The synthesis of hyaluronic acid by human synovial fibroblasts is influenced by the nature of the hyaluronate in the extracellular environment

Lubricant Strategies in Osteoarthritis Treatment: Transitioning from Natural Lubricants to Drug Delivery Particles with Lubricant Properties

Osteoarthritis (OA) is a debilitating joint disease characterized by cartilage degradation, leading to pain and functional impairment. A key contributor to OA progression is the decline in cartilage lubrication. In physiological conditions, synovial fluid (SF) macromolecules like hyaluronic acid (HA), phospholipids, and lubricin play a crucial role in the boundary lubrication of articular cartilage. In early OA, cartilage damage triggers inflammation, altering SF composition and compromising the lubrication layer. This increases friction between mating interfaces, worsening cartilage degradation and local inflammation. Therefore, early-stage restoration of lubrication (by injecting in the joint different classes of compounds and formulations) could alleviate, and potentially reverse, OA progression. In the light of this, a broad variety of lubricants have been investigated for their ability to reduce friction in OA joints and promote cartilage repair in clinical and preclinical studies. This review examines recent advancements in lubricant-based therapy for OA, focusing on natural, bioinspired, and alternative products. Starting from the currently applied therapy, mainly based on natural lubricants as HA, we will present their modified versions, either in hydrogel form or with specific biomimetic moieties with the aim of reducing their clearance from the joint and of enhancing their lubricating properties. Finally, the most advanced and recent formulation, represented by alternative strategies, will be proposed. Particular emphasis will be placed on those ones involving new types of hydrogels, microparticles, nanoparticles, and liposomes, which are currently under investigation in preclinical studies. The potential application of particles and liposomes could foster the transition from natural lubricants to Drug Delivery Systems (DDSs) with lubricant features; transition which could provide more complete OA treatments, by simultaneously providing lubrication replacement and sustained release of different payloads and active agents directly at the joint level. Within each category, we will examine relevant preclinical studies, highlighting challenges and future prospects.

A single intraarticular injection of a tranexamic acid-modified hyaluronic acid (HA/TXA) alleviates pain and reduces OA development in a murine model of monosodium iodoacetate-induced osteoarthritis

Rationale

Tranexamic acid (TXA) is a strong and specific plasminogen activator inhibitor with inhibitory effects on the matrix metalloproteases involved in the pathophysiology of osteoarthritis (OA) through targeting of the fibrinolysis pathway. In this study, we evaluated the analgesic and chondroprotective effects of a HA-tranexamic acid (HA/TXA) conjugate, compared to HA alone and placebo, in an animal model of knee OA.

Methods

Knee OA was induced in 15 C57 b l/6J mice by IA injection of 0.75 mg of Monosodium IodoAcetate (MIA). At day 28, the mice received 1 IA injection of 10 µL of saline (control-group), or of HA or of HA/TXA. Tactile sensitivity was assessed using von Frey filaments. Stimulations started at 1 g and increased until a response was obtained (up to 4 g). A response to the stimulus was counted if the animal withdrew its paw. If the animal responded to the 1 g stimulation, stimulation was reduced until the lack of response was observed (up to 0.2 g). At day 56, mice were euthanized for knee histological assessment. Cartilage degradation was assessed using the OARSI score. Statistical analysis was performed on GraphPad Prism 8.0.2 software. Kruskal-Wallis or Mann-Whitney tests were performed as appropriate.

Results

Just before treatment administration, no intergroup difference in paw withdrawal threshold was observed. Throughout the experiment animals given saline and HA had a lower paw withdrawal threshold than those treated with HA/TXA (p < 0.01). In the control group OARSI score was 5.5 ± 0.6. In HA and HA + TXA treated mice the OARSI score was 3.2 ± 0.8 and 3.1 ± 0.5 (p < 0.01) showing that both treatments were able to reduce OA progression.

Conclusion

In this animal model of MIA induced KOA, a single IA injection of a HA/TXA conjugate resulted in a greater efficacy on pain than both saline and HA. HA and HA/TXA exhibited chondroprotective effects compared to placebo.

