Repair of rabbit articular surfaces with allograft chondrocytes embedded in collagen gel

In an attempt to repair articular cartilage, allograft articular chondrocytes embedded in collagen gel, were transplanted into full-thickness defects in rabbit articular cartilage. Twenty-four weeks after the transplantation, the defects were filled with hyaline cartilage, specifically synthesising Type II collagen. These chondrocytes were autoradiographically proven to have originated from the transplanted grafts. Assessed histologically the success rate was about 80%, a marked improvement over the results reported in previous studies on chondrocyte transplantation without collagen gel. By contrast, the defects without chondrocyte transplantation healed with fibrocartilage. Immunological enhancement induced by transplanted allogenic chondrocytes or collagen was not significant at eight weeks after treatment, so far as shown by both direct and indirect blastformation reactions. Thus, allogenic transplantation of isolated chondrocytes embedded in collagen gel appears to be one of the most promising methods for the restoration of articular cartilage.     

Human autologous culture expanded bone marrow mesenchymal cell transplantation for repair of cartilage defects in osteoarthritic knees

OBJECTIVE: There is no widely accepted method to repair articular cartilage defects. Bone marrow mesenchymal cells have the potential to differentiate into bone, cartilage, fat and muscle. Bone marrow mesenchymal cell transplantation is easy to use clinically because cells can be easily obtained and can be multiplied without losing their capacity of differentiation. The objective of this study was to apply these cell transplantations to repair human articular cartilage defects in osteoarthritic knee joints. DESIGN: Twenty-four knees of 24 patients with knee osteoarthritis (OA) who underwent a high tibial osteotomy comprised the study group. Adherent cells in bone marrow aspirates were culture expanded, embedded in collagen gel, transplanted into the articular cartilage defect in the medial femoral condyle and covered with autologous periosteum at the time of 12 high tibial osteotomies. The other 12 subjects served as cell-free controls. RESULTS: In the cell-transplanted group, as early as 6.3 weeks after transplantation the defects were covered with white to pink soft tissue, in which metachromasia was partially observed. Forty-two weeks after transplantation, the defects were covered with white soft tissue, in which metachromasia was observed in almost all areas of the sampled tissue and hyaline cartilage-like tissue was partially observed. Although the clinical improvement was not significantly different, the arthroscopic and histological grading score was better in the cell-transplanted group than in the cell-free control group. CONCLUSIONS: This procedure highlights the availability of autologous culture expanded bone marrow mesenchymal cell transplantation for the repair of articular cartilage defects in humans.     

Current concepts in tissue engineering technique for repair of cartilage defect

Hunter's observation in 1743 that cartilage "once destroyed, is not repaired," has not essentially changed for 250 years. At present, there is no well-established procedure for the repair of cartilage defect with articular cartilage, which has the same biochemical and biomechanical properties as the surrounding normal intact cartilage. In 1994, transplantation of human autologous chondrocytes in suspension, as reported by Brittberg et al., provided a potential procedure for articular cartilage repair. We have improved their procedure and developed a new technique which creates new cartilage-like tissue by cultivating autologous chondrocytes embedded in Atelocollagen gel for 3 weeks before transplantation. These improvements maintained the chondrocyte phenotype, evenly distributed chondrocytes throughout the osteochondral defects, and decreased the risk of leakage of grafted chondrocytes into the defects. Good clinical results suggest that this technique should be a promising procedure for repairing articular cartilage defect.     

In vivo mechanical condition plays an important role for appearance of cartilage tissue in ES cell transplanted joint

The objective of this study was to evaluate the effects of the mechanical environment on the formation of cartilage tissue in transplanted embryonic stem (ES) cells. Full‐thickness osteochondral defects were created on the patella groove of SD rats, and ES cells (CCE ES cells obtained from 129/Sv/Ev mice and Green ES FM260 ES cells obtained from 129SV [D3] ‐ Tg [NCAG‐EGFP] CZ—001–FM260Osb mice) were transplanted into the defects embedded in collagen gel. The animals were randomly divided into either the joint‐free group (JF group) or the joint‐immobilized group (JI group) for 3 weeks after a week postoperatively. The results showed that cartilage‐like tissue formed in the defects of the JF group whereas large teratomatous masses developed in the defects of the JI group. Some parts of the cartilage‐like tissue and the teratomatous masses were positively stained with immunostain for GFP when the Green ES FM260 ES cells were transplanted. It is suggested that the environment plays an important role for ES cells in the process of repairing cartilage tissue in vivo. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 26:10–17, 2008     

The role of mandibular condylar cartilage in articular cartilage repair.

