不同持续时间的周期性压力对构建组织工程软骨的影响

目的 探讨在周期性压力条件下构建组织工程软骨每天加压的最佳持续时间.方法 构建自行没汁的生物反应器和往复式加压泵组成的"周期性压力场培养系统",将体外培养的第二代乳兔关节软骨细胞接种到聚乳酸-聚羟幕乙酸共聚物(PLGA)支架上,随机分成四组.第一、二、三组分别在每天持续时间为4、8、12 h的周期性压力(强度0～200 kPa,频率为0.1 Hz)下培养,第四组(对照组)为不加压的静态培养,各组培养时间均为2周.2周后肉眼人体观察,HE染色组织学观察工程软骨细胞增殖及分布;甲苯胺蓝染色法规察硫酸糖氨多糖(GAG)的分泌及分布,并用1,9.二甲基亚甲蓝法定量检测GAG的含接;采用Ⅱ型胶原免疫绀织化学法观察Ⅱ型胶原的分泌及分布,并用image-pro plus图像分析系统对Ⅱ型胶原染色面积行半定量分析.结果 在强度0～200 kPa,频率为0.1 Hz周期性压力作用下,8 h组支架-细胞复合体体积最大,表面光滑、有光泽、有弹性,支架内软骨细胞数量最多,排列最为规则,Ⅱ胶原和GAG含量也最高(P<0.01).结论 软骨细胞的新陈代谢受周期件压力持续时间的影响,在0～200 kPa、0.1 Hz频率作用下,每天持续8 h的周期性压力能更好地促进软骨细胞增殖,合成Ⅱ型胶原、GAG等细胞外基质.     

凝胶包埋脂肪基质细胞接受振荡载荷模式构筑工程化软骨的研究

目的 观察构建工程化软骨生物学行为,评估扩增软骨种子细胞的方法.方法 软骨诱导化脂肪基质细胞(ADSCs),接种至nβ-TCP/Cs/PCL支架构建工程化软骨:A组(凝胶+振荡培养)、B组(凝胶+静态培养)、C组(振荡培养)、D组(静态培养);每组48块构建物,各阶段每组随机取6块,第1、4、8、12、16、20、24、28天,电镜、共聚焦观察,检测存活率、细胞增殖、Ⅱ型胶原(Col-Ⅱ)、DNA及氨基葡聚糖(GAG)含量.结果 A组细胞生长旺盛、细胞外基质丰富,存活率高于其他组(86.39±5.05,P<0.05),增殖活力、Col-Ⅱ、DNA及GAG含量均高于其他组(0.57±0.12,71.30±2.51,73.21±1.38,81.25±1.29,P<0.05).结论 凝胶包埋及振荡方式能扩增种子细胞及优化软骨构建质量.     

周期性压力对组织工程软骨的影响及其作用机制

耳的探讨周期性压力对组织工程软骨的影响及其作用机制。方法取3个月龄新西兰兔关节软骨细胞，培养至第4代后，将软骨细胞随机分为两组。一组为压力组，即关节软骨细胞在周期性压力下培养；另一组为对照组，关节软骨细胞在常规条件下培养。采用组织化学、免疫组织化学观察周期性压力对组织工程软骨的结构以及Ⅱ型胶原分泌的影响。采用激光共聚焦显微镜观察周期性压力对软骨细胞内游离钙离子浓度变化的影响。结果周期性压力下培养的组织工程软骨与常规条件下培养的组织工程软骨相比，支架内软骨细胞数量多、排列规则，Ⅱ型胶原丰富，而且软骨细胞内游离钙离子浓度明显高于对照组。结论周期性压力能够通过增加细胞内游离钙离子浓度来促进软骨细胞的增殖，刺激软骨细胞合成分泌Ⅱ型胶原等细胞外基质。     

