Treatment Of Temporomandibular Joint Osteoarthritis Research Articles

An "All-in-One" Strategy to Reconstruct Temporomandibular Joint Osteoarthritic Microenvironment Using γ-Fe2O3@TA@ALN Nanoparticles.

Current clinical strategies for the treatment of temporomandibular joint osteoarthritis (TMJOA) primarily target cartilage biology, overlooking the synergetic effect of various cells and inorganic components in shaping the arthritic microenvironment, thereby impeding the effectiveness of existing therapeutic options for TMJOA. Here, γ-Fe2O3@TA@ALN magnetic nanoparticles (γ-Fe2O3@TA@ALN MNPs) composed of γ-Fe2O3, tannic acid (TA), and alendronate sodium (ALN) are engineered to reconstruct the osteoarthritic microenvironment and mitigate TMJOA progression. γ-Fe2O3@TA@ALN MNPs can promote chondrocytes' proliferation, facilitate chondrogenesis and anisotropic organization, enhance lubrication and reduce cartilage wear, and encourage cell movement. Magnetic-responsive γ-Fe2O3@TA@ALN MNPs also exhibit pH sensitivity, which undergoes decomposition within acidic environment to release ALN on demand. Under a 0.2 T static magnetic field, γ-Fe2O3@TA@ALN MNPs accelerate the synthesis of cartilage-specific proteins, and suppress catabolic-related genes expression and reactive oxygen species generation, affording additional protection to TMJ cartilage. In TMJOA mouse models, articular injection of γ-Fe2O3@TA@ALN MNPs effectively alleviates cartilage degeneration and subchondral bone loss in short and long terms, offering promising avenues for the development of therapeutic interventions for TMJOA.

Microgel Encapsulated Mesoporous Silica Nanoparticles for Releasing Wnt16 to Synergistically Treat Temporomandibular Joint Osteoarthritis.

Temporomandibular joint osteoarthritis (TMJOA) is a commonly encountered degenerative joint disease in oral and maxillofacial surgery. Recent studies have shown that the excessive unbalanced activation of Wnt/β-catenin signaling is connected with the pathogenesis of TMJOA and due to the inability to inhibit the over-activated Wnt pathway, while Wnt16-deficient mice has a more severe Knee OA. However, the efficacy of direct intra-TMJ injection of Wnt16 for the relief of TMJOA is still not directly confirmed. Moreover, small-molecule drugs such as Wnt16 usually exhibit short-lived efficacy and poor treatment adherence. Therefore, in order to obtain a stable release of Wnt16 both in the short and long term, this study fabricates a double-layer slow-release Wnt16 carrier based on mesoporous silica nanospheres (MSNs) encased within hyaluronic acid (HA) hydrogels. The biofunctional hydrogel HA/Wnt16@MSN is analyzed both in vitro and in vivo to evaluate the treatment of TMJOA. As a result, it shows superior pro-cartilage matrix restoration and inhibition of osteoclastogenesis ability, and effectively inhibits the over-activation of the Wnt/β-catenin pathway. Taken together, biofunctional hydrogel HA/Wnt16@MSN is a promising candidate for the treatment of TMJOA.

Hyaluronic Acid-Based Microparticles with Lubrication and Anti-Inflammation for Alleviating Temporomandibular Joint Osteoarthritis.

The pathogenesis of temporomandibular joint osteoarthritis (TMJOA) is closely associated with mechanical friction, which leads to the up-regulation of inflammatory mediators and the degradation of articular cartilage. Injectable drug-loaded microparticles have attracted widespread interest in intra-articular treatment of TMJOA by providing lubrication and facilitating localized drug delivery. Herein, a hyaluronic acid-based microparticle is developed with excellent lubrication properties, drug loading capacity, antioxidant activity, and anti-inflammatory effect for the treatment of TMJOA. The microparticles are facilely prepared by the self-assembly of 3-aminophenylboronic acid-modified hyaluronic acid (HP) through hydrophobic interaction in an aqueous solution, which can further encapsulate diol-containing drugs through dynamic boronate ester bonds. The resulting microparticles demonstrate excellent injectability, lubrication properties, radical scavenging efficiency, and antibacterial activity. Additionally, the drug-loaded microparticles exhibit a favorable cytoprotective effect on chondrocyte cells invitro under an oxidative stress microenvironment. Invivo experiments validate that intra-articular injection of drug-loaded microparticles effectively alleviates osteoporosis-like damage, suppresses inflammatory response, and facilitates matrix regeneration in the treatment of TMJOA. The HP microparticles demonstrate excellent injectability and encapsulation capacity for diol-containing drugs, highlighting its potential as a versatile drug delivery vehicle in the intra-articular treatment of TMJOA.

