Role In Cartilage Regeneration Research Articles

Magnetically Controlled 3D Cartilage Regeneration.

The cartilage regeneration field has not yet overcome the issue of effective "shaping": growing regenerated cartilage in the desired shape, and maintaining that shape, is problematic. This study reports on a new method of cartilage regeneration in which the cartilage is shaped in three dimensions. Since cartilage is composed only of cartilage cells and an abundant extracellular matrix with no blood circulation, once it is damaged, the lack of nutrient supply means that it is difficult to repair. Scaffold-free cell sheet technology plays an important role in cartilage regeneration, avoiding inflammation and immune response caused by scaffold materials. However, cartilage regenerated from the cell sheet needs to be sculpted and shaped before it can be used for cartilage defect transplantation. In this study, we used a new ultra-strong magnetic-responsive Fe3O4 nanoparticle (MNP) to shape the cartilage in vitro. Super-magnetic Fe3O4 microspheres are manufactured by co-assembling negatively charged Cetyltrimethylammonium bromide (CTAB) and positively charged Fe3+ under solvothermal conditions. The Fe3O4 MNPs are swallowed by chondrocytes, and the MNP-labeled chondrocytes are acted upon by the magnetic field. The predetermined magnetic force makes the tissues coalesce to form a multilayer cell sheet with a predetermined shape. The shaped cartilage tissue is regenerated in the transplanted body, and the nano magnetic control particles do not affect cell viability. The nanoparticles in this study improve the efficiency of cell interaction through super-magnetic modification, and to a certain extent change the way the cells absorb magnetic iron nanoparticles. This phenomenon allows a more orderly and compact alignment of the cartilage cell extracellular matrix, promotes ECM precipitation and cartilage tissue maturation, and improves the efficiency of cartilage regeneration. The magnetic bionic structure, which contains specific magnetic particle-labeled cells, is deposited layer by layer to generate a three-dimensional structure with repair function, and further induce the production of cartilage. This study describes a new method for the regeneration of tissue engineered cartilage which has broad application prospects in regenerative medicine.

3D Printed Chondrogenic Functionalized PGS Bioactive Scaffold for Cartilage Regeneration.

Tissue engineering is emerging as a promising approach for cartilage regeneration and repair. Endowing scaffolds with cartilaginous bioactivity to obtain bionic microenvironment and regulating the matching of scaffold degradation and regeneration play a crucial role in cartilage regeneration. Poly(glycerol sebacate) (PGS) is a representative thermosetting bioelastomer known for its elasticity, biodegradability, and biocompatibility and is widely used in tissue engineering. However, the modification and drug loading of the PGS scaffold is still a key challenge due to its high temperature curing conditions and limited reactive groups, which seriously hinders its further functional application. Here, a simple versatile new strategy of super swelling-absorption and cross-linked networks locking is presented to successfully create the 3Dprinted PGS-CS/Gel scaffold for the first time based on FDA-approved PGS, gelatin (Gel) and chondroitin sulfate (CS). The PGS-CS/Gel scaffold exhibits the desirable synergistic properties of well-organized hierarchical structures, excellent elasticity, improved hydrophilicity, and cartilaginous bioactivity, which can promote the adhesion, proliferation, and migration of chondrocytes. Importantly, the rate of cartilage regeneration can be well-matched with degradation of PGS-CS/Gel scaffold, and achieve uniform and mature cartilage tissue without scaffold residual. The bioactive scaffold can successfully repair cartilage in a rabbit trochlear groove defect model indicating a promising prospect of clinical transformation.

Human integrin α10β1-selected mesenchymal stem cells home to cartilage defects in the rabbit knee and assume a chondrocyte-like phenotype

