增强型生物活性玻璃-胶原复合支架材料的成骨效能研究

Objective To study the in vivo and vitro biocompatibility and osteogenetic capacity of enhanced bioactive glass/collagen composite scaffold. Methods Bone marrow stromal cells(BMSCs)were collected and induced to osteoblast-like cells.The growth rate of BMSCs was detected and compared progressively through Alamar Blue.The RNAs of the cells were collected and detected for bone morphogenetic protein-2(BMP-2),alkaline phosphatase(ALP),collagen Ⅰ(Col-Ⅰ)through qRT-PCR on the fourth and seventh days.Scaffolds with induced osteoblasts were embedded into 3 nude mice subcutaneously in vivo and detected after 6 weeks.X-ray,qRT-PCR and tissue staining were used to detect the mRNA expressions of BMP-2,Col Ⅰ,osteocalcin(OCN)and ostcopontin(OPN)and bone formation. Results SEM(scanning electronic microscopy)showed BMSCs attached to the scaffold tightly and viably and proliferated actively on the scaffold.The growth rate in the experimental group was significantly higher after 7 days(P<0.05)than in the control group.qRT-PCR showed that the mRNA expressions of BMP-2,ALP and Col-Ⅰ in the experimental group were significantly higher than in the control group on the seventh day(P<0.05).X-ray showed that the dense images of embedded scaffolds were locally similar to those of normal bone after 6 weeks.qRT-PCR showed that the mRNA expressions of BMP-2,Col Ⅰ,OCN and OPN in the experimental group were significantly higher than those of normal bone(P<0.05).HE and Massort staining of the paraffin sections showed the scaffolds degraded generally and osteoblasts and chondrocytes proliferated abundantly and distributed irregularly.Bone formation could be observed obviously. Conclusion Enhanced bioactive glass/collagen composite scaffolds have good biocompatibility and osteogenetic capacity in vitro and vivo.     

软骨细胞与骨髓基质细胞共培养体外构建软骨组织的实验研究

Objective To investigate the feasibility of chondrogenesis in vitro with bone marrow stromal cells (BMSCs) induced by the co-cultured chondrocytes. Methods The BMSCs and chondrocytes were separated from pig and cultured. The supernatant of chondrocytes was used as the inducing solution for BMSCs from the 2nd generation. 7 days later, samples were taken and underwent immunohistochemistry and RT-PCR for detection of the expression of specific type Ⅱ cartilage collagen,type Ⅱ collagen and aggrecan mRNA. The cultured BMSCs and chondrocytes were mixed at a ratio of 8:2(BMSC: cartilage cell) and were inoculated into a polyglycolic acid/polylactic acid (PGA/PLA) scaffold at the final concentration of 5.0 × 107/ml. The cartilage cells and BMSCs were also inoculated seperately at the same concentration as the positive and negative control. Pure cartilage cells at 20% of the abovementioned concentration (1.0 × 107/ml) were used as the low concentration cartilage cell control group. Samples were collected 8 weeks later. General observations, wet weight, glycosaminoglycans (GAGs) determination and histological and immunohistochemistry examinations were performed. Results The expression of type Ⅱ collagen, type Ⅱ collagen and aggrecan mRNA were positive in induced BMSCs.In the co-cultured group and the positive control group, pure mature cartilage was formed after 8 weeks of culture in vitro, and the size and shape of the scaffold were maintained. The newly formed cartilage in the two groups were almost the same in appearance and histological properties. The immunohistochemistry results indicated that the cartilage cells of the two groups all expressed ample cartilage-specific type Ⅱ collagen. The average wet weight and GAG content in the co-cultured group reached more than 70% of those in positive control group. Only an extremely small amount of immature cartilage tissues was formed in local regions in pure BMSC group, and the scaffold was obviously shrunk and deformed. Although the wet weight of newly generated cartilage tissue in the low concentration cartilage cell group reached 30% of that in positive control group, the scaffold was obviously shrunken and deformed. Only regional and discontinuous cartilage tissues were formed, and the amount of newly formed cartilage was obviously less than that in the co-culture group and the positive control group. Conclusions Chondrocytes can provide a micro-environment for the formation of cartilage, and also effectively induce BMSC to differentiate into chondrocytes and form tissue-engineered cartilage in vitro.     