Intra-articular and intraosseous approach to temporomandibular joint-targeted injections: a cadaveric investigation.

Temporomandibular joint osteoarthritis (TMJ-OA) management is complex, and several conservative and minimally invasive protocols have been proposed. Intra-articular injections of medications directed at OA have been performed, but in some cases, these medications do not directly contact the tissue lesion sites. Here, we propose a new real-time ultrasound-guided technique to inject medications directly into the subchondral bone. Ultrasound image screening was carried out with the point-of-care Clarius L15 device. Then, with the patient's mouth closed, a stainless-steel cannula with a concentric trocar was US-guided using an in-plane approach until the perforating tip of the internal trocar touched the lateral pole of the mandibular condyle. Then, the trocar was inserted through the medullary bone, where a posterior injection was made. The technique's precision was confirmed by capturing an iodine contrast solution that imaged the medullary condyle of fresh anatomical specimens processed by computed tomography. The proposed technique was effective in accessing the mandibular condyle subchondral bone in the inferior TMJ space for the simultaneously intra-articular (IA) and intra-osseous (IO) in-plane US-guided injections. Thus, its implementation may represent an important advance in early TMJ-OA treatment. This may be a promising approach, especially in OA cases in which the cortical bone is still preserved.

Ultrasmall Cu2I2 nanoclusters trigger metabolic-epigenetic reprogramming and endogenous antioxidant systems for alleviating osteoarthritis

Temporomandibular joint (TMJ) osteoarthritis (OA) affects millions of people worldwide, characterized by imbalance metabolism, excess reactive oxygen species (ROS), aberrant epigenetic alterations and so on. Currently, analgesics and anti-inflammatory drugs are mainly used for treatment, but they only alleviate symptoms. Here, we designed a ultrasmall copper-based nanoclusters agent (copper iodide coordination, Cu2I2), which exhibited remarkable ROS-scavenging activities. And the antioxidant properties of Cu2I2 nanoclusters (Cu2I2 NCs) were achieved by activating the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway. Excitingly, Cu2I2 NCs exhibited excellent metabolic-epigenetic regulation property via reprogramming energy metabolism to inhibit S-adenosylmethionine (SAM)-production metabolic pathway and contributing to the global hypomethylation mediated by Dnmt3a. Then, the expression of anti-osteoclastogenic genes was upregulated. Consistent with in vitro observations, Cu2I2 NCs efficiently alleviated subchondral bone destruction of TMJ OA in rats. Altogether, this study not only provides a novel nanoclusters agent for TMJ OA treatment that can activate endogenous antioxidant systems, but also reveals the significance and feasibility of therapeutic strategies to break the bridge between metabolic and epigenetic regulation.

Research progress in mesenchymal stem cell-related therapies in the treatment of temporomandibular joint osteoarthritis

Temporomandibular joint osteoarthritis (TMJOA) is a kind of organic disease with synovial inflammation, cartilage degeneration and subchondral bone remodeling as the main pathological changes. The current treatment is mainly to relieve symptoms, but cannot completely stop the progression of the disease. Mesenchymal stem cells (MSC) have multi-lineage differentiation potential and have good prospects in the repair therapy of TMJOA. Intra-articular injection of MSC from bone marrow, adipose, umbilical cord, dental pulp, etc. has been shown to be effective in numerous animal studies. The above exogenous MSCs can also be used as seed cells to participate in tissue engineering and repair more severe defects. Recent studies have shown that exosomes are important mediators of MSC action and have some potential in the treatment of TMJOA. As the mechanisms of TMJOA are further investigated, there is some prospect that endogenous repair capacity can be activated by local injection of relevant drugs targeting the resident stem cells in the joint.

