Different mechanisms of spinal fusion using equine bone protein extract,rhBMP-2 and autograft during the process of anterior lumbar interbody fusion

To elucidate the molecular mechanisms of spinal fusion with different graft materials during an anterior lumbar interbody fusion, we examined the gene-expression profiles after implantation of equine bone protein extract, rhBMP-2 and autograft using microarray technology and data analysis, including hierarchical clustering, self-organizing maps (SOM), KEGG pathway and Biological process GO analyses in a porcine model. The results suggest that equine bone protein extract exhibited a more similar expression pattern with autograft than that of rhBMP-2. rhBMP-2 recruits progenitor cells, proliferation and differentiation possibly by inducing various factors including PGHS-2, IFGBP-2, VEGF and chemokines and then leads to preferable membranous ossification and bone remodeling. Conversely, equine bone protein extract results in endochondral ossification via upregulation of cartilage-related genes. Ossification by inducing direct osteoblastic differentiation and obviating the cartilaginous intermediate phases may increase spinal fusion rate.     

不同植骨材料在腰椎融合过程中的应用及转化生长因子β的表达

背景：骨形态发生蛋白单独应用于骨移植效果不佳。而转化生长因子β能明显增强其在体内的诱导成骨作用。 目的：观察自体骨及重组人骨形态发生蛋白2复合骨用于兔腰椎融合过程中转化生长因子β的基因表达。 方法：将新西兰大白兔60只随机分为自体骨组、复合骨组和异体骨组,分别于双侧L5-6横突间植入自体骨、重组人骨形态发生蛋白2复合骨及异体骨。植入后7,14,21,28,35 d取3组节段骨痂,应用实时荧光定量RT-PCR检测转化生长因子β的基因表达水平。 结果与结论：植入后28 d,复合骨组转化生长因子β达峰值,随后有所下降,但均高于自体骨组和异体骨组(P < 0.05)。结果证实,重组人骨形态发生蛋白2复合骨缓释重组人骨形态发生蛋白2,有效地促进了转化生长因子β的表达,明显增强了体内的诱导成骨效应。     

骨形态发生蛋白7局部基因治疗和组织工程化骨对大鼠脊柱融合的影响

目的 评价腺病毒介导的人骨形态发生蛋白7 (Ad-hBMP-7)基因转染的骨髓间充质干细胞(BMSCs)和纳米羟基磷灰石/胶原复合材料(NHAC)复合后对脊柱融合的影响. 方法 抽取大鼠骨髓获得BMSCs,应用Ad-hBMP-7转染大鼠BMSCs,将NHAC材料和密度为2×105/ml的Ad-BMP-7转染大鼠的BMSCs细胞孵育2h后备用;Wistar大鼠56只,随机分成4组,建立脊柱后外侧融合模型,分别植入自体髂骨(A组)、NHAC材料(B组)、NHAC材料和BMSCs(C组)以及Ad-hBMP-7-BMSCs与NHAC材料混合物(D组).每组行RT-PCR 及Western blotting检测,8周和12周后分别行X线摄片,并对标本进行手触检测硬度、生物力学检测和组织学观察. 结果 D组10只大鼠的脊柱L4/5节段全部融合;A组12周0例融合;B组12周0例融合;C组12周3例融合.D组同A、B、C组结果 相比均有显著性差异( P <0.001). 结论 BMP-7局部基因治疗和组织工程化骨能促进脊柱融合.     

Evaluation of an injectable silk fibroin enhanced calcium phosphate cement loaded with human recombinant bone morphogenetic protein-2 in ovine lumbar interbody fusion