软骨细胞与骨髓基质细胞共培养体外构建软骨组织的实验研究

Objective To investigate the feasibility of chondrogenesis in vitro with bone marrow stromal cells (BMSCs) induced by the co-cultured chondrocytes. Methods The BMSCs and chondrocytes were separated from pig and cultured. The supernatant of chondrocytes was used as the inducing solution for BMSCs from the 2nd generation. 7 days later, samples were taken and underwent immunohistochemistry and RT-PCR for detection of the expression of specific type Ⅱ cartilage collagen,type Ⅱ collagen and aggrecan mRNA. The cultured BMSCs and chondrocytes were mixed at a ratio of 8:2(BMSC: cartilage cell) and were inoculated into a polyglycolic acid/polylactic acid (PGA/PLA) scaffold at the final concentration of 5.0 × 107/ml. The cartilage cells and BMSCs were also inoculated seperately at the same concentration as the positive and negative control. Pure cartilage cells at 20% of the abovementioned concentration (1.0 × 107/ml) were used as the low concentration cartilage cell control group. Samples were collected 8 weeks later. General observations, wet weight, glycosaminoglycans (GAGs) determination and histological and immunohistochemistry examinations were performed. Results The expression of type Ⅱ collagen, type Ⅱ collagen and aggrecan mRNA were positive in induced BMSCs.In the co-cultured group and the positive control group, pure mature cartilage was formed after 8 weeks of culture in vitro, and the size and shape of the scaffold were maintained. The newly formed cartilage in the two groups were almost the same in appearance and histological properties. The immunohistochemistry results indicated that the cartilage cells of the two groups all expressed ample cartilage-specific type Ⅱ collagen. The average wet weight and GAG content in the co-cultured group reached more than 70% of those in positive control group. Only an extremely small amount of immature cartilage tissues was formed in local regions in pure BMSC group, and the scaffold was obviously shrunk and deformed. Although the wet weight of newly generated cartilage tissue in the low concentration cartilage cell group reached 30% of that in positive control group, the scaffold was obviously shrunken and deformed. Only regional and discontinuous cartilage tissues were formed, and the amount of newly formed cartilage was obviously less than that in the co-culture group and the positive control group. Conclusions Chondrocytes can provide a micro-environment for the formation of cartilage, and also effectively induce BMSC to differentiate into chondrocytes and form tissue-engineered cartilage in vitro.     

可控微结构电子束熔化成形钛合金支架作为成骨细胞载体修复兔骨缺损的研究

Objective To evaluate effects of titanium alloy scaffolds with controlled internal architecture as an osteoblast carrier on bone response in models of rabbit defects. Methods Electron beam melting process was utilized to fabricate porous titanium alloy scaffolds with fully interconnected and controlled internal pore architecture. After osteoblasts were seeded on the scaffolds and cultured for up to 7 days, the growth of rabbit osteoblasts on the scaffolds was observed by scanning electron microscopy. The experiment was conducted in 4 groups to evaluate the bone formation in vivo: group A (cell/scaffold composite), group B (scaffold only), group C (left empty) and group D (autogenous bone implant) . The scaffolds were transplanted into the rabbit defects after cultured in vitro for 7 days. The animals were sacrificed at 4, 8, and 12 weeks after implantation. Bone formation in the scaffolds was investigated by gross observation, histology and histomorphometry of non-decalcified sections and fluorochrome markers. Results Confluent cell layers could be observed on the scaffold surface and in the internal pores after 7 days of incubation in vitro. New bone growth and revascularization could be observed not only at the margins of the scaffolds, but also inside the central pores of the scaffolds after 12 weeks. New bone formed along the controlled internal channels of the scaffolds. The scaffolds were filled fully with the new bone tissue and blood vessels. More extensive new bone formation was found to originate from the host bone towards the implant in group A than in group B (P ＜0. 05) . Conclusions The controlled scaffolds are well biocompatible enough to accelerate healing of rabbit defects and new bone formation. The controlled honeycomb-like architecture may guide and promote the formation of mineralized tissue.     

可控微结构电子束熔化成形钛合金支架作为成骨细胞载体修复兔骨缺损的研究

Objective To evaluate effects of titanium alloy scaffolds with controlled internal architecture as an osteoblast carrier on bone response in models of rabbit defects. Methods Electron beam melting process was utilized to fabricate porous titanium alloy scaffolds with fully interconnected and controlled internal pore architecture. After osteoblasts were seeded on the scaffolds and cultured for up to 7 days, the growth of rabbit osteoblasts on the scaffolds was observed by scanning electron microscopy. The experiment was conducted in 4 groups to evaluate the bone formation in vivo: group A (cell/scaffold composite), group B (scaffold only), group C (left empty) and group D (autogenous bone implant) . The scaffolds were transplanted into the rabbit defects after cultured in vitro for 7 days. The animals were sacrificed at 4, 8, and 12 weeks after implantation. Bone formation in the scaffolds was investigated by gross observation, histology and histomorphometry of non-decalcified sections and fluorochrome markers. Results Confluent cell layers could be observed on the scaffold surface and in the internal pores after 7 days of incubation in vitro. New bone growth and revascularization could be observed not only at the margins of the scaffolds, but also inside the central pores of the scaffolds after 12 weeks. New bone formed along the controlled internal channels of the scaffolds. The scaffolds were filled fully with the new bone tissue and blood vessels. More extensive new bone formation was found to originate from the host bone towards the implant in group A than in group B (P ＜0. 05) . Conclusions The controlled scaffolds are well biocompatible enough to accelerate healing of rabbit defects and new bone formation. The controlled honeycomb-like architecture may guide and promote the formation of mineralized tissue.     