Targeting l-arginine-activated signals might provide new clues for the treatment of temporomandibular joint osteoarthritis

TMJOA as a progressive degenerative disease of the TMJ, is featured as enhanced inflammation, chondrocyte apoptosis, ECM degradation and subchondral bone remodeling, resulting in local pain and functional impairment that further reduces patients’ quality of life. However, its etiology is ambiguous, leading to no consensus regarding the most effective treatment for patients with TMJOA. L-arg is a conditionally essential amino acid that participates in regulating inflammation, ECM orchestration, cellular growth and proliferation, but the role and mechanism of L-arg in TMJOA remain unclear. L-arg exerts different functions in contexts- and tissue microenvironments-dependent manner. For example, excess L-arg induces acute pancreatitis via the JAK2/STAT3 pathway, the iNOS/NO pathway and the HMGB1/TLR4/NF-κB pathway; Arg-Ⅱ in advanced atherosclerosis impairs endothelial autophagy through regulation of mTOR signaling. Interestingly, these signaling pathways are tightly involved in the reported pathological process of TMJOA. We here unexpectedly found that L-arg is significantly elevated in the plasma of TMD patients using mass spectrometry. Thus, through literature review and analysis, we proposed that the upregulation of L-arg activated iNOS/NO pathway, Arg-Ⅱ pathway, mTOR pathway and NF-κB pathway to prompt TMJOA development. Related pathway inhibitors could be an alternative treatment strategy for TMJOA.

Bioinspired nanozyme-reinforced hydrogels with free radical scavenging capability for treating temporomandibular joint osteoarthritis

Temporomandibular joint osteoarthritis (TMJ-OA) is usually caused by increased friction at the joint interface, excessive release of inflammatory factors and catabolic enzymes, and free radical accumulation, which can lead to accelerated degradation and damage of cartilage. In this study, we develop a biological metabolism-inspired injectable hydrogel crosslinking by hydrazide modified hyaluronic acid (HA-HYD), aldehyde modified hyaluronic acid (HA-ALD), and ε-polylysine coated catalase-mimic nanozyme (mesoporous manganese cobalt oxide). Herein, this nanozyme-reinforced hydrogel with outstanding and durable reactive oxygen species (ROS) depletion capability and biocompatibility can alleviate the oxidative stress microenvironment, improve cell viability and proliferation, as well as up-regulate chondrogenic related gene expression and cartilage matrix formation of chondrocytes in vitro. Intra-articular administration of this engineered hydrogel can effectively scavenge endogenous over-expressed ROS to ameliorate the harsh microenvironment in the cavity of TMJ-OA. The nanozyme-reinforced hydrogel reduced proinflammatory cytokines (TNF-α, IL-1β, and IL-6) and enhance anti-inflammatory cytokines (IL-10) expression, induced polarization of synovial macrophages towards M2 phenotype, alleviated structural damage to the cartilage and subchondral bone of the condyle, thus reducing cartilage matrix destruction and protect cartilage in osteoarthritis. In summary, the bioinspired nanozyme-reinforced hydrogels might be used as a promising ROS scavenger for treatment of TMJ-OA.

Comparison of the effectiveness of temporomandibular joint osteoarthritis treatment with corticosteroids, hyaluronic acid, and platelet-rich plasma mono-therapy