The objective of this study was to investigate the efficacy of an injectable calcium phosphate cement/silk fibroin/human recombinant bone morphogenetic protein-2 composite (CPC/SF/rhBMP-2) in an ovine interbody fusion model. Twenty-four mature sheep underwent anterior lumbar interbody fusion at the levels of L1/2, L3/4, and L5/6 with random implantation of CPC/SF, CPC/rhBMP-2, CPC/SF/rhBMP-2, or autogenous iliac bone. After the sheep were sacrificed, the fusion segments were evaluated by manual palpation, CT scan, undestructive biomechanical testing, undecalcified histology, and histomorphology. The fusion rates of CPC/SF/rhBMP-2 were 55.56% and 77.78% at 6 and 12 months, respectively. The fusion was superior to all the biomaterial grafts in stiffness, and reached the same stiffness as the autograft at 12 months. The new bone formation was less than autograft at 6 months, but similar with that at 12 months. However, the ceramic residue volume of CPC/SF/rhBMP-2 was significantly decreased compared with CPC/SF and CPC/rhBMP-2 at both times. The results indicated that CPC/SF/rhBMP-2 composite had excellent osteoconduction and osteoinduction, and balanced degradation and osteogenesis.     

Reconstruction of alveolar bone defects using bone morphogenetic protein 2 mediated rabbit dental pulp stem cells seeded on nano-hydroxyapatite/collagen/poly(L-lactide)

The objective of the present study was to evaluate the capacity of a tissue-engineered bone complex of recombinant human bone morphogenetic protein 2 (rhBMP-2)-mediated dental pulp stem cells (DPSCs) and nano-hydroxyapatite/collagen/poly(L-lactide) (nHAC/PLA) to reconstruct critical-size alveolar bone defects in New Zealand rabbit. Autologous DPSCs were isolated from rabbit dental pulp tissue and expanded ex vivo to enrich DPSCs numbers, and then their attachment and differentiation capability were evaluated when cultured on the culture plate or nHAC/PLA. The alveolar bone defects were treated with nHAC/PLA, nHAC/PLA+rhBMP-2, nHAC/PLA+DPSCs, nHAC/PLA+DPSCs+rhBMP-2, and autogenous bone (AB) obtained from iliac bone or were left untreated as a control. X-ray and a polychrome sequential fluorescent labeling were performed postoperatively and the animals were sacrificed 12 weeks after operation for histological observation and histomorphometric analysis. Our results showed that DPSCs expressed STRO-1 and vementin, and favored osteogenesis and adipogenesis in conditioned media. DPSCs attached and spread well, and retained their osteogenic phenotypes on nHAC/PLA. The rhBMP-2 could significantly increase protein content, alkaline phosphatase activity/protein, osteocalcin content, and mineral formation of DPSCs cultured on nHAC/PLA. The X-ray graph, the fluorescent, histological observation, and histomorphometric analysis showed that the nHAC/PLA+DPSCs+rhBMP-2 tissue-engineered bone complex had an earlier mineralization and more bone formation inside the scaffold than nHAC/PLA, nHAC/PLA+rhBMP-2, and nHAC/PLA+DPSCs, or even autologous bone. Implanted DPSCs' contribution to new bone was detected through transfected eGFP genes. Our findings indicated that stem cells existed in adult rabbit dental pulp tissue. The rhBMP-2 promoted osteogenic capability of DPSCs as a potential cell source for periodontal bone regeneration. The nHAC/PLA could serve as a good scaffold for autologous DPSC seeding, proliferation, and differentiation. The tissue-engineered bone complex with nHAC/PLA, rhBMP-2, and autologous DPSCs might be a better alternative to autologous bone for the clinical reconstruction of periodontal bone defects.     

Nucleofection-based ex vivo nonviral gene delivery to human stem cells as a platform for tissue regeneration

There are several gene therapy approaches to tissue regeneration. Although usually efficient, virusbased approaches may elicit an immune response against the viral proteins. An alternative approach, nonviral transfer, is safer, and can be controlled and reproduced. We hypothesized that in vivo bone formation could be achieved using human mesenchymal stem cells (hMSCs) nonvirally transfected with the human bone morphogenetic protein-2 (hBMP-2) or -9 (hBMP-9) gene. Human MSCs were transfected using nucleofection, a unique electropermeabilization-based technique. Postnucleofection, cell viability was 53.6 +/- 2.5% and gene delivery efficiency was 51% to 88% (mean 68.2 +/- 4.1%), as demonstrated by flow cytometry in enhanced green fluorescent protein (EGFP)-nucleofected hMSCs. Transgene expression lasted longer than 14 days and was very low 21 days postnucleofection. Both hBMP-2- and hBMP-9-nucleofected hMSCs in culture demonstrated a significant increase in calcium deposition compared with EGFP-nucleofected hMSCs. Human BMP-2- and hBMP-9-nucleofected hMSCs transplanted in ectopic sites in NOD/SCID mice induced bone formation 4 weeks postinjection. We conclude that in vivo bone formation can be achieved by using nonvirally nucleofected hMSCs. This could lead to a breakthrough in the field of regenerative medicine, in which safer, nonviral therapeutic strategies present a very attractive alternative.     