以软骨细胞外基质与脱细胞骨基质构建组织工程骨软骨双层支架及其性能的研究

目的 探讨采用软骨细胞外基质(CECM)与脱细胞骨基质(ACBM)为材料制作新型组织工程骨软骨双层支架的可行性,并检测其性能.方法 双层支架的骨部分以犬松质骨制备的ACBM为原料,软骨部分以人CECM为材料,采用冷冻冻干法制备CECM/ACBM双层支架并交联.测定支架孔隙率,采用四甲基偶氮唑盐(MTT)法分析支架浸提液毒性.分离培养犬骨髓基质干细胞(BMSCs),成软骨诱导后种植到支架上,倒置显微镜、电镜、Dead/Live荧光染色观察细胞在支架的生长、分化情况.结果 扫描电镜及Micro-CT观察显示支架内孔洞相互贯通呈海绵状,CECM部分孔径(155±34)μm,孔隙率为91.3%±2.0%;ACBM部分具有大然骨的孔径和空隙率,骨软骨部分结合良好.培养1～6 d不同浓度支架浸提液与对照培养液吸光度值比较羌异均无统计学意义(P＞0.05).倒置显微镜、电镜检查结果表明BMSCs在支架上黏附良好,细胞基质分泌增加,Dead/Live荧光染色表明双层支架内细胞均呈绿色.结论 CECM/ACBM骨软骨双层支架具备良好的孔径和孔隙率,骨、软骨两层间结合良好,无毒,生物相容性良好,可作为支架载体用于组织工程骨软骨复合体的构建.

Abstract：

Objective To fabricate a novel bilayered scaffold constructed with cartilage extracellular matrix (CECM) and acellular bone matrix (ACBM) for osteochondral tissue engineering.Methods The bone layer of the osteochondral scaffold was prepared using canine bone cancellous bone columns, and the cartilage layer was fabricated using CECM.After CECM microfilaments were decellularized, the biphasic scaffolds were fabricated by soaking the ACBM columns into cylindrical silicon moulds with a 30 g/L CECM suspension using simple freeze-drying method.After the scaffolds were cross-linked, the porosity was measureed.MTT test was also done to assess cytotoxicity of the scaffolds.Canine bone marrow-derived mesenchymal stem cells (BMSCs) were induced by chondrogenic medium and seeded into novel scaffold.Cell proliferation and differentiation were analyzed using inverted microscopy, scanning electron microscopy (SEM)and Dead/Live staining method.Results SEM and Micro-CT revealed a 3-D interconnected porous structure, with the CECM pore diameter of 155 ± 34 μm and the porosity of 91.3% ± 2.0%.Cytotoxicity testing with MTT revealed no significant difference in absorbance among different extracts, showing no cytotoxic effect of the scaffold on BMSCs.Inverted microscopy and SEM showed that the novel scaffold could provide a suitable 3-D environment to support the adhesion, proliferation and differentiation of BMSCs to chondroeytes in culture with chondrogenic medium.Confocal microscopy of cell-scaffold constructs revealed cells with green fluorescence.Conclusion Since the novel CECM/ACBM bilayered integrated osteochondral scaffold has good mircostructure, non-toxicity and good biocompatibility, it may be a suitable candidate as an alternative cell-carrier for osteochondral tissue engineering.     

软骨细胞与骨髓基质细胞共培养体外构建软骨组织的实验研究

目的 探讨利用软骨细胞提供的软骨微环境诱导骨髓基质细胞(BMSC)在体外构建软骨组织的可行性.方法 将分离出的猪骨髓基质细胞和软骨细胞进行体外培养,收集软骨细胞培养上清液,作为骨髓基质细胞诱导液从第2代开始进行诱导分化.7 d后取出标本,免疫组织化学检测软骨特异性Ⅱ型胶原表达,RT-PCR检测Ⅱ型胶原和aggrecan的mRNA表达.体外分离培养的骨髓基质细胞与软骨细胞,扩增后两者以8∶2比例混匀,以5.0×107/ml的终浓度接种于聚羟基乙酸/聚乳酸(PGA/PLA)支架,以相同浓度的单纯软骨细胞和单纯BMSC以及20%上述浓度(1.0×107/ml)的单纯软骨细胞作为对照组.标本于8周后取材,行大体观察、湿重、蛋白多糖(GAGs)含量测定、组织学及免疫组化等相关检测.结果 经诱导后的骨髓基质细胞的Ⅱ型胶原免疫组化检测阳性,RT-PCR检测Ⅱ型胶原和aggrecan mRNA呈阳性表达.混合细胞组及阳性对照组体外培养8周后形成了单一成熟的软骨组织,并保持了支架材料的大小和形状,两组新生软骨在外观及组织学特征上也基本相同,免疫组化结果 表明两组均大量表达软骨特异性细胞外基质Ⅱ型胶原,共培养组的平均湿重和蛋白多糖(GAGs)含量均达到阳性对照组的70%以上.而单纯骨髓基质细胞组仅在局部形成了极少量幼稚的软骨样组织,且材料支架明显皱缩变形.低软骨细胞浓度组虽新生软骨湿重量能达阳性对照组的30%,但材料支架明显皱缩变形,仅在局部形成了不连续的软骨组织,新生软骨量明显少于共培养各组及阳性对照组.结论 软骨细胞能在一定程度上提供软骨形成的微环境,有效地诱导BMSC向软骨细胞分化,并在体外形成组织工程化的软骨组织.

