羟基磷灰石/二氧化锆复合材料颗粒对骨髓间充质干细胞增殖及成骨分化的影响

Objective To evaluate the effect of the HA/ZrO2 composite particle on proliferation and osteogenesis of rabbit mesenchymal stem cells (MSCs) by using molecular biology methods.Methods The HA/ZrO2 composite particles were sintered at high temperature using the powder of HA and ZrO2 with different proportions.MSCs were isolated from rabbits and cultured.The effect of the composite particles on promoting cell proliferation of rabbit MSCs was detected using MTT method.Alkaline phosphatase activities were measured with ALP method.RT-PCR method was applied to measure the expression of collagen Ⅰ , osteocalcin and osteopontin mRNA.Results Pure HA pauicles and composite particles which contain HA promoted MSCs proliferation.Vonkossa staining showed that both pure HA particks and composite particles decreased the degree of positive stain of MSCs.ALP test showed that cell activity in the culture medium that contained pure HA particles or composite particles was significantly higher than that in the conventional culture medium and that contained pure ZrO2 particles (P ＜ 0.05＝.RT-PCR results showed that composite particles promoted the expression of collagen Ⅰ and osteocalcin gene.Conclusion The HA/ZrO2 composite particles promote proliferation and osteogenesis of MSCs.     

羟基磷灰石/二氧化锆复合材料颗粒对骨髓间充质干细胞增殖及成骨分化的影响

Objective To evaluate the effect of the HA/ZrO2 composite particle on proliferation and osteogenesis of rabbit mesenchymal stem cells (MSCs) by using molecular biology methods.Methods The HA/ZrO2 composite particles were sintered at high temperature using the powder of HA and ZrO2 with different proportions.MSCs were isolated from rabbits and cultured.The effect of the composite particles on promoting cell proliferation of rabbit MSCs was detected using MTT method.Alkaline phosphatase activities were measured with ALP method.RT-PCR method was applied to measure the expression of collagen Ⅰ , osteocalcin and osteopontin mRNA.Results Pure HA pauicles and composite particles which contain HA promoted MSCs proliferation.Vonkossa staining showed that both pure HA particks and composite particles decreased the degree of positive stain of MSCs.ALP test showed that cell activity in the culture medium that contained pure HA particles or composite particles was significantly higher than that in the conventional culture medium and that contained pure ZrO2 particles (P ＜ 0.05＝.RT-PCR results showed that composite particles promoted the expression of collagen Ⅰ and osteocalcin gene.Conclusion The HA/ZrO2 composite particles promote proliferation and osteogenesis of MSCs.     

Difference of adherence, proliferation and osteogenesis of mesenchymal stem cells cultured on different HA/ZrO2 composites

Objective: To study the adherence,proliferation and osteogenesis of mesenchymal stem cells (MSCs) cultured on different HA/ZrO2 composites.Methods: The simplex and graded HA/ZrO2 composites were prepar...     

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.     

增强型生物活性玻璃-胶原复合支架材料的成骨效能研究

目的 探讨增强型生物活性玻璃-胶原复合支架材料的体内外成骨效能.方法取第3代BMSCs种植于支架材料(支架组),以等量细胞常规培养作为非支架组,培养1、3、5、7、9、11 d采用阿尔玛蓝法动态检测细胞的增殖率.取第3代BMSCs种植于支架材料(体外实验组),以等量细胞常规培养作为体外对照组,培养4、7 d采用实时定量逆转录聚合酶链式反应(qRT-PCR)检测细胞骨形态发生蛋白-2(BMP-2)、碱性磷酸酶(ALP)、Ⅰ型胶原的mRNA表达.裸鼠皮下植入复合成骨样细胞的支架材料(体内实验组),取正常骨组织作为体内对照组,6周后以X线片、qRT-PCR、绀织学染色评估成骨情况.结果培养7～11 d支架组细胞增殖率显著高于非支架组,差异均有统计学意义(P<0.05).体外实验组培养7 d BMP-2、ALP、Ⅰ型胶原的mRNA表达显著高于体外对照组,差异均有统计学意义(P<0.05).体内实验组X线片示植入区域有密度增高影,支架材料形成白色硬性组织;BMP-2、Ⅰ型胶原、骨钙素、骨桥蛋白的mRNA表达较体内埘照组均增高,差异有统计学意义(P<0.05);组织学染色示支架材料大部分降解,新生骨形成明显.结论增强型生物活性玻璃-胶原复合支架材料具有良好的生物相容性,体内外均具有成骨效应.

