软骨PLGA-Ⅱ型胶原支架复合体修复兔膝关节骨软骨损伤

目的探讨骨髓基质干细胞(BMSCs)诱导的软骨细胞与聚乙醇酸-乳酸共聚物(PLGA)-Ⅱ型胶原支架通过管帽结构复合构建组织工程软骨复合体修复兔膝关节骨软骨损伤的效果及各界面耦合情况。方法BMSCs经软骨诱导液诱导成软骨细胞后接种于PLGA-Ⅱ型胶原支架的底层,支架表层戴管帽。将该细胞-支架复合物置入软骨条件培养液中培养2周,扫描电镜观察。将45只新西兰大白兔随机分为A、B、C 3组,每组15只,并于股骨髁处造模。分别于缺损处植入戴管帽结构复合的软骨支架复合体(A组)、PLGA-Ⅱ型胶原支架(B组)、不植入任何材料(C组)。于第4周和第12周取材行大体观察和组织学分析。结果 A组和B组缺损处均有软骨生成;C组缺损明显,只有纤维组织生长。A组软骨缺损部分软骨细胞修复,成骨区部分骨样细胞修复;两者耦合处犬牙交错,修复缺损程度及成骨区和成软骨区界面耦合情况明显优于B、C组。软骨组织学评分A组优于B、C组(P0.05)。结论 BMSCs诱导分化成的软骨细胞与PLGA-Ⅱ型胶原支架经过管帽结构构建成的软骨PLGA-Ⅱ型胶原支架复合体可有效修复兔膝关节骨软骨损伤,新生软骨、骨与宿主软骨、骨及新生软骨与软骨下骨各界面耦合良好。     

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.     

细胞复合β-磷酸三钙生物陶瓷修复软骨缺损的实验研究

[目的]通过将骨髓间充质干细胞（MCSc）诱导的具有软骨细胞、成骨细胞表型的细胞接种到三维多孔β-磷酸三钙（β-TCP）生物陶瓷支架材料上，体外构建骨软骨复合体，探讨以β-TCP为载体建造组织工程化软骨修复骨软骨缺损的可行性。[方法]将β-TCP多孔陶瓷加工成圆柱状，并将其作为构建人工软骨的细胞支架。在支架材料上分别接种从犬骨髓干细胞培养成的具有软骨细胞、成骨细胞表型的细胞，将细胞-支架复合体共同培养1周后，移植到犬关节软骨缺损处。植入后12、16周末取材，进行大体观察、组织学及组织化学等观察。[结果]复合体体内移植后，在犬关节软骨缺损处有新生软骨形成，形成的软骨基本保持了支架材料原有形态。[结论]β-TCP多孔陶瓷可作为支架材料，复合细胞后具有修复软骨缺损的作用。     

骨软骨复合体修复软骨及软骨下骨缺损

目的探讨以诱导的兔骨髓基质细胞与双层PLGA支架构建组织工程骨软骨复合体,修复兔膝关节软骨及软骨下骨缺损的方法及结果。方法健康新西兰兔28只,分为三组。A组为常规培养MSCs(10只),B组为诱导培养MSCs(10只),C组为自体骨软骨块移植(8只)。密度梯度离心法获得骨髓基质干细胞(marrow-derivedstromalcells,MSCs),分别使用常规培养液和成软骨诱导条件培养液进行体外扩增传代。提取MSCs及关节软骨细胞总RNA,RT-PCR检测Ⅰ、Ⅱ型胶原表达。扫描电镜观察MSCs在PLGA双层支架上的复合与分布情况。A、B组MSCs分别与PLGA双层支架构建直径3.5mm、高3.0mm的骨软骨复合体,植入股骨髁髌骨滑车同比例骨软骨缺损区,术后第4、8、16、24周取材,进行大体观察、组织学检查和评分。结果RT-PCR见常规培养MSCs表达Ⅰ型胶原,无Ⅱ型胶原表达;诱导后MSCs表达Ⅰ、Ⅱ型胶原。扫描电镜观察MSCs在PLGA支架黏附生长良好,孔隙深处可见细胞分布。B组标本术后24周大体观察与正常软骨无明显差别,组织学检查为成熟的类透明软骨组织(4/6),优于A组(1/4)。结论MSCs具有成骨和成软骨潜能,可在基于细胞的软骨修复中作为种子细胞与双层PLGA构建组织工程骨软骨复合体,该复合体在实验动物模型中可修复关节软骨和软骨下骨缺损。     