组织工程软骨体外构建的相关实验研究

目的 探索组织工程软骨体外构建技术体系可行性.方法 种子细胞选用胎儿软骨细胞(口服药物流产胎儿,胎龄3～6个月).酶消化法获得第1代细胞,以50×106/ml浓度均匀接种于经聚乳酸(PLA)包埋聚乙醇酸(PGA)高分子聚合物支架,形成细胞-支架复合体,在体外静态培养.分别于2周、4周、8周进行大体观察、扫描电镜及组织学检测.结果 体外构建的组织工程软骨,随培养时间延长,色泽由2周时的乳白色逐渐呈现半透明,8周时接近正常软骨外观.扫描电镜显示软骨细胞与材料具有良好相容性,培养7天PGA纤维之间有基质沉积.HE染色示2周有大量软骨陷窝形成和均匀嗜碱性基质分泌,Safranin'O染色示基质有酸性蛋白多糖分布,Massons's trichome染色示基质有胶原成分,但含量较少,经免疫组织化学检测为特异Ⅱ型胶原.培养4周胶原成分开始明显增多,软骨陷窝形态接近成熟,8周细胞外基质蛋白多糖和Ⅱ型胶原含量丰富且分布均匀.结论 以成熟软骨细胞为种子细胞,运用组织工程技术在体外能构建出具有正常软骨组织结构特征的人组织工程软骨.     

自体软骨细胞复合Ⅰ型胶原支架体外动态培养的实验研究

[目的]比较体外静态与动态培养两种方式对培养人关节软骨细胞复合Ⅰ型胶原支架材料的效果,从而探索体外构建移植物用于治疗关节软骨缺损的适宜条件及方式。[方法]分离培养人关节软骨细胞,P2代软骨细胞接种于Ⅰ型胶原支架,随机分为3组,A组:静态培养;B组:动态培养;C组:单层培养。采用倒置相差显微镜、荧光显微镜、SEM、HE染色观察细胞在支架上的分布、黏附、生长及形态特点,实时荧光定量PCR检测软骨细胞表型特异基因Ⅱ型胶原的表达情况。[结果]体外单层培养的软骨细胞(P2)以多角形为主,Ⅱ型胶原蛋白表达阳性,提示P2代细胞表型维持良好;与A组比较,B组细胞数量较多且分布均匀,细胞形态较均一,以多角形为主;A、B组样本大体结构及内部孔隙结构均保持完整,孔隙内均可见细胞黏附,B组孔隙内细胞数量及细胞外基质优于A组;A、B组的Ⅱ型胶原基因mRNA表达水平较单层培养组明显增加。[结论]软骨细胞复合Ⅰ型胶原支架体外动态培养较静态培养可明显促进细胞增殖及细胞外基质分泌。因此,动态培养有望成为体外构建自体软骨细胞移植术所需移植物的一种有效方法。     

共培养系统下软骨细胞对骨髓间质干细胞向软骨细胞分化的诱导作用

 目的观察共培养系统下正常软骨细胞和关节炎软骨细胞对骨髓间质干细胞(bone marrow mesenchymal stem cells,BMSCs)向软骨细胞分化的促进作用。方法分离新西兰兔 BMSCs及正常软骨细胞。制作兔膝关节炎模型,提取兔关节炎软骨细胞。将 BMSCs与低熔点琼脂糖复合成凝胶块,构建软骨细胞-BMCSs共培养系统,分为正常软骨细胞 P0-BMSCs组、正常软骨细胞 P3-BMSCs组、关节炎软骨细胞 P0-BMSCs组、关节炎软骨细胞 P3-BMSCs组及 BMSCs组(对照组)。在 3、7、14天取材行实时定量 PCR、糖胺聚糖含量、细胞活性检测及组织切片观察。结果(1)正常软骨细胞 P0-BMSCs组的 II 型胶原基因表达增强,在 3、7、14天分别为对照组的 5.1、7.2、11.2倍; 正常软骨细胞 P3-BMSCs组 I 、 II 型胶原及蛋白聚糖基因表达均未见增强; 关节炎软骨细胞 P0-BMSCs组蛋白聚糖基因表达增强,在 14天为对照组的 7.8倍; 关节炎软骨细胞 P3-BMSCs组 I 型胶原基因表达水平在三个时间点均低于对照组。(2)正常软骨细胞 P0-BMSCs组糖胺聚糖含量为对照组的 2.59倍。除关节炎软骨细胞 P0-BMSCs组外,其余三组与对照组比较差异均有统计学意义。阿新蓝染色各组均为阳性,正常软骨细胞 P0-BMSCs组的细胞及细胞外基质蓝染最深。结论兔正常 P0软骨细胞与兔关节炎 P0软骨细胞能够有效促进 BMSCs向软骨细胞分化,正常 P3软骨细胞的促分化作用微弱,而关节炎 P3软骨细胞不具有促分化作用。     

