Intra-articular treatment options for knee osteoarthritis

Morphological and Quantitative Parametric MRI Follow-up of Cartilage Changes Before and After Intra-articular Injection Therapy in Patients With Mild to Moderate Knee Osteoarthritis: A Randomized, Placebo-Controlled Trial

BACKGROUND

Intra-articular injections are routinely used for conservative treatment of knee osteoarthritis (OA). The detailed comparative therapeutic effects of these injections on cartilage tissue are still unclear.

OBJECTIVE

The aim of this study was to detect and compare knee cartilage changes after intra-articular injection of glucocorticoid, hyaluronic acid, or platelet-rich plasma (PRP) to placebo using quantitative (T2 and T2* mapping) and morphological magnetic resonance imaging parameters in patients with mild or moderate osteoarthritis.

MATERIALS AND METHODS

In a double-blinded, placebo-controlled, single-center trial, knees with mild or moderate osteoarthritis (Kellgren-Lawrence grade 1-3) were randomly assigned to an intra-articular injection with 1 of these substances: glucocorticoid, hyaluronic acid, PRP, or placebo. Cartilage degeneration on baseline and follow-up magnetic resonance imaging scans (after 3 and 12 months) was assessed by 2 readers using quantitative T2 and T2* times (milliseconds) and morphological parameters (modified Outerbridge grading, subchondral bone marrow edema, subchondral cysts, osteophytes).

RESULTS

One hundred twenty knees (30 knees per treatment group) were analyzed with a median patient age of 60 years (interquartile range, 54.0-68.0 years). Interreader reliability was good for T2 (ICC, 0.76; IQR, 0.68-0.83) and T2* (ICC, 0.83; IQR, 0.76-0.88) measurements. Morphological parameters showed no significant changes between all groups after 3 and 12 months. T2 mapping after 12 months showed the following significant ( P = 0.001-0.03) changes between groups in 6 of 14 compartments: values after PRP injection decreased compared with glucocorticoid in 4 compartments (complete medial femoral condyle and central part of lateral condyle) and compared with placebo in 2 compartments (anterior and central part of medial tibial plateau); values after glucocorticoid injection decreased compared with placebo in 1 compartment (central part of medial tibial plateau). No significant changes were seen for T2 and T2* times after 3 months and T2* times after 12 months. No correlation was found between T2/T2* times and Kellgren-Lawrence grade, age, body mass index, or pain (Spearman ρ, -0.23 to 0.18).

CONCLUSIONS

Platelet-rich plasma injection has a positive long-term effect on cartilage quality in the medial femoral compartment compared to glucocorticoid, resulting in significantly improved T2 values after 12 months. For morphological cartilage parameters, injections with glucocorticoid, PRP, or hyaluronic acid showed no better effect in the short or long term compared with placebo.

Intra-articular interventions in osteoarthritis: Navigating the landscape of hyaluronic acid, mesenchymal stem cells, and platelet-rich plasma

Osteoarthritis (OA) poses a substantial burden on patients, leading to pain, functional decline, and reduced quality of life. While conventional treatments focus on symptom management, disease-modifying interventions are yet to be established. This review explores the efficacy of intra-articular interventions, particularly hyaluronic acid (HA), mesenchymal stem cells (MSCs), and platelet-rich plasma (PRP), in the context of OA management. HA injections, with diverse formulations like Hylan G-F20, sodium hyaluronate, and hyaluronan, present varying outcomes, necessitating a nuanced understanding of their effectiveness and timing. MSC therapy, derived from adipose tissue, umbilical cord, or bone marrow, shows promising results in clinical improvement, with adipose-derived MSCs demonstrating efficacy in maintaining benefits over 6 mo. Conversely, bone-marrow-derived MSCs show limited effectiveness, highlighting the need for source-specific considerations. PRP has emerged as a superior option for long-term pain reduction and quality of life improvement, with leukocyte-poor formulations and a critical platelet count of 10 billion demonstrating optimal results. This comprehensive analysis underscores the potential of intra-articular interventions in OA management, emphasizing the need for personalized and evidence-based approaches to enhance treatment efficacy and patient outcomes.

Geniculate Artery Embolization for the Treatment of Mild to Moderate Knee Osteoarthritis Improves Pain and Function: A Systematic Review

PURPOSE

To evaluate procedural heterogeneity, patient reported outcomes (PRO), and complications following geniculate artery embolization (GAE) for knee OA.

METHODS

A literature search was performed using PubMed, Embase, and Scopus databases from inception to August 2023 according to the 2020 PRISMA guidelines. Human clinical studies reporting PROs following GAE for treatment of knee OA were included and a qualitative comparison across PROs, procedural descriptions and complications was performed. Study quality was assessed using the Cochrane Collaboration's risk of bias tool and the MINORS criteria. The primary outcome measures included changes in PROs at 12 months and variances in procedural methodology.

RESULTS

A total of 17 studies, consisting of 533 patients and 620 knees were identified. The reported mean improvement at 12 months for VAS pain and WOMAC scores ranged from 10-59 and 35.3-47, respectively. At 12 months, median improvements were observed in KOOS subscales such as Pain (range, 8.3-19.5), QOL (15.49-25.0), Sport (7.5-26.3) and Symptoms (1.8-25.0). Decreasing MCID achievement was observed between the 3 month and 6 month follow-up points. Patients with advanced OA and degenerative findings on MRI exhibited lower rates of MCID achievement. Transient adverse events occurred in up to 80% of patients. Limited evidence from serial MRI assessments suggests that GAE improves levels of synovitis. Significant heterogeneity exists among the GAE methodology as 4 different definitions of technical success, 4 distinct embolization targets and use of 5 embolization agents were noted.

CONCLUSION

GAE results in short-term improvements in pain and function with decreasing MCID achievement observed after 3 to 6 months. Patients with severe OA also demonstrate lower rates of MCID achievement. A high rate of transient complications are reported including skin discoloration and access site hematomas. Significant protocol heterogeneity exists which contributes to variable outcomes.

LEVEL OF EVIDENCE

IV; Systematic Review of Level IV Studies.

Construction of mitochondrial-targeting nano-prodrug for enhanced Rhein delivery and treatment for osteoarthritis in vitro

Rhein, a natural anthraquinone compound derived from traditional Chinese medicine, exhibits potent anti-inflammatory properties via modulating the level of Reactive oxygen or nitrogen species (RONS). Nevertheless, its limited solubility in water, brief duration of plasma presence, as well as its significant systemic toxicity, pose obstacles to its in vivo usage, necessitating the creation of a reliable drug delivery platform to circumvent these difficulties. In this study, an esterase-responsive and mitochondria-targeted nano-prodrug was synthesized by conjugating Rhein with the polyethylene glycol (PEG)-modified triphenyl phosphonium (TPP) molecule, forming TPP-PEG-RH, which could spontaneously self-assemble into RPT NPs when dispersed in aqueous media. The TPP outer layer of these nanoparticles enhances their pharmacokinetic profile, facilitates efficient delivery to mitochondria, and promotes cellular uptake, thereby enabling enhanced accumulation in mitochondria and improved therapeutic effects in vitro. The decline in RONS was observed in IL-1β-stimulated chondrocyte after RPT NPs treating. RPT NPs also exert excellent anti-inflammatory (IL-1β, TNF-α, IL-6 and MMP-13) and antioxidative effects (Cat and Sod) via the Nrf2 signalling pathway, upregulation of cartilage related genes (Col2a1 and Acan). Moreover, RPT NPs shows protection of mitochondrial membrane potential and inhibition of chondrocyte apoptosis. Moreover, These findings suggest that the mitochondria-targeted polymer-Rhein conjugate may offer a therapeutic solution for patients suffering from chronic joint disorders, by attenuating the progression of osteoarthritis (OA).

Management Considerations for Unicompartmental Osteoarthritis in Athletic Populations: A Review of the Literature

Unicompartmental osteoarthritis in the young athlete poses a challenge for both patients and providers. Coronal plane malalignment is frequently a concomitant finding that adds to the complexity of management. Military surgeons are presented unique challenges, in that they must consider optimal joint-preservation methods while returning patients to a high-demand occupational function. Management options range from lifestyle changes to surgical interventions. We present a concise review of the available literature on this subject, with a specific focus on indications and outcomes within the military and young athletic population.

Functional Nanomaterials for the Treatment of Osteoarthritis

Osteoarthritis (OA) is the most common degenerative joint disease, affecting more than 595 million people worldwide. Nanomaterials possess superior physicochemical properties and can influence pathological processes due to their unique structural features, such as size, surface interface, and photoelectromagnetic thermal effects. Unlike traditional OA treatments, which suffer from short half-life, low stability, poor bioavailability, and high systemic toxicity, nanotherapeutic strategies for OA offer longer half-life, enhanced targeting, improved bioavailability, and reduced systemic toxicity. These advantages effectively address the limitations of traditional therapies. This review aims to inspire researchers to develop more multifunctional nanomaterials and promote their practical application in OA treatment.

