Preparation of EGCG decorated, injectable extracellular vesicles for cartilage repair in rat arthritis

Unraveling the Molecular Mechanisms of Osteoarthritis: The Potential of Polyphenols as Therapeutic Agents

The complex nature of osteoarthritis (OA), driven by the intricate interplay of genetic, environmental, and lifestyle factors, necessitates the development of a single treatment method, which is highly challenging. The long-term use of non-steroidal anti-inflammatory drugs (NSAIDs) and corticosteroids often leads to adverse side effects like kidney damage and stomach ulcers. Major health threats like obesity and aging create a milieu of chronic low-grade inflammation and increased mechanical stress on the joints resulting in cartilage deterioration. Additionally, postmenopausal women with lower circulating 17β-estradiol levels experience accelerated joint deterioration due to increased immune activity resulting in the increased production of pro-inflammatory cytokines, with elevated MMP expression and decreased type II collagen synthesis. Polyphenols are nature's gifted magic molecules, which possess diverse biological properties like anti-oxidant, anti-bacterial, anti-inflammatory, estrogenic, and insulin-sensitizing effects, which can manage and treat all the multi-factorial contributing factors of OA effectively. Certain polyphenols can act as phytoestrogens and mimic the effects of natural estrogen by binding to ERα and ERβ and can act as SERMs and prevent degradation of the articular cartilage thereby alleviating osteoarthritic conditions. These molecules downregulate the expression of various pro-inflammatory cytokines, apoptotic genes, and matrix-degrading proteases (MMPs) while upregulating major ECM proteins like type II collagen, aggrecan, and proteoglycans in various osteoarthritic animal models. This review provides a comprehensive overview of the molecular mechanisms involved in OA development and also explores the therapeutic potential of different polyphenols in mitigating joint inflammation and their protective effect in inhibiting the degradation of cartilage extracellular matrix (ECM) and enhancing joint homeostasis.

Extracellular vesicles as therapeutic agents in rheumatoid arthritis: a systematic review of current evidence

Rheumatoid arthritis (RA) is defined as a chronic autoimmune disease that severely influences a patient's quality of life. Extracellular vesicles (EVs) have gained much attention in recent years as one of the most potent therapeutic agents for the treatment of RA. A systematic review was performed with the purpose of assessing the current evidence relating to the therapeutic applications of EVs in RA. The systematic search was performed in the databases of PubMed, Scopus, and Web of Science, from inception times to September 2024. All studies investigating the use of EVs for the treatment of RA were included. The quality appraisal of selected articles and data extraction regarding EV characteristics, therapeutic applications, and associated outcomes were performed. Of the 1418 initially identified articles, 59 studies met inclusion criteria. Regarding their cellular origins, most EVs were derived from mesenchymal stem cells, followed by immune cells. The main therapeutic mechanisms included modulation of the immune response, reduction of inflammation, and repair of tissues. Recent trends are toward increasing interest in engineered EVs and combination therapies. Indeed, most studies reported positive outcomes with regard to lowered inflammation and improved joint function. On the other hand, standardization of the metrics of evaluation considerably varied between different studies. EVs are promising therapeutic agents in the treatment of RA by modulating immune responses. Standardization, delivery systems, and clinical translation are challenges yet to be overcome. Future studies will be directed to optimize EV engineering, targeted delivery systems, and large-scale clinical trials.

