CDMP1转基因间充质干细胞片修复兔软骨缺损

目的 探讨软骨源性形态发生蛋白-1(CDMP-1)转基因细胞片修复兔软骨缺损的能力.方法 腺病毒转染CDMP1基因至第4代兔骨髓间充质干细胞(BMSCs)中,连续培养7～14 d后接种至温度敏感性培养皿中制备细胞片,real time PCR和Western blot法检测转基因细胞片的CDMP1及Ⅱ型胶原蛋白表达;用细胞片工程技术构建组织工程化细胞片并移植入兔甲状软骨缺损处修复软骨缺损.实验分:1)BMSCs细胞片组;2)转染As-CMV-eGFP细胞片组;3)转染As-CMV-hCDMP1-IRES-eGFP细胞片组.分别于术后4和8周检测工程化软骨的Ⅱ型胶原蛋白及蛋白多糖(GAG)表达.结果 检测到转基因细胞片中CDMP1的表达;所获得的工程化软骨免疫组化和阿利新蓝染色显示:A组Ⅱ型胶原蛋白和GAG表达阳性,B组和C组Ⅱ型胶原蛋白和GAG表达阴性(P＜0.05).结论 CDMP转基因细胞片具有较好的软骨分化活性,可有效地修复兔喉软骨缺损.     

骨形态发生蛋白质-4转染骨髓间充质干细胞复合双层聚乳酸羟基乙酸共聚物支架修复兔膝关节软骨缺损

目的:探讨骨形态发生蛋白质-4(BMP-4)基因转染骨髓间充质干细胞(BMSCs)复合聚乳酸羟基乙酸共聚物(PLGA)修复兔全层关节软骨缺损的效果。方法:取兔骨髓间充质干细胞,分离培养后,免疫组织化学鉴定BMSCs。采用电转法将pcDNA 3.1-BMP-4质粒导入BMSCs。转染成功后培养备用。制备直径为4 mm的双层PLGA支架。新西兰大白兔随机分成空白组、PLGA组、PLGA/BMSCs组、PLGA/BMP-4/BMSCs组4组,将双层PLGA支架置入兔双膝关节股骨内侧髁软骨缺损中。观察并记录术后动物膝关节活动情况。第8、16周时取膝关节置入组织行H-E染色,在扫描电镜下观察置入的PLO认新生组织。采用RT-PCR法定量检测4组修复软骨缺损处新生的软骨Ⅱ型胶原、SOX-9、蛋白聚糖基因的表达水平。结果:术后各组动物膝关节活动正常,未见炎症反应。第8、16周时PLGA/BMP--4/BMSCs组兔膝关节损伤修复优于其他3组。H-E染色结果可见PLGA/BMP-4/BMSCs组膝关节损伤修复效果优于其他3组。RT-PCR结果显示PLGA/BMP-4/BMSCs组兔置入的PLGA新生的软骨中Ⅱ型胶原、SOX--9、蛋白聚糖基因的表达水平显著高于其他各组。结论:BMP--4转染BMSCs后能够促进骨髓间充质干细胞分化成软骨细胞,双层PLGA支架置入有利于兔膝关节软骨缺损区的修复。     

GDF-5和Dex通过Wnt/β-catenin信号通路促进rBMSCs体外成软骨分化

目的利用生长分化因子(GDF-5)联合地塞米松(Dex)诱导大鼠BMSCs成软骨分化,并探讨Wnt/β-catenin信号通路在其中的作用。方法用全骨髓贴壁法分离培养SD大鼠BMSCs,取P3代细胞随机分成6组:BMSCs组、BMSCs+Dex组、BMSCs+GDF-5组、BMSCs+GDF-5+Dex组、BMSCs+GDF-5+Dex+SB216763组和BMSCs+GDF-5+Dex+XAV-939组。连续诱导培养14 d,倒置相差显微镜观察细胞形态,Alcian blue染色检测细胞的蛋白聚糖,RT-PCR检测成软骨分化相关基因aggrecan、Col2、Sox9、Col1,Wnt/β-catenin信号通路相关基因Dvl1、Gsk3β、β-catenin mRNA表达,Western blot检测Ⅱ型胶原蛋白和β-catenin蛋白表达。结果与BMSCs组相比,BMSCs+GDF-5+Dex组能够使诱导的细胞蛋白聚糖分泌明显增加;Aggrecan、Col2、Sox9基因表达明显增加(P0.05);Ⅱ型胶原蛋白表达增加(P0.05);β-catenin mRNA及蛋白表达水平也增加(P0.05)。与BMSCs+GDF-5+Dex组相比,添加SB216763组蛋白聚糖,Ⅱ型胶原基因和蛋白表达增加(P0.05);相反,添加XAV-939组相应的成软骨分化基因及蛋白表达下降(P0.05)。结论 GDF-5联合地塞米松(Dex)可诱导大鼠BMSCs成软骨分化,Wnt/β-catenin信号通路可能在其中发挥促进作用。     