Logic-Based Strategy for Spatiotemporal Release of Dual Extracellular Vesicles in Osteoarthritis Treatment

To effectively treat osteoarthritis (OA), the existing inflammation must be reduced before the cartilage damage can be repaired; this cannot be achieved with a single type of extracellular vesicles (EVs). Here, a hydrogel complex with logic-gates function is proposed that can spatiotemporally controlled release two types of EVs: interleukin 10 (IL-10)+ EVs to promote M2 polarization of macrophage, and SRY-box transcription factor 9 (SOX9)+ EVs to increase cartilage matrix synthesis. Following dose-of-action screening, the dual EVs are loaded into a matrix metalloporoteinase 13 (MMP13)-sensitive self-assembled peptide hydrogel (KM13E) and polyethylene glycol diacrylate/gelatin methacryloyl-hydrogel microspheres (PGE), respectively. These materials are mixed to form a "microspheres-in-gel" KM13E@PGE system. In vitro, KM13E@PGE abruptly released IL-10+ EVs after 3 days and slowly released SOX9+ EVs for more than 30 days. In vivo, KM13E@PGE increased the CD206+ M2 macrophage proportion in the synovial tissue and decreased the tumor necrosis factor-α and IL-1β levels. The aggrecan and SOX9 expressions in the cartilage tissues are significantly elevated following inflammation subsidence. This performance is not achieved using anti-inflammatory or cartilage repair therapy alone. The present study provides an injectable, integrated delivery system with spatiotemporal control release of dual EVs, and may inspire logic-gates strategies for OA treatment.

A phase 2b double-blind placebo-controlled randomized clinical trial of SB-061, an aggrecan mimetic, in patients with symptomatic knee osteoarthritis

OBJECTIVES

To evaluate the efficacy and safety of intra-articular injections of a novel aggrecan mimetic, SB-061, in subjects with knee osteoarthritis (OA).

METHODS

This was a randomized, placebo-controlled, double-blind phase II study comparing intra-articular injections of SB-061 with placebo (isotonic saline) for 52 weeks, administered at baseline, Wk 16, and Wk 32. Eligible subjects had a KL grade of 2 or 3 on X-ray of the target knee and a Western Ontario McMaster Universities Osteoarthritis Index (WOMAC) pain score ≥20 out of 50 at screening and baseline visits. Subjects having any other knee condition were excluded. Use of analgesics was prohibited, except for rescue medication. The primary endpoint was change from baseline (CFB) in WOMAC pain at Week 8. Secondary endpoints were CFB in WOMAC function and total, ICOAP, Patient Global Assessment, and 20-meter walk test. Exploratory endpoints included structural CFB in magnetic resonance imaging entities.

RESULTS

A total of 288 subjects were randomized to SB-061 (n = 145) or placebo (n = 143), and 252 (87.5%) completed injections. The groups were comparable at baseline. The primary endpoint was not met, as no significant difference in the CFB of the WOMAC pain score at Week 8 between groups was observed, nor at any other time point during the study. Similarly, neither of the secondary or exploratory endpoints indicated any significant difference between groups. The frequency and type of adverse events were similar between groups. SB-061 was well-tolerated.

CONCLUSION

Intra-articular injections of SB-061 administered at baseline, Week 16, and Week 32, over one year in subjects with knee OA, were safe but did not show any statistically significant effect on knee pain nor on other symptomatic or structural entities compared to placebo.

TRIAL REGISTRATION NUMBER EUDRACT NO

2019-004515-31.

Scutellarein alleviates osteoarthritis progression through the PI3K/Akt/NF-kappaB signaling pathway: In vitro and in vivo studies

Osteoarthritis (OA), a joint disease that is associated with inflammatory processes is involved in joint destruction. Scutellarein (Scu), a component of the medicinal herbs Scutellaria barbata D. Don and Erigeron breviscapus (vant) Hand Mass, has anti-inflammatory effects. We explored the role of Scu in the development of OA and the underlying mechanisms. CCK-8 assays, Calcein-AM/PI and EdU staining were used to determine chondrocyte viability after Scu exposure. Western blot, qPCR, as well as ELISA were utilized to measure extracellular matrix (ECM) degradation and inflammation. Immunofluorescence (IF), western blot and luciferase assays were used to examine the NF-kappaB (NF-κB) pathway. Scu interacting proteins were predicted using network pharmacology analysis and molecular docking. X-ray, H&E, Safranin O-Fast Green(S-O), toluidine blue, and immunohistochemistry analysis were used to examine the therapeutic effects of Scu in OA using destabilization of medial meniscus (DMM) models. Scu demonstrated inhibitory effects on ECM degradation and pro-inflammatory factor levels in chondrocytes treated with IL-1β. Mechanistically, Scu inhibited the IL-1β-induced activation of the PI3K/Akt/ NF-κB signaling pathway cascades. Furthermore, Scu has been shown to have significant binding capacities to PI3K. Additionally, Scu ameliorated the OA progression in DMM models. Our findings suggest that Scu may contribute to the amelioration of OA progression by targeting the PI3K/Akt/NF-κB signaling pathway, implying Scu possesses promising therapeutic potential for the treatment of OA.

On-demand release of a selective MMP-13 blocker from an enzyme-responsive injectable hydrogel protects cartilage from degenerative progression in osteoarthritis

In osteoarthritis (OA), the degradation of cartilage is primarily driven by matrix metalloprotease-13 (MMP-13). Hence, the inhibition of MMP-13 has emerged as an attractive target for OA treatment. Among the various approaches that are being explored for MMP-13 regulation, blocking of the enzyme with specific binding molecules appears to be a more promising strategy for preventing cartilage degeneration. To enhance effectiveness and ensure patient compliance, it is preferable for the binding molecule to exhibit sustained activity when administered directly into the joint. Herein, we present an enzyme-responsive hydrogel that was designed to exhibit on-demand, the sustained release of BI-4394, a potent and highly selective MMP-13 blocker. The stable and compatible hydrogel was prepared using triglycerol monostearate. The efficacy of the hydrogel to prevent cartilage damage was assessed in a rat model of OA induced by anterior cruciate ligament transection (ACLT). The results revealed that in comparison to the rats administrated weekly with intra-articular BI-4394, the hydrogel implanted rats had reduced levels of inflammation and bone erosion. In comparison to untreated control, the cartilage in animals administered with BI-4394/hydrogel exhibited significant levels of collagen-2 and aggrecan along with reduced MMP-13. Overall, this study confirmed the potential of BI-4394 delivery using an enzyme-responsive hydrogel as a promising treatment option to treat the early stages of OA by preventing further cartilage degradation.

Injectable Ozone-Rich Nanocomposite Hydrogel Loaded with D-Mannose for Anti-Inflammatory and Cartilage Protection in Osteoarthritis Treatment

Osteoarthritis (OA) is a dynamic condition characterized by cartilage damage and synovial inflammation. Ozone (O3) shows potential therapeutic effects owing to its anti-inflammatory properties; however, its high reactivity and short half-life substantially limit its effectiveness in OA treatment. In this study, an ozone-rich thermosensitive nanocomposite hydrogel loaded with D-mannose is developed for OA treatment. Briefly, O3 is encapsulated in nanoparticles (NPs) composed of perfluorotributylamine and fluorinated hyaluronic acid to improve its stability. Next, D-mannose is conjugated with α-amino of the hydroxypropyl chitin (HPCH) via Schiff base to prepare MHPCH. These nanoparticles are encapsulated in MHPCH to produce O3 NPs@MHPCH. In vitro cell experiments demonstrate that the O3 NPs@MHPCH treatment significantly reduced VEGF and inflammation levels, accompanied by a decrease in inflammatory factors such as IL-1β, IL-6, TNF-α, and iNOS. Furthermore, O3 NPs@MHPCH promotes the expression of collagen II and aggrecan and stimulates chondrocyte proliferation. Additionally, in vivo studies show that O3 NPs@MHPCH significantly alleviated OA by reducing synovial inflammation, cartilage destruction, and subchondral bone remodeling. O3 NPs@MHPCH offers a promising option for improving the efficacy of O3 therapy and reducing the risk of synovial inflammation and cartilage degeneration in OA.

Astaxanthin reduces inflammation and promotes a chondrogenic phenotype by upregulating SIRT1 in osteoarthritis

OBJECTIVE

To investigate the effects of astaxanthin (AST) on mouse osteoarthritis (OA) and lipopolysaccharide (LPS)-induced ATDC5 cell damage and to explore whether SIRT1 protein plays a role.

METHODS

In this study, some mouse OA models were constructed by anterior cruciate ligament transection (ACLT). Imaging, molecular biology and histopathology methods were used to study the effect of AST administration on traumatic OA in mice. In addition, LPS was used to stimulate ATDC5 cells to mimic the inflammatory response of OA. The effects of AST on the cell activity, inflammatory cytokines, matrix metalloproteinases and collagen type II levels were studied by CCK8 activity assay, reverse transcription polymerase chain reaction and protein imprinting. The role of SIRT1 protein was also detected.

RESULTS

In the mouse OA model, the articular surface collapsed, the articular cartilage thickness and cartilage matrix protein abundance were significantly decreased, while the expression of inflammatory cytokines and matrix metalloproteinases was increased; but AST treatment reversed these effects. Meanwhile, AST pretreatment could partially reverse LPS-induced ATDC5 cell damage and upregulate SIRT1 expression, but this protective effect of AST was attenuated by concurrent administration of the SIRT1 inhibitor Ex527.

CONCLUSION

AST can protect against the early stages of OA by affecting SIRT1 signalling, suggesting that AST might be a potential therapeutic agent for OA treatment.

Orthobiologics in delayed union and non-union of adult long bones fractures: A systematic review

Background

Fracture healing poses a significant challenge in orthopedics. Successful regeneration of bone is provided by mechanical stability and a favorable biological microenvironment. This systematic review aims to explore the clinical application of orthobiologics in treating aseptic delayed union and non-union of long bones in adults.