Abstract：

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.     

大鼠脂肪干细胞复合胶原-壳聚糖-硫酸软骨素三维支架构建组织工程软骨

Objective To evaluate the character of the collagen-chitosan-chondroitin sulfate scaffold seeded with rat adipose tissue-derived stromal cells. Methods A dipose tissue were harvested from 6 weeks old Wistar rats and the stromal cells were harvested by type Ⅰ collagenase and then cultured in vitro. Type Ⅰ collagen was fully mixed with chitosan, freeze-dried and cross-linked with chondroitin sulfate, then freeze-dried again and sterilized by ethylene oxide. The pore diameter, water content, porosity of the scaffold were tested. The adipose tissue-derived stromal cells were digested, seeded into the plates, scaffold, and cen-trifuged into pellet, and then induced into cartilage. MTT detection for cell proliferation was done. After 3 weeks, the cell morphology, and cell proliferation and adhesion were observed, and chondrngenic differenti-ation was also analyzed. Results The pore diameter, water content, porosity tested for the scaffold showed an appropriate form. Cell proliferation showed faster in the scaffold and pellet culture system after 5 day, there was still cell proliferation in the scaffold system after 14 days but no obvious changes in the pellet cul-ture system; ceils on the scaffold proliferated densely showed by histological staining, but there was a scaf-fold structure residues in the inner layer. The finding of type Ⅱ immunohistochemistry stain showed that cells express strong positive for type Ⅱ collagen in the scaffold and pellet culture system whereas it was weakly positive in the plate culture system; the specific mRNA for cartilage, type Ⅱ collagen, aggrecan and SOX-9 were expressed in all three systems showed by RT-PCR, but type X collagen was expressed continu-ously in the plate culture system and expressed after 21 days in the pellet culture system, whereas it was not detected in the collagen-chitosan-chondroitin sulfate scaffold system. Conclusion The parameters of the collagen-chitosan-chondroitin sulfate scaffold were suitable in our study. The results suggested that it can promote the adipose tissue-derived stromal cells proliferation and chondrogenic differentiation better than the plate and pellet culture systems and maintain the phenotype of chondrocytes well; it is the optimal choice for cartilage tissue engineering in the future.     

大鼠脂肪干细胞复合胶原-壳聚糖-硫酸软骨素三维支架构建组织工程软骨

Objective To evaluate the character of the collagen-chitosan-chondroitin sulfate scaffold seeded with rat adipose tissue-derived stromal cells. Methods A dipose tissue were harvested from 6 weeks old Wistar rats and the stromal cells were harvested by type Ⅰ collagenase and then cultured in vitro. Type Ⅰ collagen was fully mixed with chitosan, freeze-dried and cross-linked with chondroitin sulfate, then freeze-dried again and sterilized by ethylene oxide. The pore diameter, water content, porosity of the scaffold were tested. The adipose tissue-derived stromal cells were digested, seeded into the plates, scaffold, and cen-trifuged into pellet, and then induced into cartilage. MTT detection for cell proliferation was done. After 3 weeks, the cell morphology, and cell proliferation and adhesion were observed, and chondrngenic differenti-ation was also analyzed. Results The pore diameter, water content, porosity tested for the scaffold showed an appropriate form. Cell proliferation showed faster in the scaffold and pellet culture system after 5 day, there was still cell proliferation in the scaffold system after 14 days but no obvious changes in the pellet cul-ture system; ceils on the scaffold proliferated densely showed by histological staining, but there was a scaf-fold structure residues in the inner layer. The finding of type Ⅱ immunohistochemistry stain showed that cells express strong positive for type Ⅱ collagen in the scaffold and pellet culture system whereas it was weakly positive in the plate culture system; the specific mRNA for cartilage, type Ⅱ collagen, aggrecan and SOX-9 were expressed in all three systems showed by RT-PCR, but type X collagen was expressed continu-ously in the plate culture system and expressed after 21 days in the pellet culture system, whereas it was not detected in the collagen-chitosan-chondroitin sulfate scaffold system. Conclusion The parameters of the collagen-chitosan-chondroitin sulfate scaffold were suitable in our study. The results suggested that it can promote the adipose tissue-derived stromal cells proliferation and chondrogenic differentiation better than the plate and pellet culture systems and maintain the phenotype of chondrocytes well; it is the optimal choice for cartilage tissue engineering in the future.     

