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The hWJMSCs-ACECM scaffold complex achieved better quality repair and regeneration of hyaline cartilage without cartilage-inducing factor, while retaining the structure and functional integrity of the subchondral bone, compared with MF.

Heterogeneity of mesenchymal stem cells (MSCs) influences the cell therapy outcome and the application in tissue engineering. Also, the application of subpopulations of MSCs in cartilage regeneration remains poorly characterized. CD146+ MSCs are identified as the natural ancestors of MSCs and the expression of CD146 are indicative of greater pluripotency and self-renewal potential. Here, we sorted a CD146 + subpopulation from adipose-derived mesenchymal stem cells (ADSCs) for cartilage regeneration. Methods : CD146 + ADSCs were sorted using magnetic activated cell sorting (MACS). Cell surface markers, viability, apoptosis and proliferation were evaluated in vitro . The molecular signatures were analyzed by mRNA and protein expression profiling. By intra-articular injections of cells in a rat osteochondral defect model, we assessed the role of the specific subpopulation in cartilage microenvironment. Finally, CD146 + ADSCs were combined with articular cartilage extracellular matrix (ACECM) scaffold for long term (3, 6 months) cartilage repair. Results : The enriched CD146 + ADSCs showed a high expression of stem cell and pericyte markers, good viability, and immune characteristics to avoid allogeneic rejection. Gene and protein expression profiles revealed that the CD146 + ADSCs had different cellular functions especially in regulation inflammation. In a rat model, CD146 + ADSCs showed a better inflammation-modulating property in the early stage of intra-articular injections. Importantly, CD146 + ADSCs exhibited good biocompatibility with the ACECM scaffold and the CD146 + cell-scaffold composites produced less subcutaneous inflammation. The combination of CD146 + ADSCs with ACECM scaffold can promote better cartilage regeneration in the long term. Conclusion : Our data elucidated the function of the CD146 + ADSC subpopulation, established their role in promoting cartilage repair, and highlighted the significance of cell subpopulations as a novel therapeutic for cartilage regeneration.

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Meniscus injuries are very common and still pose a challenge for the orthopedic surgeon. Meniscus injuries in the inner two-thirds of the meniscus remain incurable. Tissue-engineered meniscus strategies seem to offer a new approach for treating meniscus injuries with a combination of seed cells, scaffolds, and biochemical or biomechanical stimulation. Cell- or scaffold-based strategies play a pivotal role in meniscus regeneration. Similarly, biochemical and biomechanical stimulation are also important. Seed cells and scaffolds can be used to construct a tissue-engineered tissue; however, stimulation to enhance tissue maturation and remodeling is still needed. Such stimulation can be biomechanical or biochemical, but this review focuses only on biochemical stimulation. Growth factors (GFs) are one of the most important forms of biochemical stimulation. Frequently used GFs always play a critical role in normal limb development and growth. Further understanding of the functional mechanism of GFs will help scientists to design the best therapy strategies. In this review, we summarize some of the most important GFs in tissue-engineered menisci, as well as other types of biological stimulation.

Abstract Exosomes are extracellular vesicles with diameters of 30–100 nm that are key for intercellular communication. Almost all types of cell, including dendritic cells, T cells, mast cells, epithelial cells, neuronal cells, adipocytes, mesenchymal stem cells, and platelets, can release exosomes. Exosomes are present in human body fluids, such as urine, amniotic fluid, malignant ascites, synovial fluid, breast milk, cerebrospinal fluid, semen, saliva, and blood. Exosomes have biological functions in immune response, antigen presentation, intercellular communication, and RNA and protein transfer. This review provides a brief overview of the origin, morphological characteristics, enrichment and identification methods, biological functions, and applications in tissue engineering and neurological diseases of exosomes.

The normal anatomical structure of articular cartilage determines its limited ability to regenerate and repair. Once damaged, it is difficult to repair it by itself. How to realize the regeneration and repair of articular cartilage has always been a big problem for clinicians and researchers. Here, we conducted a comprehensive analysis of the physical properties and cytocompatibility of hydrogels, and evaluated their feasibility as cell carriers for Adipose-derived mesenchymal stem cell (ADSC) transplantation. Concentration-matched hydrogels were co-cultured with ADSCs to confirm ADSC growth in the hydrogel and provide data supporting in vivo experiments, which comprised the hydrogel/ADSCs, pure-hydrogel, defect-placement, and positive-control groups. Rat models of articular cartilage defect in the knee joint region was generated, and each treatment was administered on the knee joint cartilage area for each group; in the positive-control group, the joint cavity was surgically opened, without inducing a cartilage defect. The reparative effect of injectable glycol chitosan/dibenzaldehyde-terminated polyethylene glycol (GCS/DF-PEG) hydrogel on injured articular cartilage was evaluated by measuring gross scores and histological score of knee joint articular-cartilage injury in rats after 8 weeks. The 1.5% GCS/2% DF-PEG hydrogels degraded quickly in vitro. Then, We perform in vivo and in vitro experiments to evaluate the feasibility of this material for cartilage repair in vivo and in vitro.

Meniscus is a fibrocartilaginous organ to redistribute stress and enhance the stability of knee joint. Meniscus injury is common and still a formidable challenge to orthopedic surgeons. Surgical techniques and allograft transplantation were primary approaches to meniscus repair, but with intrinsic limitations in clinical practice. Tissue engineering is the most promising method to repair meniscus at present. Electrospinning is a method to fabricate fibers in small scale. With different materials and parameters, electrospinning materials could have different mechanical properties, porosity, and orientation, which could mimic architectural features and mechanical properties of native meniscus. Therefore, electrospinning materials could be used in meniscus regeneration and curing. This review gave a brief introduction of meniscus structure, injury, treatment and the application of electrospinning fibers in meniscus tissue engineering and curing. Besides that, we summarized materials commonly used in electrospinning to fabricate meniscus scaffolds, and discussed the form of electrospinning fibers used such as scaffold, substitute and patch. Finally, the function of electrospinning fibers, for example, carrying drugs, providing mechanical properties were described. The potential applications of electrospinning fibers in meniscus therapy were proposed.