以交联透明质酸钠为支架体外构建组织工程软骨

背景：采用组织工程技术再生和重建软骨是目前修复软骨组织缺损效果最好、最有应用前景的方法。 目的：以体外培养的软骨细胞和交联透明质酸钠为支架材料,开发一套体外构建组织工程软骨的完整方案。 方法：分离新西兰兔膝关节软骨细胞,制成细胞悬液滴加于交联透明质酸钠支架上,体外复合培养21 d,提取RNA进行RT-PCR检测,制备冰冻切片进行显微观察和免疫组织化学观察。 结果与结论：软骨细胞接种于交联透明质酸钠支架材料后,可贴附于支架上生长,并且大量细胞聚集成团,在支架材料的纤维间隙中生长或呈单层细胞附着于支架材料纤维。细胞-支架复合物表达软骨组织特异性蛋白聚糖基因和Ⅱ型胶原α1基因,以及软骨组织特异性蛋白Ⅱ型胶原蛋白,可维持软骨细胞表型。表明培养的细胞-支架复合物在体外培养可形成软骨细胞外基质,有望获得组织工程软骨组织。中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程全文链接：     

PLGA-Fibrin杂合支架构建及与脂肪源性干细胞复合成软骨的研究

目的:探讨在特定的软骨细胞诱导培养液中,由纤维蛋白(fibrin)修饰的聚乳酸/聚羟基乙酸共聚物(PLGA)杂合支架材料对脂肪源性干细胞成软骨的影响。方法:PLGA支架材料采用快速成形技术制备;PLGA-Fibrin杂和支架材料采用低温冷冻的方法制备。分离兔脂肪源性干细胞,分别种植在未修饰的PLGA支架材料和Fbirin修饰的PLGA上,并在特定软骨诱导液中培养至14d,分别应用SEM观察杂合支架材料的性能;生化方法检测硫酸软骨素的含量;支架材料的亲水性和细胞黏附能力也被检测。通过体内实验对两种支架材料与干细胞复合修复软骨缺损的性能进行形态学染色和评分。结果:体外研究表明,与未修饰的PLGA支架材料相比,Fibrin修饰的PLGA亲水性明显被提高,同时也提高了干细胞在杂合支架材料上的黏附性能和硫酸软骨素的含量。软骨损伤修复研究表明,脂肪源性干细胞与Fibirn修饰的PLGA支架材料复合后,具有良好的修复软骨缺损的功能,其性能明显优于单纯的PLGA材料复合干细胞。结论:Fibirn修饰的PLGA支架材料可提高脂肪源性干细胞向软骨细胞分化的能力,促进缺损软骨的再生。     

功能性纳米自组装多肽KLPP凝胶修复软骨缺损的实验研究

目的 探讨功能性纳米自组装多肽KLPP凝胶对关节软骨缺损的修复作用。方法 培养人骨髓间充质干细胞（BMSCs）,将BMSCs分为BMSCs-KLD-12组（BMSCs与KLD-12凝胶共培养）和BMSCs-KLPP组（BMSCs与KLPP凝胶共培养）,分别行软骨诱导分化培养,MTT法检测细胞的增殖活性。将人软骨组织分为软骨-KLPP组（制作软骨缺损区并填充KLPP凝胶进行培养）、软骨-KLD-12组（制作软骨缺损区并填充KLD-12凝胶进行培养）、软骨组（仅制作软骨缺损区）。Calcein-AM/PI双染法检测BMSCsKLD-12组及BMSCs-KLPP组的细胞毒性。培养49 d后,收集软骨组、软骨-KLD-12组、软骨-KLPP组的软骨组织进行切片,并行阿尔新蓝染色。Western blot法检测各组中Ⅰ型胶原（Col-Ⅰ）、Ⅱ型胶原（Col-Ⅱ）、Ⅹ型胶原（Col-Ⅹ）的表达。结果 与BMSCs-KLD-12组比较,BMSCs-KLPP组培养1 d、3 d、7 d的细胞增殖率均明显增加（P<0.05）,且Col-Ⅰ、Col-Ⅱ、Col-Ⅹ的相对表达水平明显增加（P<0...     

