Bioengineered chondrocyte sheets may be potentially useful for the treatment of partial thickness defects of articular cartilage.
ABSTRACT Some treatments for full thickness defects of articular cartilage, such as cultured chondrocyte transplantation, have already been done. However, to overcome osteoarthritis, we must further study the partial thickness defect of articular cartilage. It is much more difficult to repair a partial thickness defect because few repairing cells can address such injured sites. We herein show that bioengineered layered chondrocyte sheets using temperature-responsive culture dishes may be a potentially useful treatment for partial thickness defects. We evaluated the property of these sheets using real-time PCR and histological findings, and allografted these sheets to evaluate the effect of treatment using a rabbit partial model. In conclusion, layered chondrocyte sheets were able to maintain the cartilageous phenotype, and could be attached to the sites of cartilage damage which acted as a barrier to prevent a loss of proteoglycan from these sites and to protect them from catabolic factors in the joint.
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ABSTRACT: Background In recent years, several methods have been developed for repairing full-thickness cartilage defects by tissue engineering using mesenchymal stem cells. Most of these use scaffolds to achieve sufficient thickness. However, considering the potential influence of scaffolds on the surrounding microenvironment, as well as immunological issues, it is desirable to develop a scaffold-free technique. In this study, we developed a novel technique, a scaffold-free autologous construct derived from bone marrow-derived mesenchymal stem cells (BM-MSCs), and successfully use this technique to regenerate cartilage and subchondral bone to repair an osteochondral defect in rabbit knees.MethodsBM-MSCs were isolated from bone marrow liquid aspirated from the iliac crest of rabbits. After expansion in culture dishes and re-suspension in 96-well plates, the cells spontaneously aggregated into a spheroid-like structure. The spheroids were loaded into a tube-shaped Teflon mold with a 5-mm height and maintained under air-liquid interface conditions. These loaded spheroids fused with each other, resulting in a cylinder-shaped construct made of fused cells that conformed to the inner shape of the mold. The construct was implanted into an osteochondral defect in rabbit knees and histologically analyzed 24 and 52 weeks after implantation using Wakitani¿s scoring system.ResultsBoth bone and cartilage were regenerated, maintaining a constant thickness of cartilage. The mean histological score was 10¿±¿1.7 in the 24-week group and 9.7¿±¿0.6 in the 52-week group. There was no significant difference between the 24- and 52-week groups in either parameter of the score, indicating that no deterioration of the repaired tissue occurred during the intervening period.Conclusions Using our novel technique, which employs a three-dimensional scaffold-free autologous construct derived from BM-MSCs, we successfully achieved simultaneous regeneration of bone and cartilage for up to 1 year in vivo. This method has potential for clinical use as a safe and effective method for repairing bone and cartilage defects.Journal of Orthopaedic Surgery and Research 10/2014; 9(1):98. · 1.01 Impact Factor
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ABSTRACT: Cartilage defects are normally concomitant with posttraumatic inflammation and pose a major challenge in cartilage repair. Due to the avascular nature of cartilage and its inability to surmount an inflammatory response, the cartilage is easily attacked by pro-inflammatory factors and oxidative stress; if left untreated, osteoarthritis may develop. Suppression of inflammation has always been a crux for cartilage repair. Pharmacological drugs have been successfully applied in cartilage repair; however, they cannot optimally work alone. This review paper will summarize current pharmacological drugs and their application in cartilage repair. The development of extracellular matrix-based scaffolds and preconditioned tissue-specific stem cells will be emphasized because both of these tissue engineering components could contribute to an enhanced ability not only for cartilage regeneration but also for anti-inflammation. These strategies could be combined to boost cartilage repair under inflammatory conditions.Tissue Engineering Part B Reviews 05/2014; · 4.64 Impact Factor
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ABSTRACT: An attractive cell source for cartilage tissue engineering, human adipose-derived stem cells (hASCs) can be easily expanded and signaled to differentiate into chondrocytes. This study explores the influence of growth factor distribution and release kinetics on cartilage formation within 3D hASC constructs incorporated with transforming growth factor-β1 (TGF-β1) loaded gelatin microspheres. The amount of microspheres, TGF-β1 concentration, and polymer degradation rate were varied within hASC aggregates. Microsphere and TGF-β1 loading concentrations were identified that resulted in glycosaminoglycan production comparable to those of control aggregates cultured in TGF-β1-containing medium. Self-assembling hASC sheets were then engineered for the production of larger, more clinically relevant constructs. Chondrogenesis was observed in hASC-only sheets cultured with exogenous TGF-β1 at 3 weeks. Importantly, sheets with incorporated TGF-β1-loaded microspheres achieved glycosaminoglycan production levels similar to sheets treated with exogenous TGF-β1. Cartilage formation was confirmed histologically via observation of cartilage-like morphology and glycosaminoglycan staining. This is the first demonstration of the self-assembly of hASCs into high-density cell sheets capable of forming cartilage in the presence of exogenous TGF-β1 or with TGF-β1-releasing microspheres. Microsphere incorporation may bypass the need for extended in vitro culture, potentially allowing hASC sheets to be implanted more rapidly into defects to regenerate cartilage in vivo.Tissue Engineering Part A 05/2014; · 4.07 Impact Factor