BackgroundMesenchymal stem cells (MSCs) have shown promising results in stimulating cartilage repair and in the treatment of osteoarthritis (OA). However, the fate of the MSCs after intra-articular injection and their role in cartilage regeneration is not clear. To address these questions, this study investigated (1) homing of labeled human adipose tissue derived integrin α10β1-selected MSCs (integrin α10-MSCs) to a cartilage defect in a rabbit model and (2) the ability of the integrin α10-MSCs to differentiate to chondrocytes and to produce cartilage matrix molecules in vivo.DesignIntegrin α10-MSCs were labeled with superparamagnetic iron oxide nanoparticles (SPIONs) co-conjugated with Rhodamine B to allow visualization by both MRI and fluorescence microscopy. A cartilage defect was created in the articular cartilage of the intertrochlear groove of the femur of rabbits. Seven days post-surgery, labeled integrin α10-MSCs or vehicle were injected into the joint. Migration and distribution of the SPION-labeled integrin α10-MSCs was evaluated by high-field 9.4 T MRI up to 10 days after injection. Tissue sections from the repair tissue in the defects were examined by fluorescence microscopy.ResultsIn vitro characterization of the labeled integrin α10-MSCs demonstrated maintained viability, proliferation rate and trilineage differentiation capacity compared to unlabeled MSCs. In vivo MRI analysis detected the labeled integrin α10-MSCs in the cartilage defects at all time points from 12 h after injection until day 10 with a peak concentration between day 1 and 4 after injection. The labeled MSCs were also detected lining the synovial membrane at the early time points. Fluorescence analysis confirmed the presence of the labeled integrin α10-MSCs in all layers of the cartilage repair tissue and showed co-localization between the labeled cells and the specific cartilage molecules aggrecan and collagen type II indicating in vivo differentiation of the MSCs to chondrocyte-like cells. No adverse effects of the α10-MSC treatment were detected during the study period.ConclusionOur results demonstrated migration and homing of human integrin α10β1-selected MSCs to cartilage defects in the rabbit knee after intra-articular administration as well as chondrogenic differentiation of the MSCs in the regenerated cartilage tissue.

State of the Art: The Immunomodulatory Role of MSCs for Osteoarthritis.

Osteoarthritis (OA) has generally been introduced as a degenerative disease; however, it has recently been understood as a low-grade chronic inflammatory process that could promote symptoms and accelerate the progression of OA. Current treatment strategies, including corticosteroid injections, have no impact on the OA disease progression. Mesenchymal stem cells (MSCs) based therapy seem to be in the spotlight as a disease-modifying treatment because this strategy provides enlarged anti-inflammatory and chondroprotective effects. Currently, bone marrow, adipose derived, synovium-derived, and Wharton’s jelly-derived MSCs are the most widely used types of MSCs in the cartilage engineering. MSCs exert immunomodulatory, immunosuppressive, antiapoptotic, and chondrogenic effects mainly by paracrine effect. Because MSCs disappear from the tissue quickly after administration, recently, MSCs-derived exosomes received the focus for the next-generation treatment strategy for OA. MSCs-derived exosomes contain a variety of miRNAs. Exosomal miRNAs have a critical role in cartilage regeneration by immunomodulatory function such as promoting chondrocyte proliferation, matrix secretion, and subsiding inflammation. In the future, a personalized exosome can be packaged with ideal miRNA and proteins for chondrogenesis by enriching techniques. In addition, the target specific exosomes could be a gamechanger for OA. However, we should consider the off-target side effects due to multiple gene targets of miRNA.

Mesenchymal Stem Cell-Derived Exosomes and MicroRNAs in Cartilage Regeneration: Biogenesis, Efficacy, miRNA Enrichment and Delivery.

Exosomes are the small extracellular vesicles secreted by cells for intercellular communication. Exosomes are rich in therapeutic cargos such as microRNA (miRNA), long non-coding RNA (lncRNA), small interfering RNA (siRNA), DNA, protein, and lipids. Recently, many studies have focused on miRNAs as a promising therapeutic factor to support cartilage regeneration. Exosomes are known to contain a substantial amount of a variety of miRNAs. miRNAs regulate the post-transcriptional gene expression by base-pairing with the target messenger RNA (mRNA), leading to gene silencing. Several exosomal miRNAs have been found to play a role in cartilage regeneration by promoting chondrocyte proliferation and matrix secretion, reducing scar tissue formation, and subsiding inflammation. The exosomal miRNA cargo can be modulated using techniques such as cell transfection and priming as well as post-secretion modifications to upregulate specific miRNAs to enhance the therapeutic effect. Exosomes are delivered to the joints through direct injection or via encapsulation within a scaffold for sustained release. To date, exosome therapy for cartilage injuries has yet to be optimized as the ideal cell source for exosomes, and the dose and method of delivery have yet to be identified. More importantly, a deeper understanding of the role of exosomal miRNAs in cartilage repair is paramount for the development of more effective exosome therapy.

Review On Use Of Polymeric Hydrogel For Cartilage Regeneration.