压应变作用下组织工程软骨的构建

在压应变作用下构建组织工程化软骨。以大鼠的骨髓间充质干细胞（BMSCs）为种子细胞，以壳聚糖海绵为支架材料，利用压应变加载装置对细胞．壳聚糖海绵支架材料的复合物进行体外动态加载，7d后植人大鼠背部皮下，免疫组织化学染色检测Ⅱ型胶原蛋白的分泌，甲苯胺蓝染色检测酸性糖胺多糖的分泌；利用材料试验机对组织块进行生物力学性能检测，从弹性模量方面对比工程化软骨与正常软骨的差异。在大小为1％、频率为1Hz的压应变条件下，构建的组织工程化软骨经体内移植后，分泌软骨基质Ⅱ型胶原及酸性糖胺多糖，其弹性模量较植人前显著增强。在压应变作用下，细胞复合壳聚糖支架材料可以形成初级的组织工程化软骨。     

过表达BMP-4基因的BMSCs复合生物陶瓷骨在同种异体骨缺损模型中的研究

目的 研究骨形态发生蛋白BMP-4转染骨髓间充质干细胞后与生物陶瓷骨形成复合材料对兔桡骨缺损的修复作用和机制。方法 离体分离培养鉴定兔BMSCs,构建过表达BMP-4基因的慢病毒载体并转染BMSCs细胞,并通过流式细胞术和Western blot鉴定;制备复合生物陶瓷骨,ALP试剂盒检测桡骨组织ALP活性;HE染色观察桡骨组织形态变化;依据Lane-Sandhu法评价受体兔挠骨改善情况;采用免疫荧光检测桡骨组织Col I、OC和OPN表达;Western blot检测桡骨骨膜VEGF和EGF水平。结果 成功分离兔BMSCs细胞,并获得BMP-4基因过表达的BMSCs细胞。BMP-4过表达的BMSCs复合生物陶瓷骨能够显著修复缺损的兔桡骨组织形态,提高组织的Lane-Sandhu评分,并上调挠骨的I型胶原、骨钙素和骨桥素的表达水平和骨膜中血管内皮生长因子（VEGF）和表皮生长因子（EGF）的表达。结论 BMP-4转染BMSCs与生物陶瓷骨复合材料能显著修复兔骨缺损,并增加骨膜组织中VEGF和EGF的表达。     

腺病毒携带骨形态发生蛋白14基因转染脂肪干细胞修复损伤关节软骨

背景：关节软骨损伤后自我修复能力较弱,主要是由于其缺乏滋养血管并且细胞代谢缓慢等组织特性,目前的治疗方法都不能恢复软骨组织的原有功能,近年来软骨组织工程已引起了越来越多的关注。 目的：观察Ⅰ型胶原海绵支架搭载骨形态发生蛋白14基因转染脂肪干细胞修复兔膝关节软骨损伤的效果。 方法：取兔皮下脂肪组织分离培养脂肪干细胞,用腺病毒真核表达载体Ad-CMV-BMP-14-IRES-hrGFP-1转染脂肪干细胞。Ⅰ型胶原海绵支架搭载转染后的脂肪干细胞,待细胞吸附后对兔膝关节全层软骨缺损进行修复。术后12周取手术关节,从大体方面、组织学方面综合评估缺损修复状况。 结果与结论：骨形态发生蛋白14转染后的脂肪干细胞骨形态发生蛋白14和Ⅱ型胶原蛋白表达及Sox-9基因表达明显高于普通脂肪干细胞。术后12周,支架搭载经骨形态发生蛋白14转染的脂肪干细胞组软骨组织修复良好,平整光滑,光洁度、质地及颜色良好,交界区整合良好。支架搭载脂肪干细胞组软骨组织部分修复,有正常软骨光泽,质地与颜色接近正常,修复组织与正常软骨组织界限明显。单纯支架组几乎崩解塌陷,未见透明样软骨结构形成。结果可见腺病毒携带骨形态发生蛋白14基因转染后脂肪干细胞修复软骨缺损的能力有大幅提升。中国组织工程研究杂志出版内容重点：干细胞;骨髓干细胞;造血干细胞;脂肪干细胞;肿瘤干细胞;胚胎干细胞;脐带脐血干细胞;干细胞诱导;干细胞分化;组织工程全文链接：     