Epigallocatechin-Gallate: Unraveling Its Protective Mechanisms and Therapeutic Potential

Epigallocatechin-gallate (EGCG), the predominant catechin in green tea, is a key constituent of tea polyphenols. Due to the EGCG's diverse biological activities of anti-inflammatory, antioxidant, and so forth, green tea is believed to exert a positive influence on a variety of diseases. And extensive research had uncovered a range of protective effects attributed to EGCG, indicating its potential to mitigate various pathological conditions. The precise mechanisms through which EGCG operates remain a subject of ongoing discussion among researchers. Reactive oxygen species (ROS), a primary culprit in oxidative stress, have been demonstrated to be reduced by EGCG. Furthermore, nuclear factor kappa-B (NF-κB), a pivotal signal molecular of inflammation progress, has been observed to be suppressed by EGCG. Sirtuins1 (Sirt1) is a histone deacetylase, the obligate substrate of which is NAD+. Evidence suggests that EGCG can enhance the activities of Sirt1 to induce autophagy to protect inflammation injury and oxidative stress in tissues and organs. Despite the promising protective effects of EGCG, its clinical use is constrained by its limited bioavailability. This review aims to consolidate the existing evidence and elucidate the mechanisms that support EGCG's protective role, as well as to explore the challenges and potential strategies for its clinical application.

Cartilage and bone injectable hydrogels: A review of injectability methods and treatment strategies for repair in tissue engineering

Cartilage and bone are crucial tissues causing disability in the elderly population, often requiring prolonged treatment and surgical intervention due to limited regenerative capacity. Injectable hydrogels that closely mimic the extracellular matrix (ECM) of native hard tissue have attracted attention due to their minimally invasive application and ability to conform to irregular defect sites. These hydrogels facilitate key biological processes such as cell migration, chondrogenesis in cartilage repair, osteoinduction, angiogenesis, osteoconduction, and mineralization in bone repair. This review analyzes in-vitro and in-vivo biomedical databases over the past decade to identify advancements in hydrogel formulations, crosslinking mechanisms, and biomaterial selection for cartilage and bone tissue engineering. The review emphasizes the effectiveness of injectable hydrogels as carriers for cells, growth factors, and drugs, offering additional therapeutic benefits. The relevance of these findings is discussed in the context of their potential to serve as a robust alternative to current surgical and non-surgical treatments. This review also examines the advantages of injectable hydrogels, such as ease of administration, reduced patient recovery time, and enhanced bioactivity, thereby emphasizing their potential in clinical applications for cartilage and bone regeneration with emphasis on addressing the shortcomings of current treatments.

Therapeutic Potential of Plant-Derived Compounds and Plant Extracts in Rheumatoid Arthritis-Comprehensive Review

Rheumatoid arthritis (RA) is a persistent autoimmune disorder that is characterized by joint inflammation, discomfort, and impairment. Despite the existence of several therapeutic approaches, their effectiveness is often restricted and may be linked to unfavorable side effects. Consequently, there has been growing interest in investigating naturally derived compounds as plausible therapeutic agents for RA disease. The objective of this review is to summarize the existing preclinical and clinical evidence regarding the efficacy of naturally extracted compounds and plant extracts in the treatment of RA, focusing on their anti-inflammatory, anti-oxidative, and immunomodulatory properties. Some of the problems with using natural chemicals are the uneven quality of commercially available preparations and the poor bioavailability of these compounds. Future investigations should focus on improving the formulations, conducting thorough clinical trials, and exploring different techniques to fully utilize the intrinsic potential of naturally derived chemicals in treating RA.

Potential Role of Dietary Phenolic Compounds in the Prevention and Treatment of Rheumatoid Arthritis: Current Reports

Rheumatoid arthritis (RA) is a complex illness with both hereditary and environmental components. Globally, in 2019, 18 million people had RA. RA is characterized by persistent inflammation of the synovial membrane that lines the joints, cartilage loss, and bone erosion. Phenolic molecules are the most prevalent secondary metabolites in plants, with a diverse spectrum of biological actions that benefit functional meals and nutraceuticals. These compounds have received a lot of attention recently because they have antioxidant, anti-inflammatory, immunomodulatory, and anti-rheumatoid activity by modulating tumor necrosis factor, mitogen-activated protein kinase, nuclear factor kappa-light-chain-enhancer of activated B cells, and c-Jun N-terminal kinases, as well as other preventative properties. This article discusses dietary polyphenols, their pharmacological properties, and innovative delivery technologies for the treatment of RA, with a focus on their possible biological activities. Nonetheless, commercialization of polyphenols may be achievable only after confirming their safety profile and completing successful clinical trials.