Viscosupplementation Is Effective for the Treatment of Osteoarthritis in the Hip: A Systematic Review

PURPOSE

To assess the efficacy of intra-articular viscosupplementation as a therapeutic intervention for hip osteoarthritis (OA), as well as to assess the duration of efficacy, effect of dose, composition and number of injections of the viscosupplement, and the incidence of adverse effects.

METHODS

We performed a systematic review using the literature search from the following databases: Embase, Medline, PubMed, Web of Science, and Scopus. Quality assessment of the included studies was performed using the Modified Newcastle-Ottawa Quality Assessment Scale. Random-effects meta-analysis and mixed-effects subgroup analysis were carried out, but due to the high heterogeneity, low level of evidence, and high risk of bias of the included studies after analyzing the data, weighted means and pooled estimates have not been provided. Instead, we have provided a subjective synthesis of the results.

RESULTS

Forty studies were included in the analysis from an initial search of 3,265 studies, with data from a total of 3,350 patients. The level of available evidence was low with an overall high risk of bias. Nearly all studies showed a reduction in mean pain at 1 month, 3 months, and 6 months of follow-up, as well as at the end point, and an improvement in mean patient-reported function was also seen at these time points. However, heterogeneity was extremely high at all time points and remained despite attempts at removing outliers. Subgroup analyses looking at the effects of dose, volume, composition of viscosupplement, and number of injections were carried out, but substantial heterogeneity still remained. There were no lasting adverse effects.

CONCLUSIONS

Weak evidence suggests that viscosupplementation improves patient-reported pain and function at end point compared to baseline, regardless of dose, volume, composition, and number of injections. However, due to the high heterogeneity, low level of evidence, and high risk of bias in the current available literature, the strength of our conclusions is limited.

LEVEL OF EVIDENCE

Level IV, systematic review of level I to IV studies.

Impact of hyaluronic acid injection on the knee joint friction

PURPOSE

The purpose of this in vitro study was to investigate whether or not hyaluronic acid supplementation improves knee joint friction during osteoarthritis progression under gait-like loading conditions.

METHODS

Twelve human cadaveric knee joints were equally divided into mild and moderate osteoarthritic groups. After initial conservative preparation, a passive pendulum setup was used to test the whole joints under gait-like conditions before and after hyaluronic acid supplementation. The friction-related damping properties given by the coefficient of friction µ and the damping coefficient c (in kg m2/s) were calculated from the decaying flexion-extension motion of the knee. Subsequently, tibial and femoral cartilage and meniscus samples were extracted from the joints and tested in an established dynamic pin-on-plate tribometer using synthetic synovial fluid followed by synthetic synovial fluid supplemented with hyaluronic acid as lubricant. Friction was quantified by calculating the coefficient of friction.

RESULTS

In the pendulum tests, the moderate OA group indicated significantly lower c0 values (p < 0.05) under stance phase conditions and significantly lower µ0 (p = 0.01) values under swing phase conditions. No degeneration-related statistical differences were found for µend or cend. Friction was not significantly different (p > 0.05) with regard to mild and moderate osteoarthritis in the pin-on-plate tests. Additionally, hyaluronic acid did not affect friction in both, the pendulum (p > 0.05) and pin-on-plate friction tests (p > 0.05).

CONCLUSION

The results of this in vitro study suggested that the friction of cadaveric knee joint tissues does not increase with progressing degeneration. Moreover, hyaluronic acid viscosupplementation does not lead to an initial decrease in knee joint friction.

Intra-articular Hyaluronic Acid Treatments for Knee Osteoarthritis: A Systematic Review of Product Properties

INTRODUCTION

There are many intra-articular hyaluronic acid (IA-HA) products on the market that have known intrinsic differences in molecular size, source, and structure. The current review summarizes existing evidence describing and assessing these differences, while also identifying whether these differences have an impact on clinical outcomes.

METHODS

This systematic review summarized all literature that specifically addresses IA-HA product differences. Included studies summarized basic science and mechanism of action comparisons of IA-HA product differences, or systematic reviews that assess differences in clinical outcomes between IA-HA product differences.

