成骨细胞体外培养及异体移植免疫学检测

目的：成骨细胞原代培养，检测其异体移植免疫反应情况，探讨其免疫学机制，为骨细胞移植及组织工程骨的构建寻找细胞来源。方法：用酶消化－组织块联合培养法行细胞原代培养，传代后行同胎及同种异系腹直肌袋内移植，于不同时间点行免疫学及形态学检测。结果：原代接种后1周细胞成单层，碱性磷酸酶染色阳性；2组分别于移植后2周及4周检测到特异性抗体，同种异系组在移植后2周检测到细胞介导的细胞毒反应，至4周达高峰。结论：同胎及同种异系细胞均可作为细胞移植及组织工程骨构建可靠的细胞来源。     

微小颗粒骨复合细胞移植治疗大鼠颅骨缺损

目的 观察自体微小颗粒骨复合骨髓基质细胞(MSC)或成骨细胞移植修复大鼠颅骨缺损的治疗效果。方法 制作大鼠颅骨缺损动物模型，培养同种异体新生大鼠的骨髓基质细胞及成骨细胞，复合自体颗粒骨植入骨缺损区，X线摄片观察骨愈合情况；逆转录一聚合酶链反应(RT-PCR)检测骨钙素、转化生长因子-β1(TGF-β1)表达水平。结果植入微小颗粒骨复合成骨细胞组颅骨缺损愈合最快，骨钙素、TGF-β1表达出现早，与另两组差异有统计学意义(P＜0．05)。植入微小颗粒骨复合骨髓基质细胞组颅骨缺损愈合时间居中，骨钙素、TGF-β1表达早于单纯微小颗粒骨组(P＜0．05)。结论 微小颗粒骨复合细胞移植修复颅骨缺损，细胞因子表达早，缺损愈合明显加快，具有较好的治疗效果。     

以生物衍生材料为支架的组织工程骨移植早期兔外周血T淋巴细胞亚群的变化

目的检测体外构建的组织工程骨移植后兔外周血T细胞亚群的变化，对移植组织进行组织学观察，探讨以生物衍生材料作为骨组织工程支架材料的可行性。方法组织工程骨以兔骨膜来源的成骨细胞为种子细胞，经抗原自消化、部分脱钙、冻干后的异体骨为支架材料于体外构建。将健康新西兰白兔48只制成1cm长桡骨缺损模型后，随机分成A～D4组，每组12只，分别用部分脱钙冻干骨（partial demineralized freeze—dried bone，PDFDB）、组织工程骨、自体骨、同种异体骨植入兔桡骨节段性缺损。术后1、2、4周取材，用流式细胞仪检测4种材料移植早期兔外周血T淋巴细胞亚群的变化；通过常规组织学检测观察2、4、8、12周时4种材料的成骨作用。结果B组术后2周材料孔隙内有成骨细胞和成软骨细胞，可见骨、软骨混合性新生物形成，周边分布有破骨细胞，部分网架呈蚕食状被破坏吸收。术后4周，形成的新生骨过渡为编织骨。A、B组材料植入后1、2周外周血CD4^＋和CD8^＋T细胞较术前明显升高（P〈0．05）；术后4周CD4^＋T细胞较术前轻度偏高，但无统计学差异（P〉0．05）。C组术后CD4^＋和CD8^＋T细胞升高不明显（P〉0．05）。D组术后1、2、4周外周血CD4^＋和CD8^＋T细胞较术前及其他各组同期均明显增高（P〈.．05）。结论PDFDB为支架材料构建的细胞一材料复合物移植后外周血T淋巴细胞增高，但不影响其良好的修复骨缺损能力，生物衍生骨可作为支架材料应用于骨组织工程研究。     