TGF-β1基因修饰的间充质干细胞/仿生基质材料复合移植修复兔关节软骨缺损

目的 :探讨转化生长因子 β1(TGF β1)基因转染间充质干细胞 (MSCs)能否提高关节软骨缺损的修复质量和远期疗效。方法 :把组织工程学与分子生物学有机结合 ,体外将具有促进MSCs增殖分化、抑制多种炎性介质活性及免疫排斥反应等多重生物学效应的TGF β1基因转入关节软骨组织工程首选种子细胞MSCs,并与涂覆多聚赖氨酸的聚DL乳酸可降解多孔仿生基质材料复合移植 ,修复同种异体兔关节软骨缺损。以单纯空载体转染MSCs为对照 ,通过组织学、电镜及免疫组化等方法检测。结果 :转基因细胞 /仿生基质材料体外复合培养扫描电镜观察证实TGF β1基因修饰的MSCs增殖分化活性明显优于对照组。体内实验组织学及透射电镜结果显示实验组新生组织为透明样软骨 ,关节面平整 ,软骨下骨完全再生 ,与宿主骨软骨结合紧密 ,未见免疫排斥反应 ;对照组则新生软骨质量欠佳 ,与宿主骨整合欠佳 ,有不同程度的免疫排斥反应。免疫组化结果显示转基因细胞可继续表达TGF β1至少 4周以上。结论 :利用分子组织工程学 ,使TGF β1持续高效发挥作用 ,使提高关节软骨缺损、特别是创伤和骨关节炎关节软骨缺损的修复质量和远期疗效成为可能。     

同种异体和异种来源骨髓间充质干细胞诱导成软骨修复喉软骨缺损

BACKGROUND: Because chondrocytes have no regeneration ability, to select suitable seed cells is the primary problem to repair cartilage defects. OBJECTIVE: To investigate the effect of allogeneic versus heterologous bone marrow mesenchymal stem cells (BMSCs) in repairing laryngeal cartilage defects after chondrogenic induction. METHODS: BMSCs from human and rabbits were isolated and cultured. Passage 3 cells were cultured in chondrogenic induction medium containing transforming transforming growth factor beta 1 and bone morphogenetic protein, and then were dropped onto a poly(lactic-co-glycolic acid) (PLGA) scaffold. Thirty New Zealand rabbits were randomly assigned into three groups: blank control group, human BMSCs group, rabbit BMSCs group. Animal models of laryngeal cartilage defects were made in the three groups. After modeling, saline-soaked PLGA scaffold, PLAG scaffold with human BMSCs or with rabbit BMSCs were implanted respectively into the rabbits in the normal blank, human BMSCs and rabbit BMSCs groups. The expression of type II collagen in the larynx and its surrounding tissues was detected by immunohistochemistry at 4 and 8 weeks postoperatively. RESULTS AND CONCLUSION: The animals in each group breathed normally with no presence of wheezing, and their eating and activity were good. Moreover, there was no purulency or infection in the three groups. At 4 and 8 weeks after operation, the positive rates of type II collagen in the two BMSCs groups were significantly higher than that in the blank control group (P < 0.05). There was no significant difference between two BMSCs groups (P > 0.05). These results show that both allogeneic and heterologous BMSCs have good therapeutic effects on the repair of laryngeal cartilage defects in rabbits.      