RESULTS

A total of 20 investigations assessed basic science differences between IA-HA products, while 20 investigations provided assessments of the clinical outcome differences between IA-HA product characteristics. The published basic science literature provided a differentiation between low molecular weight (LMW) and high molecular weight (HMW) HA with regard to changes within the synovial fluid, driven by the interactions that these molecules have with receptors in the joint space. These differences in receptor interaction manifest within clinical outcomes, as meta-analyses comparing pain relief after IA-HA suggest that pain reduction is superior in patients who receive HMW HA as opposed to LMW HA.

CONCLUSION

This review highlights differences between IA-HA characteristics, and how important the molecular weight, derivation of the product, and structure are to variances in reported clinical outcomes to treat osteoarthritis (OA) of the knee. HMW IA-HAs have shown greater efficacy compared to the alternative of LMW products, while avian-derived and cross-linked products have potentially demonstrated an increase in inflammatory events over non-avian-derived, non-cross-linked HAs.

Analyzing the Quality and Readability of Online Hyaluronic Acid Knee Injection Resources

INTRODUCTION

We analyzed the quality of information about Hyaluronic acid (HA) knee injections for osteoarthritis using DISCERN, a tool that grades the quality of websites. We also analyzed readability with Flesch-Kincaid grade reading levels (FKGRL).

METHODS

Lists of the top ten included sites from Google searches about HA injections were evaluated using DISCERN to determine their quality. Additional variables collected were site category, Health on Net (HON) certification, search result rank, and FKGRL. DISCERN scores were compared and grouped by these variables.

RESULTS

Most sites were measured as fair in quality. Greater DISCERN scores were produced from searches using general terminology, sites with HON labels, and academic journal publications.

CONCLUSION

This study indicates information quality for HA injections online is fair. The data also indicates that patients can best educate themselves using HON labels, general search terms, and information from academic journals when possible.

The value of injectable viscoelastic supplements for joints

Intra-articular viscoelastic supplements are commonly administered by musculoskeletal radiologists for the treatment of symptomatic osteoarthritis (OA). This article provides an overview of the putative mechanism of action of the agents, a brief review of the evidence base underlying the practice, a commentary on some of the major society guidelines regarding the treatment, and a description of the adverse events that are associated with intra-articular hyaluronic acid administration.

Intra-Articular Hyaluronic Acid in Osteoarthritis and Tendinopathies: Molecular and Clinical Approaches

Musculoskeletal diseases continue to rise on a global scale, causing significant socioeconomic impact and decreased quality of life. The most common disorders affecting musculoskeletal structures are osteoarthritis and tendinopathies, complicated orthopedic conditions responsible for major pain and debilitation. Intra-articular hyaluronic acid (HA) has been a safe, effective, and minimally invasive therapeutic tool for treating these diseases. Several studies from bedside to clinical practice reveal the multiple benefits of HA such as lubrication, anti-inflammation, and stimulation of cellular activity associated with proliferation, differentiation, migration, and secretion of additional molecules. Collectively, these effects have demonstrated positive outcomes that assist in the regeneration of chondral and tendinous tissues which are otherwise destroyed by the predominant catabolic and inflammatory conditions seen in tissue injury. The literature describes the physicochemical, mechanical, and biological properties of HA, their commercial product types, and clinical applications individually, while their interfaces are seldom reported. Our review addresses the frontiers of basic sciences, products, and clinical approaches. It provides physicians with a better understanding of the boundaries between the processes that lead to diseases, the molecular mechanisms that contribute to tissue repair, and the benefits of the HA types for a conscientious choice. In addition, it points out the current needs for the treatments.

Different molecular weights of hyaluronan research in knee osteoarthritis: A state-of-the-art review

Osteoarthritis (OA), the most common form of arthritis, is characterized by progressive cartilage destruction, concomitant adaptive osteogenesis, and loss of joint function. The progression of OA with aging is associated with a decrease in native hyaluronan (HA, hyaluronate or hyaluronic acid) with a high molecular weight (HMW) in synovial fluid and a subsequent increase in lower MW HA and fragments. As HMW HA possesses numerous biochemical and biological properties, we review new molecular insights into the potential of HA to modify OA processes. Different MWs in the formulation of products appear to have varying effects on knee OA (KOA) pain relief, improved function, and postponing surgery. In addition to the safety profile, more evidence indicates that intraarticular (IA) HA administration may be an effective option to treat KOA, with a particular emphasis on the use of HA with fewer injections of higher MW, including potential applications of HA of very HMW. We also analyzed published systemic reviews and meta-analyses of IA HA in treating KOA in order to discuss their conclusions and consensus statements. According to its MW, HA may offer a simple way to refine therapeutic information in selective KOA.