The use of a synthetic oxygen carrier-enriched hydrogel to enhance mesenchymal stem cell-based bone formation in vivo

A major hurdle to surmount in bone-tissue engineering is ensuring a sufficient oxygen supply to newly forming tissue to avoid cell death or delayed development of osteogenic features. We hypothesized that an oxygen-enriched hydrogel scaffold would enhance tissue-engineered bone formation in vivo. To test this, we used a well-characterized mesenchymal stem cell (MSC) line, Tet-off BMP2 MSC, whose cells were engineered to express recombinant human bone morphogenetic protein-2. Cells were suspended in hydrogel supplemented with perfluorotributylamine (PFTBA) and implanted subcutaneously in an ectopic site, a radial bone defect, or a lumbar paravertebral muscle (mouse model of spinal fusion) in C3H/HeN mice. For controls, we used cells suspended in the same gel without PFTBA. In the ectopic site, there were significant increases in bone formation (2.5-fold increase), cell survival, and osteocalcin activity in the PFTBA-supplemented groups. PFTBA supplementation significantly increased structural parameters of bone in radial bone defects and triggered a significant 1.4-fold increase in bone volume in the spinal fusion model. We conclude that synthetic oxygen carrier supplementation of tissue-engineered implants enhances ectopic bone formation and yields better bone quality and volume in bone-repair and spinal fusion models, probably due to increased cell survival.     

Electroporation-mediated transfer of Runx2 and Osterix genes to enhance osteogenesis of adipose stem cells

In the present study, we tested the hypothesis that electroporation-mediated transfer of Runx2, Osterix, or both genes enhances the in vitro and in vivo osteogenesis from adipose stem cells (ASCs). ASCs were transfected with Runx2, Osterix, or both genes using electroporation, and further cultured in monolayer or in PLGA scaffold under osteogenic medium for 14 days, then analyzed for in vitro osteogenic differentiation. Transfected ASC-PLGA scaffold hybrids were also implanted on nude mice to test for in vivo ectopic bone formation. Runx2 and Osterix genes were strongly expressed in ASCs transfected with each gene on day 7, decreasing rapidly on day 14. Runx2 protein was strongly expressed in ASCs transfected with the Runx2 gene, while Osterix protein was strongly expressed in ASCs transfected with either or both Runx2 and Osterix genes. Overexpression of Runx2 and Osterix significantly increased the gene expression of osteogenic differentiation markers (alkaline phosphatase [ALP], osteocalcin [OCN], type I collagen [COL1A1], and bone sialoprotein [BSP]) in ASCs. Transfection of Runx2 and Osterix genes enhanced the protein expression of OCN, type I collagen, and BSP, as demonstrated by Western blot analysis, and ALP activity as well as enhancing mineralization in the monolayer culture and ASC-PLGA scaffold hybrids. Runx2- or Osterix-transfected ASC-PLGA scaffold hybrids promoted bone formation in nude mice after 6 weeks of in vivo implantation.     