不同来源骨髓间充质干细胞的体内成软骨

背景：骨髓间充质干细胞经体外诱导后可修复软骨缺损,但目前采用的种子细胞多来源于自体或同种异体。 目的：观察同种异体及异种来源的骨髓间充质干细胞诱导成软骨后修复喉软骨缺损的效果。 方法：分别取人胚胎骨髓间充质干细胞和刚出生兔骨髓间充质干细胞的第3代细胞种植于聚乳酸-羟基乙酸共聚物生物支架上,并加入转化生长因子β1和软骨形态发生蛋白诱导成软骨细胞。将两种细胞体系植入新西兰白兔体内,并于植入后4,8周取材行大体、组织学观察。 结果与结论：植入后4,8周人胚胎骨髓间充质干细胞和兔骨髓间充质干细胞均有新生组织填充,经组织学观察大部分为软骨细胞,分泌软骨细胞基质糖胺聚糖和Ⅱ型胶原,且两种细胞支架复合物所生成的软骨细胞数大致相同,并无明显的免疫排斥反应。提示异种来源的骨髓间充质干细胞复合聚乳酸-羟基乙酸共聚物在转化生长因子β1和软骨形态发生蛋白联合诱导下所得的组织工程化软骨,与同种来源的骨髓间充质干细胞所获得的组织工程化软骨修复喉软骨缺损具有可比性。     

Repair of articular cartilage defect in non-weight bearing areas using adipose derived stem cells loaded polyglycolic acid mesh

The current study was designed to observe chondrogenic differentiation of adipose derived stem cells (ASCs) on fibrous polyglycolic acid (PGA) scaffold stabilized with polylactic acid (PLA), and to further explore the feasibility of using the resulting cell/scaffold constructs to repair full thickness articular cartilage defects in non-weight bearing area in porcine model within a follow-up of 6 months. Autologous ASCs isolated from subcutaneous fat were expanded and seeded on the scaffold to fabricate ASCs/PGA constructs. Chondrogenic differentiation of ASCs in the constructs under chondrogenic induction was monitored with time by measuring the expression of collagen type II (COL II) and glycosaminoglycan (GAG). The constructs after being in vitro induced for 2 weeks were implanted to repair full thickness articular cartilage defects (8 mm in diameter, deep to subchondral bone) in femur trochlea (the experimental group), while scaffold alone was implanted to serve as the control. Histologically, the generated neo-cartilage integrated well with its surrounding normal cartilage and subchondral bone in the defects of experimental group at 3 months post-implantation, whereas only fibrous tissue was filled in the defects of control group. Immunohistochemical and toluidine blue staining confirmed the similar distribution of COL II and GAG in the regenerated cartilage as the normal one. A vivid remolding process with post-operation time was also witnessed in the neo-cartilage as its compressive moduli increased significantly from 50.55% of the normal cartilage at 3 months to 88.05% at 6 months. The successful repair thus substantiates the potentiality of using chondrogenic induced ASCs and PGA/PLA scaffold for cartilage regeneration.     

BMP7 induces the differentiation of bone marrow-derived mesenchymal cells into chondrocytes

Injured articular cartilage has a poor capacity for spontaneous healing. So far, a satisfactory solution to repair the injured cartilage has not been found, but transgenic therapy might be a promising treatment. This study aims to evaluate the potential of transfecting bone morphogenetic protein-7 (BMP-7), a secretory protein, into bone marrow-derived mesenchymal stem cells (BMSCs), in inducing the differentiation of bone marrow stromal cells into chondrocytes in vitro. The phenotypes of the cells were observed by alcian blue staining and H&E staining with an inverted microscope. The glycosaminoglycan (GAG) content of BMSCs transfected with pcDNA3.1-BMP7 or induced by inducing medium was examined after 7, 14, or 21 days of incubation. A standard curve as reference for BMSCs’ GAG content was plotted using galacturonic acid. The content of type II collagen in culture medium was detected by ELISA. Our results demonstrated that BMP7-transfected BMSCs or BMSCs incubated with inducing medium possess the ability to differentiate into chondrocytes. BMP7-induced BMSCs secrete type II collagen and GAG. There was no significant difference between BMP7-induced BMSCs in their secreted protein content when compared with the positive control group (TGF-β1 and dexamethasone) (P > 0.05), but there was significant difference in the secreted protein profile when compared with the negative control group (P < 0.05).     

