Cartilage Defects In Rabbit Knees Research Articles

Naringin and bone marrow mesenchymal stem cells repair articular cartilage defects in rabbit knees through the transforming growth factor-β superfamily signaling pathway.

The present study aimed to assess the effect of a combination of naringin and rabbit bone marrow mesenchymal stem cells (BMSCs) on the repair of cartilage defects in rabbit knee joints and to assess possible involvement of the transforming growth factor-β (TGF-β) signaling pathway in this process. After establishing an articular cartilage defect model in rabbit knees, 20 New Zealand rabbits were divided into a sham operation group (Sham), a model group (Mod), a naringin treatment group (Nar), a BMSC group (BMSCs) and a naringin + BMSC group (Nar/BMSCs). At 12 weeks after treatment, the cartilage was evaluated using the International Cartilage Repair Society (ICRS)'s macroscopic evaluation of cartilage repair scale, the ICRS's visual histological assessment scale, the Modified O'Driscoll grading system, histological staining (hematoxylin and eosin staining, toluidine blue staining and safranin O staining) and immunohistochemical staining (type-II collagen, TGF-β3 and SOX-9 immunostaining). Using the above grading systems to quantify the extent of repair, histological quantification and macro quantification of joint tissue repair showed that the Nar/BMSCs group displayed repair after treatment in comparison to the untreated Mod group. Among the injury model groups (Mod, Nar, BMSCs and Nar/BMSCs), the Nar/BMSCs group displayed the highest degree of morphological repair. The results of histological and immunohistochemical staining of the repaired region of the joint defect indicated that the BMSCs had a satisfactory effect on the repair of the joint structure but had a poor effect on the repair of cartilage quality. The Nar/BMSCs group displayed satisfactory therapeutic effects on both repair of the joint structure and cartilage quality. The expression level of type-II collagen was high in the Nar/BMSCs group. Additionally, staining of TGF-β3 and SOX-9 in the Nar/BMSCs group was the strongest compared with that of any other group in the present study. Naringin and/BMSCs together demonstrated a more efficient repair effect on articular cartilage defects in rabbit knees than the use of either treatment alone in terms of joint structure and cartilage quality. One potential mechanism of naringin action may be through activation and continuous regulation of the TGF-β superfamily signaling pathway, which can promote BMSCs to differentiate into chondrocytes.

Chondrocyte Co-cultures with the Stromal Vascular Fraction of Adipose Tissue in Polyhydroxybutyrate/Poly-(hydroxybutyrate-co-hydroxyhexanoate) Scaffolds: Evaluation of Cartilage Repair in Rabbit

Chondral defects are challenging to repair because of the poor self-healing capacity of articular cartilage. The aim of this study was to compare and investigate the cartilage regeneration of stromal vascular fraction (SVF) cells and adipose-derived stem cells (ASCs) co-cultured with chondrocytes seeding on scaffolds composed of polyhydroxybutyrate (PHB)/poly-(hydroxybutyrate-co-hydroxyhexanoate) (PHBHHx). In this study, the cellular morphologies and proliferation capabilities on scaffolds were evaluated. Next, scaffolds with 1:1 co-culture of ASCs/SVF and chondrocytes were implanted into the full-thickness cartilage defects in rabbit knee for 10 weeks. Cells seeded on the scaffolds showed better adhesion, migration, and proliferation in vitro. Importantly, implantation with scaffolds with SVF and chondrocytes revealed more desirable in vivo healing outcomes. Our results illustrate a one-step surgical procedure for the regeneration of focal cartilage defects using a mixture of SVF from adipose tissue and uncultured chondrocytes.