Porous poly(lactic-co-glycolic acid) microsphere as cell culture substrate and cell transplantation vehicle for adipose tissue engineering

Tissue engineering often requires ex vivo cell expansion to obtain a large number of transplantable cells. However, the trypsinization process used to harvest ex vivo expanded cells for transplantation interrupts interactions between cultured cells and their extracellular matrices, facilitating apoptosis and consequently limiting the therapeutic efficacy of the transplanted cells. In the present study, open macroporous poly(lactic-co-glycolic acid) (PLGA) microspheres were used as a cell culture substrate to expand human adipose-derived stromal cells (ASCs) ex vivo and as a cell transplantation vehicle for adipose tissue engineering, thus avoiding the trypsinization necessary for transplantation of ex vivo expanded cells. Human ASCs cultured on macroporous PLGA microspheres in stirred suspension bioreactors expanded 3.8-fold over 7 days and differentiated into an adipogenic lineage. The apoptotic activity of ASCs cultured on microspheres was significantly lower than that of trypsinized ASCs. ASCs cultured on microspheres survived much better than trypsinized ASCs upon transplantation. The implantation of ASCs cultured on microspheres resulted in much more extensive adipose tissue formation than the implantation of ASCs cultured on plates, trypsinized, and subsequently mixed with microspheres. Ex vivo cell expansion and transplantation using this system would improve the therapeutic efficacy of cells over the current methods used for tissue engineering.     

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。     

重组人骨形态发生蛋白2-肝素-人工骨复合材料的骨诱导活性

背景：已有将重组人骨形态发生蛋白2应用于骨再生及修复的报道,但由于其在生物体内半衰期短而导致诱导骨形成的能力受到限制。 目的：制备具有较好缓释效果的重组人骨形态发生蛋白2-肝素-人工骨复合材料,并检测其缓释性能及骨诱导活性。 方法：通过高效液相色谱法检测重组人骨形态发生蛋白2-肝素复合物对于酶解的保护作用。将重组人骨形态发生蛋白2与肝素溶液混匀后复合于人工骨材料表面,ELISA方法检测其体外释药性质,茜素红染色法检测其诱导成骨细胞的能力,应用小鼠体内实验评价其异位骨诱导能力。 结果与结论：成功制备了具有良好缓释效果的重组人骨形态发生蛋白2-肝素-人工骨复合材料,具有较强的诱导骨钙蛋白及异位骨形成能力。     

人LIM矿化蛋白1基因腺病毒重组表达载体构建及在犬骨髓间充质干细胞中的表达

背景：研究表明LIM矿化蛋白1在体内和体外都可促使骨发生。 目的：应用Adeasy-1腺病毒系统构建含人LIM矿化蛋白1基因的腺病毒重组体,并感染犬骨髓间充质干细胞,检测其体外表达及诱导成骨作用。 方法：构建重组腺病毒质粒pAd-LMP-1,经人胚胎肾293细胞包装、扩增后得到复制缺陷重组腺病毒Ad-LMP-1,以最佳感染复数值体外感染犬骨髓间充质干细胞,行RT-PCR及 Western Blot检测LIM矿化蛋白1、骨形态发生蛋白7基因的表达。重组Ad-LMP-1和(或)外源性重组人骨形态发生蛋白7处理犬骨髓间充质干细胞,21 d后行矿化(钙)结节茜素红染色分析LIM矿化蛋白1基因的诱导成骨作用。 结果与结论：①将Ad-LMP-1以感染复数值100感染犬骨髓间充质干细胞可获得最佳感染效率,感染后骨髓间充质干细胞能在基因和蛋白水平表达LIM矿化蛋白1,未引起骨形态发生蛋白7基因的表达。②Ad-LMP-1或重组人骨形态发生蛋白7均不能单独促使骨髓间充质干细胞向成骨细胞转化,两者联合可促使骨髓间充质干细胞向成骨细胞转化。③实验成功构建重组腺病毒载体Ad-LMP-1,并实现其在犬骨髓间充质干细胞中表达,证实了LIM矿化蛋白1在诱导成骨作用中表现为与外源性重组人骨形态发生蛋白7的协同效应。     