Efficacy of Platelet-Rich Plasma Versus Hyaluronic Acid Following Arthrocentesis for Temporomandibular Joint Disc Disorders: A Randomized Controlled Trial

Purpose

Injection of intra-articular medicaments is an accepted therapy for temporomandibular joint disorders (TMDs). This study compares the efficacy of arthrocentesis followed by platelet-rich plasma (PRP) as compared to hyaluronic acid (HA) injections for TMDs unresponsive to conservative therapy. PRP injection following arthrocentesis was hypothesized to be better compared to arthrocentesis alone or when combined with HA injection.

Methods

Forty-seven patients with TMDs enrolled in an RCT were randomly assigned to three groups: Group A-PRP, Group B-HA or Group C-control group of arthrocentesis alone. Pre-operative evaluation and post-operative changes at 1-, 3-, 6-month intervals were assessed for improvement in pain, maximum mouth opening, joint sounds and excursive movements. Statistical significance was set at P value < 0.05.

Results

Post-operative joint sounds were present in three out of 16 patients in Group A; six out of 15 patients in Group B and eight out of 16 patients in Group C at 6-month follow-up. For the remaining outcome variables, no statistical difference between groups was observed.

Conclusion

Both medicaments produced significant clinical improvements when compared to the control group. When comparing PRP against HA, none showed superiority over the other.Clinical trial registration number: CTRI/2019/01/017076.

Influence of hyaluronic acid on intra-articular friction - a biomechanical study in whole animal joints

BACKGROUND

Cartilage is a mechanically highly stressed tissue in the human body and an important part of synovial joints. The joint cartilage is lubricated by synovial fluid with hyaluronic acid (HA) as main component. However, in joints with osteoarthritis HA has a lower concentration and molecular weight compared to healthy joints. In recent years, the intra-articular injection of therapeutic HA lubricant, has become a popular therapy. The effect of HA application on the friction of a complete joint with physiological movement needs to be further determined.

METHODS

The aim of the present study was to evaluate the lubrication effect of the joint by three lubricants (NaCl, fetal calf serum (FCS) and HA) and their effect on the friction in nine complete ovine carpo-metacarpal joints. The joints were mounted on a material testing machine and a physiological movement with 10° rotation was simulated with ascending axial load (100 - 400 N). Specimens were tested native, with cartilage damage caused by drying out and relubricated. Dissipated energy (DE) as a measure of friction was recorded and compared.

RESULTS

Investigating the effect of axial load, we found significant differences in DE between all axial load steps (p < .001), however, only for the defect cartilage. Furthermore, we could document an increase in DE from native (Mean: 15.0 mJ/cycle, SD: 8.98) to cartilage damage (M: 74.4 mJ/cycle, SD: 79.02) and a decrease after relubrication to 23.6 mJ/cycle (SD: 18.47). Finally, we compared the DE values for NaCl, FCS and HA. The highest values were detected for NaCl (M_Norm = 16.4 mJ/cycle, SD: 19.14). HA achieved the lowest value (M_Norm = 4.3 mJ/cycle, SD: 4.31), although the gap to FCS (M_Norm = 5.1 mJ/cycle, SD: 7.07) was small.

CONCLUSIONS

We were able to elucidate three effects in joints with cartilage damage. First, the friction in damaged joints increases significantly compared to native joints. Second, especially in damaged joints, the friction increases significantly more with increased axial load compared to native or relubricated joints. Third, lubricants can achieve an enormous decrease in friction. Comparing different lubricants, our results indicate the highest decrease in friction for HA.