Methods

A systematic review was conducted following the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines. Three databases were explored, with no date restrictions, using keywords related to orthobiologics and delayed union and non-union. Eligible studies included human clinical studies in English, with available full texts, examining orthobiologics such as platelet-rich plasma (PRP), mesenchymal stem cells (MSCs), and bone morphogenetic protein (BMPs) for treating aseptic delayed unions and non-unions in adults. Animal studies, in vitro research, and studies on non-unions due to congenital defects, tumors or infections were excluded.

Results

The initial search identified 9417 studies, with 20 ultimately included in the review. These studies involved 493 patients affected by non-union and 256 patients affected by delayed union, with an average age respectively of 40.62 years and 41.7 years. The mean follow-up period was 15.55 months for non-unions and 8.07 months for delayed unions. PRP was the most used orthobiologic, and outcomes were evaluated through time to union, functional scores, and clinical examinations. The results indicated that orthobiologics, especially PRP, tended to yield better outcomes compared to surgical procedures without biological factors.

Conclusion

This systematic review suggests that orthobiologics, such as PRP, BMPs, and MSCs, can be effective and safe in the management of delayed union and non-union fractures. These biological treatments have the potential to improve union rates, reduce healing times, and enhance functional outcomes in patients with non-union fractures. Further research is essential to refine treatment protocols and determine the most suitable orthobiologic for specific patient populations and fracture types.

Updates in the Treatment of Knee Osteoarthritis

Knee osteoarthritis (OA) is an inflammatory and degenerative condition resulting in articular cartilage destruction and functional loss. Its prevalence has grown considerably due to increased life expectancy and obesity, and its diagnosis relies on evaluation, medical examination, and confirmation by supplementary radiographic images. Knee OA is multifactorial and influenced by several local, systemic, and external aspects. In addition, its progress and therapeutic responses highly depend on the characteristics of each subject. The initial recommendation is drug treatment and alternative therapies to improve quality of life. However, if these treatments are unsuccessful, one must consider surgical treatment. Surgical options include arthroscopies, osteotomies, and partial and total arthroplasties, while non-surgical treatments include medications and alternative therapies such as infiltrations, acupuncture, and physical exercise. It is worth highlighting that biomarkers can be a significant strategy for early disease detection, assessment of disease activity, prediction of prognosis, and monitoring a better response to therapy. Nevertheless, this topic must be the focus of further research to confirm its findings.

MiR-653-5p drives osteoarthritis pathogenesis by modulating chondrocyte senescence

BACKGROUND

Due to the unclear pathogenesis of osteoarthritis (OA), effective treatment for this ailment is presently unavailable. Accumulating evidence points to chondrocyte senescence as a key driver in OA development. This study aims to identify OA-specific microRNAs (miRNAs) targeting chondrocyte senescence to alleviate OA progression.

METHODS

We screened and identified miRNAs differentially expressed in OA and normal cartilage, then confirmed the impact of miR-653-5p on chondrocyte functions and senescence phenotypes through in vitro experiments with overexpression/silencing. We identified interleukin 6 (IL-6) as the target gene of miR-653-5p and confirmed the regulatory influence of miR-653-5p on the IL-6/JAK/STAT3 signaling pathway through gain/loss-of-function studies. Finally, we assessed the therapeutic efficacy of miR-653-5p on OA using a mouse model with destabilization of the medial meniscus.

RESULTS

MiR-653-5p was significantly downregulated in cartilage tissues and chondrocytes from OA patients. Overexpression of miR-653-5p promoted chondrocyte matrix synthesis and proliferation while inhibiting chondrocyte senescence. Furthermore, bioinformatics target prediction and the luciferase reporter assays identified IL-6 as a target of miR-653-5p. Western blot assays demonstrated that miR-653-5p overexpression inhibited the protein expression of IL-6, the phosphorylation of JAK1 and STAT3, and the expression of chondrocyte senescence phenotypes by regulating the IL-6/JAK/STAT3 signaling pathway. More importantly, the cartilage destruction was significantly alleviated and chondrocyte senescence phenotypes were remarkably decreased in the OA mouse model treated by agomiR-653-5p compared to the control mice.

CONCLUSIONS

MiR-653-5p showed a significant decrease in cartilage tissues of individuals with OA, leading to an upregulation of chondrocyte senescence phenotypes in the articular cartilage. AgomiR-653-5p emerges as a potential treatment approach for OA. These findings provide further insight into the role of miR-653-5p in chondrocyte senescence and the pathogenesis of OA.

Induction of Human Wharton's Jelly of Umbilical Cord Derived Mesenchymal Stem Cells to Be Chondrocytes and Transplantation in Guinea Pig Model with Spontaneous Osteoarthritis

Osteoarthritis (OA) is a degenerative joint disease commonly found in elderly people and obese patients. Currently, OA treatments are determined based on their condition severity and a medical professional's advice. The aim of this study was to differentiate human Wharton's jelly-derived mesenchymal stem cells (hWJ-MSCs) into chondrocytes for transplantation in OA-suffering guinea pigs. hWJ-MSCs were isolated using the explant culture method, and then, their proliferation, phenotypes, and differentiation ability were evaluated. Subsequently, hWJ-MSCs-derived chondrocytes were induced and characterized based on immunofluorescent staining, qPCR, and immunoblotting techniques. Then, early-OA-suffering guinea pigs were injected with hyaluronic acid (HA) containing either MSCs or 14-day-old hWJ-MSCs-derived chondrocytes. Results showed that hWJ-MSCs-derived chondrocytes expressed specific markers of chondrocytes including Aggrecan, type II collagen, and type X collagen proteins and β-catenin, Sox9, Runx2, Col2a1, Col10a1, and ACAN gene expression markers. Administration of HA plus hWJ-MSCs-derived chondrocytes (HA-CHON) produced a better recovery rate of degenerative cartilages than HA plus MSCs or only HA. Histological assessments demonstrated no significant difference in Mankin's scores of recovered cartilages between HA-CHON-treated guinea pigs and normal articular cartilage guinea pigs. Transplantation of hWJ-MSCs-derived chondrocytes was more effective than undifferentiated hWJ-MSCs or hyaluronic acid for OA treatment in guinea pigs. This study provides a promising treatment to be used in early OA patients to promote recovery and prevent disease progression to severe osteoarthritis.

Cartilage-Specific Gene Expression and Extracellular Matrix Deposition in the Course of Mesenchymal Stromal Cell Chondrogenic Differentiation in 3D Spheroid Culture

Articular cartilage damage still remains a major problem in orthopedical surgery. The development of tissue engineering techniques such as autologous chondrocyte implantation is a promising way to improve clinical outcomes. On the other hand, the clinical application of autologous chondrocytes has considerable limitations. Mesenchymal stromal cells (MSCs) from various tissues have been shown to possess chondrogenic differentiation potential, although to different degrees. In the present study, we assessed the alterations in chondrogenesis-related gene transcription rates and extracellular matrix deposition levels before and after the chondrogenic differentiation of MSCs in a 3D spheroid culture. MSCs were obtained from three different tissues: umbilical cord Wharton's jelly (WJMSC-Wharton's jelly mesenchymal stromal cells), adipose tissue (ATMSC-adipose tissue mesenchymal stromal cells), and the dental pulp of deciduous teeth (SHEDs-stem cells from human exfoliated deciduous teeth). Monolayer MSC cultures served as baseline controls. Newly formed 3D spheroids composed of MSCs previously grown in 2D cultures were precultured for 2 days in growth medium, and then, chondrogenic differentiation was induced by maintaining them in the TGF-β1-containing medium for 21 days. Among the MSC types studied, WJMSCs showed the most similarities with primary chondrocytes in terms of the upregulation of cartilage-specific gene expression. Interestingly, such upregulation occurred to some extent in all 3D spheroids, even prior to the addition of TGF-β1. These results confirm that the potential of Wharton's jelly is on par with adipose tissue as a valuable cell source for cartilage engineering applications as well as for the treatment of osteoarthritis. The 3D spheroid environment on its own acts as a trigger for the chondrogenic differentiation of MSCs.

Unraveling the path to osteoarthritis management: targeting chondrocyte apoptosis for therapeutic intervention

Osteoarthritis (OA) is a chronic disease affecting joints and further causing disabilities. This disease affects around 240 million people worldwide. It is a multifactorial disease, and its etiology is difficult to determine. Although numerous therapeutic strategies are available, the therapies are aimed at reducing pain and improving patients' quality of life. Hence, there is an urgent need to develop disease-modifying drugs (DMOAD) that can reverse or halt OA progression. Apoptosis is a cell removal process that is important in maintaining homeostatic mechanisms in the development and sustaining cell population. The apoptosis of chondrocytes is believed to play an important role in OA progression due to poor chondrocytes self-repair abilities to maintain the extracellular matrix (ECM). Hence, targeting chondrocyte apoptosis can be one of the potential therapeutic strategies in OA management. There are various mediators and targets available to inhibit apoptosis such as autophagy, endoplasmic reticulum (ER) stress, oxidative stress, and inflammation. As such, this review highlights the importance and potential targets that can be aimed to reduce chondrocyte apoptosis.

