胶原凝胶包埋软骨细胞接种CPPf/PLLA支架体外构建组织工程软骨

目的:探讨软骨细胞均匀、高效种植于三维支架的细胞接种方法.方法:将胶原凝胶包埋的软骨细胞整合入CPPf/PLLA三维支架并进行体外培养,细胞计数检测细胞粘附情况,倒置显微镜观察细胞在支架内分布的均一性,组织形态学检测细胞-胶原凝胶-支架复合物形成软骨组织的情况.结果:超过90%的种植细胞能有效、均匀种植于CPPf/PLLA支架,体外培养3周的复合物能形成较成熟的工程化软骨组织.结论:胶原凝胶包埋软骨细胞三维接种能有效提高组织工程软骨的体外构建质量,同时结合了两种材料的优势.     

胶原凝胶包埋软骨细胞接种CPPf/PLLA支架体外构建组织工程软骨

目的：探讨软骨细胞均匀、高效种植于三维支架的细胞接种方法。方法：将胶原凝胶包埋的软骨细胞整合入CPPf／PLLA三维支架并进行体外培养，细胞计数检测细胞粘附情况，倒置显微镜观察细胞在支架内分布的均一性，组织形态学检测细胞-胶原凝胶-支架复合物形成软骨组织的情况。结果：超过90％的种植细胞能有效、均匀种植于CPPf／PLLA支架，体外培养3周的复合物能形成较成熟的工程化软骨组织。结论：胶原凝胶包埋软骨细胞三维接种能有效提高组织工程软骨的体外构建质量，同时结合了两种材料的优势。     

胶原凝胶包埋软骨细胞复合聚磷酸钙纤维/左旋聚乳酸支架异体移植修复兔关节软骨缺损

目的探讨胶原凝胶包埋软骨细胞复合聚磷酸钙纤维／左旋聚乳酸(CPPf／PLLA)支架异体移植修复兔关节软骨缺损的有效性和可行性。方法将胶原凝胶包埋的软骨细胞接种CPPf/PLLA支架构建的复合物体外培养3周，行倒置显微镜和扫描电镜观察，并将复合物异体移植入兔关节软骨缺损，术后4、8、12周取材，从大体、组织学和Ⅱ型胶原免疫组织化学对再生软骨组织进行评价。结果复合物体外培养3周，细胞被大量基质包裹，在支架内分布均匀；新形成的组织为透明软骨样组织、表面光滑且与周围组织整合良好、基质内有Ⅱ型胶原分布。结论胶原凝胶包埋软骨细胞接种CPPf／PLLA支架的方法能提高细胞一支架复合物构建质量，胶原凝胶复合CPPf／PLLA支架可作为软骨细胞载体修复关节软骨缺损。     

脱细胞软骨细胞外基质取向支架复合软骨细胞构建组织工程软骨的实验研究北大核心CSCD

目的探讨脱细胞软骨细胞外基质(acellular cartilage extracellular matrix,ACECM)取向支架复合软骨细胞构建组织工程软骨的可行性。方法取市售猪关节软骨组织,分离培养关节软骨细胞并传代。取第3代软骨细胞行PKH26荧光标记,MTT检测标记对细胞增殖无影响后,分别取标记及未标记的软骨细胞复合ACECM取向支架并体外培养后,大体观察支架形态,倒置显微镜、荧光显微镜观察软骨细胞在支架中的黏附、生长和分布情况,扫描电镜观察支架中细胞形态,Ⅱ型胶原免疫荧光染色观察软骨细胞外基质分泌情况。将PKH26标记的软骨细胞-支架复合物植入裸鼠背部皮下腔隙,术后观察裸鼠一般情况,4周后分子荧光活体成像系统无创伤性评估细胞-支架复合物生长情况,取材行大体观察以及番红O、甲苯胺蓝、Ⅱ型胶原免疫组织化学染色观察,评价形成软骨组织的能力。结果细胞-支架复合物体外培养7 d,大体观察呈半透明并具有一定硬度;倒置显微镜和荧光显微镜观察软骨细胞在支架上能良好黏附生长,并沿支架管道方向生长,分泌Ⅱ型胶原。细胞-支架复合物植入裸鼠皮下后,分子荧光活体成像系统观察示细胞均存活;术后4周,大体观察见复合物呈类软骨样组织,组织学染色及Ⅱ型胶原免疫组织化学染色示细胞周围软骨细胞外基质分泌,可见"陷窝"样结构形成。结论 ACECM取向支架有利于软骨细胞的黏附、增殖及取向性分布类似于正常软骨结构,并在裸鼠皮下成功异位构建组织工程软骨。     