组织工程颅骨缺损修复过程中超微结构观察

目的 用组织工程骨修复SD大鼠颅骨极量骨缺损，并在透射电镜下观察骨修复过程中成骨细胞、血管内皮细胞与陶瓷支架的关系。方法 14只雄性SD大鼠，随机分成实验组和对照组，每组7只。取左侧腔、股骨骨髓，体外诱导培养骨髓基质细胞。实验组将已分化的成骨细胞与含孔磷酸钙陶瓷复合用于修复大鼠自体颅骨极量骨缺损；对照组颅骨缺损处仅置入无细胞的陶瓷材料。分别于术后4、8、12、16、20、24及28周每组各处死1只动物取材，制成脱钙超薄切片，透射电镜下观察成骨细胞、血管内皮细胞与陶瓷残余支架的关系。结果 实验组动物颅骨修复12周前成骨细胞或成骨细胞样细胞毗邻新生小血管、血管内皮细胞存在，16周后成骨细胞转变为骨细胞，并围绕血管被包埋于骨基质及胶原纤维中；陶瓷残余与新生骨间有一条明显的钙化沉积带，大量胶原纤维已伸入到陶瓷支架的纳米级结构中。对照组陶瓷中央部位有大量小血管及血管内皮细胞增生，其周围多为幼稚成纤维细胞，无成骨细胞与血管内皮细胞的依附关系。结论 新型含孔磷酸钙陶瓷作为组织工程细胞支架，其间的纳米级结构有利于骨的再生和血管形成；未见来源于植骨床血管的内皮细胞衍变为成骨细胞。     

自体骨膜细胞复合胶原涂层煅烧骨修复骨缺损的实验研究

目的：观察骨膜成骨细胞（periosteal-derived osteoblast.POB)与胶原涂层煅烧骨（true bone ceramic collage,TBCc)移植的成骨性能，探讨治疗骨缺损的新方法。方法：选牛松质骨制备胶原涂层煅烧骨载体。用兔骨膜成骨细胞与TBCc复合并自体移植到15mm骨缺损模型，移植后4、8、12、16周取材，行组织学、X线拍片和X射线能谱分析，计算机图像分析新生骨面积。结果：复合细胞的TBCc组骨生成、新骨面积和骨连接情况明显优于单纯TBCc组。结论：自体骨膜细胞复合煅烧骨具有较强的促进骨修复作用。     

兔关节软骨下骨缺损骨移植后移植骨组织学变化实验研究

目的观察兔关节软骨下骨缺损后行骨水泥+自体骨或骨水泥+同种异体骨修复术后不同时间点移植骨组织学变化情况。方法选取30只成年健康新西兰大白兔,随机分为自体骨和同种异体骨组,每组各15只。模拟临床骨巨细胞瘤病灶刮除术,建立关节软骨下骨缺损动物模型,分别填充不同材料修复骨缺损。自体骨组填充骨水泥+自体骨,同种异体骨组填充骨水泥+同种异体骨,分别于术后4、6、8周取出植入骨。先行大体观察,然后通过HE染色切片观察其组织学变化。两组术后4、6、8周植入骨内成骨细胞和破骨细胞数量比较采用两因素方差分析,组间两两比较采用LSD法。P0.05为差异有统计学意义。结果术后4周自体骨组植入骨骨小梁开始吸收,植骨周围存在部分新生毛细血管和少量中性粒细胞,移植骨与宿主骨相邻的骨基质内可见少量骨细胞和破骨细胞,骨再生现象形成;同种异体骨组植入骨骨小梁未见明显吸收,植骨区可见肉芽组织,骨再生现象不明显。术后6周自体骨组植入骨骨小梁大部分被吸收,骨基质边缘新生毛细血管和新生成骨细胞增多,移植骨周边可见多核破骨细胞和排列不规则的编织骨,为成骨初期;同种异体骨组植入骨可见散在骨小梁及纤维结缔组织包绕死骨,存在溶骨现象,骨基质边缘可见少量新生毛细血管,破骨细胞及成骨细胞数量极少,无编织骨形成。术后第8周自体骨组植入骨骨小梁被吸收,可见大量新生骨、新生毛细血管和板层骨,骨基质边缘有排列较密集的成骨细胞,编织骨较术后6周时体积变小且排列逐步规整;同种异体骨组植入骨周围可见少量新生毛细血管,部分区域钙盐沉积较明显,少量新生骨小梁形成,其周围可见少量成骨细胞和破骨细胞,部分坏死钙化区内有板成骨形成。同种异体骨组术后第4、6、8周成骨细胞数量及术后第4、8周破骨细胞数量均低于自体骨组(P均0.05)。自体骨组和同种异体骨组术后第6、8周成骨细胞数量均高于术后第4周(P均0.05),自体骨组术后第8周成骨细胞数量高于术后第6周(P0.05)。自体骨组术后第8周破骨细胞数量均高于术后第4、6周(P均0.05),同种异体骨组术后第6周破骨细胞数量高于术后第4、8周(P均0.05)。结论关节软骨下骨缺损填充骨水泥+自体骨较填充骨水泥+同种异体骨植入骨区骨融合率高,成骨效能较好,术后不同时间点自体骨成骨细胞和破骨细胞表达较同种异体骨活跃。     