The prevalence of temporomandibular joint (TMJ) osteoarthritis is 18–85 % of all TMJ dysfunctional conditions. Most patients are elderly, especially women. Today, intra-articular injections are often used for treatment, so it is necessary to study the effectiveness of drug administration on the course of the disease. The number of studies on the effectiveness of certain drugs most commonly used to treat TMJ osteoarthritis is limited, that does not allow correct treatment planning in each individual case. Aim: to evaluate the effectiveness of TMJ osteoarthritis treatment with monotherapy with hyaluronic acid, corticosteroids, and platelet-rich plasma. Materials and methods. We included 90 patients who received intra-articular injections. Patients were randomly divided into 3 groups: group I, which received platelet-rich plasma (PRP, n = 30), group II, which received hyaluronic acid (HA, n = 30), group III, which received corticosteroids (CS, n = 30). To objectively evaluate the effectiveness of TMJ osteoarthritis treatment with monotherapy of hyaluronic acid, corticosteroids and platelet-rich plasma, the following indicators were used: filling in the visual analogue pain scale, maximum mouth opening (mm) and cortical plate density of the articular head of the mandible according to the Hounsfield scale using CBCT. Results. PRP therapy demonstrated the highest efficacy in the form of monotherapy for all study parameters (p < 0.05). The fastest pain reduction was achieved with the use of corticosteroids (p < 0.05). In general, during the treatment period, the reduction of pain according to the visual analogue scale in group I was 85.71 %. In patients of group II (HA) and group III (CS) – by 71.42 %. Maximum mouth opening after treatment in group I increased by 24.32 %, in group II – by 15.79 %, in group III – by 18.92 %. The density of the articular head according to the Hounsfield scale after treatment in group I increased by 12.56 %, in group II – by 6.97 %, in group III – by 4.87 %. Conclusions. All of the studied drugs demonstrated a positive effect on the treatment of TMJ osteoarthritis, but monotherapy with intra-articular PRP injections demonstrated the highest effectiveness according to the studied parameters (p < 0.05).

A randomized controlled clinical trial of concentrated growth factor combined with sodium hyaluronate in the treatment of temporomandibular joint osteoarthritis

ObjectiveTo investigate the effect of concentrated growth factor (CGF) combined with sodium hyaluronate (SH) on temporomandibular joint osteoarthritis (TMJOA).MethodsSixty patients with TMJOA who were diagnosed by cone-beam computed tomography (CBCT) between March 2020 and March 2023 at the Stomatological Hospital of Xi’an Jiaotong University were randomly divided into a control group (n = 30) and an experimental group (n = 30). The patients in the experimental group were treated with CGF + SH, and those in the control group were treated with SH only. The visual analogue scale (VAS) score indicating pain in the temporomandibular joint (TMJ) area; the Helkimo Clinical Dysfunction Index (Di); and changes in condylar CBCT at the first visit and 2 weeks, 3 months and 6 months after treatment were recorded. The CBCT data of the patients in the experimental and control groups were collected, and the three-dimensional CBCT image sequences were imported into Mimics Medical 19.0 software in DICOM format for condylar reconstruction.ResultsThe VAS scores at 2 weeks, 3 months and 6 months after treatment were significantly lower in the experimental group than in the control group (P < 0.05), and the pain in the experimental group was significantly relieved. The Di was significantly lower in the experimental group than in the control group (P < 0.05), and the clinical function of the TMJ improved. After treatment, the CBCT score was significantly lower in the experimental group than in the control group (P < 0.05), and the condylar bone cortex was obviously repaired. Observation of the condylar bone cortex by three-dimensional reconstruction showed the same results as those obtained by CBCT.ConclusionCGF combined with SH is effective in the treatment of TMJOA and can improve muscle pain, TMJ pain, Impaired TMJ function, Impaired range of movement, Pain on movement of the mandible and promote bone repair.The registration number (TRN)ChiCTR2400082712.The date of registrationApril 5, 2024.