The therapy for articular cartilage trauma was a major challenge in the medical field. However due to their 3D cross linking capability and tissue mimicking nature , hydrogel played a crucial role in cartilage regeneration. However, when compared to traditional gels, hydrogels have many distinct properties that make them desirable for several biomedical applications. Firstly, the compact size of the hydrogels enables it to pass through the compact needles and catheters, which is useful for minimally invasive cells and biological deliveries in case of cartilage tissue regeneration. Further, the physical interactions among the polymers also lead to shear thinning behavior that enables the solid-like consistency in case of hydrogel scaffolds without the need for chemical modifications. In general, the polymeric hydrogels thus approaching the ideal characteristics must adhere to the site of the application, relieve traumatic signs, facilitate the faster rate of cartilage regeneration and seek to restore the normal daily activities of the preclinical or clinical subjects. Furthermore, in this review addresses past and current efforts with a brief overview of the highlighted properties for cartilage repair applications of hydrogel scaffolds made from both natural and synthetic polymers. We reviewed the multi scale properties of the hydrogel scaffolds such as mechanical properties and porosity. Moreover, this review focuses primarily on illustrating the characteristics of ideal polymeric hydrogels that are compatible with cartilage repair

Characterization of exosomal long non-coding RNAs in chondrogenic differentiation of human adipose-derived stem cells.

The exosomes derived from chondrogenic stem cells and long non-coding RNAs (lncRNAs) play a key role in cartilage regeneration. Here, we investigated the expression profile of exosomal lncRNAs in chondrogenesis of human adipose derived stem cells (hADSCs). hADSCs were induced to differentiate into chondrocytes in vitro. Exosomes from undifferentiated hADSCs and chondrogenic hADSCs were isolated. LncRNA and mRNA expression profiles in the isolated exosomes were analyzed by RNA sequencing. The resultant data were subjected to gene ontology (GO) terms and KEGG pathway analysis to identify differentially expressed lncRNAs. We identified 23 upregulated and 163 downregulated lncRNAs in exosomes derived from chondrogenic hADSCs compared to that in exosomes from undifferentiated hADSCs. In addition, analysis of mRNA expression data revealed 968 upregulated genes and 572 downregulated genes in exosomes of chondrogenic hADSCs. Lncrna and mRNA expression levels were further validated by qRT-PCR. Differentially expressed lncRNAs and mRNAs were utilized to construct a coding-non-coding gene co-expression network (CNC network). GO terms and KEGG pathway enrichment analysis revealed several significant processes differentially regulated between undifferentiated hADSCs and chondrogenic hADSCs. Taken together, this study revealed the differential expression of exosomal lncRNAs of chondrogenic hADSCs and provided a foundation for future study on the cartilage recovery mechanism of exosomes derived from chondrogenic stem cells.

Exosome mediated transfer of miRNA-140 promotes enhanced chondrogenic differentiation of bone marrow stem cells for enhanced cartilage repair and regeneration.

Exosomes (EXs) are nanocarrier vesicles with 20-50 nm dimensions. They are involved in cell proliferation and differentiation and in protecting the integrity of materials. They can be isolated from plasma and immunoreactive components. Recent studies demonstrated their potential role in cartilage regeneration. To enhance their regenerative effect, molecules like microRNA (miR-140) can be loaded in EX that acts as RNA delivery systems. In this study, we combined EX with miR-140 to enhance cell differentiation by inducing membrane fusion and consequent miRNA released into the cytoplasm. The carrier RNA complex was successfully synthesized through freeze and thaw method leading to the formation of EX-containing miR-140. The EX morphology was assessed through transmission electron microscopy and their miR-140 uptake efficiency through real-time polymerase chain reaction (RT-PCR). The effects on bone marrow stem cells (BMSCs) were evaluated by in vitro cell culture. Cell adhesion and morphology were studied using a bio-scanning electron microscope and confocal laser scanning microscope. Differentiation BMSCs into chondrocytes was analyzed by RT-PCR and histology. Our results confirm the bioactive role of EX loaded with miR-140 in the differentiation of BMSCs into chondrocytes. EXs were biocompatible involving in the cartilage healing process through chromogenic differentiation of BMCS exploiting the tissue engineering route.

