Infliximab-based self-healing hydrogel composite scaffold enhances stem cell survival, engraftment, and function in rheumatoid arthritis treatment

Melatonin enhances therapeutic outcomes of adipose tissue-derived mesenchymal stem cell therapy in rat osteoarthritis by reducing TNF-α and IL-1β-induced injuries

Although adipose tissue-derived mesenchymal stem cell (ADSC) transplantation has been effectively used to treat osteoarthritis (OA), the low cell survival rate induced by the inflammatory and oxidative stress, severely affects the therapeutic efficiency of ADSC transplantation in OA. This study was designed to evaluate whether melatonin pretreatment could improve ADSC survival and its therapeutic efficacy in OA. The papain-induced OA rats were pretreated with melatonin via intra-articular injection and then intra-articular injected with indocyanine green (ICG)-labeled ADSCs (3 × 106/rat). Afterward, ADSC retention was evaluated by NIR-II fluorescence imaging. The tibia and synovial fluid were collected for histopathological examination and ELISA assay, respectively. To confirm the anti-inflammatory effect of melatonin, a TNF-α and IL-1β-induced cell model was used to evaluate the protective effects of melatonin on ADSC viability, cell apoptosis, and migration. Our results showed that melatonin pretreatment enhanced ADSC survival and improved the therapeutic effects of ADSC transplantation on cartilage repair, and anti-inflammation by reducing TNF-α, IL-6, IL-1β, and IL-12 in vivo. In particular, we also found that melatonin promoted ADSC viability and migration, and reduced cell apoptosis in vitro. In conclusion, this study supports that melatonin pretreatment can effectively improve ADSC survival and therapeutic efficiency in OA by reducing inflammatory injuries, which provides a novel strategy for enhancing ADSC therapy.

Emerging Landscape of In Vitro Models for Assessing Rheumatoid Arthritis Management

Rheumatoid arthritis (RA) is a complex condition that is influenced by various causes, including immunological, genetic, and environmental factors. Several studies using animal models have documented immune system dysfunction and described the clinical characteristics of the disease. These studies have provided valuable insights into the pathogenesis of inflammatory arthritis and the identification of new targets for treatment. Nevertheless, none of these animal models successfully replicated all the characteristics of RA. Additionally, numerous experimental medications, which were developed based on our enhanced comprehension of the immune system's function in RA, have shown potential in animal research but ultimately proved ineffective during different stages of clinical trials. There have been several novel therapy alternatives, which do not achieve a consistently outstanding therapeutic outcome in all patients. This underscores the importance of employing the progress in in vitro models, particularly 3D models like tissue explants, and diverse multicomponent approaches such as coculture strategies, synovial membrane, articular cartilage, and subchondral bone models that accurately replicate the structural characteristics of RA pathophysiology. These methods are crucial for the advancement of potential therapeutic strategies. This review discusses the latest advancements in in vitro models and their potential to greatly impact research on managing RA.

Enhancing regenerative medicine with self-healing hydrogels: A solution for tissue repair and advanced cyborganic healthcare devices

Considering the global burden related to tissue and organ injuries or failures, self-healing hydrogels may be an attractive therapeutic alternative for the future. Self-healing hydrogels are highly hydrated 3D structures with the ability to self-heal after breaking, this property is attributable to a variety of dynamic non-covalent and covalent bonds that are able to re-linking within the matrix. Self-healing ability specially benefits minimal invasive medical treatments with cell-delivery support. Moreover, those tissue-engineered self-healing hydrogels network have demonstrated effectiveness for myriad purposes; for instance, they could act as delivery-platforms for different cargos (drugs, growth factors, cells, among others) in tissues such as bone, cartilage, nerve or skin. Besides, self-healing hydrogels have currently found their way into new and novel applications; for example, with the development of the self-healing adhesive hydrogels, by merely aiding surgical closing processes and by providing biomaterial-tissue adhesion. Furthermore, conductive hydrogels permit the stimuli and monitoring of natural electrical signals, which facilitated a better fitting of hydrogels in native tissue or the diagnosis of various health diseases. Lastly, self-healing hydrogels could be part of cyborganics - a merge between biology and machinery - which can pave the way to a finer healthcare devices for diagnostics and precision therapies.