Comparison of the effectiveness of treatment of temporomandibular joint osteoarthritis between monotherapy with splints and splints in combination with platelet-rich plasma

Today there is a tendency to increase the prevalence of Temporomandibular Joint Osteoarthritis (TMJ) osteoarthritis, which is a chronic degenerative joint disease. According to international statistics, 28–38% of people in the age group of 9–90 years have signs of TMJ osteoarthritis. The aim of our study was to compare the effectiveness of treatment of TMJ osteoarthritis between monotherapy with splints and splinys in combination with Platelet-Rich Plasma (PRP). The experiment involved 8 patients, divided into 2 level groups. The control group (4 patients) received treatment with splints, the experimental group – splits with PRP therapy. The effectiveness of treatment was assessed by measuring the radiological density of the cortical plate of the mandibular head according to the Hounsfield scale, the degree of mouth opening, filling out a Visual Analogue Scale (VAS) and a questionnaire at the end of treatment. According to the results of the study, the experimental group received more effective treatment, which is confirmed by the VAS, the degree of mouth opening and changes in the radiological density of the cortical plate of the articular head. At the end of the treatment, patients completed a questionnaire about the improvement of their condition, where 0 points meant no effect from the treatment, and 10 points meant a subjective feeling of complete recovery. The arithmetic mean of the improvement scores in the control group was 6.75, and in the experimental group – 9.00 points. Based on the results of the experiment, we can state that the effectiveness of treatment of TMJ osteoarthritis with splints in combination with PRP therapy is greater than that of monotherapy with occlusal splints. Therefore, if the patient has no contraindications to treatment with platelet-rich plasma, we can recommend the use of splits in combination with PRP therapy for the treatment of temporomandibular joint osteoarthritis. Keywords: degenerative diseases, radiological density, articular head.

Dual-targeted lipid nanoparticles system for synergistic anti-inflammation and cartilage repair in the treatment of temporomandibular joint osteoarthritis

Synovial inflammation and cartilage degeneration are two crucial pathologic features in temporomandibular joint osteoarthritis (TMJ OA). Cartilage repair can be very thorny in inflammatory environment, which is highly associated with the activated macrophages. Thus, simultaneous inflammation suppression and cartilage repair are strongly required. However, the clinically used intra-articular injection agents face the problems of insufficient inflammation suppression, deficient cartilage repair and non-targeted therapy. Hence, we developed the novel dual-targeted lipid nanoparticles (LNPs) loaded with miR-330-3p, an important inflammation inhibitor, and kartogenin (KGN), a pro-chondrogenic small molecular, for synergistic anti-inflammation and cartilage repair of TMJ OA. The folic acid (FA) and collagen II-targeting peptide (WYRGRL) were modified on the surface of LNPs for precise delivery to macrophages or chondrocytes, respectively. The dual-targeted miR-330-3p@FA-LNP and KGN@WYRGRL-LNP (KGN@W-LNP) both manifested high bioavailability and selectively active cellular uptake. Furthermore, it functioned synergistically to alleviate synovium inflammation and cartilage degeneration via modulating the M1 to M2 repolarization of macrophages and maintaining the homeostasis of chondrocytes, with a low intra-articular injection dose of miR-330-3p@FA-LNP (0.0125 nmol) and KGN@W-LNP (0.025 nmol) in vivo. RNA-seq and further validation demonstrated that miR-330-3p functioned by inhibiting SPARC and KGN functioned by upregulating EPHB4. In summary, this dual-targeted LNPs system provides a promising therapeutic strategy for TMJ OA treatment.

Efficacy of IFN-γ-Primed Umbilical Cord-Derived Mesenchymal Stem Cells on Temporomandibular Joint Osteoarthritis.

Temporomandibular joint osteoarthritis (TMJOA) is a degenerative disease affecting the cartilage and subchondral bone, leading to temporomandibular joint pain and dysfunction. The complex nature of TMJOA warrants effective alternative treatments, and mesenchymal stem cells (MSCs) have shown promise in regenerative therapies. The aim of this study is twofold: firstly, to ascertain the optimal interferon-gamma (IFN-γ)-primed MSC cell line for TMJOA treatment, and secondly, to comprehensively evaluate the therapeutic efficacy of IFN-γ-primed mesenchymal stem cells derived from the human umbilical cord matrix in a rat model of TMJOA. We analyzed changes in the expression of several key genes associated with OA protection in MSC-secreted compounds. Following this, we performed co-culture experiments using a transwell system to predict gene expression changes in primed MSCs in the TMJOA environment. Subsequently, we investigated the efficacy of the selected IFN-γ-primed human umbilical cord matrix-derived MSCs (hUCM-MSCs) for TMJOA treatment in a rat model. IFN-γ-primed MSCs exhibited enhanced expression of IDO, TSG-6, and FGF-2. Moreover, co-culturing with rat OA chondrocytes induced a decrease in pro-inflammatory and extracellular matrix degradation factors. In the rat TMJOA model, IFN-γ-primed MSCs with elevated IDO1, TSG-6, and FGF2 expression exhibited robust anti-inflammatory and therapeutic capacities, promoting the improvement of the inflammatory environment and cartilage regeneration. These findings underscore the importance of prioritizing the mitigation of the inflammatory milieu in TMJOA treatment and highlight IFN-γ-primed MSCs secreting these three factors as a promising, comprehensive therapeutic strategy.