Abstract：

Objective To investigate the feasibility of chondrogenesis in vitro with bone marrow stromal cells (BMSCs) induced by the co-cultured chondrocytes. Methods The BMSCs and chondrocytes were separated from pig and cultured. The supernatant of chondrocytes was used as the inducing solution for BMSCs from the 2nd generation. 7 days later, samples were taken and underwent immunohistochemistry and RT-PCR for detection of the expression of specific type Ⅱ cartilage collagen,type Ⅱ collagen and aggrecan mRNA. The cultured BMSCs and chondrocytes were mixed at a ratio of 8:2(BMSC: cartilage cell) and were inoculated into a polyglycolic acid/polylactic acid (PGA/PLA) scaffold at the final concentration of 5.0 × 107/ml. The cartilage cells and BMSCs were also inoculated seperately at the same concentration as the positive and negative control. Pure cartilage cells at 20% of the abovementioned concentration (1.0 × 107/ml) were used as the low concentration cartilage cell control group. Samples were collected 8 weeks later. General observations, wet weight, glycosaminoglycans (GAGs) determination and histological and immunohistochemistry examinations were performed. Results The expression of type Ⅱ collagen, type Ⅱ collagen and aggrecan mRNA were positive in induced BMSCs.In the co-cultured group and the positive control group, pure mature cartilage was formed after 8 weeks of culture in vitro, and the size and shape of the scaffold were maintained. The newly formed cartilage in the two groups were almost the same in appearance and histological properties. The immunohistochemistry results indicated that the cartilage cells of the two groups all expressed ample cartilage-specific type Ⅱ collagen. The average wet weight and GAG content in the co-cultured group reached more than 70% of those in positive control group. Only an extremely small amount of immature cartilage tissues was formed in local regions in pure BMSC group, and the scaffold was obviously shrunk and deformed. Although the wet weight of newly generated cartilage tissue in the low concentration cartilage cell group reached 30% of that in positive control group, the scaffold was obviously shrunken and deformed. Only regional and discontinuous cartilage tissues were formed, and the amount of newly formed cartilage was obviously less than that in the co-culture group and the positive control group. Conclusions Chondrocytes can provide a micro-environment for the formation of cartilage, and also effectively induce BMSC to differentiate into chondrocytes and form tissue-engineered cartilage in vitro.     

组织工程骨-软骨复合体修复犬股骨头负重区大面积骨软骨缺损的实验研究

目的 探讨采用犬股骨头负重区骨和天然软骨制备的骨-软骨双层支架复合成软骨诱导的骨髓间质干细胞(bone marrow mesenchymal stem cells,BMSCs)修复犬股骨头负重区大面积骨软骨缺损的疗效.方法 利用软骨细胞外基质作为软骨支架部分,犬股骨头负重区骨柱经脱细胞处理后作为骨支架部分,采用相分离技术制备骨-软骨双层支架.将成软骨诱导的BMSCs种植到双层支架上体外构建组织工程骨-软骨复合体,并以此修复犬股骨头负重区大面积骨软骨缺损(直径11 mm,高10 mm),第3、6个月时分别取材,行大体、X线片、组织学、Micro-CT和生物力学等检测.结果 X线片及大体观察:3个月时可见股骨头负重区出现轻度塌陷;6个月时出现严重塌陷,呈重度骨关节炎改变.组织学观察:第3、6个月时软骨缺损部分均以纤维组织或纤维软骨充填,周围软骨退变,骨缺损部分不同程度塌陷,与宿主骨质结合紧密.第3、6个月时骨软骨缺损的骨体积分数均低于正常股骨头,差异有统计学意义.6个月时重建软骨下骨的刚度明显低于正常股骨头,差异有统计学意义.结论 结构性骨-软骨双层支架复合成软骨诱导的BMSCs修复犬股骨头负重区骨软骨缺损效果不佳,易导致股骨头塌陷.

Abstract：

Objective To investigate the effects of the novel scaffold on repairing large,high-loadbearing osteochondral defects of femoral head in a canine model.Methods The biphasic scaffolds were fabricated using cartilage extracellular matrix (ECM)-derived scaffold (cartilage layer) and acellular bone matrix (bone layer) by phase separation technique.Articular high-load-bearing osteochondral defects with a diameter of 11-mm and the depth of 10-mm were created in femoral heads.The defects were treated with constructs of a biphasic scaffold seeded with chondrogenically induced bone marrow-derived mesenehymal stem cells (BMSCs).The outcomes were evaluated for gross morphology,histological,biomechanical and micro-CT analysis at the third and sixth month after implantation.Results The gross and X-ray results showed femoral head slightly collapsed at the third month and severely collapse at the sixth month.Histological analysis showed cartilage defects were repaired with fibrous tissue or fibrocartilage with severe osteoarthritis and the varied degrees of the collapse of femoral heads were presented.Micro-CT showed that the values of bone volume fraction in defect area were always lower than those of the normal area in the femoral heads.Biomechanical analysis showed rigidity of the subchondral bone in defect area was significantly lower than that in normal area in the femoral heads at the sixth month.Conclusion The ECM-derived,integrated biphasic scaffold seeded with chondrogenically induced BMSCs could not successfully repair the large high-load-bearing osteochondral defects of the femoral head.     