胶原海绵与兔软骨细胞体外三维培养的实验研究

目的 观察用人胎盘Ⅰ型胶原海绵作为兔软骨细胞体外三维培养支架时，软骨细胞形态学特征和功能及该支架的吸附性和组织相容性。方法 将新生兔原代和传代软骨细胞接种于人胎盘Ⅰ型胶原海绵进行体外培养，用光镜和扫描电镜观察细胞形态和结构及支架的吸附性和组织相容性，用免疫组化观察细胞Ⅱ型胶原合成。结果 以胶原海绵作为支架的传代软骨细胞能维持其形态学特征及细胞功能，该支架有较好的吸附性和组织相容性。结论 人胎盘Ⅰ型胶原海绵可作为软骨细胞体外三维培养较好的支架材料。     

胶原-透明质酸支架的制备及其与软骨细胞复合培养的实验研究

目的制备胶原-透明质酸支架,评价其与兔髁状突软骨细胞的生物相容性,探讨其应用于关节软骨组织工程的可行性。方法冷冻干燥法制备胶原-透明质酸复合多孔海绵支架材料,将其与碳化二亚胺[1-ethyl-3-（3-dimethyl aminopropyl）carbodiimide,EDC]进行化学交联。分别采用体积法和体外酶解实验测定支架材料孔隙率和降解率,扫描电镜观察交联前后支架材料的形态变化。取3周龄新西兰兔髁状突软骨细胞,体外培养5d后,甲苯胺蓝染色,倒置相差显微镜下观察行细胞鉴定。取消化后第2代软骨细胞接种至支架材料复合培养,倒置相差显微镜下观察细胞生长情况。复合培养1、3、5、7和10d后,PBS液清洗3次,置入24孔板并以0.25%胰酶和0.1%EDTA消化细胞,采集细胞进行细胞计数并绘制细胞生长曲线。另取部分样本继续培养5d,行组织学和扫描电镜观察。结果胶原-透明质酸支架材料经化学交联后,具有合适的三维多孔结构,孔隙率为83.7%,孔径100-120μm;交联后抗酶解能力显著增加。髁状突软骨细胞在其表面和内部贴附良好,形成细胞-材料复合体,细胞增殖实验显示,复合培养1d,材料中细胞数为3.7×104/支架,10d后增至8.2×104/支架。电镜观察见细胞周围有基质分泌。结论EDC交联后的胶原-透明质酸支架具有良好空间结构和生物相容性,可作为支架材料用于髁状突软骨组织工程的研究。     

β-连环蛋白对猪关节软骨细胞合成糖胺多糖的影响

目的 探讨β-连环蛋白对软骨细胞合成糖胺多糖含量的影响.方法 通过Ⅱ型胶原酶消化法获得高活性的软骨细胞,定量接种6×106个细胞于培养皿,在细胞贴壁后更换培养基时,加入β-连环蛋白10μg /L,每周传代一次,连续5周,留取所有培养液,用阿利新蓝法测定软骨细胞糖胺多糖的变化;利用光镜观察原代及传代软骨细胞的生长情况.以50×106/ml浓度均匀接种于经聚乳酸包埋聚羟基乙酸(Polyglycolic acid,PGA)高分子聚合物支架,形成细胞支架复合体,扫描电镜观察细胞生长情况.结果 体外培养的软骨细胞生长情况良好;软骨细胞从传代后合成糖胺多糖类基质,第2代传代细胞分泌GAG的能力最强;加入β-连环蛋白能明显促进传代软骨细胞合成大量的糖胺多糖类基质;扫描电镜显示软骨细胞与材料具有良好的相容性,培养7 d有基质沉积.结论 β-连环蛋白能明显促进体外培养的传代软骨细胞合成大量的糖胺多糖类基质;PLA包埋PGA是软骨细胞良好的支架.     