Functional Ingredients Associated with the Prevention and Suppression of Locomotive Syndrome: A Review

In 2007, the Japanese Orthopaedic Association proposed the concept of locomotive syndrome, a comprehensive description of conditions involving the functional decline of the locomotor system. Locomotive syndrome includes bone-related diseases such as osteoporosis, joint cartilage and disc-related diseases such as osteoarthritis and lumbar spondylosis, and sarcopenia and locomotive syndrome-related diseases. If left untreated, these diseases are likely to reduce mobility, necessitating nursing care. To prevent the progression of locomotive syndrome, a daily exercise routine and well-balanced diet are important, in addition to recognizing one's own decline in mobility. Therefore, research on the effectiveness of functional ingredients in the prevention and suppression of locomotive syndrome progression is ongoing. In this review, we summarize the latest reports on the effectiveness of five functional ingredients, namely, epigallocatechin gallate, resveratrol, curcumin, ellagic acid, and carnosic acid, in the treatment of osteoarthritis, osteoporosis, and rheumatoid arthritis, which are considered representative diseases of the locomotive syndrome.

Tea polyphenol carrier-enhanced dexamethasone nanomedicines for inflammation-targeted treatment of rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic autoimmune inflammatory disease characterized by synovial inflammation, cartilage damage and bone erosion. In the progression of RA, the inflammatory mediators including ROS, NO, TNF-α, and IL-6 play important roles in the aggravation of inflammation. Hence, reducing the generation and release of inflammatory mediators is of great importance. However, the high dose and frequent administration of clinical anti-inflammatory drugs such as glucocorticoids (GCs) usually lead to severe side effects. The development of nanotechnology provides a promising strategy to overcome these issues. Here, polyphenol-based nanoparticles with inherent anti-oxidative and anti-inflammatory activities were developed and used as a kind of nanocarrier to deliver dexamethasone (Dex). The in vitro experiments confirmed that the nanoparticles and drugs could act synergistically for suppressing inflammatory mediators in the LPS/INF-γ-induced inflammatory cell model. After intravenous administration, the Dex-loaded nanoparticles with good biosafety showed effective accumulation in inflamed joints and improved therapeutic efficacy by inducing anesis of synovial inflammation and cartilage destruction over free Dex in a collagen-induced arthritis (CIA) mouse model. The results demonstrated that polyphenol-based nanoparticles with therapeutic functions may serve as an innovative platform to synergize with chemotherapeutic agents for enhanced treatment of inflammatory diseases.

Emerging drug delivery systems with traditional routes - A roadmap to chronic inflammatory diseases

Inflammation is prevalent and inevitable in daily life but can generally be accommodated by the immune systems. However, incapable self-healing and persistent inflammation can progress to chronic inflammation, leading to prevalent or fatal chronic diseases. This review comprehensively covers the topic of emerging drug delivery systems (DDSs) for the treatment of chronic inflammatory diseases (CIDs). First, we introduce the basic biology of the chronic inflammatory process and provide an overview of the main CIDs of the major organs. Next, up-to-date information on various DDSs and the associated strategies for ensuring targeted delivery and stimuli-responsiveness applied to CIDs are discussed extensively. The implementation of traditional routes of drug administration to maximize their therapeutic effects against CIDs is then summarized. Finally, perspectives on future DDSs against CIDs are presented.

Disease-microenvironment modulation by bare- or engineered-exosome for rheumatoid arthritis treatment

BACKGROUND

Exosomes are extracellular vesicles secreted by eukaryotic cells and have been extensively studied for their surface markers and internal cargo with unique functions. A deeper understanding of exosomes has allowed their application in various research areas, particularly in diagnostics and therapy.