The articular hyaline cartilage of synovial joints has a very limited capacity for repair after injury. In contrast, the mandibular condylar cartilage of the temporomandibular joint possesses as intrinsic potential for regeneration. This study aimed to test the hypothesis that cultured allografts of mandibular condylar cartilage could be used to promote biological repair of injured orthotopic joint surfaces. Using a primate animal model, cultures of mandibular condylar cartilage cells were grafted into surgically created defects in a recipient hyaline cartilage joint surface. Articular wound healing was assessed macroscopically and histologically over a postoperative period of 52 weeks. Mandibular condylar cartilage cells scheduled for allogenous transplantation were initially characterised in vitro. Expansion of primary colonies in organ culture provided the allogenic cellular material for in vivo grafting. Grafting of osteochondral articular wounds with 5-week cultures of mandibular cartilage cells led to wound regeneration with complete reconstitution of articular surface continuity by 52 weeks. There was novel synthesis of cartilage collagens and sulphated glycosaminoglycans within the repair tissue and no evidence of immunological rejection. Healing of grafted defects was thought to occur by a combination of donor cell proliferation and ingress of host mesenchymal cells. In contrast, grafted control wounds underwent largely fibrous repair with incomplete articular regeneration. In conclusion, transplanted allografts of cultured mandibular condylar cartilage appeared to have the ability, in this primate model, to promote cartilaginous repair and regeneration of orthotopic articular wounds.     

自体软骨细胞团块植入修复兔陈旧性关节软骨缺损的实验研究

目的 观察自体软骨细胞团块植入对兔关节软骨缺损的修复作用. 方法 24只成年新西兰大白兔48侧膝关节,随机分为三组(n=16)并制备双膝关节股骨滑车软骨缺损模型.空白对照组无特殊处理,骨膜移植组将骨膜覆盖缺损并缝合于缺损两侧的股骨髁上,实验组将自体软骨细胞团块植入缺损中.术后3、6个月分别取材(n=8),进行大体和组织学观察,修复组织行Wakitani评分并进行比较. 结果实验组共成功取材11个缺损关节,9个为透明软骨修复,2个因植入细胞生长状态差未修复;骨膜移植组修复组织为纤维软骨或纤维组织,修复组织薄,基质异染弱;空白对照组仅有少量纤维组织填充缺损底部.修复组织Wakitani评分:实验组3.82分,骨膜移植组6.71分,空白对照组9.23分,差异有统计学意义(F=5.96,P=0.00). 结论自体软骨细胞团块植入能较好修复关节软骨缺损,修复的质量与植入细胞的质量有关.     

Autologous bone marrow stromal cell transplantation for repair of full-thickness articular cartilage defects in human patellae: two case reports

This study assessed the effectiveness of autologous bone marrow stromal cell transplantation for the repair of full-thickness articular cartilage defects in the patellae of a 26-year-old female and a 44-year-old male. These two patients presented in our clinic because their knee pain prevented them from walking normally. After thorough examination, we concluded that the knee pain was due to the injured articular cartilage and decided to repair the defect with bone marrow stromal cell transplantation. Three weeks before transplantation, bone marrow was aspirated from the iliac crest of each patient. After erythrocytes had been removed by use of dextran, the remaining nucleated cells were placed in culture. When the attached cells reached subconfluence, they were passaged to expand in culture. Adherent cells were subsequently collected, embedded in a collagen gel, transplanted into the articular cartilage defect in the patellae, and covered with autologous periosteum. Six months after transplantation, clinical symptoms (pain and walking ability) had improved significantly and the improvement has remained in effect (5 years and 9 months posttransplantation in one case, and 4 years in the other), and both patients have been satisfied with the outcome. As early as 2 months after transplantation, the defects were covered with tissue that showed slight metachromatic staining. Two years after the first and 1 year after the second transplantation, arthroscopy was performed and the defects were repaired with fibrocartilage. Results indicate autologous bone marrow stromal cell transplantation is an effective approach in promoting the repair of articular cartilage defects.     