脱细胞异种骨基质植入后受体外周血T淋巴细胞亚型的变化

目的　观察异种脱细胞去抗原骨基质植入后受体细胞免疫状态的变化。　方法　新西兰大耳白兔2 0只,随机分为4组,每组5只,制成股后肌袋模型,分别植入自体骨、异种脱细胞猪肋骨基质和酒精浸泡猪肋骨,设立假手术组作为对照。术后1、2、4和6周采集外周血,流式细胞仪检测外周血CD4 + 、CD8+ 和CD2 5 + T淋巴细胞的变化;分别于植入后2周和6周,将植入骨块连同周围组织取出,行组织学观察。　结果　同一时间点,外周血中CD4 +、CD8+ T淋巴细胞在酒精浸泡组显著增高,与其余组差异有统计学意义(P<0 .0 5 ) ,其余各组间差异无统计学意义(P>0 .0 5 ) ;CD2 5 + T淋巴细胞在酒精浸泡猪肋骨组2周后显著高于其它组,差异有统计学意义(P<0 .0 5 )。2周时局部组织中见炎性细胞浸润,以粒细胞为主;6周时自体骨及异种脱细胞骨基质组炎性细胞明显减少,代之以大量成纤维细胞及少量淋巴细胞,可见软骨岛形成。　结论　经脱细胞处理的异种骨基质植入后,近期对受体细胞免疫无明显影响。     

异种脱蛋白松质骨为载体构建组织工程骨用于脊柱横突间融合的实验观察

目的探讨异种脱蛋白松质骨（deproteinization bone,DPB）作为骨组织工程载体的性能及其用于山羊脊柱横突间融合的作用。方法取成年猪股骨远端松质骨通过理化方法制成DPB载体,对其形态结构、组成成分、生物力学特性以及材料对种子细胞生物学行为的影响进行检测分析。将载体材料复合一定量的自体骨髓间充质干细胞（mesenchymal stem cells,MSCs）重组人骨形成蛋白2（recombinant human bone morphogenetic protein 2,rhBMP-2）构建组织工程骨。取6～8月龄雄性山羊12只,制成L3-4双侧横突间植骨模型,左侧植入组织工程骨为A组,右侧植入等体积自体髂骨作对照为B组。分别于4、8及12周行X线片和组织学观察并对比分析。结果采用脱蛋白处理后的松质骨可见大小不等、相互交通、开放孔隙的网架结构。孔径200～500μm,孔隙率60％左右。其无机成分为羟基磷灰石,有机成分为胶原,力学性能保存良好,有良好的细胞相容性。两组移植后不同时间点X线表现：A组植入横突间第4周与横突桥接处部分区域模糊,以内侧明显;第8周上下桥接部间隙变小,大量连续骨痂生成;12周后完全融合。早期A组密度略低于B组,12周后基本相同。移植区组织学观察：A组植入后第4周以多点方式形成新骨,第8周岛状生长的骨组织贯穿整个移植材料,12周编织骨交错排列,髓腔形成,成骨活性接近自体髂骨移植。B组,4周时有较多新骨形成;8周时出现大量胶原纤维,周边成骨明显;12周时,纤维组织减少,成骨活跃。结论异种DPB是一种良好的组织工程骨载体材料,可为再血管化和成骨细胞的分化提供一个稳定的环境。     