Mesenchymal Stem Cells-Involved Strategies for Rheumatoid Arthritis Therapy

Rheumatoid arthritis (RA) is a systemic autoimmune disease characterized by chronic inflammation of the joints and bone destruction. Because of systemic administration and poor targeting, traditional anti-rheumatic drugs have unsatisfactory treatment efficacy and strong side effects, including myelosuppression, liver or kidney function damage, and malignant tumors. Consequently, mesenchymal stem cells (MSCs)-involved therapy is proposed for RA therapy as a benefit of their immunosuppressive and tissue-repairing effects. This review summarizes the progress of MSCs-involved RA therapy through suppressing inflammation and promoting tissue regeneration and predicts their potential clinical application.

Advances in local drug delivery technologies for improved rheumatoid arthritis therapy

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease characterized by an inflammatory microenvironment and cartilage erosion within the joint cavity. Currently, antirheumatic agents yield significant outcomes in RA treatment. However, their systemic administration is limited by inadequate drug retention in lesion areas and non-specific tissue distribution, reducing efficacy and increasing risks such as infection due to systemic immunosuppression. Development in local drug delivery technologies, such as nanostructure-based and scaffold-assisted delivery platforms, facilitate enhanced drug accumulation at the target site, controlled drug release, extended duration of the drug action, reduced both dosage and administration frequency, and ultimately improve therapeutic outcomes with minimized damage to healthy tissues. In this review, we introduced pathogenesis and clinically used therapeutic agents for RA, comprehensively summarized locally administered nanostructure-based and scaffold-assisted drug delivery systems, aiming at improving the therapeutic efficiency of RA by alleviating the inflammatory response, preventing bone erosion and promoting cartilage regeneration. In addition, the challenges and future prospects of local delivery for clinical translation in RA are discussed.

Transdermal Delivery of Niacin Through Polysaccharide Films Ameliorates Cutaneous Flushing in Experimental Wistar Rats

BACKGROUND

Niacin, an established therapeutic for dyslipidemia, is hindered by its propensity to induce significant cutaneous flushing when administered orally in its unmodified state, thereby constraining its clinical utility.

OBJECTIVE

This study aimed to fabricate, characterize, and assess the in-vitro and in-vivo effectiveness of niacin-loaded polymeric films (NLPFs) comprised of carboxymethyl tamarind seed polysaccharide. The primary objective was to mitigate the flushing-related side effects associated with oral niacin administration.

METHODS

NLPFs were synthesized using the solvent casting method and subsequently subjected to characterization, including assessments of tensile strength, moisture uptake, thickness, and folding endurance. Surface characteristics were analyzed using a surface profiler and scanning electron microscopy (SEM). Potential interactions between niacin and the polysaccharide core were investigated through X-ray diffraction experiments (XRD) and Fourier transform infrared spectroscopy (FTIR). The viscoelastic properties of the films were explored using a Rheometer. In-vitro assessments included drug release studies, swelling behavior assays, and antioxidant assays. In-vivo efficacy was evaluated through skin permeation assays, skin irritation assays, and histopathological analyses.

RESULTS

NLPFs exhibited a smooth texture with favorable tensile strength and moisture absorption capabilities. Niacin demonstrated interaction with the polysaccharide core, rendering the films amorphous. The films displayed slow and sustained drug release, exceptional antioxidant properties, optimal swelling behavior, and viscoelastic characteristics. Furthermore, the films exhibited biocompatibility and non-toxicity towards skin cells.

CONCLUSION

NLPFs emerged as promising carrier systems for the therapeutic transdermal delivery of niacin, effectively mitigating its flushing-associated adverse effects.

Ultra-durable cell-free bioactive hydrogel with fast shape memory and on-demand drug release for cartilage regeneration

Osteoarthritis is a worldwide prevalent disease that imposes a significant socioeconomic burden on individuals and healthcare systems. Achieving cartilage regeneration in patients with osteoarthritis remains challenging clinically. In this work, we construct a multiple hydrogen-bond crosslinked hydrogel loaded with tannic acid and Kartogenin by polyaddition reaction as a cell-free scaffold for in vivo cartilage regeneration, which features ultra-durable mechanical properties and stage-dependent drug release behavior. We demonstrate that the hydrogel can withstand 28000 loading-unloading mechanical cycles and exhibits fast shape memory at body temperature (30 s) with the potential for minimally invasive surgery. We find that the hydrogel can also alleviate the inflammatory reaction and regulate oxidative stress in situ to establish a microenvironment conducive to healing. We show that the sequential release of tannic acid and Kartogenin can promote the migration of bone marrow mesenchymal stem cells into the hydrogel scaffold, followed by the induction of chondrocyte differentiation, thus leading to full-thickness cartilage regeneration in vivo. This work may provide a promising solution to address the problem of cartilage regeneration.