兔软骨细胞在可注射温敏型壳聚糖/聚乙烯醇凝胶中生长的研究

目的 探讨以壳聚糖(CS)和聚乙烯醇(PVA)制备的可注射温敏型凝胶作为兔软骨细胞生长支架的可行性.方法 将壳聚糖和聚乙烯醇溶液混合制成温敏型凝胶,取第三代软骨细胞接种于凝胶支架,于接种后24、48和72 h采用MTT测定细胞活性及毒力;于1、2及3周后采用扫描电镜及共聚焦激光扫描荧光显微镜观察软骨细胞在凝胶中的形态及生长状态.结果 MTT结果显示接种细胞数量随着接种细胞生长时间的推移而明显增加,各组之间差异有统计学意义(P＜0.05).扫描电镜及激光共聚焦荧光显微镜观察表明软骨细胞在CS/PVA凝胶支架中生长良好.软骨细胞在凝胶支架中保持了很高的增殖能力,材料对细胞无明显不良反应.结论 壳聚糖/聚乙烯醇混合凝胶可作为兔软骨细胞培养的生长支架,应用于软骨组织工程.     

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;     

软骨细胞与静电纺丝聚已内酯支架灌流培养构建组织工程软骨的实验研究

目的 采用静电纺丝聚已内酯(polycaprolactone,PCL)支架与软骨细胞复合培养,比较静态和灌流生物反应器培养条件下对细胞增殖及基质分泌的影响.方法 构建PCL支架,自制灌流生物反应器,分离兔软骨细胞,培养后接种于PCL支架,分为灌流培养组和静态培养组.在培养第3、7、14天对支架-细胞复合体行扫描电镜观察,DNA、糖胺聚糖和总胶原定量检测;在培养第14天分析软骨特异性基因表达并观察软骨基质分泌情况.结果 电镜观察PCL支架纤维直径(1.67±0.76) μm,孔径(17.65土7.11)μm,可见支架中软骨细胞黏附生长良好,灌流培养条件下细胞增殖快,且较好地保持了软骨细胞特征形态.在培养第7天,灌流培养组DNA定量高于静态培养组;在培养第3、7和14天,灌流培养组糖胺聚糖定量均高于静态培养组,灌流培养组糖胺聚糖/DNA比值均高于静态培养组.在培养第14天,灌流培养组Ⅱ型胶原、蛋白聚糖基因表达增加;软骨分化指数高于静态培养组.在培养第14天,组织学染色可见灌流培养促进细胞的增殖和渗透生长,提高了软骨基质的分泌,并见软骨陷窝样结构.结论 在灌流生物反应器培养条件下,静电纺丝PCL支架与软骨细胞复合培养可促进软骨细胞的增殖和基质的分泌,提高了组织工程软骨的质量.     

海螵蛸与兔软骨细胞组织的生物相容性

目的 探讨海螵蛸作为新生兔关节软骨体外细胞培养支架材料的可行性.方法 消化分离新生兔关节软骨细胞,接种于自制海螵蛸片支架上培养,从倒置相差显微镜和扫描电镜观察其亲水性和对细胞的吸附力.结果 预湿海螵蛸支架的亲水性优于未预湿海螵蛸支架,使软骨细胞更易扩散至支架孔隙.软骨细胞-支架复合体培养1周后,细胞开始在预湿海螵蛸支架上黏附、伸展、增殖;2周后细胞融合成片,布满整个支架孔隙并产生基质.结论 海螵蛸多孔支架与兔软骨细胞具有良好的生物相容性,可以作为软骨组织工程中细胞培养支架的新材料.     