人与家兔脂肪来源干细胞体外培养特性的比较***

背景：不同种属来源的脂肪来源干细胞在体外培养时特性是否存在差异目前尚未定论。 目的：观察在相同培养条件下,人与家兔脂肪来源干细胞体外培养特性的异同。 方法：体外分离人腹部取皮植皮术来源的脂肪来源干细胞、家兔背部皮下脂肪来源的脂肪来源干细胞,体外培养并传代,观察各自生长形态,取第3代脂肪来源干细胞,比较二者生长及增殖能力、表面CD分子鉴定情况及成脂、成骨分化能力。 结果与结论：人和家兔皮下脂肪均能在体外分离出“成纤维细胞样”贴壁生长呈长梭形的细胞;人脂肪来源干细胞一般6~     8 d可传代,兔脂肪来源干细胞则需要四五天传代。四唑盐结果显示兔、人脂肪来源干细胞分别在第4,6天达到生长高峰。表面标记流式鉴定二者均显示CD29+CD31-。体外分离培养的人脂肪来源干细胞和兔脂肪来源干细胞均具有干细胞的培养特性。与人脂肪来源干细胞相比,兔脂肪来源干细胞具有更强的增殖和诱导成脂能力,但诱导成骨能力较差,家兔是做脂肪移植研究实验动物不错的选择。      

Modulation of stromal cell-derived factor-1/CXC chemokine receptor 4 axis enhances rhBMP-2-induced ectopic bone formation

Enhancement of in vivo mobilization and homing of endogenous mesenchymal stem cells (MSCs) to an injury site is an innovative strategy for improvement of bone tissue engineering and repair. The present study was designed to determine whether mobilization by AMD3100 and/or local homing by delivery of stromal cell-derived factor-1 (SDF-1) enhances recombinant human bone morphogenetic protein-2 (rhBMP-2) induced ectopic bone formation in an established rat model. Rats received an injection of either saline or AMD3100 treatment 1 h before harvesting of bone marrow for in vitro colony-forming unit-fibroblasts (CFU-F) culture or the in vivo subcutaneous implantation of absorbable collagen sponges (ACSs) loaded with saline, recombinant human bone morphogenetic protein-2 (rhBMP-2), SDF-1, or the combination of SDF-1 and rhBMP-2. AMD3100 treatment resulted in a significant decrease in CFU-F number, compared with saline, which confirmed that a single systemic AMD3100 treatment rapidly mobilized MSCs from the bone marrow. At 28 and 56 days, bone formation in the explanted ACS was assessed by microcomputed tomography (μCT) and histology. At 28 days, AMD3100 and/or SDF-1 had no statistically significant effect on bone volume (BV) or bone mineral content (BMC), but histology revealed more active bone formation with treatment of AMD3100, loading of SDF-1, or the combination of both AMD3100 and SDF-1, compared with saline-treated rhBMP-2 loaded ACS. At 56 days, the addition of AMD3100 treatment, loading of SDF-1, or the combination of both resulted in a statistically significant stimulatory effect on BV and BMC, compared with the saline-treated rhBMP-2 loaded ACS. Histology of the 56-day ACS were consistent with the μCT analysis, exhibiting more mature and mineralized bone formation with AMD3100 treatment, SDF-1 loading, or the combination of both, compared with the saline-treated rhBMP-2 loaded ACS. The present study is the first that provides evidence of the efficacy of AMD3100 and SDF-1 treatment to stimulate trafficking of MSCs to an ectopic implant site, in order to ultimately enhance rhBMP-2 induced long-term bone formation.     

Bone morphogenetic protein 2 and retinoic acid accelerate in vivo bone formation, osteoclast recruitment, and bone turnover

Reconstruction of craniofacial defects presents a substantial biomedical burden, and requires complex surgery. Interestingly, children after age 2 years and adults are unable to heal large skull defects. This nonhealing paradigm provides an excellent model system for craniofacial skeletal tissueengineering strategies. Previous studies have documented the in vivo osteogenic potential of adipose-derived stromal (ADS) cells and bone marrow-derived stromal (BMS) cells. This study investigates the ability to accelerate in vivo osteogenesis on ex vivo recombinant human bone morphogenetic protein 2 (BMP-2) and retinoic acid stimulation. Mouse osteoblasts, ADS cells, and BMS cells were seeded onto apatite-coated PLGA scaffolds, stimulated with rhBMP-2 and retinoic acid ex vivo for 4 weeks, and subsequently implanted into critically sized (4 mm) calvarial defects. Samples were harvested after 2, 4, 8, and 12 weeks. Areas of complete bony bridging were noted as early as 2 weeks in vivo; however, osteoclasts were attracted to the scaffold as identified by calcitonin receptor staining and tartrate-resistant acid phosphatase activity staining. Although the optimal method of in vitro osteogenic priming for mesenchymal cells remains unknown, these results provide evidence that BMP-2 and retinoic acid stimulation of multipotent cells ex vivo can subsequently induce significant quantities of bone formation within a short time period in vivo.     