Novel insights into the role of ubiquitination in osteoarthritis

Ubiquitination (Ub) and deubiquitination are crucial post-translational modifications (PTMs) that precisely regulate protein degradation. Under the catalysis of a cascade of E1-E2-E3 ubiquitin enzymes, ubiquitination extensively regulates protein degradation exerting direct impact on various cellular processes, while deubiquitination opposes the effect of ubiquitination and prevents proteins from degradation. Notably, such dynamic modifications have been widely investigated to be implicated in cell cycle, transcriptional regulation, apoptosis and so on. Therefore, dysregulation of ubiquitination and deubiquitination could lead to certain diseases through abnormal protein accumulation and clearance. Increasing researches have revealed that the dysregulation of catalytic regulators of ubiquitination and deubiquitination triggers imbalance of cartilage homeostasis that promotes osteoarthritis (OA) progression. Hence, it is now believed that targeting on Ub enzymes and deubiquitinating enzymes (DUBs) would provide potential therapeutic pathways. In the following sections, we will summarize the biological role of Ub enzymes and DUBs in the development and progression of OA by focusing on the updating researches, with the aim of deepening our understanding of the underlying molecular mechanism of OA pathogenesis concerning ubiquitination and deubiquitination, so as to explore novel potential therapeutic targets of OA treatment.

Cyaonoside A-loaded composite hydrogel microspheres to treat osteoarthritis by relieving chondrocyte inflammation

Cyaonoside A (CyA), derived from the natural Chinese medicine, Cyathula officinalis Kuan, which was for a long time used to treat knee injuries and relieve joint pain in traditional Chinese medicine, showed an unclear mechanism for protecting cartilage. In addition, CyA was poorly hydrosoluble and incapable of being injected directly into the joint cavity, which limited its clinical application. This study reveals that CyA resisted IL-1β-mediated chondrogenic inflammation and apoptosis. Next, transcriptome sequencing is used to explore the potential mechanisms underlying CyA regulation of MSC chondrogenic differentiation. Based on these findings, CyA-loaded composite hydrogel microspheres (HLC) were developed and they possessed satisfactory loading efficiency, a suitable degradation rate and good biocompatibility. HLC increased chondrogenic anabolic gene (Acan, COL2A, and SOX9) expression, while downregulating the expression of the catabolic marker MMP13 in vitro. In the osteoarthritis mouse model, HLC demonstrated promising therapeutic capabilities by protecting the integrity of articular cartilage. In conclusion, this study provides insights into the regulatory mechanisms of CyA for chondrocytes and proposes a composite hydrogel microsphere-based advanced therapeutic strategy for osteoarthritis.

Intra-Articular Injection of PLGA/Polydopamine Core-Shell Nanoparticle Attenuates Osteoarthritis Progression

Osteoarthritis (OA) is a common joint disease characterized by progressive cartilage degeneration. Unfortunately, currently available clinical drugs are mainly analgesics and cannot alleviate the development of OA. Kartogenin (KGN) has been found to promote the differentiation of bone marrow mesenchymal stem cells (BMSCs) into chondrocytes for the treatment of cartilage damage in early OA. However, KGN, as a small hydrophobic molecule, is rapidly cleared from the synovial fluid after intra-articular injection. This study synthesized a KGN-loaded nanocarrier based on PLGA/polydopamine core/shell structure to treat OA. The fluorescence signal of KGN@PLGA/PDA-PEG-E7 nanoparticles lasted for 4 weeks, ensuring long-term sustained release of KGN from a single intra-articular injection. In addition, the polyphenolic structure of PDA enables it to effectively scavenge reactive oxygen species, and the BMSC-targeting peptide E7 (EPLQLKM) endows KGN@PLGA/PDA-PEG-E7 NPs with an effective affinity for BMSCs. As a result, the KGN@PLGA/PDA-PEG-E7 nanoparticles could effectively induce cartilage in vitro and protect the cartilage and subchondral bone in a rat ACLT model. This therapeutic strategy could also be extended to the delivery of other drugs, targeting other tissues to treat joint diseases.

Branched poly-l-lysine for cartilage penetrating carriers

Joint diseases, such as osteoarthritis, often require delivery of drugs to chondrocytes residing within the cartilage. However, intra-articular delivery of drugs to cartilage remains a challenge due to their rapid clearance within the joint. This problem is further exacerbated by the dense and negatively charged cartilage extracellular matrix (ECM). Cationic nanocarriers that form reversible electrostatic interactions with the anionic ECM can be an effective approach to overcome the electrostatic barrier presented by cartilage tissue. For an effective therapeutic outcome, the nanocarriers need to penetrate, accumulate, and be retained within the cartilage tissue. Nanocarriers that adhere quickly to cartilage tissue after intra-articular administration, transport through cartilage, and remain within its full thickness are crucial to the therapeutic outcome. To this end, we used ring-opening polymerization to synthesize branched poly(l-lysine) (BPL) cationic nanocarriers with varying numbers of poly(lysine) branches, surface charge, and functional groups, while maintaining similar hydrodynamic diameters. Our results show that the multivalent BPL molecules, including those that are highly branched (i.e., generation two), can readily adhere and transport through the full thickness of cartilage, healthy and degenerated, with prolonged intra-cartilage retention. Intra-articular injection of the BPL molecules in mouse knee joint explants and rat knee joints showed their localization and retention. In summary, this study describes an approach to design nanocarriers with varying charge and abundant functional groups while maintaining similar hydrodynamic diameters to aid the delivery of macromolecules to negatively charged tissues.

An injectable cartilage-coating composite with long-term protection, effective lubrication and chondrocyte nourishment for osteoarthritis treatment

The osteoarthritic (OA) environment within articular cartilage poses significant challenges, resulting in chondrocyte dysfunction and cartilage matrix degradation. While intra-articular injections of anti-inflammatory drugs, biomaterials, or bioactive agents have demonstrated some effectiveness, they primarily provide temporary relief from OA pain without arresting OA progression. This study presents an injectable cartilage-coating composite, comprising hyaluronic acid and decellularized cartilage matrix integrated with specific linker polymers. It enhances the material retention, protection, and lubrication on the cartilage surface, thereby providing an effective physical barrier against inflammatory factors and reducing the friction and shear force associated with OA joint movement. Moreover, the composite gradually releases nutrients, nourishing OA chondrocytes, aiding in the recovery of cellular function, promoting cartilage-specific matrix production, and mitigating OA progression in a rat model. Overall, this injectable cartilage-coating composite offers promising potential as an effective cell-free treatment for OA. STATEMENT OF SIGNIFICANCE: Osteoarthritis (OA) in the articular cartilage leads to chondrocyte dysfunction and cartilage matrix degradation. This study introduces an intra-articular injectable composite material (HDC), composed of decellularized cartilage matrix (dECMs), hyaluronan (HA), and specially designed linker polymers to provide an effective cell-free OA treatment. The linker polymers bind HA and dECMs to form an integrated HDC structure with an enhanced degradation rate, potentially reducing the need for frequent injections and associated trauma. They also enable HDC to specifically coat the cartilage surface, forming a protective and lubricating layer that enhances long-term retention, acts as a barrier against inflammatory factors, and reduces joint movement friction. Furthermore, HDC nourishes OA chondrocytes through gradual nutrient release, aiding cellular function recovery, promoting cartilage-specific matrix production, and mitigating OA progression.

Pain Management Strategies in Osteoarthritis

Pain is the major symptom of osteoarthritis (OA) and is an important factor in strategies to manage this disease. However, the current standard of care does not provide satisfactory pain relief for many patients. The pathophysiology of OA is complex, and its presentation as a clinical syndrome is associated with the pathologies of multiple joint tissues. Treatment options are generally classified as pharmacologic, nonpharmacologic, surgical, and complementary and/or alternative, typically used in combination to achieve optimal results. The goals of treatment are the alleviation of symptoms and improvement in functional status. Several studies are exploring various directions for OA pain management, including tissue regeneration techniques, personalized medicine, and targeted drug therapies. The aim of the present narrative review is to extensively describe all the treatments available in the current practice, further describing the most important innovative therapies. Advancements in understanding the molecular and genetic aspects of osteoarthritis may lead to more effective and tailored treatment approaches in the future.

Implantable celecoxib nanofibers made by electrospinning: fabrication and characterization

Background: Osteoarthritis causes tremendous damage to the joints, reducing the quality of life and imposing significant financial burden. An implantable drug-delivery system can improve the symptomatic manifestations with low doses and frequencies. However, the free drug has short retention in the joint cavity. Materials & methods: This study used electrostatic spinning technology to create an implantable drug-delivery system loaded with celecoxib (celecoxib nanofibers [Cel-NFs]) to improve retention and bioavailability. Results: Cel-NFs exhibited good formability, hydrophilicity and tensile properties. Cel-NFs were able to continuously release drugs for 2 weeks and increase the uptake capacity of Raw 264.7 cells, ultimately ameliorating symptoms in osteoarthritis rats. Conclusion: These results suggest that Cel-NFs can effectively ameliorate cartilage damage, reduce joint pain and alleviate osteoarthritis progression.