组织工程骨软骨复合物的构建与形态学观察

目的探讨采用组织工程技术构建骨软骨复合物的可行性。方法将骨髓基质细胞(BMSCs)成诱导软骨后接种于快速成形的三维支架材料聚乳酸／聚羟乙酸共聚物(PLGA)构建组织工程软骨，经成骨诱导的BMSCs接种于聚乳酸／聚羟乙酸共聚物／磷酸三钙(PLGA／TCP)构建组织工程骨，在体外分别培养2周后，将两种工程化组织及两者以无损伤线缝合形成的组织工程骨软复合体分别植入自体股部肌袋，术后8周取材，行组织学观察。结果术后组织学观察表明。组织工程软骨在体内可形成软骨组织组织工程骨在体内可形成骨组织，两者的复合体在体内可形成骨软骨复合物。结论以骨髓基质细胞为种子细胞、以快速成形的生物降解材料为支架体外构建的组织工程骨软骨复合物，可在体内形成骨软骨组织，有望用于骨软骨缺损的修复。     

三种不同方式构建组织工程软骨修复犬膝关节骨软骨缺损对比的实验研究

[目的]通过对比三种不同方式构建的骨软骨复合体修复比格犬膝关节骨软骨缺损的修复情况,探讨构建组织工程化软骨的最佳可行性方案.[方法]本研究分别采用体外单体培养、分体培养、生物反应器内分体培养体内构建三种方式构建骨软骨复合体,模仿马赛克移植术植入比格犬膝关节骨软骨缺损处,通过大体观察、组织学分析观察其修复情况.[结果]术后3个月,3种方式构建的骨软骨复合体均不同程度修复了犬关节软骨缺损,采用生物反应器内分体培养体内构建方式修复骨软骨缺损效果优于前两种方式.[结论]灌注型生物反应器使软骨和成骨细胞在三维载体内存活并增殖,提高细胞在载体内的复合效率,软骨修复情况优于前两种方法.     

动物源性骨软骨支架修复兔膝关节复合缺损

目的探讨软骨细胞-动物源性骨软骨支架复合体修复兔膝关节骨软骨复合缺损的可行性和影响因素。方法将改良贴壁离心法获取的骨髓间充质干细胞（bone marrowm esenchymal stem cells,BMSCs）/诱导分化的软骨细胞共培养后与经深低温冷冻、脱脂、脱钙、真空冷冻干燥和辐照消毒的动物源性骨软骨支架复合,构建共培养细胞＋软骨-骨一体化复合支架。27只新西兰大白兔随机分为实验组（A组）、对照组（B组）和空白组（C组）,每组9只。于兔股骨髁间窝处钻一深6mm的骨软骨复合缺损,A组植入共培养细胞＋骨软骨复合支架,B组植入骨软骨复合支架,C组不植入任何支架材料和细胞,分别于术后4周、8周和12周取材,行大体观察、苏木精—伊红染色和甲苯胺蓝染色,并对各标本的软骨切片进行组织学评分。结果随着时间的延长,A组大体观察见复合缺损区已完全修复,局部无凹陷,新生组织和周围组织融合;B组新生组织仍不能完全填充缺损;C组缺损区仍明显。苏木精—伊红染色和甲苯胺蓝染色见A组软骨缺损区由新生的透明软骨样组织修复,细胞呈柱状排列,极性好,软骨陷窝明显,骨缺损区由骨样组织修复,新生软骨和软骨下骨以及宿主骨界面耦合良好;B组新生软骨细胞无软骨陷窝,排列混乱,各界面藕合欠理想;C组可见陈旧性肉芽组织生长并突出于缺损区表面。甲苯胺蓝染色阳性率和组织学评分结果表明,A组与B、C两组之间的差异具有统计学意义（P〈0.05）。结论 BMSCs/诱导分化的软骨细胞共培养细胞复合动物源性骨软骨支架对兔膝关节软骨和软骨下骨的复合缺损具有修复作用。     