Cell-based therapies for the treatment of rheumatoid arthritis

Autoimmune diseases, including rheumatoid arthritis that is the most prevalent rheumatic autoimmune disorder, affect autologous connective tissues caused by the breakdown of the self-tolerance mechanisms of the immune system. During the last two decades, cell-based therapy, including stem cells and none-stem cells has been increasingly considered as a therapeutic option in various diseases. This is partly due to the unique properties of stem cells that divide and differentiate from the specialized cells in the damaged tissue. Moreover, stem cells and none-stem cells, impose immunomodulatory properties affecting the diseases caused by immunological abnormalities such as rheumatic autoimmune disorders. In the present review, the efficacy of cell-based therapy with four main types of stem cells, including mesenchymal stem cells, hematopoietic stem cells, embryonic stem cells, and human amniotic membrane cells, as well as none-stem cells, including regulatory T cells, chimeric antigen receptor T cells, and tolerogenic dendritic cells will be evaluated. Moreover, other related issues, including safety, changes in immunological parameters, suitable choice of stem cell and none-stem cell origin, conditioning regimen, limitations, and complications will be discussed.

Advancement in nanotechnology for treatment of rheumatoid arthritis: scope and potential applications

Rheumatoid arthritis is a hyperactive immune disorder that results in severe inflammation in synovial joints, cartilage, and bone deterioration, resulting in immobilization of joints. Traditional approaches for the treatment of rheumatoid arthritis are associated with some limiting factors such as suboptimal patient compliance, inability to control the progression of disorder, and safety concerns. Therefore, innovative drug delivery carriers for efficient therapeutic delivery at inflamed synovial sites with better safety assessment are urgently needed to address these issues. From this perspective, nanotechnology is an outstanding alternative to traditional drug delivery approaches, and it has shown great promise in developing novel carriers to treat rheumatoid arthritis. Considering the current research and future application of nanocarriers, it is believed that nanocarriers can be a crucial element in rheumatoid arthritis treatment. This paper covers all currently available pathophysiological aspects of rheumatoid arthritis and treatment options. Future research for the reduction of synovial inflammation should focus on developing multifunction nanoparticles capable of delivering therapeutic agents with improved safety, efficacy, and cost-effectiveness to be commercialized.

Fabricating the cartilage: recent achievements

This review aims to describe the most recent achievements and provide an insight into cartilage engineering and strategies to restore the cartilage defects. Here, we discuss cell types, biomaterials, and biochemical factors applied to form cartilage tissue equivalents and update the status of fabrication techniques, which are used at all stages of engineering the cartilage. The actualized concept to improve the cartilage tissue restoration is based on applying personalized products fabricated using a full cycle platform: a bioprinter, a bioink consisted of ECM-embedded autologous cell aggregates, and a bioreactor. Moreover, in situ platforms can help to skip some steps and enable adjusting the newly formed tissue in the place during the operation. Only some achievements described have passed first stages of clinical translation; nevertheless, the number of their preclinical and clinical trials is expected to grow in the nearest future.

Self-healing hydrogels for bone defect repair

Severe bone defects can be caused by various factors, such as tumor resection, severe trauma, and infection. However, bone regeneration capacity is limited up to a critical-size defect, and further intervention is required. Currently, the most common clinical method to repair bone defects is bone grafting, where autografts are the "gold standard." However, the disadvantages of autografts, including inflammation, secondary trauma and chronic disease, limit their application. Bone tissue engineering (BTE) is an attractive strategy for repairing bone defects and has been widely researched. In particular, hydrogels with a three-dimensional network can be used as scaffolds for BTE owing to their hydrophilicity, biocompatibility, and large porosity. Self-healing hydrogels respond rapidly, autonomously, and repeatedly to induced damage and can maintain their original properties (i.e., mechanical properties, fluidity, and biocompatibility) following self-healing. This review focuses on self-healing hydrogels and their applications in bone defect repair. Moreover, we discussed the recent progress in this research field. Despite the significant existing research achievements, there are still challenges that need to be addressed to promote clinical research of self-healing hydrogels in bone defect repair and increase the market penetration.