大鼠脂肪干细胞复合胶原-壳聚糖-硫酸软骨素三维支架构建组织工程软骨

Objective To evaluate the character of the collagen-chitosan-chondroitin sulfate scaffold seeded with rat adipose tissue-derived stromal cells. Methods A dipose tissue were harvested from 6 weeks old Wistar rats and the stromal cells were harvested by type Ⅰ collagenase and then cultured in vitro. Type Ⅰ collagen was fully mixed with chitosan, freeze-dried and cross-linked with chondroitin sulfate, then freeze-dried again and sterilized by ethylene oxide. The pore diameter, water content, porosity of the scaffold were tested. The adipose tissue-derived stromal cells were digested, seeded into the plates, scaffold, and cen-trifuged into pellet, and then induced into cartilage. MTT detection for cell proliferation was done. After 3 weeks, the cell morphology, and cell proliferation and adhesion were observed, and chondrngenic differenti-ation was also analyzed. Results The pore diameter, water content, porosity tested for the scaffold showed an appropriate form. Cell proliferation showed faster in the scaffold and pellet culture system after 5 day, there was still cell proliferation in the scaffold system after 14 days but no obvious changes in the pellet cul-ture system; ceils on the scaffold proliferated densely showed by histological staining, but there was a scaf-fold structure residues in the inner layer. The finding of type Ⅱ immunohistochemistry stain showed that cells express strong positive for type Ⅱ collagen in the scaffold and pellet culture system whereas it was weakly positive in the plate culture system; the specific mRNA for cartilage, type Ⅱ collagen, aggrecan and SOX-9 were expressed in all three systems showed by RT-PCR, but type X collagen was expressed continu-ously in the plate culture system and expressed after 21 days in the pellet culture system, whereas it was not detected in the collagen-chitosan-chondroitin sulfate scaffold system. Conclusion The parameters of the collagen-chitosan-chondroitin sulfate scaffold were suitable in our study. The results suggested that it can promote the adipose tissue-derived stromal cells proliferation and chondrogenic differentiation better than the plate and pellet culture systems and maintain the phenotype of chondrocytes well; it is the optimal choice for cartilage tissue engineering in the future.     

大鼠脂肪干细胞复合胶原-壳聚糖-硫酸软骨素三维支架构建组织工程软骨

Objective To evaluate the character of the collagen-chitosan-chondroitin sulfate scaffold seeded with rat adipose tissue-derived stromal cells. Methods A dipose tissue were harvested from 6 weeks old Wistar rats and the stromal cells were harvested by type Ⅰ collagenase and then cultured in vitro. Type Ⅰ collagen was fully mixed with chitosan, freeze-dried and cross-linked with chondroitin sulfate, then freeze-dried again and sterilized by ethylene oxide. The pore diameter, water content, porosity of the scaffold were tested. The adipose tissue-derived stromal cells were digested, seeded into the plates, scaffold, and cen-trifuged into pellet, and then induced into cartilage. MTT detection for cell proliferation was done. After 3 weeks, the cell morphology, and cell proliferation and adhesion were observed, and chondrngenic differenti-ation was also analyzed. Results The pore diameter, water content, porosity tested for the scaffold showed an appropriate form. Cell proliferation showed faster in the scaffold and pellet culture system after 5 day, there was still cell proliferation in the scaffold system after 14 days but no obvious changes in the pellet cul-ture system; ceils on the scaffold proliferated densely showed by histological staining, but there was a scaf-fold structure residues in the inner layer. The finding of type Ⅱ immunohistochemistry stain showed that cells express strong positive for type Ⅱ collagen in the scaffold and pellet culture system whereas it was weakly positive in the plate culture system; the specific mRNA for cartilage, type Ⅱ collagen, aggrecan and SOX-9 were expressed in all three systems showed by RT-PCR, but type X collagen was expressed continu-ously in the plate culture system and expressed after 21 days in the pellet culture system, whereas it was not detected in the collagen-chitosan-chondroitin sulfate scaffold system. Conclusion The parameters of the collagen-chitosan-chondroitin sulfate scaffold were suitable in our study. The results suggested that it can promote the adipose tissue-derived stromal cells proliferation and chondrogenic differentiation better than the plate and pellet culture systems and maintain the phenotype of chondrocytes well; it is the optimal choice for cartilage tissue engineering in the future.     