转BMP-7软骨细胞在Matrigel胶支架中修复兔膝关节软骨缺损的实验研究

[目的]研究骨形态发生蛋白(bone morphogenic protein,BMP-7)在构建 Matrigel 胶支架软骨膜块修复关节软骨缺损中的作用.[方法]将软骨细胞种植于 Matrigel 胶支架上,体外培养,在培养系统中加入 BMP-7,观察软骨细胞在支架中的繁殖以及载体降解情况;将培养出的软骨膜块植入于动物关节软骨缺损模型中进行定期观测(4周).[结果]Matrigel 胶支架可满足组织工程软骨修复需要,BMP-7 在用于构建膜块修复关节软骨缺损模型中可促进软骨细胞增殖,并在植入 4 周动物试验中发现与对照组比较在关节软骨缺损修复质量上有显著性差异(P<0.01).[结论]BMP-7 在 Matrigel 胶软骨膜块中可明显促进组织工程软骨膜块构建以及关节软骨缺损的修复.     

软骨细胞—支架复合的修复兔耳廓软骨缺损

目的 在有免疫力的动物兔体内探索组织工程化软骨对软骨缺损的修复能力。方法 软骨细胞种于经不同物质修饰的聚羟基乙酸支架体外培养后修复兔耳廓软骨缺损，与对照组比较，并从大体及组织学进行评价。结果 软骨细胞种于经不同物质修饰的聚羟基乙酸支架体外培养后回植到兔耳廓软骨缺损部位，软骨缺损得到修复，但人骨交上为纤维组织。注射软骨细胞悬液、以聚羟基乙酸支架修复及空白对照组软骨缺损均未修复。结论 软骨细胞种于经不     

兔骨髓间充质干细胞修复膝关节软骨缺损的实验研究

目的研究由同种异体兔骨髓间充质干细胞(MSCs)诱导分化的软骨细胞和聚乳酸-聚乙醇酸共聚物(PLGA)双层支架构建复合体对兔软骨缺损的修复作用。方法用密度梯度离心法和贴壁培养法获得5月龄兔骨髓来源间充质干细胞,在体外培养并进行分化诱导后作为种子细胞复合双层PLGA构建成复合体。36只兔在股骨髁间制造骨软骨缺损模型,分成三组,A组植入复合体,B组植入单纯双层PLGA支架,C组植入自体骨软骨。第24周取材进行大体观察、组织学检查和Wakitani评分。结果 A组及C组植入物愈合良好,组织学检查见Ⅰ、Ⅱ型胶原纤维形成。A组可见透明软骨修复。Wakitani评分A组2.75,B组7.00,C组1.98,A、C组与B组间统计学分析单项指标得分差异有统计学意义(P0.05),A组与C组间差异无统计学意义(P0.05)。结论诱导兔MSCs+PLGA双层支架能较好地修复兔膝关节骨软骨损伤。     

脱细胞骨软骨支架复合自体骨髓间充质干细胞修复羊骨软骨缺损的研究

目的探讨脱细胞骨软骨支架接种自体骨髓间充质干细胞(BMSCs)修复羊骨软骨缺损效果,探索骨软骨缺损新的修复方式。方法制备直径为8mm骨软骨脱细胞支架,培养羊BMSCs,接种于骨软骨支架,制备羊负重区骨软骨缺损模型,分空白、空白支架及细胞支架复合物3组,每组4只羊,3个月后处死动物取标本行大体及组织学检测。结果修复羊负重区骨软骨缺损模型实验结果显示细胞支架复合修复组骨软骨有较好修复,空白支架组软骨下骨基本修复、软骨侧无明显修复,空白对照组未见明显修复,缺损边缘软骨退变。结论含骨软骨连接结构的脱细胞骨软骨支架接种种子细胞能较好的修复羊负重区骨软骨缺损。     