力学刺激对体外立体培养软骨细胞基质代谢的影响

目的 分析周期性动态压缩刺激对体外海藻酸钠立体培养关节软骨细胞基质合成代谢的影响。方法 取2月龄新西兰白兔10只,酶解消化获取膝关节全层软骨细胞,以海藻酸钠凝胶立体培养,分为实验组和对照组两组,对照组行静态培养,未施加任何压力;实验组利用Flexcell-5000力学加载系统对体外培养软骨细胞进行周期性压缩应力加载,1 h/d。于加载第7、14、21天留取软骨细胞,采用实时定量聚合酶联反应对软骨细胞蛋白聚糖(aggrecan,AGG)、Ⅱ型胶原、Ⅹ型胶原及基质金属蛋白酶-13(matrix metalloproteinase-13,MMP-13)mRNA进行定量分析。结果实验组在第7天AGG及Ⅱ型胶原mRNA的表达明显增高(P0.05),随加载时间延长,其表达量逐渐下降,在第14、21天两组比较均无明显差异。同时,实验组在第7天时,Ⅹ型胶原及MMP-13的表达无明显差异。第14天,实验组Ⅹ型胶原及MMP-13 mRNA的表达与对照组比较明显增高(P0.05)。结论 立体培养软骨细胞在生理力学刺激7 d时可明显促进其基质合成能力,但随刺激时间的延长,其基质合成能力逐渐减弱,软骨细胞趋于肥大分化。     

胶原-透明质酸-硫酸软骨素复合三维支架体外构建组织工程软骨的实验研究

目的探讨以胶原(collagen,Col)透明质酸(hyaluronic acid,HA)硫酸软骨素(chondroitin sulfate,CS)为支架材料构建组织工程软骨的可行性.方法以乙基-(3-二甲基氨基丙基)碳化二亚胺盐酸盐为交联剂通过冷冻干燥的方法制备Col-HA-CS复合支架及单纯Col支架.通过扫描电镜、HE染色对Col-HA-CS复合支架材料形态进行观察.分离培养幼兔关节软骨细胞,将体外扩增的软骨细胞接种在两种支架上,通过组织学、扫描电镜观察软骨细胞在支架上的生长形态;通过生物化学功能检测细胞-支架复合物中DNA、糖胺聚糖(glycosaminoglycan,GAG)含量;RTPCR方法检测在Col HA CS复合支架上的软骨细胞ColⅡ的表达情况.结果软骨细胞在Col-HA-CS复合支架材料上增殖分化良好,并保持软骨细胞特异的分化ColⅡ表型,培养21 d后已有软骨样组织形成,出现软骨陷窝.DNA和GAG含量测定显示软骨细胞在复合支架上随时间增加逐渐扩增并分泌大量的GAG,含量明显高于单纯Col支架材料,差异有统计学意义(P＜0.05).结论 Col-HA-CS复合支架材料可为软骨细胞生长分化及组织形成提供一个良好的环境,在软骨组织工程的支架材料领域有较广泛的应用前景.     

软骨细胞膜片复合3D打印内支撑构建管状软骨的初步研究

目的 利用猪耳廓软骨细胞制备软骨细胞膜片,与3D打印聚酰胺带孔管状支架结合,构建管状软骨组织,用于气管软骨的缺损重建。方法 用酶消化法分离获得原代猪耳廓软骨细胞,以5×105cells/m L的密度将第2代软骨细胞接种于6 cm细胞培养皿上,在软骨细胞膜片培养环境中培养约14 d,获得完整软骨细胞膜片;4层软骨细胞膜片依次卷叠于3D打印的聚酰胺(PA12)带孔管状内支架上,以构建管状软骨组织复合物;体外静态培养12周或裸鼠皮下培养8周,对形成的管状软骨组织行大体观察及石蜡切片组织学染色鉴定。结果 体外静态培养12周后,半透明管状软骨组织形成,组织学染色可见少量分泌的软骨细胞外基质,质软,弹性差;体内培养8周后,白色管状软骨组织形成,其组织学染色可见大量软骨细胞外基质分泌,质较硬,有一定弹性。结论 利用软骨细胞膜片复合3D打印聚酰胺支架,可构建组织工程管状软骨,有望将其用于气管软骨缺损的修复。     