Hydrogel Drug Delivery Systems for Bone Regeneration

With the in-depth understanding of bone regeneration mechanisms and the development of bone tissue engineering, a variety of scaffold carrier materials with desirable physicochemical properties and biological functions have recently emerged in the field of bone regeneration. Hydrogels are being increasingly used in the field of bone regeneration and tissue engineering because of their biocompatibility, unique swelling properties, and relative ease of fabrication. Hydrogel drug delivery systems comprise cells, cytokines, an extracellular matrix, and small molecule nucleotides, which have different properties depending on their chemical or physical cross-linking. Additionally, hydrogels can be designed for different types of drug delivery for specific applications. In this paper, we summarize recent research in the field of bone regeneration using hydrogels as delivery carriers, detail the application of hydrogels in bone defect diseases and their mechanisms, and discuss future research directions of hydrogel drug delivery systems in bone tissue engineering.

A comprehensive review of advanced drug delivery systems for the treatment of rheumatoid arthritis

Rheumatoid arthritis (RA), a chronic autoimmune disease, is characterized by articular pain and swelling, synovial hyperplasia, and cartilage and bone destruction. Conventional treatment strategies for RA involve the use of anti-rheumatic drugs, which warrant high-dose, frequent, and long-term administration, resulting in serious adverse effects and poor patient compliance. To overcome these problems and improve clinical efficacy, drug delivery systems (DDS) have been designed for RA treatment. These systems have shown success in animal models of RA. In this review, representative DDS that target RA through passive or active effects on inflammatory cells are discussed and highlighted using examples. In particular, DDS allowing controlled and targeted drug release based on a variety of stimuli, intra-articular DDS, and transdermal DDS for RA treatment are described. Thus, this review provides an improved understanding of these DDS and paves the way for the development of novel DDS for efficient RA treatment.

The Role of Extracellular Matrix and Hydrogels in Mesenchymal Stem Cell Chondrogenesis and Cartilage Regeneration

Diseases associated with articular cartilage disintegration or loss are still therapeutically challenging. The traditional treatment approaches only alleviate the symptoms while potentially causing serious side effects. The limited self-renewal potential of articular cartilage provides opportunities for advanced therapies involving mesenchymal stem cells (MSCs) that are characterized by a remarkable regenerative capacity. The chondrogenic potential of MSCs is known to be regulated by the local environment, including soluble factors and the less discussed extracellular matrix (ECM) components. This review summarizes the process of chondrogenesis, and also the biological properties of the ECM mediated by mechanotransduction as well as canonical and non-canonical signaling. Our focus is also on the influence of the ECM's physical parameters, molecular composition, and chondrogenic factor affinity on the adhesion, survival, and chondrogenic differentiation of MSCs. These basic biological insights are crucial for a more precise fabrication of ECM-mimicking hydrogels to improve cartilage tissue reconstruction. Lastly, we provide an overview of hydrogel classification and characterization. We also include the results from preclinical models combining MSCs with hydrogels for the treatment of cartilage defects, to support clinical application of this construct. Overall, it is believed that the proper combination of MSCs, hydrogels, and chondrogenic factors can lead to complex cartilage regeneration.

Nanozyme-reinforced hydrogel as a H2O2-driven oxygenerator for enhancing prosthetic interface osseointegration in rheumatoid arthritis therapy

Stem cell-based therapy has drawn attention for enhancing the osseointegration efficiency after joint replacement in the rheumatoid arthritis (RA). However, therapeutic efficacy of this approach is threatened by the accumulated reactive oxygen species (ROS) and poor oxygen supply. Herein, we develop a nanozyme-reinforced hydrogel for reshaping the hostile RA microenvironment and improving prosthetic interface osseointegration. The engineered hydrogel not only scavenges endogenously over-expressed ROS, but also synergistically produces dissolved oxygen. Such performance enables the hydrogel to be utilized as an injectable delivery vehicle of bone marrow-derived mesenchymal stem cells (BMSCs) to protect implanted cells from ROS and hypoxia-mediated death and osteogenic limitation. This nanozyme-reinforced hydrogel encapsulated with BMSCs can alleviate the symptoms of RA, including suppression of local inflammatory cytokines and improvement of osseointegration. This work provides a strategy for solving the long-lasting challenge of stem cell transplantation and revolutionizes conventional intervention methods for improving prosthetic interface osseointegration in RA.