软骨细胞外基质源性取向支架与骨髓基质干细胞体外软骨组织工程的初步研究

Objective To fabricate cartilage extracellular matrix (ECM) oriented scaffolds and investigate the attachment, proliferation, distribution and orientation of bone marrow mesenchymal stem cells (BMSCs) cultured within the scaffolds in vitro. Methods Cartilage slices were shattered in sterile phosphate-buffered saline (PBS) and the suspension were differentially centrifugated untill the micro- fiber of the cartilage extracellular matrix was disassociated from the residue cartilage fragments. At last the supernatant were centrifugated, the precipitation were collected and were made into 2%-3% suspension. Using unidirectional solidification as a freezing process and freeze-dried method, the cartilage extracellular matrix derived oriented scaffolds was fabricated. The scaffolds were then cross-linked by exposure to ultraviolet radiation and immersion in a carbodiimide solution. By light microscope and scan electron microscope (SEM) observation, histological staining, and biomechanical test, the traits of scaffolds were studied. After being labelled with PKH26 fluorescent dye, rabbit BMSCs were seeded onto the scaffolds. The attachment, proliferation and differentiation of the cells were analyzed using inverted fluorescent microscope. Results The histological staining showed that toluidine blue, safranin O, alcian blue and anti-collagen Ⅱ immunohistochemistry staining of the scaffolds were positive. A perpendicular pore-channel structures which has a diameter of 100 μm were verified by light microscope and SEM analysis. The cell-free scaffolds showed the compression moduli were (2.02±0.02) MPa in the mechanical testing. Inverted fluorescent microscope showed that most of the cells attached to the scaffold. Cells were found to be widely distributed within the scaffold, which acted as a columnar arrangement. The formation of a surface cells layer was found on the surface of the scaffolds which resembled natural cartilage. Coclusion The cartilage extracellular matrix derived oriented scaffolds have promising biological, structural, and mechanical properties.     

灌注培养对骨髓基质干细胞在大段材料上增殖与分布的影响

Objective To study the role of perfusion bioreactor in proliferation and distribution of rat bone marrow stromal cells (BMSCs) in a large-scale scaffold. Methods SD rat BMSCs transfected with enhanced green fluorescent protein (eGFP) (eGFP-BMSCs) were planted in large-scale porous β-tricalcium phosphate (β-TCP) scaffolds. In the dynamic perfusion culture group, the scaffold with eGFP-BMSCs was continuously cultured in our self-designed three-dimensional perfusion bioreactor for 7, 14 and 28 days. In the static culture group, the scaffold was put into a medium reservoir without perfusion for 7, 14 and 28 days.Proliferation and distribution of the cells in the scaffold were examined by scanning electronic microscopy (SEM), fluorescence microscopy (FM), measuring daily glucose consumption, and counting eGFP-BMSCs in each layer. Results SEM and FM showed that eGFP-BMSCs distributed and proliferated throughout the scaffold in dynamic perfusion culture, but distributed and proliferated only in the peripheral pores of the scaffold in static culture. The daily glucose consumption in both groups increased with time. Cell proliferation reached the plateau phase after culture for 14 days in the static culture group, but after culture for 21 days in the perfusion culture group. The rate and margin of increase were much more evident in the perfusion culture group. On day 28, glucose consumption in the perfusion culture group was 36. 33 ± 3. 14 mg/d, 3. 7 times as large as that in the static culture group (9. 82 ± 1. 33 mg/d). The eGFP-BMSCs counting revealed there were no significant differences in cell number between layers of the scaffold on days 7 and 28 d ( P > 0. 05), but there were significant differences on day 14 in the perfusion culture group ( P < 0. 05); while in the static culture group, there were significant differences in cell number between layers of the scaffold ( P < 0. 05),with most of the cells assembled at the bottom of the scaffold.Conclusion Our self-designed three-dimensional perfusion bioreactor may help eGFP-BMSCs proliferate and distribute uniformly in a large-scale porous scaffold.     

白茅苷对去卵巢大鼠骨髓间充质干细胞功能和骨量的影响

目的观察白茅苷治疗去卵巢大鼠骨髓间充质干细胞功能和骨量的影响并初步探索可能机制。方法通过双侧去卵巢建立骨质疏松大鼠模型;随后随机分为假手术组(Sham)、去卵巢组(OVX)以及白茅苷组(BMG),每组10只;其中BMG组去卵巢大鼠每天给予白茅苷(20 mg/kg)灌胃治疗;待12周治疗结束后分离培养各组大鼠骨髓间充质干细胞(BMSCs),使用碱性磷酸酶(ALP)和茜素红(ARS)染色并使用蛋白质印迹检测BMP-2、Runx2、OPN、OCN、ALP和Col1蛋白表达;进一步使用Micro-CT和骨生物力学检测观察治疗效果。结果 OVX组大鼠BMSCs向成骨细胞分化后ALP和ARS染色阳性面积以及BMP-2、Runx2、OPN、OCN、ALP和Col1表达较Sham组明显降低(P0.05);而经过BMG治疗,BMG组大鼠BMSCs向成骨细胞分化后ALP和ARS染色阳性面积以及BMP-2、Runx2、OPN、OCN、ALP和Col1表达较OVX组明显增加(P0.05)。OVX组股骨最大载荷和弹性模量、BMD、BV/TV、Tb.N和Tb.Th较Sham组明显降低,而Tb.Sp则明显升高(P0.05)。BMG组左侧股骨最大载荷和弹性模量、BMD、BV/TV、Tb.N和Tb.Th均明显高于OVX组(P0.05),而Tb.Sp明显低于OVX组(P0.05)。结论白茅苷通过促进BMSCs诱导成骨分化来减少去卵巢大鼠骨骨密度、骨量和骨强度下降。     