Repair of osteochondral defects with hyaluronan- and polyester-based scaffolds

OBJECTIVE: The natural repair of osteochondral defects can be enhanced with biocompatible, biodegradable materials that support the repair process. It is our hypothesis that hyaluronan-based scaffolds are superior to synthetic scaffolds because they provide biological cues. We tested this thesis by comparing two hyaluronan-based scaffolds [auto cross-linked polysaccharide polymer (ACP) and HYAFF-11] to polyester-based scaffolds [poly(DL-lactic-co-glycolic acid) (PLGA) and poly(L-lactic acid) (PLLA)] with similar pore size, porosity and degradation times. DESIGN: Fifty-four rabbits received bilateral osteochondral defects. One defect received a hyaluronan-based scaffold and the contralateral defect received the corresponding polyester-based scaffold. Rabbits were euthanized 4, 12 and 20 weeks after surgery and the condyles dissected and processed for histology. RESULTS: Only ACP-treated defects presented bone at the base of the defect at 4 weeks. At 12 weeks, only defects treated with rapidly dissolving implants (ACP and PLGA) presented bone reconstitution consistently, while bone was present in only one third of those treated with slowly dissolving scaffolds (HYAFF-11 and PLLA). After 20 weeks, the articular surface of PLGA-treated defects presented fibrillation more frequently than in ACP-treated defects. The surface of defects treated with slowly dissolving scaffolds presented more cracks and fissures. CONCLUSIONS: The degradation rate of the scaffolds is critical for the repair process. Slowly dissolving scaffolds sustain thicker cartilage at the surface but, it frequently presents cracks and discontinuities. These scaffolds also delay bone formation at the base of the defects. Hyaluronan-based scaffolds appear to allow faster cell infiltration leading to faster tissue formation. The degradation of ACP leads to rapid bone formation while the slow degradation of HYAFF-11 prolongs the presence of cartilage and delays endochondral bone formation.     

A new bioabsorbable cotton-textured synthetic polymer scaffold for osteochondral repair

Purpose

We have previously reported that a cylindrical bioabsorbable synthetic polymer scaffold made of poly (DL-lactide-co-glycolide) (PLG) can be used to repair osteochondral defects without using cultured cells in a rabbit model. This cylindrical scaffold has a solid and pre-formed design, which limits its widespread application. Therefore, we created a cotton-textured PLG scaffold, which would be superior to other scaffolds in terms of plastic property and operability. The purpose of the present study was to examine the efficacy of the cotton-textured PLG scaffold in the repair of osteochondral defects.

Methods

Cotton-textured PLG scaffolds were prepared using the electrospinning method and used to repair osteochondral defects produced on the right femoral condyle in 36 rabbits. As a control, the defect was left untreated. The outcomes of repair were examined histologically at postoperative weeks four, eight, and 12.

Results

In the untreated control group, the surface of the defect remained concave and the regenerated cartilaginous tissue partially covered the articular surface even at postoperative week 12. In the scaffold group, cartilaginous tissue covered the surface of the defect at postoperative week four, and the surface was smooth and the cartilaginous tissue was well regenerated and integrated with the native cartilage at postoperative week 12.

Conclusions

The cotton-textured PLG scaffold could repair the osteochondral defect with good outcomes similar to those previously reported for the cylindrical scaffold, with its characteristic advantages of better plasticity and operability. We conclude that the cotton-textured PLG scaffold has potential for clinical application in comminuted osteochondral injury.     