MAIN BODY

Exosomes have great potential as biomarkers and delivery vehicles for encapsulating therapeutic cargo. However, the limitations of bare exosomes, such as rapid phagocytic clearance and non-specific biodistribution after injection, pose significant challenges to their application as drug delivery systems. This review focuses on exosome-based drug delivery for treating rheumatoid arthritis, emphasizing pre/post-engineering approaches to overcome these challenges.

CONCLUSION

This review will serve as an essential resource for future studies to develop novel exosome-based therapeutic approaches for rheumatoid arthritis. Overall, the review highlights the potential of exosomes as a promising therapeutic approach for rheumatoid arthritis treatment.

Dexamethasone Liposomes Alleviate Osteoarthritis in miR-204/-211-Deficient Mice by Repolarizing Synovial Macrophages to M2 Phenotypes

We undertook this study to investigate the effects and mechanisms of dexamethasone liposome (Dex-Lips) on alleviating destabilization of the medial meniscus (DMM)-induced osteoarthritis (OA) in miR-204/-211-deficient mice. Dex-Lips was prepared by the thin-film hydration method. The characterization of Dex-Lips was identified by the mean size, zeta potential, drug loading, and encapsulation efficiencies. Experimental OA was established by DMM surgery in miR-204/-211-deficient mice, and then Dex-Lips was treated once a week for 3 months. Von Frey filaments was used to perform the pain test. The inflammation level was evaluated with quantitative real-time polymerase chain reaction and enzyme-linked immunosorbent assay. Polarization of macrophages was evaluated by immunofluorescent staining. X-ray, micro-CT scanning, and histological observations were conducted in vivo on DMM mice to describe the OA phenotype. We found that miR-204/-211-deficient mice displayed more severe OA symptoms than WT mice after DMM surgery. Dex-Lips ameliorated DMM-induced OA phenotype and suppressed pain and inflammatory cytokine expressions. Dex-Lips could attenuate pain by regulating PGE2. Dex-Lips treatments reduced the expression of TNF-α, IL-1β, and IL-6 in DRG. Moreover, Dex-Lips could reduce inflammation in the cartilage and serum. Additionally, Dex-Lips repolarize synovial macrophages to M2 phenotypes in miR-204/-211-deficient mice. In conclusion, Dex-Lips inhibited the inflammatory response and alleviated the pain symptoms of OA by affecting the polarization of macrophages.

Epigallocatechin-3-gallate (EGCG) based metal-polyphenol nanoformulations alleviates chondrocytes inflammation by modulating synovial macrophages polarization

The activation of M1-type macrophages are dominant cells secreting proinflammatory present within the inflamed synovium in the progression of osteoarthritis (OA). Increased oxidative stress, such as redundant ROS and hydrogen peroxide (H2O2), are important factors in driving macrophages to polarize into M1 type. In this study, metal-polyphenol nanoformulations (Cu-Epigallocatechin-3-gallate (Cu-EGCG) nanosheets) were synthesized through the coordination interaction between EGCG and copper ions, which possessed the antioxidant effect of EGCG and anti-inflammatory of Cu2+. Results showed that Cu-EGCG nanosheets were biocompatible and the Cu2+ could be sustained released from the nanoparticles. Cu-EGCG nanosheets with multienzyme-like antioxidative activity could effectively scavenge the excessive intracellular ROS, leading to significantly decreased expression of the pro-inflammatory cytokines, which could reduce the expression of M1-type macrophages and exhibit excellent promotion on shifting macrophages to M2 phenotypes. Moreover, the secreted factor from the cell supernatant of Cu-EGCG treated macrophages exhibited anti-inflammatory potential in chondrocytes of inflamed synovial joints. This study suggests a novel strategy for OA therapy by using metal-polyphenol nanoformulations targeting macrophages.

Testing relationship between tea intake and the risk of rheumatoid arthritis and systemic lupus erythematosus: a Mendelian randomization study

BACKGROUND

We performed Mendelian randomization (MR) to assess the causal effect of tea intake on rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE).