基底膜对异种脱细胞真皮基质移植免疫排斥反应的影响

目的比较去基底膜与保留完整基底膜的异种脱细胞真皮基质（Xeno-ADM）移植免疫学方面的差异。方法建立SD大鼠皮下脱细胞真皮基质（ADM）移植模型，120只SD大鼠随机分为4组：去基底膜组、基底膜组、自体组、空白对照组。分别将带基底膜和去基底膜的Xeno-ADM植入大鼠背部皮下，自体组分别将大鼠自体真皮基质植入大鼠背部皮下，空白对照组不植入任何材料。于术后2-32周进行组织学观察，并采用Elisa和实时定量PCR方法，检测ADM移植后血清中TNFα、IFNγ、IL-6和IgG表达水平的动态变化。结果移植早期（〈16周）基底膜组移植物炎性反应程度较去基底膜组强烈，IgG表达水平在ADM移植2周时最高，而TNFα、IFNγ、1L-6表达水平在ADM移植后8周最高，上述所有指标在移植后16周时趋向稳定，接近对照组。但3个实验组的TNFα、IFNγ、IL-6和IgG表达水平高低依次为：基底膜组〉去基底膜组〉自体组。结论移植早期（〈16周），去基底膜的Xeno-ADM移植优于带基底膜的Xeno-ADM移植。基底膜成分是Xeno-ADM移植早期引发宿主免疫反应增强的一个因素。     

自体移植的大鼠骨髓间充质干细胞在脊髓损伤处的存活及分化

目的观察自体移植的骨髓间充质干细胞(BMSC)在脊髓损伤(SCI)处的存活及向神经细胞分化情况。方法将36只雄性SD大鼠随机分为PBS注射组(PBS组)和BMSC自体移植组(BMSC组)。BMSC组大鼠在术前均进行自体BMSC分离培养。2组大鼠均采用改良Allen撞击装置制备T9水平的SCI模型,PBS组于损伤处注射PBS,BMSC组注射第4代自体BMSC。于移植后2、3、5周采用Basso-Beattie-Bresnahan(BBB)评分法进行运动功能评分;移植后2、3、5周取损伤部位脊髓,采用Hoechst33342染色法观察移植细胞存活情况,同时行免疫荧光化学染色检测自体移植的BMSC中微管相关蛋白2(MAP-2)及胶质纤维酸性蛋白(GFAP)的表达情况。结果移植后2、3、5周,BMSC组大鼠BBB评分均高于PBS组,差异有统计学意义(P<0.05)。移植后2、3、5周,BMSC组大鼠损伤处脊髓有不同数量Hoechst33342标记细胞存活,其中2周时细胞存活较多,5周时细胞存活较少;移植后2、3周,未检测到移植细胞表达MAP-2及GFAP,5周时检测到部分移植细胞表达MAP-2和GFAP。结论SCI后立即进行移植的自体BMSC可在损伤处存活,部分存活细胞可向神经元和星形胶质细胞方向分化,促进大鼠后肢运动功能的恢复。     

Osteocyte viability and regulation of osteoblast function in a 3D trabecular bone explant under dynamic hydrostatic pressure.