Repair of articular cartilage defects with cultured chondrocytes in Atelocollagen gel

We attempted to repair full-thickness articular cartilage defects in rabbit knee joints with allogeneic cultured chondrocytes embedded in Atelocollagen gel. An articular cartilage defect was created on the patellar groove of the femur. The defect was filled with chondrocytes cultured in the collagen gel and covered with periosteal flap (G group). In three other experimental groups, the same defects were transplanted with chondrocytes in monolayer culture with periosteal flap (M group), periosteal graft only (P group), or left empty (E group). At 4, 12, and 24 weeks after operation, the reparative tissue was analyzed macroscopically and histologically. At 4 weeks after operation, the surfaces of the reparative tissue were smooth, and the defects were filled with reparative tissues that resembled hyaline cartilage in all four groups. However, the reparative tissues degenerated gradually with time in the M, P, and E groups. In contrast, in the G group, the reparative tissue retained its thickness, and there was a steady integration of the grafted tissue into the adjacent normal cartilage at 24 weeks after operation. The results suggest that transplantation of allogeneic chondrocytes cultured in Atelocollagen gel is effective in repairing an articular cartilage defect.     

Rabbit articular cartilage defects treated by allogenic chondrocyte transplantation

Articular cartilage defects have a poor capacity for repair. Most of the current treatment options result in the formation of fibro-cartilage, which is functionally inferior to normal hyaline articular cartilage. We studied the effectiveness of allogenic chondrocyte transplantation for focal articular cartilage defects in rabbits. Chondrocytes were cultured in vitro from cartilage harvested from the knee joints of a New Zealand White rabbit. A 3 mm defect was created in the articular cartilage of both knees in other rabbits. The cultured allogenic chondrocytes were transplanted into the defect in the right knees and closed with a periosteal flap, while the defects in the left knees served as controls and were closed with a periosteal flap alone, without chondrocytes. Healing of the defects was assessed at 12 weeks by histological studies. Allogenic chondrocyte transplantation significantly increased the amount of newly formed repair tissue (P=0.04) compared with that found in the control knees. The histological quality score of the repair tissue was significantly better (P=0.05), with more hyaline characteristics in the knees treated with allogenic chondrocytes than in the control knees. Articular cartilage defects treated with allogenic chondrocyte transplantation result in better repair tissue formation with hyaline characteristics than those in control knees.     

Repair of articular cartilage defects with cultured chondrocytes on polysulphonic membrane: experimental studies in rabbits

INTRODUCTION: Autologous osteochondral transplantation is one method that can be used to create hyaline or hyaline-like repair in a defect area. The purpose of the present study was to repair full-thickness articular cartilage defects in 9 rabbit knee joints with autologous cultured chondrocytes. METHODS: An articular cartilage defect was created on the patellar groove of the femur. The defect was filled with chondrocytes cultured in vitro and placed into the knee on a polysulphonic membrane. At 8 weeks after the operation, the reparative tissue was analyzed macroscopically and histologically. RESULTS: At 8 weeks after the operation, the surfaces of the reparative tissue were smooth, and the defects were filled with mature hyaline cartilage in 5 cases. In 2 cases, the reparative hyaline cartilage was immature and there was worse integration of grafted tissue into the adjacent normal cartilage. In 2 cases, the surface of the grafted area was irregular, and the reparative tissue was disintegrated and incompletely differentiated. CONCLUSION: The results suggest that transplantation of autologous chondrocytes cultured in vitro and placed into the knee on polysulphonic membrane is effective in repairing an articular cartilage defect.     