3D Cell Culture as Tools to Characterize Rheumatoid Arthritis Signaling and Development of New Treatments

Rheumatoid arthritis (RA) is one of the most common autoimmune disorders affecting 0.5-1% of the population worldwide. As a disease of multifactorial etiology, its constant study has made it possible to unravel the pathophysiological processes that cause the illness. However, efficient and validated disease models are necessary to continue the search for new disease-modulating drugs. Technologies, such as 3D cell culture and organ-on-a-chip, have contributed to accelerating the prospecting of new therapeutic molecules and even helping to elucidate hitherto unknown aspects of the pathogenesis of multiple diseases. These technologies, where medicine and biotechnology converge, can be applied to understand RA. This review discusses the critical elements of RA pathophysiology and current treatment strategies. Next, we discuss 3D cell culture and apply these methodologies for rheumatological diseases and selected models for RA. Finally, we summarize the application of 3D cell culture for RA treatment.

Hydrogels for the treatment of rheumatoid arthritis

Rheumatoid Arthritis is a universal disease that severely affects the normal function of human joints and the quality of life. Millions of people around the world are diagnosed with rheumatoid arthritis every year, carrying a substantial burden for both the individual and society. Hydrogel is a polymer material with good mechanical properties and biocompatibility, which shows great potential in the treatment of rheumatoid arthritis. With the progress of tissue engineering and biomedical material technology in recent years, more and more studies focus on the application of hydrogels in rheumatoid arthritis. We reviewed the progress of hydrogels applied in rheumatoid arthritis in recent years. Also, the needed comprehensive performance and current applications of therapeutic hydrogels based on the complex pathophysiological characteristics of rheumatoid arthritis are also concluded. Additionally, we proposed the challenges and difficulties in the application of hydrogels in rheumatoid arthritis and put forward some prospects for the future research.

Adipose‑derived stem cells postpone the progression of Sjögren's syndrome by upregulating the Hippo signaling pathway

The aim of the present study was to explore the effect and mechanism of action of adipose-derived stem cells (ADSCs) on Sjögren syndrome (SS) to develop novel and more effective methods for SS treatment. ADSCs, dexamethasone or normal saline was injected into the submandibular gland (SMG) of three 12-week-old non-obese diabetic (NOD) mice. The degree of lymphocyte infiltration was considered as a criterion for judging disease progression, hematoxylin and eosin staining was performed to observe the pathological state, and the expression levels of TAZ, E-cadherin and α-catenin were assessed by western blotting. ADSC transplantation triggered an inhibitory effect on the progression of SS, which was slightly stronger compared with that of dexamethasone treatment. This was found to be related to the Hippo signaling pathway. In addition, TAZ protein expression levels decreased gradually with the progression of the disease; immunofluorescence staining showed that the expression of E-cadherin and TAZ followed similar trends. Notably, the expression of TAZ, p-TAZ, E-cadherin and α-catenin in NOD mice were lower compared with that in Control mice. Similarly, the ratio of p-TAZ/TAZ also decreased, which means that the activation level of Hippo signal pathway decreased. The results suggest that ADSCs may exert a therapeutic effect against SS and may postpone its progression by upregulating the Hippo signaling pathway.

Mechanism of Self-Healing Hydrogels and Application in Tissue Engineering

Self-healing hydrogels and traditional hydrogels both have three-dimensional polymeric networks that are capable of absorbing and retaining a large amount of water. Self-healing hydrogels can heal and restore damage automatically, and they can avoid premature failure of hydrogels caused by mechanical damage after implantation. The formation mechanism of self-healing hydrogels and the factors that hydrogels can load are various. Researchers can design hydrogels to meet the needs of different tissues through the diversity of hydrogels Therefore, it is necessary to summarize different self-healing mechanisms and different factors to achieve different functions. Here, we briefly reviewed the hydrogels designed by researchers in recent years according to the self-healing mechanism of water coagulation. Then, the factors for different functions of self-healing hydrogels in different tissues were statistically analyzed. We hope our work can provide effective support for researchers in the design process of self-healing hydrogel.