Microgel-based carriers enhance skeletal stem cell reprogramming towards immunomodulatory phenotype in osteoarthritic therapy

Skeletal stem cells (SSC) have gained attentions as candidates for the treatment of osteoarthritis due to their osteochondrogenic capacity. However, the immunomodulatory properties of SSC, especially under delivery operations, have been largely ignored. In the study, we found that Pdpn+ and Grem1+ SSC subpopulations owned immunoregulatory potential, and the single-cell RNA sequencing (scRNA-seq) data suggested that the mechanical activation of microgel carriers on SSC induced the generation of Pdpn+Grem1+Ptgs2+ SSC subpopulation, which was potent at suppressing macrophage inflammation. The microgel carriers promoted the YAP nuclear translocation, and the activated YAP protein was necessary for the increased expression of Ptgs2 and PGE2 in microgels-delivered SSC, which further suppressed the expression of TNF-ɑ, IL-1β and promoted the expression of IL-10 in macrophages. SSC delivered with microgels yielded better preventive effects on articular lesions and macrophage activation in osteoarthritic rats than SSC without microgels. Chemically blocking the YAP and Ptgs2 in microgels-delivered SSC partially abolished the enhanced protection on articular tissues and suppression on osteoarthritic macrophages. Moreover, microgel carriers significantly prolonged SSC retention time in vivo without increasing SSC implanting into osteoarthritic joints. Together, our study demonstrated that microgel carriers enhanced SSC reprogramming towards immunomodulatory phenotype to regulate macrophage phenotype transformation for effectively osteoarthritic therapy by promoting YAP protein translocation into nucleus. The study not only complement and perfect the immunological mechanisms of SSC-based therapy at the single-cell level, but also provide new insight for microgel carriers in stem cell-based therapy.

Effect of l-Carnitine Supplementation on Osteoarthritis: A Systematic Review

SCOPE

Comprehensive assessment of l-carnitine's safety and effectiveness in reducing inflammatory markers in osteoarthritis (OA) patients.

METHODS AND RESULTS

Journal articles on l-carnitine for OA are gathered using computer searches of PubMed, Embase, the Cochrane Library, and Web of Science. The kind of literature that is found is restricted to clinical randomized controlled trials (RCTs). The Cochrane Handbook risk of bias assessment tool RevMan 5.4 software is used to conduct a meta-analysis. The systematic assessment comprises eight trials totaling 619 patients; the included studies' quality is mediocre. The study's findings demonstrate that OA patients' Western Ontario and McMaster University (WOMAC) function improves and that treatment efficacy outperforms that of the control group (mean difference [MD] = -7.75, 95% CI [-14.63, -0.86]; Z = 2.21; p = 0.03), WOMAC total (MD = -10.24, 95% CI [-18.97, -1.51]; Z = 2.30; p = 0.02), and visual analogue scale (VAS) pain (MD = -14.01, 95% CI [-16.16, -11.85]; Z = 12.74; p < 0.00001). The studies that are methodically reviewed also discover heterogeneity, which may have resulted from the created pooled data and requires more analysis.

CONCLUSION

In patients with OA, l-carnitine effectively decreases clinical signs and symptoms, inflammatory markers, pain, and stiffness indicators, and significantly improves WOMAC and VAS scores.

Intraarticular monomethyl fumarate as a perspective therapy for osteoarthritis by macrophage polarization

BACKGROUND

Osteoarthritis (OA) is a chronic disease that may lead to joint structure degeneration, cartilage destruction, osteophyte formation, subchondral bone disruption, and pain. In this scenario, a higher proportion of the proinflammatory macrophage type 1 (M1) than the anti-inflammatory macrophage type 2 (M2) could be highlighted as a hallmark of OA progression. The balance between these two macrophage types emerges as a new therapeutic target in OA. This study aimed to evaluate the analgesia and macrophage profile in the treatment of experimental osteoarthritis (EOA) with systemic dimethyl fumarate (DMF) or local intra-articular monomethyl fumarate (MMF).

RESULTS

DMF via gavage or MMF via intra-articular in the right knee of EOA rats showed improvements in gait parameters and the nociceptive recovery of the mechanical threshold assessment by adapted electronic von Frey treatment on the twenty-first day (long-lasting phase). DMF treatment decreased proinflammatory TNF-α while increasing anti-inflammatory IL-10 cytokines from the macerated capsule on the fifth day (inflammatory phase). MMF treatment showed joint capsule mRNA extraction downregulating iNOS and TNF-α gene expression while upregulating IL-10 and MCP-1. However, CD206 was not significant but higher than untreated EOA rats' joints on the seventh day (inflammatory phase).

CONCLUSIONS

Our studies with EOA model induced by MIA suggest a new perspective for human treatment committed with OA based on macrophage polarization as a therapeutic target, switching the proinflammatory profile M1 to the anti-inflammatory profile M2 with DMF systematic or by MMF locally treatment according to the OA severity.

Achieving Precision Healthcare through Nanomedicine and Enhanced Model Systems

The ability to customize medical choices according to an individual's genetic makeup and biomarker patterns marks a significant advancement toward overall improved healthcare for both individuals and society at large. By transitioning from the conventional one-size-fits-all approach to tailored treatments that can account for predispositions of different patient populations, nanomedicines can be customized to target the specific molecular underpinnings of a patient's disease, thus mitigating the risk of collateral damage. However, for these systems to reach their full potential, our understanding of how nano-based therapeutics behave within the intricate human body is necessary. Effective drug administration to the targeted organ or pathological niche is dictated by properties such as nanocarrier (NC) size, shape, and targeting abilities, where understanding how NCs change their properties when they encounter biomolecules and phenomena such as shear stress in flow remains a major challenge. This Review specifically focuses on vessel-on-a-chip technology that can provide increased understanding of NC behavior in blood and summarizes the specialized environment of the joint to showcase advanced tissue models as approaches to address translational challenges. Compared to conventional cell studies or animal models, these advanced models can integrate patient material for full customization. Combining such models with nanomedicine can contribute to making personalized medicine achievable.

MiR-29a-3p mediates phosphatase and tensin homolog and inhibits osteoarthritis progression

Despite substantial progress in clinical trials of osteoarthritis (OA) gene therapy, the prevalence of OA is still on the rise. MiRNAs have a potential biomarker and therapeutic target for OA. OA cartilage and chondrosarcoma cells were studied to determine the role of miR-29a-3p and PTEN. OA cartilage and human chondrosarcoma cells (SW1353) were obtained. miR-29a-3p and PTEN signature expression was determined by RT-qPCR. The binding relationship between miR-29a-3p and PTEN was investigated by dual-luciferase reporter gene and western blot assay. TUNEL, immunohistochemistry, CCK-8, and flow cytometry were utilized to determine the proliferation and apoptosis of SW1353 cells. This study indicated downregulation of miR-29a-3p expression and upregulation of PTEN expression in human OA primary chondrocytes or OA tissue samples, compared with the normal cartilage cells or tissues. PTEN expression was negatively correlated with miR-29a-3p expression, and miR-29a-3p targeted PTEN mechanistically. miR-29a-3p reduced SW1353 cell activity and proliferation and promoted cell apoptosis. However, the aforementioned effects could be reversed by downregulating PTEN. miR-29a-3p can stimulate chondrocyte proliferation and inhibit apoptosis by inhibiting PTEN expression.

Characterization of Calcium- and Strontium-Polyphosphate Particles Toward Drug Delivery into Articular Cartilage

Drug delivery into articular cartilage poses many challenges due in part to its lack of vasculature. While intra-articular injections are effective for the local administration of drugs, small molecules are rapidly cleared from the synovial fluid. As such, there is a need to develop effective drug delivery strategies to improve the residence times of bioactive molecules in the joint and elicit a sustained therapeutic effect. In this study, calcium- and strontium-polyphosphate particles are synthesized and characterized as potential drug carriers into articular cartilage. Physicochemical characterization reveals that the particles exhibit a spherical morphology, have a negative zeta potential, and are nanoscale in size. Biological characterization in chondrocytes confirms cellular uptake of the particles and demonstrates both size and concentration-dependent cytotoxicity at high concentrations. Furthermore, treatment of chondrocytes with these particles results in a reduction in cell proliferation and metabolic activity, confirming biological effects. Finally, incubation with cartilage tissue explants suggests successful uptake, despite the particles exhibiting a negative surface charge. Therefore, from the results of this study, these polyphosphate-based particles have potential as a drug carrier into articular cartilage and warrant further development.

PPAR γ activation in chondrocytes alleviates glucocorticoid-induced oxidative stress, mitochondrial impairment, and pyroptosis via autophagic flow enhancement

Osteoarthritis (OA) is a progressive age-related disease characterised by pathological changes in the synovium, articular cartilage, and subchondral bone, significantly reducing the patients' quality of life. This study investigated the role of glucocorticoids, specifically dexamethasone, in OA progression, with a particular focus on their effects on chondrocytes. Although glucocorticoids are commonly used for OA pain relief, our research demonstrated that high concentrations of dexamethasone may accelerate OA progression by enhancing the ability of reactive oxygen species to inhibit chondrocyte autophagy, resulting in cell death and accelerated cartilage degeneration. Despite reports on the acceleration of pathogenesis and cartilage damage in some patients of OA taking corticosteroids, the mechanism behind the same has not been investigated. This necessitates an investigation of the concentration-dependent changes in the cartilage cells upon dexamethasone administration. In addition, the protective effect of PPAR γ on chondrocytes can prevent the decrease in chondrocyte autophagy and delay cartilage degeneration. Therefore, our study suggests that the therapeutic use of glucocorticoids in OA treatment should be more nuanced considering their potential detrimental effects. Future investigations should focus on the mechanisms underlying the glucocorticoid-mediated modulation of cell death processes, which could provide insights into new therapeutic strategies for OA treatment.