大鼠脂肪干细胞复合胶原-壳聚糖-硫酸软骨素三维支架构建组织工程软骨

Objective To evaluate the character of the collagen-chitosan-chondroitin sulfate scaffold seeded with rat adipose tissue-derived stromal cells. Methods A dipose tissue were harvested from 6 weeks old Wistar rats and the stromal cells were harvested by type Ⅰ collagenase and then cultured in vitro. Type Ⅰ collagen was fully mixed with chitosan, freeze-dried and cross-linked with chondroitin sulfate, then freeze-dried again and sterilized by ethylene oxide. The pore diameter, water content, porosity of the scaffold were tested. The adipose tissue-derived stromal cells were digested, seeded into the plates, scaffold, and cen-trifuged into pellet, and then induced into cartilage. MTT detection for cell proliferation was done. After 3 weeks, the cell morphology, and cell proliferation and adhesion were observed, and chondrngenic differenti-ation was also analyzed. Results The pore diameter, water content, porosity tested for the scaffold showed an appropriate form. Cell proliferation showed faster in the scaffold and pellet culture system after 5 day, there was still cell proliferation in the scaffold system after 14 days but no obvious changes in the pellet cul-ture system; ceils on the scaffold proliferated densely showed by histological staining, but there was a scaf-fold structure residues in the inner layer. The finding of type Ⅱ immunohistochemistry stain showed that cells express strong positive for type Ⅱ collagen in the scaffold and pellet culture system whereas it was weakly positive in the plate culture system; the specific mRNA for cartilage, type Ⅱ collagen, aggrecan and SOX-9 were expressed in all three systems showed by RT-PCR, but type X collagen was expressed continu-ously in the plate culture system and expressed after 21 days in the pellet culture system, whereas it was not detected in the collagen-chitosan-chondroitin sulfate scaffold system. Conclusion The parameters of the collagen-chitosan-chondroitin sulfate scaffold were suitable in our study. The results suggested that it can promote the adipose tissue-derived stromal cells proliferation and chondrogenic differentiation better than the plate and pellet culture systems and maintain the phenotype of chondrocytes well; it is the optimal choice for cartilage tissue engineering in the future.     

阻断钙调磷酸酶/激活T细胞核因子通路对聚甲基丙烯酸甲酯颗粒抑制骨祖细胞向成骨细胞分化的影响

目的 探讨VIVIT肽阻断钙调磷酸酶(Cn)/激活T细胞核因子(NFAT)信号通路对聚甲基丙烯酸甲酯(PMMA)颗粒抑制骨祖细胞向成骨细胞分化的影响. 方法 体外分离培养Sprague-Drawley大鼠胎鼠颅骨原代细胞(包含大量骨祖细胞),根据处理条件不同分为4组:对照组、PMMA组、PMMA/VIVIT组和VIVIT组.细胞培养2、4、7和14 d用MTT法检测细胞增殖情况,7 d和14d用碱性磷酸酶(ALP)定量反映细胞分化;细胞培养14 d后菏素红染色观察细胞矿化,RT-PCR法观察ALP、骨钙素、Ⅰ型胶原、Fra-2(与成骨细胞分化有关的转录因子)、NFATc1的基因表达,Western Blot法检测细胞核和细胞质中NFATc1蛋白的表达. 结果 PMMA组较对照组NFATc1基因和蛋白表达增加,并伴有NFATc1蛋白转位入核明显增加,成骨细胞分化、矿化和相关基因表达明显降低.PMMA/VIVIT组较PMMA组细胞分化、矿化和相关基因表达增加,但低于VIVIT组,NFATc1基因表达降低,转位入核的NFATc1蛋白明显减少.各组细胞增殖差异均无统计学意义(P>0.05). 结论 PMMA颗粒抑制骨祖细胞向成骨细胞分化与Cn/NFAT信号通路激活有关,VIVIT肽阻断Cn/NFAT信号通路可促进PMMA颗粒抑制的骨祖细胞向成骨细胞分化.     