Icariin-conditioned serum engineered with hyaluronic acid promote repair of articular cartilage defects in rabbit knees

BackgroundOsteochondral defects mostly occur as a result of trauma or articular degeneration. The poor regenerative ability of articular cartilage remains osteochondral defects are a tricky problem to deal with. The modern treatment strategies mainly focus on cartilage tissue engineering with bioactive materials. In this study, we aimed to develop icariin conditioned serum (ICS) together with hyaluronic acid (HA) and determine their ability in reparing osteochondral tissue in a critical-sized defect in rabbit knees.MethodsPrimary chondrocytes were incubated with serum conditioned with icariin at different concentrations, then cell proliferation rates and glycosaminoglycan (GAG) secretion were detected. Rabbits were treated with intra-articular injection of 0.5 mL normal saline (NS), ICS, HA and ICS + HA in the right knee joint, respectively. ICRS scores were used to assess the macroscopic cartilage regeneration. Histological and immunohistochemical analysis including H&E, Safranin O, toluidine blue and collagen II staining were used to determine the repair of cartilage and the regeneration of chondrocytes.ResultsIcariin at a low dose of 0.94 g/kg was identified to have significantly promoted the proliferation of chondrocytes and enhance the secretion of GAG. Femoral condyle from rabbits treated by ICS together with HA was observed to be integrated with native cartilage and more subchondral bone regeneration. ICS together with HA could promote repair of the cartilage defect and increase the neoformation of cartilage.ConclusionsThese results demonstrated the potential of ICS combined with HA to promote reparative response in cartilage defects and the possible application in bioactive material based cartilage regeneration therapies.

Similar regeneration of articular cartilage defects with autologous & allogenic chondrocytes in a rabbit model.

Background & objectives:Articular cartilage defects in the knee have a very poor capacity for repair due to avascularity. Autologous chondrocyte transplantation (ACT) is an established treatment for articular cartilage defects. Animal studies have shown promising results with allogenic chondrocyte transplantation since articular cartilage is non-immunogenic. In addition to being economical, allogenic transplantation has less morbidity compared to ACT. This study was undertaken to compare ACT with allogenic chondrocyte transplantation in the treatment of experimentally created articular cartilage defects in rabbit knee joints.Methods:Cartilage was harvested from the left knee joints of six New Zealand white rabbits (R1-R6). The harvested chondrocytes were cultured to confluence and transplanted onto a 3.5 mm chondral defect in the right knees of 12 rabbits [autologous in 6 rabbits (R1-R6) and allogenic in 6 rabbits (R7-R12)]. After 12 wk, the rabbits were euthanized and histological evaluation of the right knee joints were done with hematoxylin and eosin and safranin O staining. Quality of the repair tissue was assessed by the modified Wakitani histological grading scale.Results:Both autologous and allogenic chondrocyte transplantation resulted in the regeneration of hyaline/mixed hyaline cartilage. The total histological scores between the two groups showed no significant difference.Interpretation & conclusions:Allogenic chondrocyte transplantation seems to be as effective as ACT in cartilage regeneration, with the added advantages of increased cell availability and reduced morbidity of a single surgery.

Matrigel scaffold combined with Ad-hBMP7-transfected chondrocytes improves the repair of rabbit cartilage defect.

The aim of this study was to explore an effective method for the repair of cartilage defects using chitosan/glycerophosphate (C/GP) gel- and Matrigel-engineered human bone morphogenetic protein 7 (hBMP7)-expressing chondrocytes. Rabbit chondrocytes were obtained, cultured in vitro and transfected with an adenovirus containing hBMP7 and green fluorescent protein (Ad-hBMP7-GFP). The expression of hBMP7 in the transfected cells was tested by reverse transcription-polymerase chain reaction (RT-PCR) and western blotting. The phenotype of the transfected cells was evaluated by detecting the yields of collagen II and hyaluronic acid using RT-PCR and enzyme-linked immunosorbent assay (ELISA). The growth of chondrocytes in the C/GP gel and Matrigel was accessed by measuring the cell growth rate, hematoxylin and eosin (H&E) staining and observation under a scanning microscope. Twelve adult male New Zealand white rabbits were randomly divided into three groups. Two cartilage defects were created in the rabbits' knees by aseptic surgery. Group A (n=4) did not receive any treatment, group B (n=4) were treated with C/GP gel and Matrigel-engineered Ad-mock-GFP-transfected chondrocytes, and group C (n=4) were treated with C/GP gel and Matrigel-engineered Ad-hBMP7-GFP-transfected chondrocytes. Rabbits were sacrificed at 4 weeks after transplantation, and the repair effect was measured by the Wakitani scoring method. On the basis of the RT-PCR and western blot results, hBMP7 was efficiently overexpressed in the Ad-hBMP7-GFP-transfected chondrocytes. The ELISA results showed that the yields of collagen II and hyaluronic acid in Ad-hBMP7-GFP-transfected chondrocytes were significantly higher than those in Ad-mock-GFP-transfected chondrocytes. Chondrocytes have a better morphology and arrangement in a Matrigel scaffold than in C/GP, as assessed by H&E staining and scanning microscopy. According to the Wakitani score, Matrigel combined with Ad-hBMP7-GFP-transfected chondrocytes successfully promoted the repair of cartilage defects in rabbit knees.