Time to Total Knee Arthroplasty after Intra-Articular Hyaluronic Acid or Platelet-Rich Plasma Injections: A Systematic Literature Review and Meta-Analysis

Intra-articular (IA) hyaluronic acid (HA) and platelet-rich plasma (PRP) injections are increasingly being prescribed for knee osteoarthritis (KOA). However, failure of the medical treatment may result in total knee arthroplasty (TKA). We wondered if IA HA or PRP injections (intervention) may delay the time to TKA (outcome) among KOA patients (population), compared to KOA patients not receiving these injections (comparator). For this systematic literature review (SLR) and meta-analysis, we selected observational studies with at least one group of patients receiving IA HA or PRP and with TKA data available. The main outcome was time from the diagnosis of KOA to TKA. We included 25 articles in the SLR (2,824,401 patients) and four in the meta-analysis. The mean strengthening the reporting of observational studies in epidemiology (STROBE) score was 63%. For patients receiving versus not receiving HA injections, the delay between a declared diagnosis of KOA to TKA was increased by 9.8 months (95% CI (8.2-11.4)). As compared with standard of care, the effect size of HA injections for this outcome was 0.57 (95% CI (0.36-0.76)). Only one study described a median time from PRP injections to TKA of 4.1 years (range 0.3-14.7). IA HA injections were associated with increased time to TKA. Causality cannot be concluded because of missing confounder factors as comorbidities. Data were insufficient to conclude any effect of PRP injections on TKA delay.

Orthobiologics for the Management of Early Arthritis in the Middle-Aged Athlete

This article is dedicated to the use of orthobiologic therapies in the management of early osteoarthritis in middle-aged athletes. Understanding a patient's presenting symptoms, physical examination, imaging results, and goals is of critical importance in applying orthobiologic therapies. The field of orthobiologics is expanding at a rapid pace, and the clinical studies examining the utility of each treatment lag behind the direct-to-consumer marketing that leads to these products being used. Here we provide a review of the available treatments, emerging treatments, and the current literature supporting or refuting their use. Currently studied orthobiologics include autologous and allogenic cell therapies, autologous blood products, hyaluronic acid, gene therapies, Wnt inhibitors, and a variety of systemic treatments.

Management of osteoarthritis: From drug molecules to nano/micromedicines

With the change in lifestyle and aging of the population, osteoarthritis (OA) is emerging as a major medical burden globally. OA is a chronic inflammatory and degenerative disease initially manifesting with joint pain and eventually leading to permanent disability. To date, there are no drugs available for the definitive treatment of osteoarthritis and most therapies have been palliative in nature by alleviating symptoms rather than curing the disease. This coupled with the vague understanding of the early symptoms and methods of diagnosis so that the disease continues as a global problem and calls for concerted research efforts. A cascade of events regulates the onset and progression of osteoarthritis starting with the production of proinflammatory cytokines, including interleukin (IL)‐1β, IL‐6, tumor necrosis factor (TNF)‐α; catabolic enzymes, such as matrix metalloproteinases (MMPs)‐1, ‐3, and ‐13, culminating into cartilage breakdown, loss of lubrication, pain, and inability to load the joint. Although intra‐articular injections of small and macromolecules are often prescribed to alleviate symptoms, low residence times within the synovial cavity severely impair their efficacy. This review will briefly describe the factors dictating the onset and progression of the disease, present the current clinically approved methods for its treatment and diagnosis, and finally elaborate on the main challenges and opportunities for the application of nano/micromedicines in the treatment of osteoarthritis. Thus, future treatment regimens will benefit from simultaneous consideration of the mechanobiological, the inflammatory, and tissue degradation aspects of the disease.