Fabrication and Characterization of Bioactive Gelatin-Alginate-Bioactive Glass Composite Coatings on Porous Titanium Substrates

In this research work, the fabrication of biphasic composite implants has been investigated. Porous, commercially available pure Ti (50 vol % porosity and pore distributions of 100-200, 250-355, and 355-500 μm) has been used as a cortical bone replacement, while different composites based on a polymer blend (gelatin and alginate) and bioactive glass (BG) 45S5 have been applied as a soft layer for cartilage tissues. The microstructure, degradation rates, biofunctionality, and wear behavior of the different composites were analyzed to find the best possible coating. Experiments demonstrated the best micromechanical balance for the substrate containing 200-355 μm size range distribution. In addition, although the coating prepared from alginate presented a lower mass loss, the composite containing 50% alginate and 50% gelatin showed a higher elastic recovery, which entails that this type of coating could replicate the functions of the soft tissue in areas of the joints. Therefore, results revealed that the combinations of porous commercially pure Ti and composites prepared from alginate/gelatin/45S5 BG are candidates for the fabrication of biphasic implants not only for the treatment of osteochondral defects but also potentially for any other diseases affecting simultaneously hard and soft tissues.

Polymeric Hydrogels for Controlled Drug Delivery to Treat Arthritis

Rheumatoid arthritis (RA) and osteoarthritis (OA) are disabling musculoskeletal disorders that affect joints and cartilage and may lead to bone degeneration. Conventional delivery of anti-arthritic agents is limited due to short intra-articular half-life and toxicities. Innovations in polymer chemistry have led to advancements in hydrogel technology, offering a versatile drug delivery platform exhibiting tissue-like properties with tunable drug loading and high residence time properties This review discusses the advantages and drawbacks of polymeric materials along with their modifications as well as their applications for fabricating hydrogels loaded with therapeutic agents (small molecule drugs, immunotherapeutic agents, and cells). Emphasis is given to the biological potentialities of hydrogel hybrid systems/micro-and nanotechnology-integrated hydrogels as promising tools. Applications for facile tuning of therapeutic drug loading, maintaining long-term release, and consequently improving therapeutic outcome and patient compliance in arthritis are detailed. This review also suggests the advantages, challenges, and future perspectives of hydrogels loaded with anti-arthritic agents with high therapeutic potential that may alter the landscape of currently available arthritis treatment modalities.

Implication of Mesenchymal Stem Cells and Their Derivates for Osteochondral Regeneration

Healing of articular cartilage defects presents a challenging issue, due to its regenerative shortcomings. Lacking vascularity and innervation of cartilage and low proliferative potential of chondrocytes are the main reasons for the limited healing potential of articular cartilage. Traditional reparative approaches are limited in their efficiency, hence there is a demand for novel reparative treatments. Mesenchymal stromal cells, preferred for clinical uses, can be readily derived from various sources and have been proven to have a therapeutic effect on cartilage and subchondral bone. Therefore, mesenchymal stromal cells, their derivates, and scaffolds have been utilized in research targeting osteochondral regeneration. The present review aims to comprehensively outline and discuss literature considering this topic published within last 5 years.

Biomaterial-based immunotherapeutic strategies for rheumatoid arthritis

Rheumatoid arthritis (RA) is an extremely painful autoimmune disease characterized by chronic joint inflammation leading to the erosion of adjacent cartilage and bone. Rheumatoid arthritis pathology is primarily driven by inappropriate infiltration and activation of immune cells within the synovium of the joint. There is no cure for RA. As such, manifestation of symptoms entails lifelong management via various therapies that aim to generally dampen the immune system or impede the function of immune mediators. However, these treatment strategies lead to adverse effects such as toxicity, general immunosuppression, and increased risk of infection. In pursuit of safer and more efficacious therapies, many emerging biomaterial-based strategies are being developed to improve payload delivery, specific targeting, and dose efficacy, and to mitigate adverse reactions and toxicity. In this review, we highlight biomaterial-based approaches that are currently under investigation to circumvent the limitations of conventional RA treatments.