A new trabecular bone explant model was used to examine osteocyte-osteoblast interactions under DHP loading. DHP loading enhanced osteocyte viability as well as osteoblast function measured by osteoid formation. However, live osteocytes were necessary for osteoblasts to form osteoids in response to DHP, which directly show osteoblast-osteocyte interactions in this in vitro culture. INTRODUCTION: A trabecular bone explant model was characterized and used to examine the effect of osteocyte and osteoblast interactions and dynamic hydrostatic pressure (DHP) loading on osteocyte viability and osteoblast function in long-term culture. MATERIALS AND METHODS: Trabecular bone cores obtained from metacarpals of calves were cleaned of bone marrow and trabecular surface cells and divided into six groups, (1) live cores + dynamic hydrostatic pressure (DHP), (2) live cores + sham, (3) live cores + osteoblast + DHP, (4) live cores + osteoblast + sham, (5) devitalized cores + osteoblast + DHP, and (6) devitalized cores + osteoblast + sham, with four culture durations (2, 8, 15, and 22 days; n = 4/group). Cores from groups 3-6 were seeded with osteoblasts, and cores from groups 5 and 6 were devitalized before seeding. Groups 1, 3, and 5 were subjected to daily DHP loading. Bone histomorphometry was performed to quantify osteocyte viability based on morphology and to assess osteoblast function based on osteoid surface per bone surface (Os/Bs). TUNEL staining was performed to evaluate the mode of osteocyte death under various conditions. RESULTS: A portion of osteocytes remained viable for the duration of culture. DHP loading significantly enhanced osteocyte viability up to day 8, whereas the presence of seeded osteoblasts significantly decreased osteocyte viability. Cores with live osteocytes showed higher Os/Bs compared with devitalized cores, which reached significant levels over a greater range of time-points when combined with DHP loading. DHP loading did not increase Os/Bs in the absence of live osteocytes. The percentage of apoptotic cells remained the same regardless of treatment or culture duration. CONCLUSION: Enhanced osteocyte viability with DHP suggests the necessity of mechanical stimulation for osteocyte survival in vitro. Furthermore, osteocytes play a critical role in the transmission of signals from DHP loading to modulate osteoblast function. This explant culture model may be used for mechanotransduction studies in long-term cultures.     

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。     

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

目的 探讨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可行性.方法 应用电子束熔化成形技术制备支架,将成骨细胞与支架复合培养7 d后,通过扫描电镜观察细胞与材料复合情况.将培养7 d的支架/细胞复合物及单纯支架植入兔体内.72只雄性新西兰白兔均制作骨膜-骨缺损模型后随机分为4组(n=18):A组缺损处植入细胞/支架复合物,B组缺损处植入单纯支架,C组缺损处旷置,D组缺损处置入自体骨.分别在第4、8、12周取材,行大体观察、四环素荧光标记、组织学观察以及新生骨定量分析等评价新骨形成及缺损愈合情况.结果 支架与细胞体外共培养7 d后,支架表面及内部孔隙有大量细胞黏附并与材料牢固结合.第12周,新生骨组织和血管不仅在支架周围有生长,而且沿着支架的管道结构向支架内部生长并逐渐填满支架内部,新生骨组织与支架牢固结合并形成一个相互嵌合的复合体.新生骨定量分析显示:第4周,各组间两两比较,差异均无统计学意义(P＞0.05).第8周,A组分别与B、C组比较,差异均有统计学意义(P＜0.05);D组分别与B、C组比较,差异均有统计学意义(P＜0.05).第12周,组间两两比较,差异均有统计学意义(P＜0.05).结论 可控微结构电子束熔化成形钛合金支架具有良好的生物相容性,能够促进支架内新骨生成及缺损的愈合.     