Cartilage regeneration using mesenchymal stem cells and a PLGA-gelatin/chondroitin/hyaluronate hybrid scaffold

The study was to produce a novel hybrid poly-(lactic-co-glycolic acid) (PLGA)-gelatin/chondroitin/hyaluronate (PLGA-GCH) scaffold and evaluate its potentials in cartilage repair. The porous PLGA-GCH scaffold was developed to mimic the natural extra cellular matrix of cartilage. The differentiated mesenchymal stem cells (MSCs) seeded on PLGA-GCH or PLGA scaffold were incubated in vitro and showed that, compared to PLGA scaffold, the PLGA-GCH scaffold significantly augmented the proliferation of MSCs and GAG synthesis. Then autologous differentiated MSCs/PLGA-GCH was implanted to repair full-thickness cartilage defect in rabbit, while MSCs/PLGA for the contra lateral cartilage defect (n=30). Fifteen additional rabbits without treatment for defects were used as control. Histology observation showed the MSCs/PLGA-GCH repair group had better chondrocyte morphology, integration, continuous subchondral bone, and much thicker newly formed cartilage compared with MSCs/PLGA repair group 12 and 24 weeks postoperatively. There was a significant difference in histological grading score between these two groups, which both showed much better repair than control. The present study implied that the hybrid PLGA-GCH scaffold might serve as a new way to keep the differentiation of MSCs for enhancing cartilage repair.     

The use of poly(lactic-co-glycolic acid) microspheres as injectable cell carriers for cartilage regeneration in rabbit knees

The use of injectable scaffolding materials for in vivo tissue regeneration has raised great interest because it allows cell implantation through minimally invasive surgical procedures. Previously, we showed that poly(lactic-co-glycolic acid) (PLGA) microspheres can be used as an injectable scaffold to engineer cartilage in the subcutaneous space of athymic mice. The purpose of this study was to determine whether PLGA microspheres can be used as an injectable scaffold to regenerate hyaline cartilage in the osteochondral defects of rabbit knees. A full-thickness wound to the patellar groove of the articular cartilage was made in the knees of rabbits. Rabbit chondrocytes were mixed with PLGA microspheres and injected immediately into these osteochondral wounds. Both chondrocyte transplantations without PLGA microspheres and culture medium injections without chondrocytes served as controls. Sixteen weeks after implantation, chondrocytes implanted using the PLGA microspheres formed white cartilaginous tissues. Histological scores indicating the extent of the cartilaginous tissue repair and the absence of degenerative changes were significantly higher in the experimental group than in the control groups (P < 0.05). Histological analysis by a hematoxylin and eosin stain of the group transplanted with microspheres showed thicker and better-formed cartilage compared to the control groups. Alcian blue staining and Masson's trichrome staining indicated a higher content of the major extracellular matrices of cartilage, sulfated glycosaminoglycans and collagen in the group transplanted with microspheres than in the control groups. In addition, immunohistochemical analysis showed a higher content of collagen type II, the major collagen type in cartilage, in the microsphere transplanted group compared to the control groups. In the group transplanted without microspheres, the wounds were repaired with fibro-cartilaginous tissues. This study demonstrates the feasibility of using PLGA microspheres as an injectable scaffold for cartilage regeneration in a rabbit model of osteochondral wound repair.     

The use of poly(lactic-co-glycolic acid) microspheres as injectable cell carriers for cartilage regeneration in rabbit knees

The use of injectable scaffolding materials for in vivo tissue regeneration has raised great interest because it allows cell implantation through minimally invasive surgical procedures. Previously, we showed that poly(lactic-co-glycolic acid) (PLGA) microspheres can be used as an injectable scaffold to engineer cartilage in the subcutaneous space of athymic mice. The purpose of this study was to determine whether PLGA microspheres can be used as an injectable scaffold to regenerate hyaline cartilage in the osteochondral defects of rabbit knees. A full-thickness wound to the patellar groove of the articular cartilage was made in the knees of rabbits. Rabbit chondrocytes were mixed with PLGA microspheres and injected immediately into these osteochondral wounds. Both chondrocyte transplantations without PLGA microspheres and culture medium injections without chondrocytes served as controls. Sixteen weeks after implantation, chondrocytes implanted using the PLGA microspheres formed white cartilaginous tissues. Histological scores indicating the extent of the cartilaginous tissue repair and the absence of degenerative changes were significantly higher in the experimental group than in the control groups (P < 0.05). Histological analysis by a hematoxylin and eosin stain of the group transplanted with microspheres showed thicker and better-formed cartilage compared to the control groups. Alcian blue staining and Masson's trichrome staining indicated a higher content of the major extracellular matrices of cartilage, sulfated glycosaminoglycans and collagen in the group transplanted with microspheres than in the control groups. In addition, immunohistochemical analysis showed a higher content of collagen type II, the major collagen type in cartilage, in the microsphere transplanted group compared to the control groups. In the group transplanted without microspheres, the wounds were repaired with fibro-cartilaginous tissues. This study demonstrates the feasibility of using PLGA microspheres as an injectable scaffold for cartilage regeneration in a rabbit model of osteochondral wound repair.     