Circular RNA CircACAP2 regulates temporomandibular joint osteoarthritis via miR-21-5p/PLAG1 axis.

The pathogenesis of temporomandibular joint osteoarthritis (TMJOA) remains not fully understood. Our previous studies demonstrated that miR-21-5p may participate in the TMJOA development and the interaction between circRNA-ACAP2 (CircACAP2) and miR-21-5p. Our present study aimed to explore the biological functions and regulatory mechanisms of CircACAP2 in TMJOA. The differential expression pattern of CircACAP2 in OA and normal tissues or cells was detected. CircACAP2 biological functions experiments were performed in chondrocytes by overexpression and interference techniques. The interaction of CircACAP2 with miR-21-5p and downstream target mRNA, polymorphic adenoma gene 1 (PLAG1), was predicted by bioinformatic databases and then demonstrated by dual-luciferase reporter assay. The biological role of CircACAP2 in TMJOA was investigated and validated in a mouse model. The expression level of CircACAP2 was markedly reduced in OA cartilage and directly related to chondrocyte proliferation and apoptosis as well as ECM metabolism in the cartilage. CircACAP2 functioned in chondrocytes via targeting miR-21-5p and PLAG1. Overexpressing of CircACAP2 alleviated TMJOA in mouse models. The present study unveiled that CircACAP2/miR-21-5p/PLAG1 axis may play an important regulatory role in TMJOA progression, which may highlight a potentially effective intervention and therapeutic strategy for the treatment of TMJOA.

Low-frequency pulsed electromagnetic fields alleviate the condylar cartilage degeneration and synovitis at the early stage of temporomandibular joint osteoarthritis.

Temporomandibular joint osteoarthritis (TMJOA) is characterized by articular cartilage degeneration and progressive synovitis. How to effectively inhibit TMJOA in the early stage has been a hot topic in the biomedical field. As a non-invasive physiotherapy, pulsed electromagnetic field (PEMF) treatment has shown great potential in the treatment of osteoarthritis (OA) in extremity joints. This study aims to investigate the biological effect of PEMF intervention on TMJ cartilage degeneration and synovium inflammation at the early stage of TMJOA. PEMF (2.0 mT, 15 Hz, 2 h/day) treatment was given to rats in which TMJOA was induced by applying the unilateral anterior crossbite (UAC). Histological and immunohistochemical staining, TUNEL assay, real-time PCR and western blotting assay were performed to detect the changes of the morphology and the expression of pro-inflammatory and degradative factors in condylar cartilage and synovium. Obvious condylar cartilage degeneration, characterized by decreased cartilage thickness, degraded cartilage extracellular matrix, increased expression of pro-inflammatory and degradative factors (TNF-α, IL-1β, MMP-13, ADAMTS-5, IL-6, MMP-3, MMP-9 and COL-X) and increased chondrocytes death, was observed in UAC group, accompanied by synovium hyperplasia and up-regulation of pro-inflammatory and degradative factors in synovium. PEMF intervention reversed the decreased cartilage thickness at 3 weeks and degraded cartilage extracellular matrix at 6 weeks. Moreover, the up-regulation of pro-inflammatory, degradative and hypertrophyic factors and chondrocytes death in condylar cartilage induced by UAC were inhibited to some extent. In addition, the synovium hyperplasia and the up-regulation of pro-inflammatory and degradative factors in synovium were inhibited at 3 weeks and 6 weeks. Appropriate PEMF stimulation can reverse the loss of cartilage extracellular matrix, the chondrocytes death, the increased expression of pro-inflammatory and degradative factors in cartilage, the decreased cartilage thickness and synovium inflammation induced by UAC at the early stage of TMJOA to some extent. PEMF stimulation may be a promising method in clinical TMJOA treatment.