骨形态发生蛋白2和富血小板血浆凝胶对兔骨髓间充质干细胞体外成软骨分化的影响

目的观察富血小板血浆(PRP)凝胶及腺病毒介导的骨形态发生蛋白2(BMP-2)基因转染对兔骨髓间充质干细胞(BMSCs)体外成软骨分化的影响。方法取新西兰大白兔骨髓培养BMSCs,抽取静脉血制备PRP,以Ad-GFP-hBMP-2(BMP-2-BMSCs组)及Ad-GFP(对照组)转染的BMSCs分别与PRP凝胶复合,继续培养。用扫描电镜、MTT检测PRP凝胶的生物相容性,RT-PCR检测各组的Ⅰ型胶原、Ⅱ型胶原、Ⅹ型胶原、蛋白聚糖、SOX-9表达。结果扫描电镜及MTT检测证实PRP凝胶具有良好的生物相容性。RT-PCR分析表明,单层培养的BMP-2-BMSCs组的Ⅱ型胶原、蛋白聚糖和SOX-9的表达水平均高于对照组(P0.05),但Ⅰ型胶原表达水平较对照组明显下降(P0.05),同时Ⅹ型胶原表达水平与对照组相比差异无统计学意义(P0.05);与PRP复合后,BMP-2-BMSCs组的Ⅱ型胶原、蛋白聚糖和SOX-9表达水平较对照组升高(P0.05),而Ⅰ型胶原和Ⅹ型胶原表达水平与对照组比较差异无统计学意义(P0.05)。结论转染BMP-2的BMSCs在PRP凝胶中生长良好,BMP-2基因转染能促进BMSCs的体外成软骨分化。     

骨形态发生蛋白-2活性多肽修饰的重组胶原矿化骨对骨髓基质干细胞生物学行为的影响

目的 探讨骨形态发生蛋白-2(BMP-2)活件多肽修饰的重组胶原矿化骨复合材料对骨髓基质干细胞(BMSCs)增殖、黏附及分化等生物学行为的影响. 方法制备重组胶原矿化骨支架材料,将BMP-2活性多肽通过交联剂共价结合到材料上,扫描电镜观察支架材料表面微观形貌;取第3代BMSCs接种到材料上,以未结合多肽的重组胶原矿化骨作为对照,采用MTT法检测BMSCs在材料表面的增殖;沉淀法检测BMSCs在材料表面的黏附率;扣描电镜观察比较BMSCs在材料表面的生长形态;通过检测细胞中的碱性磷酸酶活性及钙含量,观察BMSCs在材料表面的分化情况. 结果扫描电镜结果显示:支架材料旱多孔状;X射线光电子能谱法证实BMP-2活性多肽成功共价结合到材料表面;BMP-2活性多肽修饰的重组胶原矿化骨复合材料表面BMSCs的黏附和向成骨细胞方向分化能力均高于对照组,差异有统计学意义(P＜0.05),而BMSCs的增殖能力与对照组相比,差异无统计学意义(P＞0.05). 结论BMP-2活性多肽可以显著改善重组胶原矿化骨复合材料的细胞相容性和生物活性,经BMP-2活性多肽修饰的重组胶原矿化骨复合材料是一种理想的骨组织工程支架材料.     

Bone Morphogenetic Protein-6-loaded Chitosan Scaffolds Enhance the Osteoblastic Characteristics of MC3T3-E1 Cells

The purpose of this study is to investigate the convenience of bone morphogenetic protein-6 (BMP-6)-loaded chitosan scaffolds with preosteoblastic cells for bone tissue engineering. MC3T3-E1 cells were seeded into three different groups: chitosan scaffolds, BMP-6-loaded chitosan scaffolds, and chitosan scaffolds with free BMP-6 in culture medium. Tissue-engineered constructs were characterized by 3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazoliumbromide assay, scanning electron microscopy (SEM), mineralization assay (von Kossa), alkaline phosphatase (ALP) activity, and osteocalcin (OCN) assays. BMP-6-loaded chitosan scaffolds supported proliferation of the MC3T3-E1 mouse osteogenic cells in a similar pattern as the unloaded chitosan scaffolds group and as the chitosan scaffolds with free BMP-6 group. SEM images of the cell-seeded scaffolds revealed significant acceleration of extracellular matrix synthesis in BMP-6-loaded chitosan scaffolds. Both levels of ALP and OCN were higher in BMP-6-loaded chitosan scaffold group compared with the other two groups. In addition, BMP-6-loaded scaffolds showed strong staining in mineralization assays. These findings suggest that BMP-6-loaded chitosan scaffold supports cellular functions of the osteoblastic cells; therefore, this scaffold is considered as a new promising vehicle for bone tissue engineering applications.     