Chondrocyte membrane-coated nanoparticles promote drug retention and halt cartilage damage in rat and canine osteoarthritis

Osteoarthritis (OA) is a chronic joint disease characterized by progressive degeneration of articular cartilage. A challenge in the development of disease-modifying drugs is effective delivery to chondrocytes. The unique structure of the joint promotes rapid clearance of drugs through synovial fluid, and the dense and avascular cartilage extracellular matrix (ECM) limits drug penetration. Here, we show that poly(lactide-co-glycolic acid) nanoparticles coated in chondrocyte membranes (CM-NPs) were preferentially taken up by rat chondrocytes ex vivo compared with uncoated nanoparticles. Internalization of the CM-NPs was mediated primarily by E-cadherin, clathrin-mediated endocytosis, and micropinocytosis. These CM-NPs adhered to the cartilage ECM in rat knee joints in vivo and penetrated deeply into the cartilage matrix with a residence time of more than 34 days. Simulated synovial fluid clearance studies showed that CM-NPs loaded with a Wnt pathway inhibitor, adavivint (CM-NPs-Ada), delayed the catabolic metabolism of rat and human chondrocytes and cartilage explants under inflammatory conditions. In a surgical model of rat OA, drug-loaded CM-NPs effectively restored gait, attenuated periarticular bone remodeling, and provided chondroprotection against cartilage degeneration. OA progression was also mitigated by CM-NPs-Ada in a canine model of anterior cruciate ligament transection. These results demonstrate the feasibility of using chondrocyte membrane-coated nanoparticles to improve the pharmacokinetics and efficacy of anti-OA drugs.

M2 macrophage-derived exosomal miR-26b-5p regulates macrophage polarization and chondrocyte hypertrophy by targeting TLR3 and COL10A1 to alleviate osteoarthritis

Osteoarthritis (OA) is one of the most prevalent chronic musculoskeletal diseases among the elderly population. In this study, macrophage-derived exosomes were isolated and identified. Exosomes were subjected to microRNA (miRNA) sequencing and bioinformatic analysis, and differentially expressed miRNAs were verified. miR-26b-5p target genes were confirmed through target-site mutation combined with a dual-luciferase reporter assay. The effects of miR-26b-5p on macrophage polarization and chondrocyte hypertrophy were assessed in vitro. miR-26b-5p agomir was applied to mice with OA induced by anterior cruciate ligament transection (ACLT). The therapeutic effects of miR-26b-5p were evaluated via pain behavior experiments and histological observations. In vitro, miR-26b-5p repolarized M1 macrophages to an anti-inflammatory M2 type by targeting the TLR3 signaling pathway. miR-26b-5p could target COL10A1, further inhibiting chondrocyte hypertrophy induced by M1 macrophage-conditioned medium (M1-CM). In vivo, miR-26b-5p agomir ameliorated gait abnormalities and mechanical allodynia in OA mice. miR-26b-5p treatment attenuated synovitis and cartilage degeneration, thereby delaying OA progression. In conclusion, M2 macrophage-derived exosomal miR-26b-5p could protect articular cartilage and ameliorate gait abnormalities in OA mice by targeting TLR3 and COL10A1. miR-26b-5p further affected macrophage polarization and chondrocyte hypertrophy. Thus, this exosomal miR-26b-5p-based strategy might be a potential method for OA treatment.

Nitisinone attenuates cartilage degeneration and subchondral osteoclastogenesis in osteoarthritis and concomitantly inhibits the cGAS/STING/NF-κB pathway

Osteoarthritis (OA) is a chronic degenerative joint disease characterized by cartilage degeneration and subchondral bone remodelling. Currently, conservative treatment strategies cannot effectively alleviate the progression of OA. In this study, we used computer network analysis to show that Nitisinone (NTBC) is closely related to extracellular matrix degradation in OA and mainly interferes with the TNF-α signaling pathway. NTBC is an orphan drug used to treat hereditary type I tyrosinemia by altering phenylalanine/tyrosine metabolic flow. In this study, we found that NTBC effectively reduced chondrocyte inflammation and extracellular matrix degradation induced by TNF-α. Mechanistically, NTBC inhibited the cGAS/STING signaling pathway and reduced activation of the STING-dependent NF-κB pathway to alleviate inflammation. In addition, NTBC inhibited osteoclastogenesis and delayed the occurrence of subchondral bone remodelling. In mice with ACLT-induced osteoarthritis, intra-articular injection of NTBC significantly reduced cartilage degradation and subchondral bone remodelling. NTBC showed impressive therapeutic efficacy as a potential pharmaceutical intervention for the treatment of OA.

Zhuifeng Tougu capsules in the treatment of knee osteoarthritis (cold dampness obstruction syndrome): a randomized, double blind, multicenter clinical study

BACKGROUND

In Traditional Chinese Medicine (TCM) theory, cold dampness obstruction is one of the common syndromes of osteoarthritis. Therefore, in clinical practice, the main treatment methods are to dispel wind, remove dampness, and dissipate cold, used to treat knee osteoarthritis (KOA). This report describes a mulitercenter clinical study to assess Zhuifeng Tougu Capsule's efficacy and safety in the treatment of patients who are cold dampness obstruction syndrome in KOA, and to provide evidence-based medical for the rational use of Zhuifeng Tougu Capsules in clinical practice.

METHODS

This randomized, parallel group controlled, double-blind, double dummy trial will include a total of 215 KOA patients who meet the study criteria. 215 patients underwent 1:1 randomisation, with 107 cases assigned the experimental group (Zhuifeng Tougu Capsules + Glucosamine Sulfate Capsules Simulator) and 108 assigned the control group (Glucosamine Sulfate Capsules + Zhuifeng Tougu Capsules Simulator). After enrolment, patients received 12 weeks of treatment. The main efficacy measure is the Western Ontario and McMaster University Osteoarthritis Index (WOMAC) pain score. Visual analogue scale (VAS) pain score, Self-condition assessment VAS score, WOMAC KOA score, TCM syndrome score and TCM syndrome efficacy, ESR level, CRP level, suprapatellar bursa effusion depth, use of rescue drugs, and safety indicators are secondary efficacy indicators.

RESULTS

Compared with before treatment, WOMAC pain score, VAS pain score, Self-condition assessment VAS score, WOMAC KOA score, and TCM syndrome score decreased significantly in both groups (P < 0.01). Also, the experimental group showed significant differences in the above indicators compared to control (P < 0.01). However, after treatment, no significant differences were showed in the ESR level, CRP level, and suprapatellar bursa effusion depth between the two groups (P > 0.05). No any serious adverse effects showed in the experimental group and control group.

CONCLUSIONS

Zhuifeng Tougu Capsules can effectively improve knee joint function and significantly alleviate the pain of KOA.

TRIAL REGISTRATION

Clinical trial registration was completed with the China Clinical Trial Registration Center for this research protocol (No. ChiCTR2000028750) on January 2, 2020.

The circUbqln1, regulated by XBP1s, interplays with 14-3-3ζ to inhibit collagen synthesis and promote osteoarthritis by controlling PRODH activity and proline metabolism

INTRODUCTION

Osteoarthritis (OA) is a degenerative bone disease associated with ageing, characterized by joint pain, stiffness, swelling and deformation. Currently, pharmaceutical options for the clinical treatment of OA are very limited. Circular RNAs(cirRNAs) have garnered significant attention in OA and related drug development due to their unique RNA sequence characteristics.Therefore,exploring the role of cirRNAs in the occurrence and development of OA is of paramount importance for the development of effective medications for OA.

OBJECTIVES

To identify a novel circRNA, circUbqln1, for treating osteoarthritis and elucidate its pathophysiological role and mechanisms in the treatment of OA.

METHODS

The circUbqln1 expression and distribution were determined by qRT-PCR and FISH. XBP1 gene knockout(XBP1 cKO) spontaneous OA and DMM model and WT mouse CIOA model were used to explore the role of XBP1 and circUbqln1 in OA.Overexpression or knockdown of circUbqln1 lentivirus was used to observe the impacts of circUbqln1 on primary chondrocytes,C28/I2 and mice in vitro and in vivo.Chromatin immunoprecipitation,luciferase reporter assay,RNA pulldown,mass spectrometry,RNA immunoprecipitation,fluorescence in situ hybridization,and flow cytometry to explore the molecular mechanisms of circUbqln1.

RESULTS

It was found that cartilage-specific XBP1 cKO mice exhibited a faster OA progression compared to normal's.Importantly,transcript factor XBP1s has the capacity to impede the biogenesis of circUbqln1,derived from Ubqln1. The circUbqln1 promotes cartilage catabolism and inhibits anabolism, therefore accelerates the occurrence of OA.Mechanismly,circUbqln1 can translocate to the chondrocyte nucleus with the assistance of phosphorylated 14-3-3ζ, upregulate the transcriptional activity of the proline dehydrogenase(Prodh) promoter and PRODH enzyme activity. Consequently, this leads to the promotion of proline degradation and the inhibition of collagen synthesis,ultimately culminating in the impairment of cartilage and its structural integrity.

CONCLUSION

CircUbqln1 plays a crucial role in the occurrence and development of OA, indicating that the inhibition of circUbqln1 holds promise as a significant approach for treating OA in the future.

Downregulation of Gadd45β alleviates osteoarthritis by repressing lipopolysaccharide-induced fibroblast-like synoviocyte inflammation, proliferation and migration

OBJECTIVE

Gadd45β have a regulatory role in cellular inflammation, proliferation and migration. However, the role of Gadd45β in synovial inflammation in osteoarthritis (OA) remains to be explored. This study aimed to ascertain whether Gadd45β is involved in OA synovial inflammation.