Isolation and identification of stem cells in different subtype of cartilage tissue

Background: Cartilage tissue engineering provided a promising therapy for the repair of cartilage defects, and seeding cells play a vital role in cartilage regeneration. Chondrocytes and bone marrow-derived mesenchymal stem cells (BMSCs) were reported to be the ideal seeding cells, but ‘dedifferentiation’ and ‘unstable phenotype’ of tissue-engineered cartilage constructed by the two cell type hamper their clinical application. Recently, cartilage tissue was reported to possess a stem cell population, which may be a more superior cell source in cartilage tissue engineering.Methods: In current study, we isolated a cell population from different subtype of cartilage tissue via a differential adhesion assay to fibronectin.Results: Flow cytometry analysis demonstrates the cell lines expressed mesenchyme stem cell positive surface marker such as CD29 and CD90. Meanwhile, the cells are highly proliferative and multipotent. Reverse transcription–PCR detection showed the cell population expressed osteogenic and adipogenic differentiation under different induction conditions. More interesting, monolayer cells underwent chondrogenic differentiation in the presence of dexamethasone and insulin-like growth factor 1. In addition, the expression of chondrogenic genes in cartilage-derived stem cells (CSCs) was higher than those in BMSCs.Conclusion: CSC may become an ideal seeding cell in cartilage tissue engineering, owing to its stemness and chondrogenic characteristics.

Growth factors in oral and maxillofacial surgery: potentials and challenges.

A growth factor (GF) is a naturally occurring substance capable of stimulating cellular growth, proliferation, and cellular differentiation, one of the key factors for tissue regeneration. Usually, it is a protein or a steroid hormone, with unique functions according to the need of the body. For example, bone morphogenic proteins (BMPs) stimulate bone cell differentiation, whereas fibroblast GFs and vascular endothelial GFs trigger blood vessel differentiation (angiogenesis)1. Various GFs have been tested in the field of oral and maxillofacial surgery to regenerate defective tissues and to enhance the therapeutic effect of conventional treatment. Among GFs, BMP-2, and BMP-7 have been predominantly studied for clinical applications and used in combination with collagen/collagen composite scaffolds2-5. To date, it has been possible to reconstruct mandibular defect measuring 4 to 8 cm, maxillary sinus augmentation, and cleft alveolus using BMP-2 or BMP-7 combined with collagen sponge as carrier2-5. Based on previous controlled studies, in the United States, BMP-2, BMP-7 are now commercially available for clinical use; the use of BMPs is approved by the Food and Drug Administration (FDA) for sinus augmentation and alveolar ridge augmentation associated with extraction sockets5. Nowadays, beyond these approved applications, the use of BMPs to treat several refractory diseases--including bisphosphonate-related osteonecrosis of the jaw (BRONJ)--is being attempted in the field of oral and maxillofacial surgery6. As another popular GF in our field, platelet-derived growth factor (PDGF) is known as a 'starter' of wound healing process when a tissue needs regeneration. Therefore, it is known to be effective for both soft and hard tissues. So far, periodontal defect and alveolar bone defect have been successfully regenerated using PDGF, which is also commercially available. Transforming growth factor (TGF)-β and insulin-like growth factor (IGF) may be the next candidates of commercially available products following BMPs and PDGF. TGF-β and IGF play an important role in cartilage regeneration in the temporomandibular joint, although those are somehow effective for a variety of cells2.

RhoA/Rho kinase signaling regulates transforming growth factor-β1-induced chondrogenesis and actin organization of synovium-derived mesenchymal stem cells through interaction with the Smad pathway