同种异体软骨细胞移植术后关节软骨蛋白多糖的测定

目的 应用Pluronic F-127负载同种异体软骨细胞移植修复兔全厚关节软骨损伤,对于新生的修复组织进行基质蛋白多糖含量测定,以探讨此方法修复全厚关节软骨损伤的可行性.方法 取3个月龄新西兰大白兔关节软骨细胞体外培养扩增,与20%Plurortic F-127凝胶混合.选27只健康同种成年大白兔,人为造成双侧膝关节软骨缺损.实验组软骨缺损处植入培养的软骨细胞/Pluronic F-127混合物,对照组缺损处单纯注入Pluronic F-127凝胶和空白对照.然后,对修复组织进行大体观察及蛋白多糖含量测定.结果 移植的软骨细胞-载体复合物中的软骨细胞能良好地生长,12周时再生组织与周围正常软骨组织外观相似,界限模糊.实验组与对照组各时期蛋白多糖含量均有非常显著性差异,实验组不同时期的蛋白多糖含量之间均有显著性差异,实验组12周时蛋白多糖含量与正常软骨组织无显著性差异.结论 Pluronic F-127负载同种异体软骨细胞移植是治疗关节软骨缺损的有效方法.     

培养软骨移植修复关节软骨缺损的实验研究

目的：为探讨一种新的关节软骨缺损修复方法。方法：将体外培养２周形成软骨样组织,移植修复兔关节软骨全层缺损。于移植术后２、４、８周分别行功能评价、大体形态及组织学检查。结果：全部实验兔于术后２周内恢复正常活动。２周时移植修复组织由非成熟透明软骨组成。４周时部分移植组出现成熟透明软骨。８周时移植组关节软骨缺损全部由成熟透明软骨充填修复,修复组织与邻近关节软骨融合。培养软骨移植修复关节软骨全层缺损明显优于自身修复（Ｐ＜００１）。结论：本实验提示使用具有高有丝分裂率的软骨细胞,经离心管培养形成骺软骨样组织,植入关节软骨全层缺损后,软骨细胞生长良好,逐渐成熟和转化,能发挥良好的修复作用。     

Fate of transplanted bone-marrow-derived mesenchymal cells during osteochondral repair using transgenic rats to simulate autologous transplantation

OBJECTIVE: The fate of transplanted cells used in tissue engineering strategies should be followed. With this aim in view, the survival of transplanted bone-marrow-derived mesenchymal cells within osteochondral defects was determined using transgenic rats to simulate autologous transplantation. DESIGN: An autologous transplantation model was simulated using transgenic rats - whose transgenes produce no foreign proteins - as donors, and wild-type rats as recipients. Dense masses of mesenchymal cells were prepared from the transgenic rats using the hanging-drop culture technique. These cell masses were then transplanted into osteochondral defects created within the medial femoral condyle of wild-type rats, wherein they are affixed with fibrin glue. The course of repair was assessed histologically. The survival of the transplanted cells was ascertained by in situ hybridization of the transgenes. RESULTS: Twenty-four weeks after transplantation, the defects were repaired with hyaline-like cartilage, which was thicker than normal, and with subchondral bone. Using the in situ hybridization technique, cells derived from the transplanted ones were detected within both the cartilaginous and the subchondral bone layers. CONCLUSION: Using this simulated autologous transplantation model, the survival of transplanted mesenchymal cells was monitored in vivo. The findings indicate that the transplanted mesenchymal cells contributed to the repair of the osteochondral defects.     