大鼠雪旺细胞对两种来源的成骨细胞增殖分化影响的研究

目的 研究应用雪旺细胞(SCs)对两种来源的成骨细胞(OB)的增殖与分化的影响,为构建神经化组织工程骨提供体外实验理论依据.方法 通过采用股骨、胫骨髓腔冲洗法获得SD大鼠骨髓基质干细胞(BMSCs),采用胰蛋白酶消化新生鼠颅骨获得OB及采用消化后组织块法获得SCs.将BMSCs在成骨诱导液作用3周,鉴定BMSCs向OB分化.采用96孔共培养板将第2代SCs种植于上室,颅骨来源OB种植下室,共培养为实验组,无SCs干预共培养为对照组.将诱导分化的OB种植于下室,第2代SCs种植于上室,共培养为实验组,无SCs干预共培养为对照组,分别于共培养后1、3、5、7、9d采用甲基噻唑基四唑(MTT)进行增殖比较.采用6孔共培养板,实验组上室种植SCs,下室分别种植颅骨来源及BMSCs来源的OB,不加SCs的两种来源的OB作为对照组,分别共培养后于3、7 d检测两种来源OB的碱性磷酸酶、骨钙素、骨桥蛋白、骨形态发生蛋白-2 mRNA表达.结果 SCs对颅骨来源的OB在共培养3、5、7、9 d 4个时间点均有明显促增殖作用,在碱性磷酸酶、骨桥蛋白、骨形态发生蛋白-2mRNA在各个时间段均起到抑制作用.SCs对大鼠BMSCs来源的OB在共培养1、3 d无明显促增殖作用,在5、7、9 d有明显促增殖作用,在成骨培养基的环境里,SCs可促进BMSCs诱导的OB分化.结论 选择BMSCs来源的OB 与 SCs共培养更适合用于构建神经化组织工程骨.     

大鼠雪旺细胞对两种来源的成骨细胞增殖分化影响的研究

目的 研究应用雪旺细胞(SCs)对两种来源的成骨细胞(OB)的增殖与分化的影响,为构建神经化组织工程骨提供体外实验理论依据.方法 通过采用股骨、胫骨髓腔冲洗法获得SD大鼠骨髓基质干细胞(BMSCs),采用胰蛋白酶消化新生鼠颅骨获得OB及采用消化后组织块法获得SCs.将BMSCs在成骨诱导液作用3周,鉴定BMSCs向OB分化.采用96孔共培养板将第2代SCs种植于上室,颅骨来源OB种植下室,共培养为实验组,无SCs干预共培养为对照组.将诱导分化的OB种植于下室,第2代SCs种植于上室,共培养为实验组,无SCs干预共培养为对照组,分别于共培养后1、3、5、7、9d采用甲基噻唑基四唑(MTT)进行增殖比较.采用6孔共培养板,实验组上室种植SCs,下室分别种植颅骨来源及BMSCs来源的OB,不加SCs的两种来源的OB作为对照组,分别共培养后于3、7 d检测两种来源OB的碱性磷酸酶、骨钙素、骨桥蛋白、骨形态发生蛋白-2 mRNA表达.结果 SCs对颅骨来源的OB在共培养3、5、7、9 d 4个时间点均有明显促增殖作用,在碱性磷酸酶、骨桥蛋白、骨形态发生蛋白-2mRNA在各个时间段均起到抑制作用.SCs对大鼠BMSCs来源的OB在共培养1、3 d无明显促增殖作用,在5、7、9 d有明显促增殖作用,在成骨培养基的环境里,SCs可促进BMSCs诱导的OB分化.结论 选择BMSCs来源的OB 与 SCs共培养更适合用于构建神经化组织工程骨.     

大鼠雪旺细胞对两种来源的成骨细胞增殖分化影响的研究

目的 研究应用雪旺细胞(SCs)对两种来源的成骨细胞(OB)的增殖与分化的影响,为构建神经化组织工程骨提供体外实验理论依据.方法 通过采用股骨、胫骨髓腔冲洗法获得SD大鼠骨髓基质干细胞(BMSCs),采用胰蛋白酶消化新生鼠颅骨获得OB及采用消化后组织块法获得SCs.将BMSCs在成骨诱导液作用3周,鉴定BMSCs向OB分化.采用96孔共培养板将第2代SCs种植于上室,颅骨来源OB种植下室,共培养为实验组,无SCs干预共培养为对照组.将诱导分化的OB种植于下室,第2代SCs种植于上室,共培养为实验组,无SCs干预共培养为对照组,分别于共培养后1、3、5、7、9d采用甲基噻唑基四唑(MTT)进行增殖比较.采用6孔共培养板,实验组上室种植SCs,下室分别种植颅骨来源及BMSCs来源的OB,不加SCs的两种来源的OB作为对照组,分别共培养后于3、7 d检测两种来源OB的碱性磷酸酶、骨钙素、骨桥蛋白、骨形态发生蛋白-2 mRNA表达.结果 SCs对颅骨来源的OB在共培养3、5、7、9 d 4个时间点均有明显促增殖作用,在碱性磷酸酶、骨桥蛋白、骨形态发生蛋白-2mRNA在各个时间段均起到抑制作用.SCs对大鼠BMSCs来源的OB在共培养1、3 d无明显促增殖作用,在5、7、9 d有明显促增殖作用,在成骨培养基的环境里,SCs可促进BMSCs诱导的OB分化.结论 选择BMSCs来源的OB 与 SCs共培养更适合用于构建神经化组织工程骨.     