METHODS

The rat model was induced by sodium iodoacetate and the cellular model was constructed with lipopolysaccharide (LPS)-induced fibroblast-like synoviocytes (FLSs). siRNA was applied to interfere with the expression of intracellular Gadd45β. Real-time quantitative polymerase chain reaction (RT-qPCR) and western blotting were used to detect the expression of Gadd45β mRNA and protein. The inflammation, proliferation, and migration of OA-FLSs were detected by enzyme-linked immunosorbent assay, cell scratch assay, 5-ethynyl-2'-deoxyuridine assay, etc. The effect of downregulation of Gadd45β on the nuclear factor-κB (NF-κB) pathway was investigated.

RESULTS

Expression of Gadd45β in OA rat synovial tissues and OA-FLSs was increased, and LPS treatment promoted cell proliferation and enhanced cell migration. Gadd45β interference inhibited the inflammation, proliferation and migration of cells induced by LPS. LPS promoted P65 expression in the nucleus and activated the NF-κB signaling pathway, whereas si-Gadd45β reversed this situation.

CONCLUSIONS

si-Gadd45β inhibited the inflammatory response, proliferation and migration of FLSs, and activation of the NF-κB signaling pathway, which could delay the progression of OA. Hence, it may become a potential therapeutic target for OA.

TCF12 regulates the TGF-β/Smad2/3 signaling pathway to accelerate the progression of osteoarthritis by targeting CXCR4

Objective

Osteoarthritis (OA), which involves total joint damage and dysfunction, is a leading cause of disability worldwide. However, its exact pathogenesis remains unclear. Here, we identified TCF12 as an important regulator of the progression of OA.

Methods

qRT-PCR, immunoblotting and immunohistochemistry (IHC) were used to detect the expression level of TCF12. The interaction of TCF12 with its downstream factor CXCR4 was assessed by Western blotting, immunofluorescence, qRT-PCR and luciferase assays. A mouse model was generated to examine the functions and mechanism of TCF12 in vivo.

Result

TCF12 expression was upregulated in chondrocytes stimulated with IL-1β and osteoarthritic chondrocytes. TCF12 upregulates the expression of CXCR4 and leads to dysfunction of the TGF-β signaling pathway. Furthermore, knockdown of TCF12 alleviated cartilage damage in a mouse model generated by destabilization of the medial meniscus (DMM).

Conclusion

TCF12 aggravates the progression of OA by targeting CXCR4 and then activating the TGF-β signaling pathway, suggesting that TCF12 may be a new target for the treatment of OA.

The translational potential of this article

Transcription Factor 12(TCF12), is known to regulate cell development and differentiation, It has been widely studied in various organs and diseases, but its role in OA remains unclear. Here, we identified Transcription Factor 12(TCF12) as an important regulator mediating chondrocyte senescence and cartilage extracellular matrix degradation indicating its role in OA. We found that TCF12 expression was upregulated both locally and systemically as OA advanced in patients with OA, and in mice after DMM surgery to induce OA. TCF12 expression caused striking progressive articular cartilage damage, synovial hyperplasia in OA mice, and remarkably, it was relieved by intra-articular administration of mutant mouse TCF12 lentiviral vector (shTCF12). Furthermore, TCF12 upregulated the expression of CXCR4, leading to exacerbation of experimental OA partially through activation of TGF-β signaling in chondrocytes. TCF12 expression was upregulated in chondrocytes treated with IL-1β and osteoarthritic chondrocytes. Our findings established an essential role of TCF12 in chondrocyte senescence and cartilage extracellular matrix degradation during OA, and identified intra-articular injection of TCF12 as a potential therapeutic strategy for OA prevention and treatment.

H3K36 methyltransferase NSD1 protects against osteoarthritis through regulating chondrocyte differentiation and cartilage homeostasis

Osteoarthritis (OA) is one of the most common joint diseases, there are no effective disease-modifying drugs, and the pathological mechanisms of OA need further investigation. Here, we show that H3K36 methylations were decreased in senescent chondrocytes and age-related osteoarthritic cartilage. Prrx1-Cre inducible H3.3K36M transgenic mice showed articular cartilage destruction and osteophyte formation. Conditional knockout Nsd1Prrx1-Cre mice, but not Nsd2Prrx1-Cre or Setd2Prrx1-Cre mice, replicated the phenotype of K36M/+; Prrx1-Cre mice. Immunostaining results showed decreased anabolic and increased catabolic activities in Nsd1Prrx1-Cre mice, along with decreased chondrogenic differentiation. Transcriptome and ChIP-seq data revealed that Osr2 was a key factor affected by Nsd1. Intra-articular delivery of Osr2 adenovirus effectively improved the homeostasis of articular cartilage in Nsd1Prrx1-Cre mice. In human osteoarthritic cartilages, both mRNA and protein levels of NSD1 and OSR2 were decreased. Our results indicate that NSD1-induced H3K36 methylations and OSR2 expression play important roles in articular cartilage homeostasis and OA. Targeting H3K36 methylation and OSR2 would be a novel strategy for OA treatment.

MiR-203a-3p attenuates apoptosis and pyroptosis of chondrocytes by regulating the MYD88/NF-κB pathway to alleviate osteoarthritis progression

BACKGROUND

Osteoarthritis (OA) is a degenerative joint disease that imposes a significant socioeconomic burden worldwide. Our previous studies revealed a down-regulation of miR-203a-3p in the knee tissues of OA patients. However, the underlying mechanism through which miR-203a-3p mediates the pathological process of OA remains unknown. Thus, we aimed to determine the effects of miR-203a-3p in the progression of OA.

METHODS

Rat primary chondrocytes were stimulated with 10 μg/mL lipopolysaccharide (LPS) for 24 hours, followed by transfection with 50 nM miR-203a-3p mimic, inhibitor, and siRNA for MYD88 or consistent negative controls for 48 hours. To evaluate the effects of miR-203a-3p on cartilage matrix degradation, oxidative stress, apoptosis, and pyroptosis in chondrocytes, various techniques such as immunofluorescence staining, biochemical analysis, Western blotting, and the TUNEL staining were utilized. In the rat OA model, all rats were randomly divided into four groups: Sham, OA, OA+Agomir negative control (NC), and OA+Agomir. They received intra-articular injections of 25 nmol miR-203a-3p agomir, agomir NC, or normal saline twice a week for the duration of 8 weeks after OA induction. Immunofluorescence staining was performed to evaluate the effects of miR-203a-3p on cartilage matrix degradation in rats.

RESULTS

MiR-203a-3p was down-regulated in LPS-treated rat chondrocytes and OA cartilage, and directly targeted MYD88. Moreover, miR-203a-3p significantly inhibited LPS-induced cartilage matrix degradation, oxidative stress, apoptosis, and pyroptosis of chondrocytes via targeting MYD88. Mechanistically, miR-203a-3p exerted protective effects via the inhibition of the MYD88/NF-κB pathway. In the rat OA model, intra-articular injections of miR-203a-3p agomir also significantly inhibited cartilage matrix degradation, thereby alleviating OA progression. Furthermore, the miR-203a-3p agomir-treated arthritic rat dramatically exhibited better articular tissue morphology and lower OARSI scores.

CONCLUSIONS

MiR-203a-3p plays a role in alleviating the progression of OA by regulating the MYD88/NF-κB pathway, thereby inhibiting cartilage matrix degradation, oxidative stress, apoptosis, and pyroptosis of chondrocytes. It highlights the potential significance of miR-203a-3p as an important regulator of OA.

Biomaterial-Based Gene Delivery: Advanced Tools for Enhanced Cartilage Regeneration

Gene therapy has emerged as a promising and innovative approach in cartilage regeneration. Integrating biomaterials into gene therapy offers a unique opportunity to enhance gene delivery efficiency, optimize gene expression dynamics, modulate immune responses, and promote tissue regeneration. Despite the rapid progress in biomaterial-based gene delivery, there remains a deficiency of comprehensive discussions on recent advances and their specific application in cartilage regeneration. Therefore, this review aims to provide a thorough overview of various categories of biomaterials employed in gene delivery, including both viral and non-viral vectors, with discussing their distinct advantages and limitations. Furthermore, the diverse strategies employed in gene therapy are discussed and summarized, such as the utilization of growth factors, anti-inflammatory cytokines, and chondrogenic genes. Additionally, we highlights the significant challenges that hinder biomaterial-based gene delivery in cartilage regeneration, including immune response modulation, gene delivery efficiency, and the sustainability of long-term gene expression. By elucidating the functional properties of biomaterials-based gene therapy and their pivotal roles in cartilage regeneration, this review aims to enhance further advances in the design of sophisticated gene delivery systems for improved cartilage regeneration outcomes.

Intra-articular delivery of geraniol encapsulated by pH/redox-responsive nanogel ameliorates osteoarthritis by regulating oxidative stress and inflammation

Osteoarthritis (OA) remains a challenging condition due to limited drug bioavailability within the avascular and dense cartilage matrix. This study introduces a pH/redox-responsive nanogel for enhanced delivery of geraniol in OA therapy. We investigated geraniol's role in preventing chondrocyte matrix degradation and designed a pH/redox-responsive nanogel as a delivery platform. Our methods included Western blot, histological staining, and immunohistochemistry. Geraniol treatment reduced Keap1 expression while elevating Nrf2 and HO-1 levels, effectively inhibiting cartilage matrix degradation. The pH/redox-responsive nanogel further enhanced geraniol's therapeutic impact. Our study demonstrates that geraniol encapsulated within a pH/redox-responsive nanogel mitigates OA by regulating oxidative stress and inflammation. This innovative approach holds potential as an effective OA therapeutic strategy.