Three-dimensional seeding of chondrocytes encapsulated in collagen gel into PLLA scaffolds

Tissue engineering approaches have been clinically tried to repair damaged articular cartilages. It is an essential step to uniformly seed chondrocytes into 3D scaffolds in order to reconstruct tissue-engineered cartilages in vitro, but the tissue engineering could not have been provided with efficient cell seeding methods. Type I collagen is clinically used and known as a cytocompatible material, having recognition sites for integrins. Collagen gel encapsulating chondrocytes has been tried for making regenerated cartilages, but it is found difficult to have the gel keep its original shape after long-term culture, because of shrinking. On the other hand, 3D scaffolds, either of a nonwoven structure or a sponge-like structure, involve difficulty in that chondrocytes could not be uniformly seeded, although they have adequate initial mechanical properties. In this study, by combining collagen gelation with a nonwoven PLLA scaffold, we achieved uniform cell seeding into the 3D scaffold. Bovine articular chondrocytes were mixed with type I collagen solution, and the solution was poured into the nonwoven PLLA scaffold (1.5 mm thick, diameter 15 mm). The collagen-chondrocyte mixture was made into gel at 37 degrees C for 1 h. The 0.39% collagen mixture was viscous enough to prevent cells from precipitating during gelation. Almost all chondrocytes were able to be incorporated into the PLLA scaffolds by mixing with collagen solution and subsequently making into gel, while 30-40% of the chondrocytes seeded as a cell suspension were not trapped into the PLLA scaffolds. The method presented, where chondrocytes were mixed with collagen solution, and the mixture was incorporated into a 3D scaffold, then made into gel in the scaffold, could serve as an alternative for in vitro cartilage regeneration, also simultaneously having the advantages of both materials.     

胶原/羟基磷灰石支架负载软骨细胞修复兔膝关节骨软骨缺损

目的 探讨胶原复合梯度羟基磷灰石(Col/HA)双相支架负载软骨细胞修复兔膝关节骨软骨缺损的可行性及疗效.方法 构建Col/HA双相支架,将软骨细胞种植于支架培养1周,再将软骨细胞-支架复合体移植修复兔膝关节股骨髁的骨软骨缺损,并对骨软骨缺损的修复进行检测.结果 光镜及扫描电镜观察显示软骨细胞在Col/HA支架中贴附良好,表型维持稳定,分泌胞外基质.大体观察和组织学检测显示,植入体内16周后实验组软骨层呈透明软骨样修复,软骨下骨缺损有新骨构建;对照组骨软骨缺损修复不良,组织学检测以纤维性组织或纤维软骨组织形成.Wakitani评分显示实验组修复组织优于对照组,差异有统计学意义(P＜0.05).结论 双相Col/HA复合支架可作为骨软骨组织工程支架,负载软骨细胞可修复兔膝关节骨软骨缺损,重建关节软骨的结构和功能.     

取向聚乙醇酸聚乳酸共聚物支架的制备及初步实验观察

目的 研制聚乙醇酸聚乳酸共聚物(PLGA)材料的纵向取向支架,观察体外生物相容性、细胞在支架内分布等特性,探讨其作为关节软骨组织工程支架的可能性.方法 相分离法制备纵向取向PLGA支架,等离子改性、胶原包埋处理,体外接种关节软骨细胞,在环境扫描电镜下观察细胞生长、分布情况.结果 研制的PLGA取向支架生物相容性明显提高,细胞沿纵向管道垂直排列,细胞分布均匀,单侧加载细胞进入深度可达2.5 nlln.结论 取向支架能明显改善细胞在载体内的分布,细胞纵向排列接近关节软骨细胞排列方式.     

Effects of serial expansion of septal chondrocytes on tissue-engineered neocartilage composition.