Poly(3-hydroxybutyrate-co-4-hydroxybutyrate) Based Electrospun 3D Scaffolds for Delivery of Autogeneic Chondrocytes and Adipose-Derived Stem Cells: Evaluation of Cartilage Defects in Rabbit.

The management of chondral defects has long been a challenge because of the poor self-healing capacity of articular cartilage. Many approaches ranging from symptomatic treatment to structural cartilage regeneration have obtained very limited satisfactory results. Cartilage tissue engineering, which involves an optimized combination of novel scaffolds, cell sources and growth factors, has emerged as a promising strategy for cartilage regeneration and repair. In this study, the cellular morphologies and the adhesion, migration and proliferation capabilities of adipose-derived stem cells (ASCs) and chondrocytes seeded on 3D scaffolds composed of electrospun poly(3-hydroxybutyrate-co-4-hydroxybutyrate) (P3HB4HB) were evaluated. Next, TGF-β1/scaffolds with 4:1 co-culture of ASCs and chondrocytes were implanted into the full thickness cartilage defects in rabbit knee for 16 weeks. ASCs and chondrocytes seeded on the scaffolds showed better adhesion, migration and proliferation than that on petri dishes in vitro. Importantly, implantation with TGF-β1/scaffolds with delivery of ASCs and chondrocytes revealed desirable in vivo healing outcomes. These results demonstrate that ASCs have great potential in the field of tissue engineering. It is possible that the improvement in ASC-seeded electrospun 3D P3HB4HB scaffolds may ultimately lead to improved repair of cartilage injuries.

Potential of exogenous cartilage proteoglycan as a new material for cartilage regeneration

Although proteoglycan (PG) is one of the major components of cartilage matrices, its biological function is not fully elucidated. The objectives of this study were to investigate the proliferation and differentiation of chondrocytes embedded in atelocollagen gel with exogenous cartilage PG (PG-atelocollagen gel) in vitro, and also to evaluate the repair of cartilage defects by PG-atelocollagen gel in vivo. In the in vitro study, rabbit chondrocytes were cultured in the PG-atelocollagen gel. Cell proliferation and mRNA expression levels were measured, and gels were histologically evaluated. In the in vivo study, cultured PG-atelocollagen gel containing chondrocytes were transplanted into full-thickness articular cartilage defects in rabbit knees, and evaluated macroscopically and histologically. For the in vitro study, chondrocyte proliferation in 5.0 mg/ml PG-atelocollagen gel was enhanced, and the gene expression of Col2a1 and Aggrecan were decreased. In contrast, chondrocyte proliferation in 0.1 and 1.0 mg/ml PG-atelocollagen gel was not enhanced. The gene expression of Aggrecan in 0.1 and 1.0 mg/ml PG-atelocollagen gel was increased. For the in vivo study, the histological average total score of the 0.1 mg/ml PG-atelocollagen gel was significantly better than that of the group without PG. Although the appropriate concentration of PG has not been defined, this study suggests the efficacy of PG for cartilage repair.