不同相对分子质量透明质酸对兔骨髓来源间充质干细胞成软骨分化的影响

目的 观察不同相对分子质量透明质酸(HA)对兔骨髓来源间充质干细胞(MSCs)向软骨方向定向分化的影响.方法 取P3代未诱导的骨髓来源间充质干细胞,培养液中分别添加不同相对分子质量透明质酸做诱导剂,分为3个实验组,A组:相对低分子质量组(基础培养基+ HA 0.1 g/L,相对分子质量约1000×103),B组:相对中分子质量组(基础培养基+HA0.1 g/L,相对分子质量约1800×103),C组:相对高分子质量组(基础培养基+HA 0.1 g/L,相对分子质量约2000×103).同时设立阳性对照组[基础培养基+ 10 μg/L转化生长因子-β3( TGF-β3)]及空白对照组(基础培养基),观察细胞形态及增殖情况,分别于诱导后第7、14、21天行甲苯胺蓝染色检测蛋白聚糖表达,另外采用免疫组织化学染色及逆转录-聚合酶链反应(RT-PCR)方法检测细胞Ⅱ型胶原表达.结果 经添加软骨诱导剂后,干细胞细胞增殖速度放缓,形态逐渐改变,细胞外基质呈甲苯胺蓝异染性,Ⅱ型胶原免疫组织化学染色阳性.RT-PCR检测示实验组Ⅱ型胶原mRNA表达阳性,诱导至21 d可见各实验组Ⅱ型胶原基因相对表达量分别为0.64±0.06、0.72±0.03、0.75±0.01,与阴性对照组(0.09±0.03)、阳性对照组(0.96±0.15)比较差异均有统计学意义,但B、C组间Ⅱ型胶原表达相似.结论 不同相对分子质量外源性HA诱导兔MSCs向软骨细胞分化的能力存在差异,相对高分子质量的HA的诱导能力较相对低分子质量HA的诱导能力强.证明透明质酸的相对分子质量与MSCs的软骨分化有关联性,但均比TGF-β3的诱导能力弱.     

新型羟磷灰石涂层的聚乳酸支架体外细胞相容性研究

目的研究新型的用固定化尿素酶的方法制备的羟基磷灰石／聚乳酸（HA／PLLA）复合材料的生物相容性和成骨活性。方法将成骨样MG63细胞种植在HA／PLLA和PLLA（对照材料）三维支架材料上。在培养2,4和6天后通过改良的MTI＂法检测细胞在材料上的增殖情况;用pNPP磷酸酶检测试剂盒测定ALP含量来评估成骨样细胞在材料上的分化情况;在培养4天后用扫描电镜观察细胞在材料上的形貌变化：用RT—PCR检测磷酸酶（AIJP）,骨钙素（0C）,1型胶原等基因变化情况。结果在培养2天和4天后,HA／PLLA材料上的细胞数量要明显多于PLLA材料组,说明相对于传统的PLLA材料,HA／PLLA材料更能促进成骨细胞的增殖。电镜结果提示,在培养4天后HA／PuJA材料上的MG63细胞铺展在材料孔壁表面,提示细胞具有良好的活力,而PLLA组的细胞表现为圆球形,未见明显的细胞伪足形成,其形态明显不及HA／PuA材料组。ALP检测结果提示,HA／PLLA组的细胞具有更高的ALP活性。RT—PCT结果也提示,HA／PLLA组具有更高的ALP和0c基因表达．提示HA／PLLA材料更能促进成骨细胞的分化。结论通过固定化尿素酶的方法制备的新型羟基磷灰石／聚乳酸材料相比传统的PLLA材料更能促进成骨细胞的增殖和分化,提示该材料是一种良好的骨组织工程支架材料。     

Effect of type I collagen on the adhesion, proliferation, and osteoblastic gene expression of bone marrow-derived mesenchymal stem cells

tificially synthesizedpolymericproductssuchaspolylactide (PLA ) ,polyglycolide (PGA ) ,andtheircopolymersarefrequently usedtissueengineeringmatrixsubstitutivematerials .Unfortunately ,theirapplicationisseriouslyrestrictedfortheirpoorhydrophilicproperty ,weakcelladsorptionforces ,anddifficultyininteractionwithcells .1,2 ThisstudyintendstoevaluatethecapacityofcollagenIinpromotingadhesion ,proliferation ,anddifferentiationofMSCs ,tolayanexperimentalbasisforbonytissueengineering .METHODSPrep…     

负载人骨形态发生蛋白-7基因的兔脂肪干细胞向成骨细胞分化的实验研究

目的 探讨人骨形态发生蛋白-7(hBMP-7)基因修饰对兔脂肪干细胞(ADSCs)成骨能力的影响. 方法 原代培养兔脂肪干细胞,免疫组织化学方法检测细胞表面抗原CD44、CD49d、CD106的表达,对细胞进行鉴定;阳离子脂质体介导hBMP-7基因转染ADSCs,绿色荧光蛋白表达观察转染效率、逆转录-聚合酶链反应(RT-PCR)检测目的基因hBMP-7的表达;ALP定量测定,Western blot检测Ⅰ型胶原、骨钙素的表达,以评价转基因ADSCs向成骨细胞分化的情况. 结果 从兔脂肪组织中分离出来的ADSCs CD44、CD49d表达呈阳性,CD106表达呈阴性.RT-PCR检测筛选后的ADSCs稳定表达hBMP-7.转染后7、10、14 d ALP定量测定转染组明显高于未转染组,差异有统计学意义(P<0.05);成骨标志物Ⅰ型胶原、骨钙素的表达转染组明显高于未转染组.结论 从脂肪组织中分离出的ADSCs是一种较好的组织工程种子细胞.hBMP-7重组质粒转染ADSCs后表达目的蛋白,并诱导ADSCs向成骨细胞分化.     