Platelet-rich plasma therapy for temporomandibular joint osteoarthritis: A randomized controlled trial

The study aimed to compare the efficacy of platelet-rich plasma (PRP) injections for the treatment of temporomandibular joint osteoarthritis (TMJ-OA) with hyaluronic acid (HA) therapy.This randomized controlled trial included 70 patients with TMJ-OA, randomly divided into either a PRP or HA group. The pain intensity, maximum mouth opening (MMO), TMJ sound score, and proportion of crepitus were recorded and compared at baseline and at 1, 3, and 6 months.Both groups showed statistically significant improvements in pain intensity, MMO, TMJ sound, and scale scores during the 6-month follow-up period. The improvements in pain intensity during mouth opening at 1 month, MMO at 1, 3, and 6 months, TMJ sound score at 1 and 3 months, and GAD-7 score at 6 months in the PRP group were greater than in the HA group (p < 0.05). Compared with the HA group, imaging improvement in the PRP group was also higher (p < 0.05).Within the limitations of the study it seems that the application of PRP therapy in TMJ-OA is should be considered whenever possible.

Bergapten exerts a chondroprotective effect in temporomandibular joint osteoarthritis by combining intestinal flora alteration and reactive oxygen species reduction

Bergapten, a furanocoumarin naturally occurring in bergamot essential oil, has been demonstrated to have the potential to alleviate osteoarthritis-related symptoms via its anti-inflammatory activity. Although its systemic bioavailability is limited, its precise mechanisms of action and effects on temporomandibular joint osteoarthritis (TMJOA) and its relationship with the intestinal flora remain unclear. Here, we explored the anti-TMJOA effect of BGT combined with the interleukin-1β-induced inflammatory response of chondrocytes in a monosodium iodoacetate (MIA)-induced TMJOA rat model. It was confirmed that BGT effectively reduced proinflammatory mediators and increased type II collagen, bone volume, and trabecular number of condyles in TMJOA rats. Importantly, the oral administration of BGT altered the intestinal flora of rats by increasing the relative abundances of nine prebiotic species and decreasing the relative abundance of one potential species. In addition, BGT considerably reduced reactive oxygen species (ROS) levels by suppressing glutathione, oxidized glutathione, and superoxide dismutase in the serum and malondialdehyde in urine. These results suggest that BGT exerts a chondroprotective effect, most likely by improving the intestinal flora and reducing ROS production associated with TMJOA in rats. This finding indicates a novel beneficial effect of BGT on the prevention and treatment of TMJOA.

MiR-335-5p inhibits endochondral ossification by directly targeting SP1 in TMJ OA.

During the development of temporomandibular joint osteoarthritis, endochondral ossification is compromised which leads to condylar degeneration; miR-335-5p in endochondral ossification in osteoarthritic condylar cartilage tissue remains unclear. Up-regulated microRNA and its target gene were searched for endochondral ossification in osteoarthritis articular cartilage. The effect of increased or decreased miR-335-5p on endochondral ossification was evaluated by transfecting miR-335-5p mimics or miR-335-5p inhibitor in vitro in chondrocytes C28/I2. Finally, we injected the temporomandibular joint of rats intra-articularly with agomiR-335 in a unilateral anterior crossbite rat model to determine the in vivo regulation of miR-335. After the onset of temporomandibular joint osteoarthritis, miR-335-5p levels were gradually up-regulated, whereas endochondral ossification-related genes were down-regulated in condylar cartilage specimens. Our results showed that miR-335 inhibited endochondral ossification after administration of a miR-335 antagonist into the temporomandibular joint articular cavity of a unilateral anterior crossbite rat model. AgomiR-335, a miR-335 agonist, inhibited matrix mineralization in fibrocartilage stem cells in vitro and then miR-335-5p negatively regulated chondrocyte activity by directly targeting SP1 via promoting transforming growth factor-β/Smad signalling. miR-335-5p can significantly inhibit endochondral ossification; therefore, its inhibition may be beneficial for the treatment of temporomandibular joint osteoarthritis.