A Comparison Study of Periosteal and Perichondrial Autografts for Full Thickness Articular Cartilage Defects in Rabbit Knees

A Comparison Study of Periosteal and Perichondrial Autografts for Full Thickness Articular Cartilage Defects in Rabbit Knees

A cellular implantation system using an injectable ultra‐purified alginate gel for repair of osteochondral defects in a rabbit model

We developed a novel cellular implantation system using an in situ forming ultra-purified alginate gel with quite low endotoxity. The aims of this study were to determine the superiority of chondrogenic potential of bone marrow stromal cells (BMSCs) cultured in the purified alginate gel compared with a commercial grade gel, and to assess reparative tissues treated with BMSCs implanted using the developed system into cartilage defects in rabbit knees. The effects of each alginate gel on cellular proliferation and chondrogenesis of rabbit BMSCs were determined by in vitro assessments. Using our purified alginate gel, a novel vehicle system for injecting BMSCs into osteochondral defects without periosteal patch was successfully established in this animal models. The in vitro analyses demonstrated that the purification of alginate significantly enhanced the cellular proliferation and chondrogenic differentiation of BMSCs. The in vivo assessments suggested that the implantation of BMSCs with the developed system using the purified alginate gel histologically and mechanically improved the reparative tissue of osteochondral defects. This system using the purified alginate gel shows the clinical potential for arthroscopically injectable implantation of BMSCs for the treatment of cartilaginous lesions.

Performance of novel bioactive hybrid hydrogels in vitro and in vivo used for artificial cartilage

The long-term fixation of poly(vinyl alcohol) PVA hydrogels cartilage implants on ambient tissue is a difficult problem, which is one of the obstacles for PVA hydrogels to be used as articular cartilage implants. In this work, a novel bioactive PVA/HA hydrogel was prepared by the in situ sol–gel synthesis method. Simulated experiments were performed to evaluate and compare the bioactive ability and properties of the hydrogels in simulated body fluid (SBF). Gradual-structure PVA/HA cartilage implants were developed and used to repair articular cartilage defects in rabbit knees. In vitro bioactive evaluation showed that PVA/HA hydrogels could be bio-mineralized to form bone-like hydroxyl–carbonate–apatite deposit in SBF solution. The macroscopic and histological observation of animal experiments displayed that the implanted hydrogels combined tightly with ambient tissues, and some bone-like tissue grew into the bottom of the implants from the base bone to form more deep-set binding between replacement and cartilage tissues.

Tissue engineering of articular cartilage with autologous cultured adipose tissue‐derived stromal cells using atelocollagen honeycomb‐shaped scaffold with a membrane sealing in rabbits

Adipose tissue derived stromal cells (ATSCs), which were isolated from adipose tissue of rabbit, have shown to possess multipotential, that is, they differentiate into osteoblasts and adipocytes in plate-culturing and into chondrocytes in an established aggregate culture using defined differentiation-inductive medium. The aim of this study was to evaluate the utility of ATSCs in tissue engineering procedures for repair of articular cartilage-defects using the atelocollagen honeycomb-shaped scaffold with a membrane sealing (ACHMS-scaffold). We intended to repair full-thickness articular cartilage defects in rabbit knees using autologously cultured ATSCs embedded in the ACHMS-scaffold. ATSCs were incubated within the ACHMS-scaffold to allow a high density and three-dimensional culture with control medium. An articular cartilage defect was created on the patellar groove of the femur, and the defect was filled with the ATSCs-containing ACHMS-scaffold, ACHMS-scaffold alone, or empty (control). Twelve weeks after the operation, the histological analyses showed that only the defects treated with the ATSCs-containing ACHMS-scaffold were filled with reparative hyaline cartilage, highly expressed Type II collagen. These results indicate that transplantation of autologous ATSCs-containing ACHMS-scaffold is effective in repairing articular cartilage defects.

Tissue engineered cartilage repair using cryopreserved and noncryopreserved chondrocytes.