A cell-free ROS-responsive hydrogel/oriented poly(lactide-co-glycolide) hybrid scaffold for reducing inflammation and restoring full-thickness cartilage defectsin vivo

The modulation of inflammation in tissue microenvironment takes an important role in cartilage repair and regeneration. In this study, a novel hybrid scaffold was designed and fabricated by filling a reactive oxygen species (ROS)-scavenging hydrogel (RS Gel) into a radially oriented poly(lactide-co-glycolide) (PLGA) scaffold. The radially oriented PLGA scaffolds were fabricated through a temperature gradient-guided phase separation and freeze-drying method. The RS Gel was formed by crosslinking the mixture of ROS-responsive hyperbranched polymers and biocompatible methacrylated hyaluronic acid (HA-MA). The hybrid scaffolds exhibited a proper compressive modulus, good ROS-scavenging capability, and cell compatibility.In vivotests showed that the hybrid scaffolds significantly regulated inflammation and promoted regeneration of hyaline cartilage after they were implanted into full-thickness cartilage defects in rabbits for 12 w. In comparison with the PLGA scaffolds, the neo-cartilage in the hybrid scaffolds group possessed more deposition of glycosaminoglycans and collagen type II, and were well integrated with the surrounding tissue.

Mesenchymal stem/stromal cell-based therapy for the treatment of rheumatoid arthritis: An update on preclinical studies

Rheumatoid arthritis (RA) is a chronic systemic autoimmune disease characterized by synovial inflammation and progressive joint destruction and is a primary cause of disability worldwide. Despite the existence of numerous anti-rheumatic drugs, a significant number of patients with RA do not respond or are intolerant to current treatments. Mesenchymal stem/stromal cell (MSCs) therapy represents a promising therapeutic tool to treat RA, mainly attributable to the immunomodulatory effects of these cells. This review comprises a comprehensive analysis of the scientific literature related to preclinical studies of MSC-based therapy in RA to analyse key aspects of current protocols as well as novel approaches which aim to improve the efficacy of MSC-based therapy.

CircMAPK9 promotes the progression of fibroblast-like synoviocytes in rheumatoid arthritis via the miR-140-3p/PPM1A axis

Background

Rheumatoid arthritis (RA) is a chronic inflammatory joint disease, and fibroblast-like synoviocytes (FLSs) are key effector cells in RA development. Mounting evidence indicates that circular RNAs (circRNAs) participate in the occurrence and development of RA. However, the precise mechanism of circRNA mitogen-activated protein kinase (circMAPK9) in the cell processes of FLSs has not been reported.

Methods

The expression levels of circMAPK9, microRNA-140-3p (miR-140-3p), and protein phosphatase magnesium-dependent 1A (PPM1A) were determined by quantitative real-time polymerase chain reaction (qRT-PCR) or western blot assay. Cell proliferation was examined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Cell apoptosis and cycle distribution were assessed by flow cytometry. Cell migration and invasion were tested by transwell assay. All the proteins were inspected by western blot assay. Inflammatory response was evaluated by enzyme-linked immunosorbent assay (ELISA). The interaction between miR-140-3p and circMAPK9 or PPM1A was verified by dual-luciferase reporter assay.

Results

CircMAPK9 and PPM1A were upregulated and miR-140-3p was downregulated in RA patients and FLSs from RA patients (RA-FLSs). CircMAPK9 silence suppressed cell proliferation, migration, invasion, inflammatory response, and promoted apoptosis in RA-FLSs. MiR-140-3p was a target of circMAPK9, and miR-140-3p downregulation attenuated the effects of circMAPK9 knockdown on cell progression and inflammatory response in RA-FLSs. PPM1A was targeted by miR-140-3p, and circMAPK9 could regulate PPM1A expression by sponging miR-140-3p. Furthermore, miR-140-3p could impede cell biological behaviors in RA-FLSs via targeting PPM1A.

Conclusion

CircMAPK9 knockdown might inhibit cell proliferation, migration, invasion, inflammatory response, and facilitate apoptosis in RA-FLSs via regulating miR-140-3p/PPM1A axis, offering a new mechanism for the comprehension of RA development and a new insight into the potential application of circMAPK9 in RA treatment.