成骨细胞复合β-磷酸三钙异位成骨的实验研究

目的：评价成骨细胞复合多孔β-磷酸三钙支架在大鼠肌肉中的成骨效果。方法：分别在植入1、4、8周后,将成骨细胞β-磷酸三钙复合物取出行HE染色观察新骨形成情况,并应用KS4003．0软件进行新骨生成分析。结果：植入1周后所有标本都未发现骨生成;在4周后实验组新骨生成量为6．35％,对照组为1．32％：8周后实验组新骨生成晕为21．58％,对照组新骨生成量为4．78％。两组比较有显著性差异。结论：成骨细胞复合多孔β-磷酸二钙支架可以促进新骨生成。     

Biological alchemy: engineering bone and fat from fat-derived stem cells

Adipose tissue contains a population of pluripotent stem cells capable of differentiating along multiple mesenchymal cell lineages. In this study the authors isolated these fat-derived stem cells successfully from Lewis rats and induced differentiation along adipogenic and osteogenic lineages in vitro and in vivo. Induction was stimulated by exposing stem cells to lineage-specific induction factors. Adipocyte-inducing media contained dexamethasone, insulin, and isobutyl-methylxanthine. Osteoblast inducing media contained dexamethasone, beta-glycerophosphate, and ascorbic acid. Undifferentiated stem cells were maintained in minimal essential media alpha and fetal bovine serum. At 10 days, cells cultured in adipogenic media differentiated into adipocytes in vitro, as evidenced by positive Oil red O staining of lipid vacuoles. At 21 days, cells cultured in osteogenic media differentiated into osteoblasts in vitro as demonstrated by Alizarin red staining of a calcified extracellular matrix and immunohistochemical staining for osteocalcin. Differentiated cells were seeded at a density of 5 x 106 cells onto 15 x 15-mm polyglycolic acid grafts and implanted subcutaneously into three groups of Lewis rats: Group I contained undifferentiated stem cell grafts, group II contained adipocyte grafts, and group III contained osteoblast grafts. At weeks 4 and 8, in vivo fat formation was demonstrated in group II rats, as confirmed by Oil red O staining. At 8 weeks, group III rats demonstrated in vivo bone formation, as confirmed by the presence of osteocalcin on immunohistochemistry and the characteristic morphology of bone on hematoxylin-eosin staining. Group I rats demonstrated no in vivo bone or fat formation at either time interval. These results demonstrate the ability to isolate pluripotent stem cells from adipose tissue, to induce their differentiation into osteoblasts and adipocytes in vitro, and to form bone and fat subsequently in vivo. This is the first published report of in vivo bone formation from fat-derived stem cells. These cells may eventually serve as a readily available source of autologous stem cells for the engineering of bone and fat.     

