间与对照组相比显著缩短(P<0.05);观察组并发症发生比率及死亡比率均较对照组降低(P<0.05);疼痛数字评分(NRS评分),住院时间两组之间对比无统计学意义(P>0.05)。结论:PFNa内固定术治疗骨质疏松性粗隆间骨折联合rhBMP-2经加压铰刀钉道植入术治疗效果显著,对促进患者髋关节功能恢复及减少并发症的发生具有较大意义。

重组人骨形成蛋白2诱导的骨膜细胞构建组织工程骨的实验研究

目的 通过组织工程技术方法 ,研究细胞 -材料复合体体内骨再生的能力。 方法 采用材料学自组装技术的原理 ,以 I型胶原蛋白为分子模板 ,引导钙磷盐在液相中的矿化 ,制备具有天然骨基质层状结构的羟基磷灰石 /胶原复合材料 ,并以热致分相法制备羟基磷灰石 /胶原 -聚乳酸 [hydroxyapatite/collagen- poly- (L- lactic acid) ,HAC-PL A]复合三维多孔框架 ,与重组人骨形成蛋白 2 (recombinant human bone morphogenetic protein2 ,rh BMP- 2 )诱导分化后的兔骨膜细胞构建组织工程骨 ,进行体外电镜及组织学观察。将 3月龄裸鼠 18只 ,分为 3组 ,每组 6只。A组皮下注射经 rh BMP- 2处理后的骨膜细胞悬液 ,B组植入未复合细胞的 HAC- PL A,C组植入 rh BMP- 2处理后的细胞 -材料复合体。术后 8周取材行组织学观察 ,C组与 B组及 A组进行比较。 结果 三维多孔 HAC- PL A框架材料孔隙率大于 90 % ,孔径为 5 0～ 30 0 μm。骨膜细胞经 5 0 0 ng/ml的 rh BMP- 2处理后 ,与改善亲水性后的 HAC- PL A三维多孔框架复合 ,构建组织工程骨。电镜显示接种的细胞能在此组织工程骨内部生长增殖 ,术后 8周 C组有新骨形成 ,A组注射部位表面平整 ,无新生物 ,B组为纤维组织 ,无骨及软骨形成。 结论 所构建的组织工程骨有望成?

复合基因重组人骨形成蛋白-2异种骨的研制及成骨活性研究

目的 研制新型具有诱导成骨活性的异种骨植骨材料。方法 在重组合异种骨 (RBX)基础上 ,以基因重组人骨形成蛋白 - 2 (rh BMP- 2 )取代从牛皮质骨中提取的牛 BMP,与去抗原牛松质骨载体 (BCB)复合 ,制成复合 rh BMP- 2的异种骨 (rh BMP- 2 / BCB) ;将 4周龄雄性 BAL B/ C小鼠 6 0只 ,随机分为实验组和对照组 ,于实验组小鼠左股部肌袋植入 rh BMP- 2 / BCB骨粒 ,对照组小鼠左股部肌袋植入 BCB骨粒 ,术后 7、14及 2 1天取材 ,通过组织学、骨计量学方法检测 rh BMP- 2 / BCB的诱导成骨活性。结果 1实验组术后 7天在小鼠肌袋可诱导软骨生成 ,14天形成编织骨 ,2 1天改建成板层骨并形成大量骨髓 ;对照组于术后各时间点均未见有软骨及骨形成。 2实验组的碱性磷酸酶活性和钙含量均高于对照组 ,具有统计学意义 (P<0 .0 1)。结论 rh BMP- 2 / BCB具有较好的骨诱导能力 。

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复合重组人骨形成蛋白 - 2 (rh BMP- 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 rh BMP- 2的 3种钙磷陶瓷材料 (1∶ 1)植于鼠背部肌袋内 ,未复合 rh BMP- 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 (AL P)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 AL P活性测定从高到低依次为 HA、HA/ TCP、TCP,但在相同 rh BMP- 2剂量下 ,其差异无统计学意义 (P>0 .0 5 ) ,与相对应单纯支架材料比较有统计学意义 (P<0 .0 5 ) ;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/ rh BMP- 2成骨量较多 ,但 3组间差异无统计学意义(P>0 .0 5 ) ;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 .0 5 ) ,成骨量 8周较 2、4周多 ,有统计学意义 (P<0 .0 1) ;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 rh BMP- 2的钙磷陶瓷良好支架材料。

重组人骨形成蛋白-2/珊瑚复合人工骨的研制及其诱导成骨的实验研究

目的：制备珊瑚（ｃｏｒａｌ）与重组人骨形成蛋白－２（ｒｈＢＭＰ－２）复合人工骨并测试其骨诱导活性。方法：将ｒｈＢＭＰ－２与珊瑚复合后植入鼠肌袋内。６６只小鼠随机分为３组：第１组为复合骨（１∶２０ｗ／ｗ）；第２组为复合骨（１∶４０ｗ／ｗ）；第３组为单独珊瑚。术后１、３、６周处死动物，光镜下观察，并用图象分析法作成骨定量测定，结果：术后１周，可见复合材料表面及孔洞内有软骨形成。３周出现编织骨。６周形成含骨髓的板层骨。珊瑚被部分吸收。诱导成骨的量有时间依赖性和ｒｈＢＭＰ－２剂量依赖性。结论：ｒｈＢＭＰ－２／ｃｏｒａｌ复合人工骨具有良好的诱导成骨能力；珊瑚可能是目前能使用的ｒｈＢＭＰ－２最合适的缓释载体。

重组人骨形成蛋白-2-珊瑚复合人工骨修复骨缺损的生物力学研究

将珊瑚与具有骨诱导特性的重组人骨形成蛋白－２（ｒｈＢＭＰ－２）复合，制成ｒｈＢＭＰ－２－ｃｏｒａｌ复合人工骨，将其植入兔颅骨标准大小缺损，并与单纯珊瑚植入作对照。通过Ｘ线片、组织学和生物力学方法来评价此复合人工骨的骨修复能力。结果显示：ｒｈＢＭＰ－２－ｃｏｒａｌ复合人工骨具有较强的骨修复作用，植入骨缺损后，材料被逐渐降解吸收，新骨不断形成，机械强度不断增大；１２周后，植入物完全被成熟的骨组织取代，缺损区抗压强度接近正常的骨组织。该复合人工骨是一种较理想的骨移植替代材料。

携载rhBMP-2微球的新型可注射自凝固复合人工骨的制备及特性研究

[目的]制备一种具有良好降解性和成骨活性、可注射的自凝固新型骨修复材料。[方法]制备携载rh-BMP-2的聚乳酸与聚乙醇酸共聚物(PLGA)微球,并将其与rhBMP-2/磷酸钙骨水泥(CPC)复合,制备出rhBMP-2/PLGA微球/CPC复合人工骨。探讨了材料的特性,包括形貌、固化时间、抗压强度及反映材料体外降解速度的指标—体外降解液Ca、P浓度变化,测定复合材料rhBMP-2的释药速度及体外诱导MSCs细胞成骨分化的能力。[结果]与单纯CPC-rhBMP-2相比,复合材料的固化时间少量增加,抗压强度下降明显。体外降解速度及体外释药明显提高,释放的rhBMP-2具有骨诱导活性。[结论]rhBMP-2/PLGA微球/磷酸钙骨水泥新型复合人工骨是具有良好应用前景的骨修复材料。