梯度降解软骨支架材料应力刺激下与骨髓基质干细胞复合三维培养的实验研究

[目的]探讨梯度降解软骨支架材料（GDABM）的细胞生物相容性及诱导后的骨髓基质干细胞（MSCs）在三维支架上培养的生物学行为.[方法]将MSCs与复合转化生长因子-β（TGF-β）的胶原共同混合后培养于三维软骨支架材料上,离心管内培养,10次/d,以600 r/min离心10 min.8 h、24 h、72 h、4 d、7 d进行倒置显微镜形态学观察、扫描电镜观察.1～8 d采用MTT法检测细胞增殖活性,描绘生长曲线.通过3H-Proline掺入实验了解材料对MSCs胶原合成的影响.[结果]8 h后MSCs在支架材料上呈球型黏附生长,4 d后MSCs在支架材料上呈菱形或多角型复层生长,包裹于大量细胞外基质内.GDABM组细胞第3 d进入对数增长期,倍增时间为4.75 d,而单纯软骨细胞培养对照组倍增时间为5.25 d.GDABM组与单纯软骨细胞培养对照组比较胶原合成略低,3H-Proline掺入值有显著性差异（P＜0.05）,说明经诱导MSCs的细胞胶原分泌功能仍低于软骨细胞.[结论]经TGF-β诱导和低转速离心应力刺激后的MSCs向软骨细胞功能分化,复合细胞因子梯度降解软骨支架材料具有良好的生物相容性,可作为MSCs的有效载体应用于组织工程化软骨的构建.     

Variations in matrix composition and GAG fine structure among scaffolds for cartilage tissue engineering

OBJECTIVE: To compare matrix composition and glycosaminoglycan (GAG) fine structure among five scaffolds commonly used for in vitro chondrocyte culture and cartilage tissue engineering. DESIGN: Bovine articular chondrocytes were seeded into agarose, alginate, collagen I, fibrin and polyglycolic acid (PGA) constructs and cultured for 20 or 40 days. In addition to construct DNA and sulfated GAG (sGAG) contents, the delta-disaccharide compositions of the chondroitin/dermatan sulfate GAGs were determined for each scaffold group via fluorophore-assisted carbohydrate electrophoresis (FACE). RESULTS: Significant differences were found in cell proliferation and extracellular matrix accumulation among the five scaffold groups. Significant cell proliferation was observed for all scaffold types but occurred later (20-40 days) in PGA constructs compared to the other groups (0-20 days). By 40 days, agarose constructs had the highest sGAG to DNA ratio, while alginate and collagen I had the lowest levels. Quantitative differences in the Delta-disaccharide composition of the GAGs accumulated in the different scaffolds were also found, with the most striking variations in unsulfated and disulfated delta-disaccharides. Agarose constructs had the highest fraction of disulfated residues and the lowest fraction of unsulfated residues, with a 6-sulfated/4-sulfated disaccharide ratio most similar to that of native articular cartilage. CONCLUSIONS: The similarities and differences among scaffolds in proteoglycan accumulation and GAG composition suggest that the scaffold material directly or indirectly influences chondrocyte proteoglycan metabolism and may have an influence on the quality of tissue engineered cartilage.     

Effect of expansion medium on ex vivo gene transfer and chondrogenesis in type II collagen-glycosaminoglycan scaffolds in vitro

OBJECTIVE: Growth factors can profoundly affect the behaviour of chondrocytes during expansion and subsequent growth in three-dimensional (3-D) scaffolds. Prolonging such effects has stimulated investigation of the transfer of growth factor genes to chondrocytes. This study evaluated the effects of the monolayer expansion medium on the proliferation and cartilage matrix molecule synthesis of chondrocytes in 3-D pellet culture and in type II collagen-glycosaminoglycan (CG) scaffolds, and on ex vivo insulin-like growth factor-1 (IGF-1) gene transfer to articular chondrocytes in monolayer. The possibility of transfecting cells in 3-D culture using CG scaffolds was also investigated and the resulting effect of IGF-1 overexpression on glycosaminoglycan (GAG) biosynthesis in 3-D culture was assessed. METHODS: Two expansion media were compared-one that has been widely used for growing chondrocytes (Medium 1) and one that has been found to increase chondrocyte proliferation rates and preserve the redifferentiation potential of monolayer-expanded chondrocytes when subsequently placed in pellet cultures (Medium 2). Chondrocytes were expanded in monolayer culture and then 1) redifferentiated in 3-D culture, or 2) infected with the IGF-1 gene in monolayer or in type II CG scaffolds. RESULTS: The cell count for first passage chondrocytes was more than 3-fold higher when using Medium 2. In 3-D culture, cells expanded with Medium 2 and seeded in CG scaffolds produced more total GAG/DNA and displayed more intense immunohistochemical staining for collagen type II. Gene transfer and IGF-1 release kinetics from infected cells in monolayer were significantly affected by the composition of the expansion medium, the gene transfer method and time. IGF-1 gene transfer in CG scaffolds resulted in a 35-fold elevation in accumulated IGF-1 released from transfected Medium 2-expanded chondrocytes over controls, and resulted in a 40% increase in accumulated GAG/DNA. CONCLUSION: The composition of the expansion medium significantly affects monolayer proliferation of adult canine chondrocytes, GAG synthesis when the cells are subsequently grown in CG scaffolds, and ex vivo IGF-1 gene transfer.     