聚乳酸/聚羟基乙酸复合骨形成蛋白修复兔关节软骨缺损

目的以聚乳酸/聚羟基乙酸(poly-lactide-co-glycolide,PLGA)为载体,探讨重组人骨形成蛋白2(recombinant human bone morphogenetic protein2,rhBMP-2)在关节软骨修复方面的作用及可行性。方法将PLGA制成直径4mm,厚3mm的圆柱形,与rhBMP-2复合(0.5mg/块),制备PLGA-rhBMP-2复合物。选取2月龄新西兰兔,抽取骨髓行原代及传代培养,调整细胞密度为2×107/ml,与PLGA共培养24h,制备PLGA-细胞复合物。另取2月龄新西兰兔72只,于双侧髌股关节股骨髁部制备直径4mm、深达髓腔的缺损。其中36只兔右侧缺损处植入PLGA-rhBMP-2复合物,为实验组;左侧植入PLGA,为单纯载体组;另36只兔左侧缺损不作任何处理,为空白对照组,右侧缺损处植入PLGA-细胞复合物,作为细胞组。术后4、8、12、24、36和48周取材,行大体、组织学观察以及组织学评分。结果术后动物均存活。术后4周,实验组和细胞组缺损内被半透明组织填充,触之柔软,表面较光滑,软骨细胞周围基质异染弱,新生软骨厚度较正常软骨厚;空白对照组和单纯载体组未见明显组织形成。8周,实验组和细胞组内新生组织呈白色,半透明,质较韧,表面平整,与周围正常软骨界限模糊;新生软骨细胞分布均一,但仍较正常软骨厚,PLGA已大部分降解,仅遗留少量颗粒;单纯载体组和空白对照组缺损明显,底部形成少量白色膜状组织。12、24周,实验组和细胞组缺损内完全充填白色半透明新生软骨组织,质韧,表面平整,与正常软骨界限消失,厚度接近正常软骨,与正常软骨连接良好,表面细胞平行排列,深层有纵向排列的倾向,呈团状,陷窝形成,但有别于正常软骨细胞;单纯载体组和空白对照组缺损边缘及底部形成少量软骨细胞,大部分为纤维组织。36、48周,实验组和细胞组新生软骨组织色稍发白,表面连续,欠平整,与正常软骨界限消失,未见滑膜增生;新生软骨厚度较正常软骨薄,软骨细胞周围基质异染较弱;单纯载体组及空白对照组缺损仍存在,但较以前缩小,基底形成纤维组织,髁部可见部分软骨面不平整、剥脱,部分软骨下骨外露,滑膜增厚。组织学评分,实验组和细胞组术后12、24周分别与4、8和48周比较,差异均有统计学意义(P<0.01);各时间点实验组、细胞组分别与单纯载体组和空白对照组比较,差异均有统计学意义(P<0.01),实验组与细胞组在各时间点比较差异均无统计学意义(P>0.05)。结论PLGA-rhBMP-2复合物在降解过程中释放出rhBMP-2,rhBMP-2作用于缺损局部的骨髓基质细胞,诱导其向软骨细胞分化,从而修复软骨缺损;此方法简便易行,有实用价值,有望成为治疗软骨缺损的一种新方法。     

β-磷酸三钙复合骨髓间充质干细胞修复山羊骨软骨缺损的实验研究

目的将β-磷酸三钙（β-TCP）与山羊骨髓间充质干细胞（BMSCs）复合后,在生物反应器中分别向成软骨和成骨诱导,并植入骨软骨缺损处,观察软骨修复效果。方法分离、培养山羊BMSCs,在生物反应器中分别向成软骨及成骨诱导2周,植入骨软骨缺损部位。实验组分为A组：旋转力刺激＋成软骨、成骨诱导组（力学刺激组）,B组：单纯成软骨、成骨诱导组（无力学刺激组）,并设空白对照组。术后12周和24周进行大体观察、组织学染色等,并行O＇Driscoll Keeley and Salter评分。结果 A、B组均有新生软骨形成;A组软骨在12周与24周均优于B组（P〈0.05）;术后12、24周A组评分优于B组,差异有统计学意义（P〈0.05）。对照组无新生软骨形成。结论将BMSCs复合于β-TCP,可用于组织工程修复骨软骨缺损;体外培养阶段的旋转力刺激有利于改善组织工程软骨的质量。     

Effects of a cultured autologous chondrocyte-seeded type II collagen scaffold on the healing of a chondral defect in a canine model.