METHODS

Genetic instruments for tea intake were obtained from a large genome-wide association study (GWAS) dataset of the UK Biobank. Genetic association estimates for RA (6236 cases and 147,221 controls) and SLE (538 cases and 213,145 controls) were obtained from the FinnGen study through the IEU GWAS database.

RESULTS

MR analyses using the inverse-variance weighted method showed that tea intake was not associated with risk of RA [odds ratio (OR) per standard deviation increment in genetically predicted tea intake = 0.997, 95% confidence interval (CI) 0.658-1.511] and SLE (OR per standard deviation increment in genetically predicted tea intake = 0.961, 95% CI 0.299-3.092). Weighted median, weighted mode, MR-Egger, leave-one-out and multivariable MR controlling for several confounding factors including current tobacco smoking, coffee intake, and alcoholic drinks per week yielded completely consistent results. No evidence of heterogeneity and pleiotropy was found.

CONCLUSION

Our MR study did not suggest a causal effect of genetically predicted tea intake on RA and SLE.

Injectable hydrogels for sustained delivery of extracellular vesicles in cartilage regeneration

Extracellular vesicles (EVs) are a population of small vesicles secreted by essentially all cell types, containing a wide variety of biological macromolecules. Due to their intrinsic capabilities for efficient intercellular communication, they are involved in various aspects of cellular functioning. In the past decade, EVs derived from stem cells attracted interest in the field of regenerative medicine. Owing to their regenerative properties, they have great potential for use in tissue repair, in particular for tissues with limited regenerative capabilities such as cartilage. The maintenance of articular cartilage is dependent on a precarious balance of many different components that can be disrupted by the onset of prevalent rheumatic diseases. However, while cartilage is a tissue with strong mechanical properties that can withstand movement and heavy loads for years, it is virtually incapable of repairing itself after damage has occurred. Stem cell-derived EVs (SC-EVs) transport regenerative components such as proteins and nucleic acids from their parental cells to recipient cells, thereby promoting cartilage healing. Many possible pathways through which SC-EVs execute their regenerative function have been reported, but likely there are still numerous other pathways that are still unknown. This review discusses various preclinical studies investigating intra-articular injections of free SC-EVs, which, while often promoting chondrogenesis and cartilage repair in vivo, showed a recurring limitation of the need for multiple administrations to achieve sufficient tissue regeneration. Potentially, this drawback can be overcome by making use of an EV delivery platform that is capable of sustainably releasing EVs over time. With their remarkable versatility and favourable chemical, biological and mechanical properties, hydrogels can facilitate this release profile by encapsulating EVs in their porous structure. Ideally, the optimal delivery platform can be formed in-situ, by means of an injectable hydrogel that can be administered directly into the affected joint. Relevant research fulfilling these criteria is discussed in detail, including the steps that still need to be taken before injectable hydrogels for sustained delivery of EVs can be applied in the context of cartilage regeneration in the clinic.

Extracellular vesicle-guided in situ reprogramming of synovial macrophages for the treatment of rheumatoid arthritis

Activation state of synovial macrophages is significantly correlated with disease activity and severity of rheumatoid arthritis (RA) and provides valuable clues for RA treatment. Classically activated M1 macrophages in inflamed synovial joints secrete high levels of pro-inflammatory cytokines and chemokines, resulting in bone erosion and cartilage degradation. Herein, we propose extracellular vesicle (EV)-guided in situ macrophage reprogramming toward anti-inflammatory M2 macrophages as a novel RA treatment modality based on the immunotherapeutic concept of reestablishing M1-M2 macrophage equilibrium in synovial tissue. M2 macrophage-derived EVs (M2-EVs) were able to convert activated M1 into reprogrammed M2 (RM2) macrophages with extremely high efficiency (>90%), producing a distinct protein expression pattern characteristic of anti-inflammatory M2 macrophages. In particular, M2-EVs were enriched for proteins known to be involved in the generation and migration of M2 macrophages as well as macrophage reprogramming factors, allowing for rapid and efficient driving of macrophage polarization toward M2 phenotype. After administration of M2-EVs into the joint of a collagen-induced arthritis mouse model, the synovial macrophage polarization was significantly shifted from M1 to M2 phenotype, a process that benefited greatly from the long residence time (>3 days) of M2-EVs in the joint. This superb in situ macrophage-reprogramming ability of EVs resulted in decreased joint swelling, arthritic index score and synovial inflammation, with corresponding reductions in bone erosion and articular cartilage damage and no systemic toxicity. The anti-RA effects of M2-EVs were comparable to those of the conventional disease-modifying antirheumatic drug, Methotrexate, which causes a range of toxic adverse effects, including gastrointestinal mucosal injury. Overall, our EV-guided reprogramming strategy for in situ tuning of macrophage responses holds great promise for the development of anti-inflammatory therapeutics for the treatment of various inflammatory diseases in addition to RA.