The effect of two different bioreactors on the neocartilage formation in type II collagen modified polyester scaffolds seeded with chondrocytes

The effect of dynamic culture conditions on neocartilage formation in type II collagen modified polyester scaffolds was studied. Porcine or human articular chondrocytes were seeded in the scaffolds. The cell-scaffold constructs were cultivated statically, in a rotating-type bioreactor or in a shaker for up to 4 weeks. The cell proliferation, morphology, NO production, synthesis of proteoglycans and collagen, and mechanical properties were evaluated. The results demonstrated that the rotating-type bioreactor promoted the growth of primary porcine chondrocytes, helped to maintain their phenotype, and increased the production of extracellular matrix. The constructs also had the largest dynamic compressive modulus. In the static condition, chondrocytes occupied only the outer margin of the cell-polymer constructs. The poor mass transfer in static condition may have caused a lower pH value in the middle of the constructs and lead further to faster scaffold degradation as well as the weakest neocartilage. Constructs in the shaker produced the highest amount of NO as well as the lowest amount of cells and matrix production. Human or porcine chondrocytes of the second passage seeded in scaffolds were much less viable, with the largest amount of cells and matrix when cultured in rotating-type bioreactors. A larger seeding density was required to form neocartilage from passaged adult chondrocytes.     

Culture of human septal chondrocytes in a rotary bioreactor

Objectives (1) To show that extracellular matrix deposition in 3-dimensional culture of human septal chondrocytes cultured in a rotary bioreactor is comparable to the deposition achieved under static culture conditions. (2) To demonstrate that the biomechanical properties of human septal chondrocytes cultured in a bioreactor are enhanced with time and are analogous to beads cultured under static culture. Study Design Prospective, basic science. Setting Research laboratory. Methods Human septal chondrocytes from 9 donors were expanded in monolayer and seeded in alginate beads. The beads were cultured in a rotary bioreactor for 21 days in media supplemented with growth factors and human serum, using static culture as the control. Biochemical and biomechanical properties of the beads were measured. Results Glycosaminoglycan (GAG) accumulation significantly increased during 2 measured time intervals, 0 to 21 days and 10 to 21 days (P < .01). No significant difference was seen between the static and bioreactor conditions. Substantial type II collagen production was demonstrated in the beads terminated at day 21 of culture in both conditions. In addition, the biomechanical properties of the beads were significantly improved at 21 days in comparison to beads from day 0. Conclusion Human septal chondrocytes cultured in alginate beads exhibit significant matrix deposition and improved biomechanical properties after 21 days. Alginate bead diameter and stiffness positively correlated with GAG and type II collagen accretion. Matrix production in beads is supported by the use of a rotary bioreactor.     

蚕丝在软骨细胞立体培养中的应用

目的 观察蚕丝对软骨细胞的吸附作用及蚕丝对软骨细胞形态和功能的影响。方法 从家蚕蚕茧中抽丝所得的蚕丝经胰蛋白酶消化和聚乳酸包埋,制成三维支架,软骨细胞与蚕丝三维支架进行复合培养,利用相差倒置显微镜、扫描电镜观察软骨细胞生长情况。结果 蚕丝三维支架上滴加软骨细胞悬液后,软骨细胞在不规则轻微漂动和缓慢下沉过程中粘附在蚕丝上,１～２天后完全贴壁。培养３天后软骨细胞开始分裂;５天后,细胞生长增殖十分活跃;     