The Effect of Osteochondral Regeneration Using Polymer Constructs and Continuous Passive Motion Therapy in the Lower Weight-Bearing Zone of Femoral Trocheal Groove in Rabbits

Remedying patellofemoral osteochondral defects using clinical therapy remains challenging. Construct-based and cell-based regenerative medicine with in vitro physical stimuli has been progressively implemented. However, the effect of physical stimuli in situ in knee joints with degradable constructs is still not well-documented. Therefore, we studied whether it was practical to achieve articular cartilage repair using a poly(lactic-co-glycolic acid) (PLGA) construct in addition to early short-term continuous passive motion (CPM) for treatment of full-thickness osteochondral defects in the lower-weigh bearing (LWB) zone of the femoral trocheal groove. Twenty-six rabbits were randomly allocated into either intermittent active motion (IAM) or CPM treatment groups with or without PLGA constructs, termed PLGA construct-implanted (PCI) and empty defect knee models, respectively. Gross observation, histology, inflammatory cells, which were identified using H&E staining, total collagen and alignment, studied qualitatively using Masson’s trichrome staining, glycosaminoglycan (GAG), identified using Alcian blue staining, and newly formed bone, observed using micro-CT, were evaluated at 4 and 12 weeks after surgery. Repair of osteochondral defects in the PCI-CPM group was more promising than all other groups. The better osteochondral defect repair in the PCI-CPM group corresponded to smooth cartilage surfaces, no inflammatory reaction, hyaline cartilaginous tissues composition, sound collagen alignment with positive collagen type II expression, higher GAG content, mature bone regeneration with osteocyte, clear tidemark formation, and better degradation of PLGA. In summary, the use of a simple PLGA construct coupled with passive motion promotes positive healing and may be a promising clinical intervention for osteochondral regeneration in LWB defects.     

重组hTGF-β1基因转染的BMSCs在体内成软骨能力的初步研究

目的重组hTGF-β1腺病毒(adeno-hTGF-β1)转染的BMSCs在体内成软骨能力的初步研究,探讨其作为组织工程化软骨的种子细胞的可行性。方法重组adeno-hTGF-β1转染猪BMSCs,酶联免疫吸附定量检测(ELISA法)重组腺病毒转染hTGF-β1蛋白的表达。然后消化收集重组腺病毒转染后的BMSCs,均匀接种于圆盘状PGA支架上,对照组转染adeno-LacZ,然后植入裸鼠背部皮下,在植入后第3周取材,分别行大体观察、组织学、II型胶原免疫组化和蛋白聚糖含量检测对形成组织进行评价。结果 ELISA结果显示adeno-hTGF-β1转染的BMSCs,其hTGF-β1表达量是转染adeno-lacZ 的BMSCs 2.65倍( P0.05)。植入裸鼠体内后3周取材,实验组HE染色观察可见有软骨形成,但较不均匀,并被纤维组织分割,形成的软骨组织区域可见软骨细胞包埋在软骨陷窝内;对照组可见仅有少量软骨形成,被大量的纤维组织和未降解的PGA支架包裹,实验组和对照组形成软骨占总组织百分比,分别为(41.83±4.64)%和(17.50±2.85)%,P0.05。Safranin’O染色显示,实验组形成的软骨组织区域都有被染成桔红色蛋白多糖类基质分泌,着色比对照组更深。实验组形成的软骨组织区域有大量棕黄色的II型胶原颗粒,而对照组仅有少量的棕黄色的II型胶原颗粒,实验组形成的软骨组织中的蛋白聚糖含量多于正常猪耳软骨。结论重组hTGF-β1腺病毒转染BMSCs作为种子细胞,在裸鼠体内能促使软骨组织形成,从而为hTGF-β1基因转染的BMSCs在软骨组织工程应用中奠定了基础。