Harnessing the multifunctionality of lipid-based drug delivery systems for the local treatment of osteoarthritis

Osteoarthritis (OA) is a widespread joint condition affecting millions globally, presenting a growing socioeconomic burden thus making the development of more effective therapeutic strategies crucial. This review emphasizes recent advancements in lipid-based drug delivery systems (DDSs) for intra-articular administration of OA therapeutics, encompassing non-steroidal anti-inflammatory drugs, corticosteroids, small molecule disease-modifying OA drugs, and RNA therapeutics. Liposomes, lipid nanoparticles, lipidic mesophases, extracellular vesicles and composite systems exhibit enhanced stability, targeted delivery, and extended joint retention, which contribute to improved therapeutic outcomes and minimized systemic drug exposure. Although active targeting strategies hold promise, further research is needed to assess their targeting efficiency in physiologically relevant conditions. Simultaneously, multifunctional DDSs capable of delivering combinations of distinct therapeutic classes offer synergistic effects and superior OA treatment outcomes. The development of such long-acting systems that resist rapid clearance from the joint space is crucial, where particle size and targeting capabilities emerge as vital factors. Additionally, combining cartilage lubrication properties with sustained drug delivery has demonstrated potential in animal models, meriting further investigation in human clinical trials. This review highlights the crucial need for direct, head-to-head comparisons of novel DDSs with standard treatments, particularly within the same drug class. These comparisons are essential in accurately evaluating their effectiveness, safety, and clinical applicability, and are set to significantly shape the future of OA therapy.

TissueGene-C induces long-term analgesic effects through regulation of pain mediators and neuronal sensitization in a rat monoiodoacetate-induced model of osteoarthritis pain

OBJECTIVE

TissueGene-C (TG-C), a combination of human allogeneic chondrocytes and irradiated GP2-293 cells engineered to overexpress transforming growth factor-β1 (TGF-β1), has been developed as a novel cell-based gene therapy and a candidate for disease modifying osteoarthritis drug (DMOAD). We aim to investigate analgesic mechanism of TG-C in a pre-clinical animal model with monoiodoacetate (MIA)-induced pain.

DESIGN

We used a rat MIA model of osteoarthritis (OA) pain. We examined that TG-C can regulate pain by inhibiting the upregulation of various pain mediators in both knee joint tissue and dorsal root ganglia (DRG) (n = 112) and alleviating pain behavior (n = 41) and neuronal hyperexcitability in DRG (n = 60), afferent nerve fiber (n = 24), and spinal cord (n = 35).

RESULTS

TG-C significantly alleviated pain-related behavior by restoring altered dynamic weight bearing and reduced mechanical threshold of the affected hindlimb. TG-C significantly suppressed the expression of nerve growth factor (NGF) and calcitonin gene-related peptide (CGRP) in inflamed joint tissue. TG-C significantly suppressed the upregulation of tropomyosin receptor kinase A (TrkA) and nerve injury/regeneration protein (GAP43) and activation of Iba1-positive microglial cells in DRG. TG-C significantly recovered neuronal hyperexcitability by restoring RMP and firing threshold and frequency of DRG neurons, attenuating firing rates of mechanosensitive C- or Aδ-nerve fiber innervating knee joint, and lowering increased miniature and evoked excitatory postsynaptic currents (mEPSCs and eEPSCs) in the spinal cord.

CONCLUSION

Our results demonstrated that TG-C exerted potent analgesic effects in a rat MIA model of OA pain by inhibiting the upregulation of pain mediators and modulating neuronal sensitization.

Articular Cartilage Regeneration via Induced Chondrocyte Autophagy by Sustained Release of Leptin Inhibitor from Thermo-Sensitive Hydrogel through STAT3/REDD1/mTORC1 Cascade

The pathophysiology of osteoarthritis (OA) is closely linked to autophagy abnormalities in articular chondrocytes, the sole mature cell type in healthy cartilage. Nevertheless, the precise molecular mechanism remains uncertain. Previous research has demonstrated that leptin activates mTORC1 , thereby inhibiting chondrocyte autophagy during the progression of OA. In this study, it is demonstrated that the presence of leptin induces a substantial increase in the expression of STAT3, leading to a notable decrease in REDD1 expression and subsequent phosphorylation of p70S6K, a recognized downstream effector of mTORC1. Conversely, inhibition of leptin yields contrasting effects. Additionally, the potential advantages of utilizing a sustained intra-articular release of a leptin inhibitor (LI) via an injectable, thermosensitive poly(D,L-lactide)-poly(ethylene glycol)-poly(D,L-lactide) (PDLLA-PEG-PDLLA: PLEL) hydrogel delivery system for the purpose of investigating its impact on cartilage repair are explored. The study conducted on LI-loaded PLEL (PLEL@LI) demonstrates remarkable efficacy in inhibiting OA and displays encouraging therapeutic advantages in the restoration of subchondral bone and cartilage. These findings establish a solid foundation for the advancement of a pioneering treatment approach utilizing PLEL@LI for OA.

Cationic mesoporous silica nanoparticles alleviate osteoarthritis by targeting multiple inflammatory mediators

Osteoarthritis (OA) is a common and complex inflammatory disorder that is frequently compounded by cartilage degradation, synovial inflammation, and osteophyte formation. Damaged chondrocytes release multiple danger mediators that exacerbate synovial inflammation and accelerate the progression to OA. Conventional treatments targeting only a single mediator of OA have failed to achieve a strong therapeutic effect. Addressing the crucial role of multiple danger mediators in OA progression, we prepared polyethylenimine (PEI)-functionalized diselenide-bridged mesoporous silica nanoparticles (MSN-PEI) with cell-free DNA (cfDNA)-binding and anti-oxidative properties. In models of surgery-induced and collagenase-induced arthritis, we showed that these cationic nanoparticles attenuated cartilage degradation and provided strong chondroprotection against joint damage. Mechanistically, multiple target blockades alleviated oxidative stress and dampened cfDNA-induced inflammation by suppressing the M1 polarization of macrophages. This study suggests a beneficial direction for targeting multiple danger mediators in the treatment of intractable arthritis.

Infliximab microencapsulation: an innovative approach for intra-articular administration of biologics in the management of rheumatoid arthritis-in vitro evaluation

Microencapsulation of the therapeutical monoclonal antibody infliximab (INF) was investigated as an innovative approach to improve its stability and to achieve formulations with convenient features for intra-articular administration. Ultrasonic atomization (UA), a novel alternative to microencapsulate labile drugs, was compared with the conventional emulsion/evaporation method (Em/Ev) using biodegradable polymers, specifically Polyactive® 1000PEOT70PBT30 [poly(ethylene-oxide-terephthalate)/poly(butylene-terephthalate); PEOT-PBT] and its polymeric blends with poly-(D, L-lactide-co-glycolide) (PLGA) RG502 and RG503 (PEOT-PBT:PLGA; 65:35). Six different formulations of spherical core-shell microcapsules were successfully developed and characterized. The UA method achieved a significantly higher encapsulation efficiency (69.7-80.25%) than Em/Ev (17.3-23.0%). Mean particle size, strongly determined by the microencapsulation method and to a lesser extent by polymeric composition, ranged from 26.6 to 49.9 µm for UA and 1.5-2.1 µm for Em/Ev. All formulations demonstrated sustained INF release in vitro for up to 24 days, with release rates modulated by polymeric composition and microencapsulation technique. Both methods preserved INF biological activity, with microencapsulated INF showing higher efficacy than commercial formulations at comparable doses regarding bioactive tumor necrosis factor-alpha (TNF-α) neutralization according to WEHI-13VAR bioassay. Microparticles' biocompatibility and extensive internalization by THP-1-derived macrophages was demonstrated. Furthermore, high in vitro anti-inflammatory activity was achieved after treatment of THP-1 cells with INF-loaded microcapsules, significatively reducing in vitro production of TNF-α and interleucine-6 (Il-6).

Clinical and Biochemical Implications of Hyaluronic Acid in Musculoskeletal Rehabilitation: A Comprehensive Review

Hyaluronic acid (HA) naturally occurs as a biopolymer in the human body, primarily in connective tissues like joints and skin. Functioning as a vital element of synovial fluid, it lubricates joints, facilitating fluid movement and diminishing bone friction to protect articular well-being. Its distinctive attributes encompass notable viscosity and water retention capacities, ensuring flexibility and absorbing shock during motion. Furthermore, HA has gained significant attention for its potential benefits in various medical applications, including rehabilitation. Ongoing research explores its properties and functions, especially its biomedical applications in several clinical trials, with a focus on its role in improving rehabilitation outcomes. But the clinical and biochemical implications of HA in musculoskeletal rehabilitation have yet to be fully explored. This review thoroughly investigates the properties and functions of HA while highlighting its biomedical applications in different clinical trials, with a special emphasis on its role in rehabilitation. The presented findings provide evidence that HA, as a natural substance, enhances the outcomes of musculoskeletal rehabilitation through its exceptional mechanical and biochemical effects.