Comparison of meshes, gels and ceramic for cartilage tissue engineering in vitro

Full-thickness articular cartilage defects lack the capacity of healing because of lack of blood supply and lack of chondrocyte proliferation around the injury site. These factors contribute to the difficulty of getting good healing of cartilage defects. Autologous chondrocyte transplantation has been proposed as a method for treating cartilage defects using chondrocytes grown in vitro, which are then transplanted into the defects using a periosteal flap to retain the cells at the defect site. Studies that followed have attempted to refine this technique by using a cell matrix to support the chondrocytes. The reason for adding a resorbable cell matrix support that acts as a temporary scaffold until the chondrocytes are capable of producing extracellular matrix. Moreover, such a matrix may help in maintaining chondrocyte differentiation and phenotype. In this study, we have investigated the biocompatibility between human chondrocytes and biomaterials that could be used as matrix implants. It is a comparative study in vitro that involves assessing the proliferation and differentiation of human articular chondrocytes cultured on different resorbable biomaterials. Human chondrocytes were isolated from collagenase digest of articular cartilage provided by patients undergoing total knee replacements for osteoarthritis from the non-involved areas of the knee. The chondrocytes were then allowed to proliferate in vitro to increase the number of cells available for study. After adequate multiplication, the cells were seeded onto different biomaterials and allowed to from a cell biomaterial construct. The biomaterials used in this study were collagen I, calcium alginate, agarose, polyglycolic acid and Bioglass 45S5. The cell–biomaterial constructs were then collected at specific time points 3, 7, 14 and 21 days for histological and biochemical studies. The assessment includes studying proliferation, differentiation and extracellular matrix production. This was performed by immunostaining for collagen I and II production and histochemistry staining for glycosaminoglycans. Chondrocyte proliferation was more effective on 3D gels compared to ceramics and mesh. Cells on Bioglass expressed the same collagen type and at the same proportion as that expressed by freshly isolated cells. Moreover, Bioglass has induced cells to re-differentiate after they lost their differentiation in monolayer culture. Overall, however, there was no clear relationship between the cell morphology and type of collagen produced. Bioactive glass seems to behave as a suitable material for chondrocyte tissue engineering because it can maintain a chondrocyte phenotype.     

软骨细胞与脂肪基质细胞共培养体外构建软骨的初步研究

目的 探讨软骨细胞与脂肪基质细胞(adipose-derived stromal cells,ADSCs)共培养体外构建软骨的可行性,并阐明软骨细胞提供的软骨微环境能否诱导ADSCs向软骨细胞分化并形成软骨组织.方法 分别培养扩增人ADSCs与猪耳软骨细胞,将2种细胞按7:3(ADSCs:软骨细胞)比例混匀,以5.0×107/ml的细胞终浓度接种于聚羟基乙酸/聚乳酸(PGA/PLA,直径8 mm,高2 mm)支架作为共培养组,以相同终浓度的单纯软骨细胞和单纯ADSCs分别接种相同支架作为阳性对照组及阴性对照组,以30％上述浓度(1.5×107/ml)的单纯软骨细胞接种作为低浓度软骨细胞对照组.每组各接种6例标本,每例接种细胞悬液200μl.全部标本均于体外培养8周时取材,通过大体观察、组织学、免疫组化及湿重、蛋白多糖定量检测等方法对新生软骨进行初步评价.多样本t检验统计分析各组湿重及蛋白多糖含量差异.结果 各组细胞均与材料粘附良好.共培养组及阳性对照组体外培养8周时基本保持了复合物初始大小和形状,大体观察2组均形成了较成熟软骨组织,组织学显示大量软骨基质和软骨陷窝形成,免疫组化显示软骨特异性细胞外基质Ⅱ型胶原分泌.定量测定结果表明,共培养组的平均湿重为(174±12) mg,平均蛋白多糖含量为(7.6±0.4) mg,两者分别达到阳性对照组的75％ (P＜ 0.01)和79％ (P＜ 0.01).阴性对照组(单纯ADSCs组)明显皱缩变形,组织学未见成熟软骨陷窝.低浓度软骨细胞组明显变薄,新生软骨平均湿重为(85 ±5) mg,是阳性对照组的37％ (P＜ 0.01),只在局部形成了不连续的软骨组织.结论 软骨细胞与ADSCs共培养能够在体外构建较成熟的软骨组织,软骨细胞能够诱导ADSCs成软骨分化及体外形成软骨组织.     