This article is categorized under:

Nanotechnology Approaches to Biology > Nanoscale Systems in Biology

Implantable Materials and Surgical Technologies > Nanotechnology in Tissue Repair and Replacement

Effects and Safety of Intra-Articular Sodium Hyaluronate Injection for the Treatment of Ankle Osteoarthritis: A Prospective Clinical Trial

Various nonoperative treatments have been implemented to reduce pain and improve the quality of life in patients with ankle osteoarthritis. Among these treatments, intra-articular hyaluronate injection has proven efficacy and safety in patients with knee osteoarthritis. The purpose of this study was to evaluate the efficacy and complications of hyaluronate injection using various clinical scoring systems. This study included 37 patients with unilateral ankle osteoarthritis (grade 2 or 3 according to the Takakura classification) who did not respond to previous pharmacological treatment. 3 weekly hyaluronate injections (2 mL Hyruan Plus®) were administered. The efficacy of intra-articular hyaluronate injection was evaluated on the basis of patient-reported foot and ankle clinical assessment at a mean follow-up of 13.8 ± 8.3 (range 6-33) months. Ankle Osteoarthritis Scale scores for pain and disability, American Orthopedic Foot and Ankle Society ankle-hindfoot scores, and visual analog scale for pain significantly improved at the final follow-up compared to that before intra-articular hyaluronate injection (p ≤ .05). When patients were dichotomized according to age, sex, body mass index, symptom duration, and Takakura classification, all these factors were not related to clinical outcomes. This study suggests that 3 weekly intra-articular hyaluronate injections can be performed safely to reduce pain and improve function without serious complications in patients with early or intermediate-grade ankle osteoarthritis when patients inadequately respond to medication. Larger controlled studies are needed to clarify the effects of hyaluronate injection and identify patients who can benefit most from hyaluronate injection.

Safety of Intra-Articular Hyaluronic Acid for Knee Osteoarthritis: Systematic Review and Meta-Analysis of Randomized Trials Involving More than 8,000 Patients

OBJECTIVE

The objective of this systematic review and meta-analysis was to report the safety of intra-articular hyaluronic acid (IAHA) in patients with symptomatic knee osteoarthritis (OA).

METHODS

We identified randomized controlled trials reporting the safety of IAHA versus IA saline in adults with symptomatic knee OA. Main safety outcomes were adverse events (AEs), local AEs, serious adverse events (SAEs), study withdrawals, and AE-related study withdrawals.

RESULTS

A total of 35 randomized controlled trials with 38 group comparisons comprising 8,078 unique patients (IAHA: 4,295, IA saline: 3,783) were included in the meta-analysis. Comparing IAHA with IA saline over a median of 6 months follow-up, there were no differences in the risk of AEs (42.4% vs. 39.7%, risk ratio [RR] = 1.01, 95% CI = 0.96-1.07, P = 0.61), SAEs (1.8% vs. 1.2%, RR = 1.44, 95% CI = 0.91-2.26, P=0.12), study withdrawals (12.3% vs. 12.7%, RR = 0.99, 95% CI = 0.87-1.12, P = 0.83), or AE-related study withdrawals (2.7% vs. 2.1%, RR = 1.37, 95% CI = 0.97-1.93, P = 0.08). Local AEs, all of which were nonserious, were more common with IAHA vs. IA saline (14.5% vs. 11.7%, RR = 1.21, 95% CI = 1.07-1.36, P = 0.003) and typically resolved within days.

CONCLUSION

IAHA was shown to be safe for use in patients with symptomatic knee OA. Compared with IA saline, IAHA is associated with an increased risk of nonserious, transient local reactions. There was no evidence to suggest any additional safety risks of IAHA.

Molecular Weight of Hyaluronic Acid Has Major Influence on Its Efficacy and Safety for Viscosupplementation in Hip Osteoarthritis: A Systematic Review and Meta-Analysis

BACKGROUND

This study aimed to compare the efficacy and safety of intra-articular hyaluronic acid (HA) injection with different molecular weights (MWs) for treating hip osteoarthritis (OA).

METHODS

A systematic literature search for relevant studies was conducted in 3 electronic databases, including PubMed, BMJ Journals, and Cochrane Library, from inception to April 2020. Extracted outcomes included visual analogue scale (VAS) (1, 3, and 6 months), Lequesne index (3 and 6 months), and adverse effects. HAs were classified into low-molecular-weight (LMW), moderate-molecular-weight (MMW), high-molecular-weight (HMW), and ultra-high-molecular-weight (UHMW) groups. Meta-analysis was performed using Review Manager 5.3.