绝经后血清BMP-7、OCN水平与骨质疏松的相关性研究

目的探究骨形态发生蛋白-7(BMP-7)、骨钙素(OCN)在绝经后骨质疏松(OP)患者血清中的水平与骨代谢指标骨特异性碱性磷酸酶(BAP)、I型胶原交联氨基末端肽(NTX)及骨密度(BMD)的相关性。方法选取2017年5月至2019年3月收治的93例绝经女性OP患者作为OP组;并以同期来我院进行健康体检的86例绝经女性作为对照组进行研究;以实时荧光定量PCR(qRT-PCR)法检测两组受试者血清BMP-7、OCN表达水平;以酶联免疫吸附法(ELISA)检测两组受试者血清BAP、NTX水平,计算BAP/NTX比值;利用双能X线骨密度仪测定两组受试者骨密度;分析OP患者血清BMP-7、OCN表达水平与骨代谢相关指标、BMD的相关性及BMP-7表达水平与OCN的关系; Logistic回归分析OP发生的影响因素。结果 OP组患者雌二醇水平、血清BMP-7、OCN、BAP/NTX、BMD水平均明显低于对照组(t=11.962、9.969、12.823、4.052、18.215,P均0.05); OP组患者血清BAP、NTX水平均明显高于对照组(t=4.014、9.092,P均0.05); OP患者血清BMP-7、OCN表达水平与BAP、NTX均呈负相关(P均0.05),与BAP/NTX、BMD均呈正相关(P均0.05),BMP-7表达水平与OCN呈正相关(P 0.05);雌二醇、BMD是影响OP发生的保护险因素(95%CI=0.536～0.978、0.335～0.916,P均0.05),BAP、NTX是影响OP发生的危险因素(95%CI=1.336～1.859、1.427～2.357,P均0.05)。结论绝经女性血清BMP-7、OCN表达水平下调,BMP-7、OCN与骨代谢指标及BMD密切相关,两者可能与BAP、NTX、BMD相互影响,从而在OP发展进程中发挥作用。     

BMSCs来源成骨细胞和内皮细胞复合壳聚糖-羟基磷灰石多孔支架构建血管化组织工程骨研究

目的探讨大鼠BMSCs来源的成骨细胞和内皮细胞复合壳聚糖-羟基磷灰石多孔支架植入大鼠桡骨缺损处的成骨作用和成血管作用。方法取分离培养至第3代的SD大鼠BMSCs行成骨和成内皮细胞诱导并鉴定。分别将内皮细胞(A组)、成骨细胞(B组)、混合细胞(成骨细胞和内皮细胞比例为1∶1,C组)均匀滴加于壳聚糖-羟基磷灰石多孔支架上制备3组细胞-支架复合物,MTT检测支架内细胞增殖活性。取2月龄雄性SD大鼠30只,制作大鼠桡骨5 mm长缺损模型并分别植入3组细胞-支架复合物(n=10)。术后4、8、12周分别取移植物行HE染色观察,CD34免疫组织化学染色计数微血管密度,RT-PCR法检测骨桥蛋白(osteopontin,OPN)和骨保护素(osteoprotegrin,OPG)mRNA表达。结果 BMSCs成骨诱导7 d后ALP染色可见细胞质内蓝染颗粒,细胞核呈红染;内皮细胞诱导14 d后,CD34免疫细胞化学染色可见细胞内棕色颗粒。MTT检测示3组细胞活性随时间延长逐渐升高。HE染色示,术后12周A组未见明显类骨质形成,而有较密集的微血管结构及较多纤维组织形成;B、C组可见均质的类骨质,呈条索状和岛状分布,可见大量成骨样细胞存在。术后各时间点A、C组微血管密度均显著高于B组(P<0.05);A组术后12周微血管密度高于C组(P<0.05),其余2个时间点A、C组间差异无统计学意义(P>0.05)。A组3个时间点OPN和OPG mRNA表达水平均较低,与B、C组比较差异有统计学意义(P<0.05);B、C组分别于术后8、12周OPN mRNA表达达峰值,4周时OPG mRNA表达达峰值。结论 BMSCs来源的成骨细胞和内皮细胞按1∶1比例共培养于壳聚糖-羟基磷灰石多孔支架作为组织工程骨移植物,可以促进大鼠桡骨缺损部位骨的形成和血管化,促进骨缺损愈合。     

miR-187-5p 对骨髓间充质干细胞成骨分化能力的调控作用

目的利用小鼠骨髓间充质干细胞(BMSCs)的成骨分化模型,探讨miR-187-5p在成骨分化中的表达趋势及调控作用。方法通过切除雌性小鼠双侧卵巢构建小鼠骨质疏松模型;应用qRT-PCR技术检测组织和细胞中miR-187-5p的表达;应用基因转染技术观察过表达或敲减miR-187-5p对BMSCs向成骨分化的影响;应用茜素红和碱性磷酸酶染色检测BMSCs中矿化结节的数量和矿化区域的染色面积。结果 qRT-PCR结果显示miR-187-5p在骨质疏松模型小鼠的骨组织及BMSCs中均表达下降。过表达miR-187-5p可提高ALP、Collagen-1、Runx2、BMP4、OCN和OPN等成骨分化相关基因mRNA的表达,促进BMSCs向成骨分化;而敲减miR-187-5p降低ALP等成骨分化相关基因mRNA的表达,抑制BMSCs向成骨分化。在体实验同样证实,过表达miR-187-5p可以显著促进骨质疏松小鼠BMSCs向成骨分化,改善小鼠的骨质疏松表型。结论过表达miR-187-5p促进BMSCs向成骨分化,敲减miR-187-5p抑制BMSCs向成骨分化。