Preparation of epigallocatechin gallate decorated Au-Ag nano-heterostructures as NIR-sensitive nano-enzymes for the treatment of osteoarthritis through mitochondrial repair and cartilage protection

Osteoarthritis (OA), a widespread degenerative disease characterized by cartilage destruction, has emerged as a public health challenge in the current aging society. In addition to applied steroids and surgery, near-infrared (NIR) sensitive nano-enzyme for the treatment of osteoarthritis through mitochondrial repair and cartilage protection is attractive and promising. In this study, a NIR sensitive multifunctional heterostructure (EGCG (Epigallocatechin gallate) decorated Au-Ag nano-jars (E@Au-Ag)) was introduced as an enzyme-sensitive active nanoplatform for the treatment of osteoarthritis. Molecular biology results indicated that E@Au-Ag possesses intrinsic properties of anti-oxidative stress and was able to reduce the apoptosis rate of chondrocytes by 83.3%. The area of the intra-articular joint cavity injected with E@Au-Ag can be elevated to 46.6 °C under NIR to promote the release of EGCG further to induce cartilage regeneration. X-ray radiography and section staining showed that E@Au-Ag reduced cartilage damage and decreased OARSI scores by approximately 52% after 8 weeks of treatment in a surgically induced OA model. The results demonstrated that this multifunctional enzyme-like nanoplatform with a synergistic NIR sensitive property to facilitate cartilage migration and regeneration repair provides a promising OA treatment strategy. STATEMENT OF SIGNIFICANCE: 1. NIR-sensitive nano-enzyme is gaining much attention in the field of biomedical materials. 2. EGCG decorated Au-Ag nano-heterostructures were utilized as NIR-sensitive nano-enzymes for the treatment of osteoarthritis through mitochondrial repair and cartilage protection. 3. The obtained multifunctional Au-Ag nano-heterostructures are promising for osteoarthritis treatment.

Small extracellular vesicles from iPSC-derived mesenchymal stem cells ameliorate tendinopathy pain by inhibiting mast cell activation

Aim: This study aimed to explore the effect of small extracellular vesicles from induced pluripotent stem cell-derived mesenchymal stem cells (iMSC-sEVs) on acute pain and investigate the underlying mechanisms. Materials & methods: The pathology of tendons was accessed by hematoxylin and eosin staining, immunohistochemical and immunofluorescent staining. The pain degree was measured by pain-related behaviors. In vitro, we performed β-hexosaminidase release assay, RT-qPCR, toluidine blue staining, ELISA and RNA sequencing. Results: iMSC-sEVs effectively alleviated acute pain in tendinopathy as well as inhibiting activated mast cell infiltration and interactions with nerve fibers in vivo. In vitro, iMSC-sEVs reduced the degranulation of mast cells and the expression of proinflammatory cytokines and genes involved in the HIF-1 signaling pathway. Conclusion: This study demonstrated that iMSC-sEVs relieved tendinopathy-related pain through inhibiting mast cell activation via the HIF-1 signaling pathway.