LincRNA-EPS Alleviates Inflammation in TMJ Osteoarthritis by Binding to SRSF3

Temporomandibular joint osteoarthritis (TMJOA) is a common inflammatory disease that can cause pain, cartilage degradation, and subchondral bone loss. However, the key regulatory factors and new targets for the treatment of TMJOA have yet to be determined. Long noncoding RNAs (lncRNAs) have shown remarkable potential in regulating tissue homeostasis and disease development. The long intergenic RNA–erythroid prosurvival (lincRNA-EPS) is reported to be an effective inhibitor of inflammation, but its role in TMJOA is unexplored. Here, we found that lincRNA-EPS is downregulated and negatively correlated with inflammatory factors in the condyles of TMJOA mice. LincRNA-EPS knockout aggravated inflammation and tissue destruction after TMJOA modeling. The in vitro studies confirmed that loss of lincRNA-EPS facilitated inflammatory factor expression in condylar chondrocytes, while recovered expression of lincRNA-EPS showed anti-inflammatory effects. Mechanistically, RNA sequencing revealed that the inflammatory response pathway nuclear factor–kappa B (NF-κB) was mostly affected by lincRNA-EPS deficiency. Moreover, lincRNA-EPS was proved to effectively bind to serine/arginine-rich splicing factor 3 (SRSF3) and inhibit its function in pyruvate kinase isoform M2 (PKM2) formation, thus restraining the PKM2/NF-κB pathway and the expression of inflammatory factors. In addition, local injection of the lincRNA-EPS overexpression lentivirus significantly alleviated inflammation, cartilage degradation, and subchondral bone loss in TMJOA mice. Overall, lincRNA-EPS regulated the inflammatory process of condylar chondrocytes by binding to SRSF3 and showed translational application potential in the treatment of TMJOA.

Near-Infrared Light-Activated Mesoporous Polydopamine for Temporomandibular Joint Osteoarthritis Combined Photothermal-Chemo Therapy.

The treatments generally employed for temporomandibular joint osteoarthritis (TMJOA) involve physical therapy and chemotherapy, etc., whose therapeutic efficacies are impaired by the side effects and suboptimal stimulus responsiveness. Although the intra-articular drug delivery system (DDS) has shown effectiveness in addressing osteoarthritis, there is currently little reported research regarding the use of stimuli-responsive DDS in managing TMJOA. Herein, we prepared a novel near-infrared (NIR) light-sensitive DDS (DS-TD/MPDA) by using mesoporous polydopamine nanospheres (MPDA) as NIR responders and drug carriers; diclofenac sodium (DS) as the anti-inflammatory medication; and 1-tetradecanol (TD) with a phase-inversion temperature of 39 °C as the drug administrator. Upon exposure to 808 nm NIR laser, DS-TD/MPDA could raise the temperature up to the melting point of TD through photothermal conversion, and intelligently trigger DS release. The resultant nanospheres exhibited an excellent photothermal effect and effectively controlled the release of DS through laser irradiation to accommodate the multifunctional therapeutic effect. More importantly, the biological evaluation of DS-TD/MPDA for TMJOA treatment was also performed for the first time. The experiments' results demonstrated that DS-TD/MPDA displayed a good biocompatibility in vitro and in vivo during metabolism. After injection into the TMJ of rats afflicted with TMJOA induced by unilateral anterior crossbite for 14 days, DS-TD/MPDA could alleviate the deterioration of TMJ cartilage, thus ameliorating osteoarthritis. Therefore, DS-TD/MPDA could be a promising candidate for photothermal-chemotherapy for TMJOA.