Controlled-release of rhBMP-2 carriers in the regeneration of osteonecrotic bone

Untreated osteonecrosis of the hip causes collapse of the femoral head and eventually leads to the development of premature degenerative arthritis. In order to reverse this late complication after the core decompression procedure, we studied three different types of carriers used to entrap recombinant human bone morphogenetic protein-2 (rhBMP-2) in terms of their performance in osteonecrosis regeneration and creeping substitution in Balb/C mice. The rhBMP-2 was loaded into PLGA–HAp microsphere in three different ways. We first verified the therapeutic dose in vitro using D1 and C2C12 cells. Then the individual performance of the three carrier preparations in vivo was examined by soft X-ray observation, histological analysis and immunostaining of bone tissue. In addition, the BMP-2 protein concentration activity in the serum was monitored. The results revealed that the bioactivity of rhBMP-2 released from a carrier with an ideal therapeutic dose was well maintained; this eventually helped to improve the healing and substitution of necrotic bone in vivo. These observations demonstrate that the in vivo performance of these newly developed rhBMP-2 delivery carriers correlates well with their in vitro release profiles. We concluded that sustained controlled-release of rhBMP-2 above a therapeutic dose could not only induce early callus wrapping of the necrotic bone but also produce neovascularization and substitution inside of the dead bone.     

Adipogenesis induced by human adipose tissue-derived stem cells

Adipose tissue-derived stem cells (ASCs), including preadipocytes, may play an important role in de novo adipogenesis and are expected to be a useful external source of cells for adipose tissue engineering. In this study, we examined in vivo adipogenesis up to 24 weeks after implantation, induced by human ASCs that were isolated from adipose tissues and expanded in vitro. ASCs proliferated in vitro in the presence of basic fibroblast growth factor (bFGF), and the number of cells increased by more than 1000-fold at the fourth passage. The ability to differentiate into mature adipocytes was maintained up to the third passage. We incorporated designated numbers of third-passage-expanded cells into a type I collagen scaffold and implanted them into the back of nude mice with or without controlled-release bFGF. After the implantation of 2 x 10(6) ASCs with controlled-release bFGF, the greatest cross-sectional surface area of adipose tissue in the scaffold was 1.19 mm(2) at 12 weeks and 2.14 mm(2) at 24 weeks. About 2 x 10(6) ASCs with controlled-release bFGF was the best condition for total adipogenesis. Immunohistochemical analysis with antihuman vimentin antibody showed that the area of human-origin adipose tissue was maximum in the group with 8 x 10(6) ASCs incorporated in a scaffold at both 12 and 24 weeks. The amount of human-origin adipose tissue increased in all groups with implanted ASCs from 12 to 24 weeks. Only trace of human-origin adipose tissue was observed in other groups implanted ASCs. Our results show that human ASCs not only function as progenitor cells for in vivo adipogenesis, but also induce de novo adipogenesis for long period.     

A tissue engineering solution for segmental defect regeneration in load-bearing long bones

The reconstruction of large defects (>10 mm) in humans usually relies on bone graft transplantation. Limiting factors include availability of graft material, comorbidity, and insufficient integration into the damaged bone. We compare the gold standard autograft with biodegradable composite scaffolds consisting of medical-grade polycaprolactone and tricalcium phosphate combined with autologous bone marrow-derived mesenchymal stem cells (MSCs) or recombinant human bone morphogenetic protein 7 (rhBMP-7). Critical-sized defects in sheep--a model closely resembling human bone formation and structure--were treated with autograft, rhBMP-7, or MSCs. Bridging was observed within 3 months for both the autograft and the rhBMP-7 treatment. After 12 months, biomechanical analysis and microcomputed tomography imaging showed significantly greater bone formation and superior strength for the biomaterial scaffolds loaded with rhBMP-7 compared to the autograft. Axial bone distribution was greater at the interfaces. With rhBMP-7, at 3 months, the radial bone distribution within the scaffolds was homogeneous. At 12 months, however, significantly more bone was found in the scaffold architecture, indicating bone remodeling. Scaffolds alone or with MSC inclusion did not induce levels of bone formation comparable to those of the autograft and rhBMP-7 groups. Applied clinically, this approach using rhBMP-7 could overcome autograft-associated limitations.     