Recent studies have suggested that synovium-derived mesenchymal stem cells (SMSCs) may be promising candidates for tissue engineering and play an important role in cartilage regeneration. However, the mechanisms of SMSC chondrogenesis remain to be identified and characterized. The aim of this study was to evaluate the activation of the RhoA/Rho kinase (ROCK) pathway, as well as the manner by which it may contribute to chondrogenesis and the actin cytoskeletal organization of rat temporomandibular SMSCs in response to transforming growth factor-β1 (TGF-β1). Primary isolated SMSCs were treated with TGF-β1, and their actin organization was examined by fluorescein isothiocyanate-phalloidin staining. The specific biochemical inhibitors, C3 transferase, Y27632 and SB431542, were employed to evaluate the function of RhoA/ROCK and Smads. The effect of C3 transferase and Y27632 on the gene expression of chondrocyte-specific markers was evaluated by quantitative real-time polymerase chain reaction. To examine the effect of Y27632 on Smad2/3 phosphorylation induced by TGF-β1, western blot analysis was also performed. The stimulation of TGF-β1 in SMSCs resulted in the activation of the RhoA/ROCK pathway and concomitantly induced cytoskeletal reorganization, which was specifically blocked by C3 transferase and Y27632. The TGF-β-induced gene expression of Sox9, type I collagen, type II collagen and aggrecan was also inhibited by both C3 transferase and Y27632, at different levels. Y27632 treatment reduced the phosphorylation of Smad2/3 in a concentration-dependent manner. These results demonstrate the RhoA/ROCK activation regulates chondrocyte-specific gene transcription and cytoskeletal organization induced by TGF-β1 by interacting with the Smad pathway. This may have significant implications for the successful utilization of SMSCs as a cell source for articular cartilage tissue engineering.

Role of Polymorphisms in Adamantiades-Behçet’s Disease

We previously showed that Adamantiades-Behçet's disease (A-BD) is associated with a lower incidence of malignancy compared with the general population. Transforming growth factor-beta (TGF-beta) has been shown to play a role in cartilage regeneration and is increased in patients with A-BD. We also found 2 functional polymorphisms of the TGF-beta pathway, TGFBR1*6A and TGFB1*CC, that are associated with risk of malignancy. We tested whether incidence of these polymorphisms would differ in patients with A-BD compared with healthy controls of similar age and geographic location. We performed a case-control study including 139 cases and 128 controls from Greece. Cases and controls were genotyped for TGFBR1*6A and TGFB1*CC. We found that cases had lower incidence of TGFBR1*6A compared with controls (11.3% vs 13.3%, respectively). Also, the incidence of TGFB1*CC was lower in cases than controls (24.6% vs 27.0%, respectively). These differences were not statistically significant. Although there is a suggestion that the lower incidence of TGFBR1*6A in A-BD patients may play a protective role against development of malignancy, larger studies would be needed to fully evaluate the role of TGF-beta and its polymorphisms in A-BD.

The fate of implanted autologous chondrocytes in regenerated articular cartilage

Autologous chondrocyte implantation (ACI) is used to treat some articular cartilage defects. However, the fate of the cultured chondrocytes after in-vivo transplantation and their role in cartilage regeneration remains unclear. To monitor the survival and fate of such cells in vivo, the chondrocytes were labelled with a lipophilic dye and the resultant regenerated tissue in dogs examined. It was found that, 4 weeks after implantation, the osteochondral defects were filled with regenerative tissue that resembled hyaline cartilage. Fluorescence microscopy of frozen sections of the regenerated tissue revealed that the majority of cells were derived from the DiI-labelled implanted chondrocytes. From these results, it was concluded that a large population of implanted autologous chondrocytes can survive at least 4 weeks after implantation and play a direct role in cartilage regeneration. However, it remains unknown whether other cells, such as periosteal cells or bone marrow stromal stem cells, are involved in the regeneration of cartilage after ACI.

Identification and initial characterization of small cells in adult cartilage and bone marrow.

Small cells in the range of less than 5 microm have been suspected to lie dormant and to be dispersed throughout the parenchyma of every tissue in the body. In bone marrow, small mesenchymal stem cells with rapidly renewing properties and differentiation potentials have been found. The aim of this study was to isolate and identify small cells from normal and osteoarthritic cartilages and compare their properties with those of small stem cells in bone marrow. Small cells were isolated from cartilages and bone marrow. Characterization of these small cells was performed by hematoxylin and eosin staining and bromodeoxyuridine labeling. Scanning electron and atomic force microscopy were used for ultrastructural investigation and analysis of the cells. Small cells (< or = 5 microm) from both cartilages and bone marrow were shown to have mitotic activity on the basis of bromodeoxyuridine labeling, with the same replication time of 18 to 20 hours for population doubling. Ultrastructural and atomic force microscopy revealed these cells had spherical shape and were about 0.2 to 2.2 microm in diameter. This study demonstrated the presence of small cells in adult cartilage and bone marrow, which were about 0.2 to 2.2 microm in diameter and exhibited proliferation potential. These cells were able to be activated and differentiate into chondrocytes, and might have differentiation potential similar to small stem cells in bone marrow and thus play an important role in cartilage regeneration.