间充质干细胞在藻酸盐微球溶液中增殖和分化的实验研究

[目的]探讨藻酸盐微球作为缓释材料在骨组织工程中对种子细胞的增殖和分化的影响。[方法]制成不同浓度的藻酸盐微球溶液，将间充质干细胞接种于其中，观察其生长和增殖情况；置换成骨诱导培养基后，通过检测细胞内碱性磷酸酶的量以及细胞外钙基质分泌来评价间充质干细胞的分化情况。[结果]不同浓度的藻酸盐微球溶液对间充质干细胞的增殖影响不同，随着浓度的增高间充质干细胞的增殖越受抑制，浓度达到10g／L时不适合细胞生长；在成骨诱导培养基中，藻酸盐可以促进细胞内碱性磷酸酶合成量的增加，并表现剂量依赖性，即藻酸盐浓度越高效应越明显，生长在藻酸盐溶液中的间充质干细胞分化为成骨细胞并分泌细胞外钙基质。[结论]一定剂量的藻酸盐微球溶液对间充质干细胞的增殖影响很小，且可促进细胞内成骨活性分子的合成，适于作为骨组织工程的缓释材料。     

腺病毒介导入BMP-2对骨髓间质干细胞成骨能力的影响

目的　探讨腺病毒介导的人骨形态发生蛋白 (BMP 2 )转染对体外培养骨髓间质干细胞(MSCs)成骨能力的影响。　方法　取日本大耳白兔 2 0只自双侧股骨大转子取材培养MSCs ,左侧来源细胞为实验组 ,右侧为对照组。以复制缺陷重组腺病毒介导人BMP 2基因转染MSCs后 ,用ALP检测两组细胞的ALP活性 ;骨钙素RT PCR检测两组细胞Ⅰ型胶原的表达 ;BGP放免分析检测两组细胞的骨钙素含量。　结果　转基因组和对照组ALP分泌量 (U/L)分别为 7 0 1± 0 5 9、5 2 3± 0 5 5 ;RT PCRⅠ型胶原的表达为 1 3 5± 0 12、3 65± 0 3 7;骨钙素 (ng/ml)为 2 4 5 0± 0 93和 15 45± 1 81。两组间差异均有显著性 (P <0 0 5 )。　结论　用腺病毒介导人BMP 2蛋白作用后的MSCs具有成骨细胞的生物学特性。腺病毒介导人BMP 2转基因可以提高MSCs的体外成骨能力。     

Pulsed electromagnetic fields enhance BMP‐2 dependent osteoblastic differentiation of human mesenchymal stem cells

Mesenchymal stem cells (MSCs) express an osteoblastic phenotype when treated with BMP‐2, and BMP‐2 is used clinically to induce bone formation although high doses are required. Pulsed electromagnetic fields (PEMF) also promote osteogenesis in vivo, in part through direct action on osteoblasts. We tested the hypothesis that PEMF enhances osteogenesis of MSCs in the presence of an inductive stimulus like BMP‐2. Confluent cultures of human MSCs were grown on calcium phosphate disks and were treated with osteogenic media (OM), OM containing 40 ng/mL rhBMP‐2, OM + PEMF (8 h/day), or OM + BMP‐2 + PEMF. MSCs demonstrated minor increases in alkaline phosphatase (ALP) during 24 days in culture and no change in osteocalcin. OM increased ALP and osteocalcin by day 6, but PEMF had no additional effect at any time. BMP‐2 was stimulatory over OM, and PEMF + BMP‐2 synergistically increased ALP and osteocalcin. PEMF also enhanced the effects of BMP‐2 on PGE2, latent and active TGF‐β1, and osteoprotegerin. Effects of PEMF on BMP‐2–treated cells were greatest at days 12 to 20. These results demonstrate that PEMF enhances osteogenic effects of BMP‐2 on MSCs cultured on calcium phosphate substrates, suggesting that PEMF will improve MSC response to BMP‐2 in vivo in a bone environment. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 26:1250–1255, 2008