辛伐他汀联合BMSCs治疗激素性股骨头坏死的实验研究

目的 单纯BMSCs治疗激素性股骨头坏死的效果尚不理想,探讨辛伐他汀联合BMSCs治疗激素性股骨头坏死的可行性. 方法 取24只新西兰大白兔骨髓分离培养BMSCs,取第2代细胞制备为1×107/mL,细胞悬液,与明胶海绵复合.取70只新西兰大白兔经耳缘静脉注射10.μg/kg脂多糖,24 h后臀肌注射20 mg/kg甲基强的松龙琥珀酸钠,共3次,每次间隔24 h,制备股骨头坏死模型.选取制备成功的48只,随机分为4组,每组12只.A组不作任何处理B组单纯减压,并于减压通道植入明胶海绵;C组减压同时植入复合BMSCs的明胶海绵;D组减压同时植入复合BMSCs的明胶海绵,每日灌服辛伐他汀(10 mg/kg)至处死.观察动物一般情况,于术后4、8周各组取6只行MRI扫描后,处死取股骨头行组织学及免疫组织化学染色,扫描电镜观察. 结果 术后8周C、D组动物走路姿势逐步好转.术后4周各组MRI未见明显坏死区信号改变,8周时A组可见坏死低信号区明显扩大,B组无变化,C组范围缩小,D组明显缩小.组织病理学观察,术后4周A组见空骨陷窝,无新生毛细血管;B组空骨陷窝较多,有少量新生毛细血管;C、D组空骨陷窝减少,坏死区有大量增生活跃的成骨细胞及新生毛细血管.D组空骨陷窝阳性数及微血管密度分别为19.30±1.52和7.08±1.09,与其他组比较差异有统计学意义(P＜0.05).术后8周,A组可见部分骨小梁断裂;B组减压孔道有纤维性骨痂形成;C组空骨陷窝少见,髓腔形态不规则;D组大量新生骨形成,髓腔较规则,髓内脂肪细胞大小及分布均匀.D组空骨陷窝阳性数及微血管密度分别为11.31±1.28和12.37±1.32,与其他组比较差异有统计学意义(P＜0.05),与术后4周比较差异有统计学意义(P＜0.05).扫描电镜观察术后8周,A组骨小梁见多处断裂塌陷,骨小梁表面未见骨细胞,髓腔内有大量脂肪细胞堆积;B组部分骨小梁可见裂痕;C组骨小梁不致密;D组骨小梁结构规整致密,成骨细胞多,骨细胞及基质胶原纤维正常,髓腔规则. 结论 辛伐他汀能促进BMSCs成骨及成血管化,辛伐他汀联合BMSCs治疗激素性股骨头坏死具有较好的应用前景.     

Osteogenic evaluation of glutaraldehyde crosslinked gelatin composite with fetal rat calvarial culture model

The cytotoxicity of the synthetic bone substitute composed of tricalcium phosphate and glutaraldehyde crosslinked gelatin (GTG) were evaluated by osteoblast cell culture. In a previous study, the GTG composites were soaked in distilled water for 1, 2, 4, 7, 14, 28, and 42 days, and then the solutions (or extracts) were cocultured with osteoblasts to evaluate the cytotoxicity of GTG composites by alive cell counting. In this study, the extracts were cocultured with the osteoblasts; thereafter, the concentration of transforming growth factor-beta (TGF-beta1) and prostaglandin E2 (PGE2) in the medium was analyzed to strictly reflect the biological effects of GTG composites on the growth of osteoblasts. In order to investigate the osteoconductive potential of the GTG composites on new bone formation in a relative short term, a model of neonatal rat calvarial organ culture was designed prior to animal experiments. Three experimental materials of 4, 8, and 12% GTG composites were evaluated by fetal rat calvarial organ culture for their ability for bone regeneration. Deproteinized bovine and porcine cancellous bone matrixes were used as the controlled materials. All the organ culture units were maintained in cultured medium for 5 weeks. Following the culture period, the morphology of tissue was observed under an optical microscope, and the quantitative evaluation of the new generation bone was determined by using a semiautomatic histomorphometeric method. Except in the initial 4 days, the concentration of TGF-beta1 of 4% and 8% GTG composites was higher than that of the blank group for all the other experimental time periods. The PGE2 concentration for 4% and 8% GTG composites was lower than that of the blank group. It revealed that the 4% and 8% GTG composites would not lead to inflammation and would promote osteoblast growth. The morphology and activity of the osteoblasts were not transformed or changed by the 2 GTG composites. For the 12% GTG composite, the performance of the in vitro condition was inferior to the blank group and the other 2 GTG composites. Although the concentration of TGF-beta1 and PGE2 was gradually back to normal after 14 days, the morphology of the osteoblasts was abnormal with features such as contracted cytoplast structures. The osteoblast was damaged perhaps in the initial stage. We suggested that the 4% and 8% GTG composites should be soaked in distilled water at least for 4 days before medical applications. The 12% GTG composite and the composites with a concentration of glutaraldehyde solution higher than 12% were not recommended as a medical prostheses in any condition. The fetal rat calvaria culture also showed the same results with the analysis of TGF-beta1 and PGE2. From the study, we could predict the results of animal experiments in the future.