Using a previously established canine model for repair of articular cartilage defects, this study evaluated the 15-week healing of chondral defects (i.e., to the tidemark) implanted with an autologous articular chondrocyte-seeded type II collagen scaffold that had been cultured in vitro for four weeks prior to implantation. The amount and composition of the reparative tissue were compared to results from our prior studies using the same animal model in which the following groups were analyzed: defects implanted with autologous chondrocyte-seeded collagen scaffolds that had been cultured in vitro for approximately 12 h prior to implantation, defects implanted with autologous chondrocytes alone, and untreated defects. Chondrocytes, isolated from articular cartilage harvested from the left knee joint of six adult canines, were expanded in number in monolayer for three weeks, seeded into porous type II collagen scaffolds, cultured for an additional four weeks in vitro and then implanted into chondral defects in the trochlear groove of the right knee joints. The percentages of specific tissue types filling the defects were evaluated histomorphometrically and certain mechanical properties of the repair tissue were determined. The reparative tissue filled 88+/-6% (mean+/-SEM; range 70-100%) of the cross-sectional area of the original defect, with hyaline cartilage accounting for 42+/-10% (range 7-67%) of defect area. These values were greater than those reported previously for untreated defects and defects implanted with a type II collagen scaffold seeded with autologous chondrocytes within 12 h prior to implantation. Most striking, was the decreased amount of fibrous tissue filling the defects in the current study, 5+/-5% (range 0-26%) as compared to previous treatments. Despite this improvement, indentation testing of the repair tissue formed in this study revealed that the compressive stiffness of the repair tissue was well below (20-fold lower stiffness) that of native articular cartilage.     

不同应力环境对兔骨髓间充质干细胞修复关节软骨缺损的影响

目的探讨不同应力环境对骨髓间充质干细胞(MSCs)修复关节软骨缺损的影响. 方法将日本大耳白兔15只制成髌骨外侧脱位动物模型,平均分成3组,每组5只:即单纯载体脱位组(对照组)、移植物正常应力组及移植物脱位组.对兔MSCs进行分离、培养,以兔MSCs为种子细胞构建自体组织工程移植物修复关节软骨缺损.6周后处死动物,观察修复组织的成分和结构. 结果术后6周,移植物正常应力组修复组织浅层为软骨组织,甲苯胺蓝染色接近正常关节软骨;深层为软骨下骨,与正常关节软骨结构相似.移植物脱位组为骨组织所修复,缺损周围的正常关节软骨变薄,软骨下血管侵入正常关节软骨内,遗留在股骨髁滑车槽内的移植物在滑车槽正常关节软骨表面形成新生类透明软骨组织.单纯载体脱位组为纤维组织修复. 结论 MSCs修复关节软骨缺损,只有在正常应力状态下修复效果最佳;提示维持负重关节正常的应力刺激,对组织工程软骨修复组织的形成和维持必不可少.     

Repair of osteochondral defects with a new porous synthetic polymer scaffold

We developed a new porous scaffold made from a synthetic polymer, poly(DL-lactide-co-glycolide) (PLG), and evaluated its use in the repair of cartilage. Osteochondral defects made on the femoral trochlear of rabbits were treated by transplantation of the PLG scaffold, examined histologically and compared with an untreated control group. Fibrous tissue was initially organised in an arcade array with poor cellularity at the articular surface of the scaffold. The tissue regenerated to cartilage at the articular surface. In the subchondral area, new bone formed and the scaffold was absorbed. The histological scores were significantly higher in the defects treated by the scaffold than in the control group (p<0.05). Our findings suggest that in an animal model the new porous PLG scaffold is effective for repairing full-thickness osteochondral defects without cultured cells and growth factors.