自体骨软骨移植与含富集骨髓干细胞松质骨移植修复兔关节软骨缺损

目的:评价自体骨软骨移植与含富集骨髓干细胞松质骨镶嵌移植两种方法修复全层关节软骨缺损的生物学特征和效果。方法:采用新西兰大白兔制作左右后肢全层软骨缺损模型,分别进行自体骨软骨镶嵌移植、含富集骨髓干细胞松质骨镶嵌移植修复,对照组不作任何修复,每组12只。术后第4、8、12周处死动物取材,分别进行膝关节活动度测定、大体观察、光镜观察与电镜观察。结果:移植实验组在第12周时均能以类透明软骨组织修复缺损,对照组为纤维肉芽组织。形态学检查表明,两种方法均能以类透明软骨组织覆盖缺损,骨软骨移植组无明显免疫排斥现象,随着时间延长,修复高度逐渐增加。骨软骨移植组同含富集骨髓干细胞松质骨镶嵌移植组效果无显著差别。结论:骨软骨移植、含富集骨髓干细胞松质骨镶嵌移植两种方法均能以类透明软骨组织修复全层关节软骨缺损,含富集骨髓干细胞松质骨镶嵌移植更适用于较大面积软骨缺损的修复。     

骨髓基质细胞修复兔关节软骨的实验研究

目的　研究骨髓基质细胞修复兔关节软骨的可行性。方法　取自体骨髓基质细胞体外培养扩增 ,聚乳酸吸附骨髓基质细胞植入兔膝关节软骨负重 (内髁 )和非负重区 (外髁 )缺损内 ,观察 4、 8、 12周后软骨缺损的修复情况 ,并对组织切片评分。结果　 8、 12周后 ,骨髓基质细胞在负重区缺损内可以形成透明软骨 ,组织评分接近正常软骨优于对照 ,非负重区内没有形成透明软骨。结论　骨髓基质细胞可以修复关节软骨缺损 ,摩擦和压应力是成软骨的重要条件。     

异种半月板移植实验研究的初步报告

目的观察生物型异种半月板移植修复羊半月板缺失的效果,探讨生物型半月板重建正常膝关节半月板的可行性。方法以猪膝关节内侧半月板为供体,应用环氧固定技术对猪半月板进行去抗原处理,制成生物型异种半月板移植体。随机切除6只山羊一侧膝关节内侧半月板,将生物型异种半月板塑形并与羊内侧半月板的形态和尺寸相匹配,原位植入半月板缺失部位。分别于术后12周、24周、36周处死动物,对移植半月板、股骨内侧髁及内侧胫骨平台进行大体形态、病理切片和电镜扫描观察。结果随着时间延长,异种移植半月板与周边组织愈合良好,并逐渐被新生组织替代;术后12周,移植膝关节软骨未见退变,24～36周后移植膝关节软骨出现轻度退变,移植半月板出现被吸收和宿主纤维母细胞爬行替代现象。结论我们初步认定,生物型异种半月板作为羊半月板缺失移植的供体可被宿主细胞逐渐替代,逐步形成新生的自体半月板,且短期内对移植膝关节软骨具有明显的保护作用;在实验各阶段均未出现明确的免疫排斥反应。     

Repair of rabbit articular surfaces with allografts of chondrocytes embedded in collagen gels

In an attempt to restore articular cartilage, allogeneic articular chondrocytes embedded in collagen gels were transplanted onto full-thickness defects in rabbit articular cartilage. Within 24 weeks after the transplantation, the defects were filled with hyaline cartilage, specifically synthesizing type II collagen. These chondrocytes were autoradiographically proven to be originated from the originally transplanted chondrocytes. As histologically assessed, success rate was about 80%, a marked improvement over the results (40% success rate) in previous studies reporting chondrocyte transplantation without collagen gels. On the other hand, the defects without chondrocyte transplantation healed with fibrocartilaginous tissue more than 24 weeks after treatment. Immunological enhancement induced by transplanted allogeneic chondrocytes or collagen was not significant for eight weeks after treatment, so far as shown by both direct and indirect blastformation reactions. Thus, allogeneic transplantation of isolated chondrocytes embedded in collagen gels appears to be one of the most promising methods for the restoration of articular cartilage.     