OBJECTIVES: Cartilage grafts for reconstructive surgery may someday be created from harvested autologous chondrocytes that are expanded and seeded onto biodegradable scaffolds in vitro. This study sought to quantify the biochemical composition of neocartilage engineered from human septal chondrocytes and to examine the effects of cell multiplication in monolayer culture on the ultimate composition of the neocartilage. METHODS: Human septal chondrocytes from 10 donors were either seeded immediately after harvest (passage 0 [P(0)]) onto polyglycolic acid (PGA) scaffolds or underwent multiplication in monolayer culture before scaffold seeding at passage 1 (P(1)) and passage 2 (P(2)). Cell/scaffold constructs were grown in vitro for 7, 14, and 28 days. Neocartilage constructs underwent histologic analysis for matrix sulfated glycosaminoglycan (S-GAG) and type II collagen as well as quantitative assessment of cellularity (Hoescht 33258 assay), S-GAG content (dimethylmethylene blue assay), and collagen content (hydroxyproline assay). RESULTS: Histologic sections of constructs seeded with P(0) cells stained strongly for S-GAG and type II collagen, whereas decreased staining for both matrix components was observed in constructs derived from P(1) and P(2) cells. Cellularity, S-GAG content, and total collagen content of constructs increased significantly from day 7 to day 28. S-GAG accumulation in P(0) constructs was higher than in either P(1) (P < 0.05) or P(2) (P < 0.01) constructs, whereas cellularity and total collagen content showed no difference between passages. CONCLUSION: Neocartilage created from chondrocytes that have undergone serial passages in monolayer culture exhibited decreased matrix S-GAG and type II collagen, indicative of cellular dedifferentiation. SIGNIFICANCE: The alterations of matrix composition produced by dedifferentiated chondrocytes may limit the mechanical stability of neocartilage constructs.     

人脐带间充质干细胞的分离培养及其与胶原支架材料的相容性

目的探讨人脐带间充质干细胞(Mesenchymal stem cells,MSCs)体外分离、培养的方法,观察其与胶原蛋白支架的相容性,为进一步研究提供依据。方法利用组织体外培养法分离人脐带MSCs,流式细胞学分析细胞表型,组织化学观察细胞分化能力;将细胞接种于胶原蛋白支块架上,观察细胞在材料中的形态、粘附情况和增殖特点。结果直接贴壁法分离的细胞表型均一,体外具有成骨和成脂肪能力;细胞在支架上有较好的粘附铺展,培养2周后,MSCs占据支架总体积的80%,细胞分布较均匀。结论组织块培养法可获得高纯度的人脐带MSCs,细胞在体外与胶原蛋白支架有较好的组织相容性。     

Effects of a chitosan scaffold containing TGF-beta1 encapsulated chitosan microspheres on in vitro chondrocyte culture

The objectives of this study were (1) to develop a three-dimensional chitosan scaffold in combination with transforming growth factor-beta1 (TGF-beta1)-loaded chitosan microspheres and (2) to evaluate the effect of the TGF-beta1 release on the chondrogenic potential of rabbit chondrocytes in the scaffolds. TGF-beta1 was loaded into chitosan microspheres using an emulsion-crosslinking method, resulting in spherical shapes with a size ranging from 0.3 to 1.5 microm. Controlled release of TGF-beta1, as measured by enzyme-linked immunosorbent assay (ELISA), was observed with chitosan microspheres over 7 days. Chitosan solutions (2% and 3%) were fabricated into two types of scaffolds with different pore morphologies and mechanical properties using a freeze-drying technique, with the result that scaffold with higher concentrations showed smaller pores and lower porosity, leading to a much stronger scaffold. The TGF-beta1 microspheres were incorporated into the scaffolds at a concentration of 10 ng TGF-beta1/scaffold and then chondrocytes seeded into each scaffold and incubated in vitro for 2 weeks. The 2% chitosan scaffolds showed higher cell attachment levels than the 3% chitosan scaffolds (P < 0.01), regardless of the TGF-beta1 microspheres. Both the proliferation rate and glycosaminoglycan (GAG) production were significantly higher for scaffolds incorporating TGF-beta1 microspheres than for the control scaffolds without microspheres 10 days after incubation. Extracellular matrix staining by Safranin O and immunohistochemistry for type II collagen both significantly increased in scaffolds containing TGF-beta1 microspheres. These results suggest that the TGF-beta1 microsphere incorporated in scaffolds have the potential to enhance cartilage formation.     

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。