重组人骨形态发生蛋白2联合自体骨行椎间植骨融合治疗胸腰椎结核

文题释义：重组人骨形态发生蛋白2：是一种利用基因重组技术在体外克隆出来的蛋白,属于骨形态发生蛋白家族中活性最强的成员,是骨形成中重要的调控因子。它能够将体内未分化的间充质干细胞定向诱导分化为骨细胞,形成新生骨和软骨,促进骨组织修复。 椎间植骨融合术：是临床上重建和保持脊柱稳定性的手术方式,它不但能够恢复脊柱的稳定性,避免因脊柱不稳带来的疼痛,而且能维持椎体和椎间孔的高度,降低神经根压迫的风险,能够起保护神经功能和保证远期疗效作用。 背景：重组人骨形态发生蛋白2(recombinant human bone morphogenetic protein-2, rhBMP-2)联合自体骨行椎间植骨融合术治疗腰椎滑脱、椎管狭窄、椎间盘突出等脊柱退行性变疾病的疗效和安全性已经得到认可,但对于治疗脊柱结核等脊柱感染性疾病的疗效和安全性少有临床研究。 目的：评价rhBMP-2联合自体骨行椎间植骨融合术对脊柱结核的临床疗效及其安全性。 方法：回顾性分析2010年11月至2018年5月广州中医药大学第一附属医院收治的胸腰椎结核患者的临床资料,所有患者均采用后路经椎弓根螺钉内固定+植骨融合术,根据植骨时是否使用rhBMP-2将其分为2组,试验组33例采用1 mg rhBMP-2联合自体骨植入大小适宜的支撑体中,对照组35例单纯用自体骨植入支撑体。术后随访1年以上,并对术前、术后疼痛目测类比评分、脊髓损伤ASIA分级、围术期并发症以及融合率进行统计学分析。研究通过广州中医药大学第一附属医院伦理委员会的批准,患者对治疗方案均知情同意。 结果与结论：①所有患者均完成1年以上的随访,随访中未发现内固定断裂移动和椎体的明显塌陷;②两组手术时间、术中出血量、住院时间、围术期并发症比例差异无显著性意义(P > 0.05);③两组术后1周和术后1年的目测类比评分、ASIA分级与术前相比,有显著改善(P < 0.05),但两组之间对比差异无显著性意义(P > 0.05);④在融合率方面,试验组术后6个月的融合率明显高于对照组(P < 0.05),然而,两组术后1年的融合率比较却无统计学差异(P > 0.05)。提示：rhBMP-2联合自体骨行植骨融合术治疗胸腰椎结核能在短期内加快骨性融合,具有良好的疗效和安全性。 ORCID: 0000-0002-3809-4431(翁汭) 中国组织工程研究杂志出版内容重点：组织构建;骨细胞;软骨细胞;细胞培养;成纤维细胞;血管内皮细胞;骨质疏松;组织工程     

骨形成蛋白介导的基因治疗研究进展

基因治疗是指通过导入基因的功能片段改善机体生理状况或者治疗疾病.利用基因治疗可在骨缺损或骨折局部释放骨形成蛋白（bone morphogenetic proteins,BMP）,并且无需异体载体,方法包括体内法和离体法.BMP基因治疗可以促进骨和软骨形成、脊柱融合、颌面骨和牙齿修复、肌腱韧带形成,此外对椎间盘退变性疾病也可采用BMP基因治疗.总之BMP基因治疗方法经济有效,是有前景的治疗手段.