RESULTS

A total of 15 studies with 614 patients were included. Our meta-analysis showed that the HMW HA group had the best improvement in VAS and Lequesne index compared with other HA groups for all the follow-up visits. Moreover, the HMW group demonstrated significantly better improvement than the other groups in VAS at 6-month follow-up and in Lequesne index at 3- and 6-month follow-ups. Analysis for adverse effects revealed low rates of systemic adverse effects (≤0.6%) in all groups and similar rate of local adverse effects (around 10%) among the groups except for UHMW HA group (37.5%).

CONCLUSION

Among different MWs of HA for treating hip OA, HMW HA injection demonstrated the best efficacy for up to 6 months after treatment without increased risk of adverse effects. Further studies with more comprehensive data and a higher level of evidence are required to prove our results.

Immunomodulatory biomaterials and their application in therapies for chronic inflammation-related diseases

The degree of tissue injuries such as the level of scarring or organ dysfunction, and the immune response against them primarily determine the outcome and speed of healing process. The successful regeneration of functional tissues requires proper modulation of inflammation-producing immune cells and bioactive factors existing in the damaged microenvironment. In the tissue repair and regeneration processes, different types of biomaterials are implanted either alone or by combined with other bioactive factors, which will interact with the immune systems including immune cells, cytokines and chemokines etc. to achieve different results highly depending on this interplay. In this review article, the influences of different types of biomaterials such as nanoparticles, hydrogels and scaffolds on the immune cells and the modification of immune-responsive factors such as reactive oxygen species (ROS), cytokines, chemokines, enzymes, and metalloproteinases in tissue microenvironment are summarized. In addition, the recent advances of immune-responsive biomaterials in therapy of inflammation-associated diseases such as myocardial infarction, spinal cord injury, osteoarthritis, inflammatory bowel disease and diabetic ulcer are discussed.

Effects of low and high molecular weight hyaluronic acid on the osteoarthritic temporomandibular joint in rabbit

OBJECTIVE

To compare the effect between intra-articular infiltration of low molecular weight (LMW-HA) and high molecular weight hyaluronic acid (HMW-HA) on the histopathological characteristics of the cartilage and disc of the temporomandibular joint (TMJ) osteoarthritis (OA) induced in rabbits.

MATERIAL AND METHODS

An experimental study was conducted on 38 rabbit TMJs. The effect of different hyaluronic acids was compared at 30 and 135 days. Histopathological analysis was performed. Cartilage damage was assessed with the OARSI scale.

RESULTS

The severity of the induced OA according to OARSI was 3.4 degrees in the mandibular condyle (MC) and 3.2 in the mandibular fossa (MF); the articular disc (AD) presented disorganization of the collagen fibers, with randomly arranged hypertrophic chondrocytes. At 30 days, untreated TMJs worsened. TMJ treated with LMW-HA reduced its severity to 1.5 degrees in MC and 1.6 in MF, the AD presented histological aspects within normal limits. TMJ treated with HMW-HA presented 2.4 degrees in MC and 2.2 in MF, the AD maintained characteristics similar to the group with OA. At 135 days, all groups worsened.

CONCLUSION

Exogenous HA is effective in the management of TMJ-OA induced in rabbits, showing cartilage and articular disc repair at 30 days. The LMW-HA group had better effects on joint tissue than HMW-HA 30 days after treatment. However, at 135 days, both groups presented regression of joint tissue repair.

CLINICAL RELEVANCE

HA is effective in the anti-arthritic treatment of TMJ-OA induced in rabbits; LMW-HA shows better results in cartilage and articular disc repair than HMW-HA.

One-year follow-up of efficacy and cost of repeated doses versus single larger dose of intra-articular hyaluronic acid for knee osteoarthritis

PURPOSE

A recent 3-month randomized, open-label controlled trial found that the intra-articular hyaluronic acid injection (GO-ON^®) given as a single dose of 5 mL is as effective and safe as three repeated doses of 2.5 mL in patients with knee osteoarthritis. However, the information on the long-term efficacy and economic implications of the single-dose regimen is still limited. Hence, this follow-up study was designed to compare the effectiveness and costs of the two regimens 12 months following the treatment.