The objective of this study was to reconstruct full thickness cartilage defects in rabbit knees with in vitro engineered cartilage tissue based on noncryopreserved and cryopreserved chondrocytes in polymer fleece scaffolds. Osteochondral defects in rabbits were filled with polymer cylinders with noncryopreserved or cryopreserved allogeneic chondrocytes and compared with empty defects and defects filled with polymers alone. The defects were evaluated macroscopically and histologically 4 and 12 weeks after surgery. Transplant samples were graded using a semiquantitative score system. Successful healing was defined as complete integration of a hyalinelike and structurally intact cartilage into the defect and occurred in 71% of the group with noncryopreserved chondrocytes after 4 weeks and 100% of the rabbit knees after 12 weeks, whereas hyalinelike cartilage was seen in 71% of the group with cryopreserved chondrocytes after 4 weeks, and in 85% after 12 weeks. No newly formed cancellous bone was present in the subchondral bone. In the control groups, no cartilagelike tissue was seen. Transplantation of chondrocytes in polymer fleece constructs is a suitable approach for joint cartilage repair. Noncryopreserved chondrocytes are preferred to cryopreserved chondrocytes because of their regenerative potential. In vitro engineered cartilage offers broad opportunities for optimization of cartilage transplantation based on the controlled use of morphogenic and biologically active factors such as transforming growth factor-beta and bone morphogenetic proteins.

The influence of transforming growth factor beta1 on mesenchymal cell repair of full-thickness cartilage defects.

To repair full-thickness articular cartilage defects in rabbit knees, we transplanted periosteal cells in a fibrin gel and determined the influence of transforming growth factor beta (TGF-beta) in vitro. Alginate served as a temporary supportive matrix component and was removed prior to transplantation. The defects were analyzed macroscopically, histologically, and electron microscopically, and evaluated with a semi-quantitative score system. Periosteal cell transplants showed a chondrogenic differentiation, which results in the development of embryonic-like cartilage tissue after 4 weeks and complete resurfacing of the patellar groove after 12 weeks. In the control groups, no repair was observed. Under the influence of TGF-beta1 we observed a reduction of the cartilage layer, whereas the osteochondral integration and the zonal architecture were improved. Periosteal cell-beads are stable cartilage transplants and have stiffness and elasticity enough for easy and sufficient transplant fixation. Further investigations are necessary to optimize the application of TGF-beta1 for cartilage repair.

Transplantation of allograft chondrocytes embedded in agarose gel into cartilage defects of rabbits

Objective: Durable healing of full-thickness articular cartilage defects has been considered for a long time as a highly desirable, but unlikely event to occur. In recent years, conflicting reports on the outcome ofin vitroandin vivostudies on chondrocyte and cartilage grafting into animal and human joints have raised new arguments for and against controlled repair of articular cartilage following injury. Some of the problems result from insufficient characterization of implant and repair tissue, and from too short follow up phases. Here we describe a new approach to repair articular cartilage defects in rabbit knees by allografting chondrocytes cultured in agarose gels.Design: The implants were monitored over 6–18 months and graded histologically, immunohistochemically, and electron microscopically, using a grading scale based on seven evaluation criteria. Control implants of pure agarose produced poor fibrous substitute tissue, insufficient healing and incomplete filling of the cartilage defects. After transplantation of allogenic chondrocytes embedded in agarose, the quality of the newly formed repair cartilage was superior with respect to type II collagen and proteoglycan content and cellular architecture when compared with untreated defects. Superficial fibrillation and degradation were significantly diminished or prevented.Results: New subchondral bone formed at the level of the previous subchondral bone. In most cases the repair tissue merged with the host articular cartilage; normal calcified cartilage was the only tissue zone that did not participate in the integration of the transplant. By gross evaluation 24% of grafts showed an extent of recovery never observed in controls. The best results were obtained after 18 months when 47% of the grafts (N=15) developed a morphologically stable hyaline cartilage.Conclusion: These studies demonstrate that agarose-embedded chondrocyte may prove a valuable tool for controlled repair of articular cartilage defects.