Chondrocyte transplantation in PGLA/polydioxanone fleece

The transplantation of chondrogenic cells in a supportive carrier structure proved to be a promising alternative for the treatment of cartilage defects. In the study presented we focused on the transplantation of allogeneic chondrocytes in a biodegradable polymer scaffold (PGLA/Polydioxanon) in articular cartilage defects in a rabbit defect model. Isolated allogeneic chondrocytes embedded in a PGLA polymer scaffold were transplanted into osteochondrogenic defects of the patellar groove and compared with empty defects and transplants of polymer scaffolds without cells. The histological and histochemical analysis was performed after 4 and 12 weeks. The transplant integration and the architecture of the newly formed cartilage were evaluated with a semiquantitative score. After 4 weeks the development of a hyaline-like cartilage tissue of the cell-polymer-transplants was observed, after 12 weeks the defects were nearly completely filled with hyaline-like cartilage. The biodegradation of the polymer construct did not affect the histological structure of the transplant area. Defects of the groups with empty defect and polymer transplants without cells revealed no or insufficient healing indices. The study demonstrated that biodegradable polymers served as suitable carriers for the chondrocyte transplantation, which is due to the in-vitro establishment of a semi-solid cartilage transplant and the resulting effective transplant fixation into the defect. In-vivo the polymer cell transplants seem to provide a supportive microenvironment for the development of hyaline cartilage. The controlled release of morphogenic factors or bioactive molecules and the use of pluripotent mesenchymal progenitor cells opens new perspectives for the optimization of cartilage repair procedures.     

软骨脱细胞基质-Ⅱ型胶原纳米支架复合BMSC修复兔关节软骨缺损的实验研究

目的 观察软骨脱细胞基质(Cartilage acellular extracellular matrix,CAEM)-Ⅱ型胶原(CollagenⅡ,COLⅡ)纳米支架,复合骨髓基质干细胞(Bone marrow stem cells,BMSCs)修复兔关节软骨缺损的效果。方法 CAEM和COLⅡ按质量比1∶1混合,通过静电纺丝技术制备组织工程纳米支架。将第二代BMSCs种植到该支架上,培养箱内静置2 h。12只日本大耳白兔随机分为实验组和对照组,将细胞支架复合物植入实验组兔膝关节软骨缺损处,对照组仅行膝关节软骨缺损建模。12周后实验动物取材,大体观察修复效果,并行HE染色、Ⅱ型胶原染色观察。结果 大体观察见实验组软骨缺损修复良好,对照组软骨缺损处由肉芽样组织充填。HE染色显示,实验组关节软骨缺损处可见软骨陷窝形成,对照组关节软骨缺损处仅有纤维组织充填。实验组修复区Ⅱ型胶原染色为阳性,对照组为阴性。结论 CAEM-COLⅡ纳米支架复合BMSC,对兔关节软骨缺损具有较好的修复能力,具有潜在的临床应用价值。     

The cellular origin of cartilage-like tissue after periosteal transplantation of full-thickness articular cartilage defects: an experimental study using transgenic rats expressing green fluorescent protein

BACKGROUND: Periosteal transplantation is commonly used for the treatment of articular cartilage defects. However, the cellular origin of the regenerated tissue after periosteal transplantation has not been well defined. The objective of this study was to investigate the cellular origin of the regenerated tissue after periosteal transplantation. METHOD: Free periosteum was harvested from the tibia of 10-week-old adolescent enhanced green fluorescent protein (GFP-) expressing transgenic Sprague Dawley (SD) rats and was transplanted to full-thickness articular cartilage defects of the patellar groove in normal 10-week-old adolescent SD rats. The periosteum was sutured to the defect with the cambium layer facing the joint cavity. 8 SD rats were killed at 4 weeks and 8 SD rats were killed at 8 weeks after surgery. The repaired tissue was assessed histologically and histochemically. GFP-positive cells derived from the donor periosteum could easily be detected in the repaired tissue by use of a fluorescent microscope. RESULTS: At both 4 and 8 weeks after transplantation, the entire area of the defects had been repaired, with the regenerated tissue being well stained histologically with safranin-O. Most cells in the whole area of the regenerated tissue were GFP-positive, indicating that very few of the cells were GFP-negative cells originating from the recipient rats. INTERPRETATION: This experiment demonstrates that most cells in regenerated tissue after periosteal transplantation using adolescent animals do not originate from recipient cells but from the periosteal cells of the donor.