Activation by IL-1 of bovine articular chondrocytes in culture within a 3D collagen-based scaffold. An in vitro model to address the effect of compounds with therapeutic potential in osteoarthritis

OBJECTIVE: To determine the best protocol for the preparation of a tissue-engineered cartilage to investigate the potential anti-arthritic and/or anti-osteoarthritic effects of drugs. METHODS: Calf articular chondrocytes, seeded in collagen sponges were grown in culture for up to 1 month. At day 14 cultures received interleukin (IL)-1beta (ranging from 0.1 to 20 ng/ml) for 1 to 3 days. Analyses of gene expression for extracellular matrix proteins, collagen-binding integrins, matrix metalloproteinases (MMPs), aggrecanases, TIMPs, IL-1Ra and Ikappa-Balpha were carried out using real-time polymerase chain reaction (PCR). Metalloproteinase activities were analysed in the culture medium using both zymography and fluorogenic peptide substrates. RESULTS: We selected a culture for 15 or 17 days with collagen sponges seeded with 10(7) chondrocytes showing a minimal cell proliferation, a maximal sulphated glycosaminoglycan (sGAG) deposition and a high expression of COL2A1, aggrecan and the alpha10 integrin sub-unit and low expression of COL1A2 and the alpha11 integrin sub-unit. In the presence of 1 ng/ml IL-1beta, we observed at day 15 up-regulations of 450-fold for MMP-1, 60-fold for MMP-13, 54-fold for ADAMTS-4 and MMP-3 and 10-fold for ADAMTS-5 and IL-1Ra. Down-regulations of 2.5-fold for COL2A1 and aggrecan were observed only at day 17. At the protein level a dose-dependent increase of total MMP-1 and MMP-13 was noted with less than 15% in the active form. CONCLUSIONS: This in vitro model of chondrocyte culture in three dimensional (3D) seems well adapted to investigate the responses of these cells to inflammatory cytokines and to evaluate the potential anti-inflammatory effects of drugs.     

壳聚糖作为组织工程软骨支架的实验研究

目的 探索壳聚糖作为组织工程技术中软骨细胞培养支架的可行性。方法 消化分离猪耳郭软骨细胞，接种于自制壳聚糖、壳聚糖-胶原复合多孔支架上培养，从光镜和扫描电镜观察其亲水性和对细胞吸附力，MTT检测软骨细胞在壳聚糖、壳聚糖-胶原上的黏附率及壳聚糖、壳聚糖-胶原复合多孔支架对细胞的增殖、功能的影响。结果 软骨细胞能够在壳聚糖、壳聚糖-胶原支架上黏附、伸展、增殖和发挥正常功能，MTT测得细胞黏附率分别为81.25%和87.50%，MTT测得软骨细胞在壳聚糖-胶原支架中的增殖能力较强。结论 壳聚糖、壳聚糖-胶原复合多孔支架与软骨细胞具有较好的相容性，壳聚糖-胶原复合多孔支架更适合作为软骨组织工程中的细胞培养支架。     

Intra-scaffold continuous medium flow combines chondrocyte seeding and culture systems for tissue engineered trachea construction

In this study we tested the possibility of seeding chondrocytes into poly (ethylene glycol)-terephthalate-poly (butylene terephthalate) PEOT/PBT scaffold through an intra-scaffold medium flow and the impact of this continuous medium flow on subsequent chondrocyte-scaffold culture. Eight cubic PEOT/PBT co-polymers (1 cm(3)) were assigned into two groups. In the semi-dynamic seeding group a continuous medium flow was created inside the scaffolds by a pump system. Around six million chondrocytes were harvested each day, suspended in 1 ml medium and delivered onto the scaffold through the perfusion for a sequential five days. Traditional chondrocytes directly seeding and static culture method was performed as control. Scanning electron microscopy (SEM) and histology assessments were performed to evaluate the distribution of chondrocytes inside the scaffolds and MTT test was chosen to check cell vitality. SEM pictures and histology slices from the perfusion group showed a better three-dimensional cell growth and extensive cell distribution inside the scaffolds; while in the control group chondrocytes only dispersedly formed a monolayer on the surface of scaffolds. Accordingly, MTT results from the perfusion group were much higher than those from control group (0.123 vs. 0.067, P<0.01). Continuous medium perfusion inside PEOT/PBT scaffold effectively combines chondrocyte seeding and culture systems for the reconstruction of tissue engineered trachea.