METHODS

All the 127 patients, who received either three repeated doses (n = 64) or a single dose (n = 63) of GO-ON in the previous trial, were followed up in month 12 following the treatment. The effectiveness of both the regimens was assessed using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and the mean WOMAC scores were compared with those recorded at the baseline and in month 3. Additionally, the total treatment costs of the two regimens, taking account of both direct and indirect costs, were computed and compared.

RESULTS

A total of 125 patients (98.4%) completed the assessment. Despite the reduction of the overall mean WOMAC score from 39.24 to 19.93 (p < 0.001) in the first 3 months following the treatment with GO-ON, no further changes were observed up to month 12 (p > 0.95). In the meantime, the two regimens did not differ in the mean WOMAC scores (p = 0.749) and in the subscale scores for pain (p = 0.970), stiffness (p = 0.526), and physical functioning (p = 0.667) in month 12. The cost for single-dose injection was found to be approximately 30% lower compared to the repeated doses.

CONCLUSION

These findings indicate that the single larger dose of GO-ON is as effective as the repeated doses over 12 months, and yet the total treatment cost is lowered.

Acromioclavicular osteoarthritis and shoulder pain: a review of the role of ultrasonography

Acromioclavicular joint osteoarthritis is often a cause of shoulder pain. On the other hand, imaging frequently leads to such a diagnosis, especially in elderly patients, and some authors believe it to have a poor correlation with the clinical picture. It is, however, widely accepted that such a condition can be the cause of rotator cuff impingement. In the case of shoulder pain, it is important to distinguish between symptomatic acromioclavicular osteoarthritis and other causes, especially rotator cuff pathology, which is more common. Sometimes, the clinical picture does not allow for differential diagnosis; in these cases, the injection of a local anesthetic into the acromioclavicular joint or into the subacromial bursa can be of great help. Ultrasonography can easily detect acromioclavicular osteoarthritis and rotator cuff pathology, and it is highly effective in guiding the articular or bursal injection of a local anesthetic to assess the origin of the pain. In addition, in conservative therapy, ultrasonography can guide the articular or bursal injection of corticosteroids and hyaluronic acid.

Comparison of patient-reported outcomes of treatment with low- and intermediate molecular weight hyaluronic acid in Japanese patients with symptomatic knee osteoarthritis: A prospective, randomized, single-blind trial

Objectives

The objective of this study was to compare the clinical outcomes of treatment with low- or intermediate-molecular-weight hyaluronic acid (HA) in patients with knee osteoarthritis (OA).

Methods

In total, 59 patients with OA who fulfilled the criteria of the American College of Rheumatology for OA were enrolled. Patients were randomly assigned in a 1:1 ratio to the low- or intermediate-molecular-weight HA group. An intraarticular injection of HA into the knee joint was performed five times per week. The visual analog scale for pain (pain VAS) and Japanese Knee Osteoarthritis Measure (JKOM) score were analyzed at baseline and week 6 to assess the outcomes.

Results

Pain VAS and JKOM score were significantly improved in both groups. At follow-up, there were no significant between-group differences in pain VAS or total JKOM score. Moreover, reduction in pain VAS and JKOM score was not significantly different between the two groups.

Conclusions

Both low- and intermediate-molecular-weight HA have significant efficacy in the first-line treatment of patients with knee OA as indicated by patient-reported outcomes. However, there does not appear to be any difference between the efficacy of low- and intermediate-molecular-weight HA as indicated by the JKOM score. We believe that the results of this study provide important insights into the clinical management of Japanese patients with knee OA.

Effect of diclofenac etalhyaluronate (SI-613) on the production of high molecular weight sodium hyaluronate in human synoviocytes

BACKGROUND

We have reported that a single intra-articular injection of diclofenac etalhyaluronate (SI-613) exerted a potent and long-lasting analgesic effect in experimental arthritis models. In the present study, we investigated the effect of SI-613 on the production of high molecular weight hyaluronic acid (HMW-HA) in synoviocytes from osteoarthritis (OA) patients and compared its efficacy with that of hyaluronic acid (HA).

METHODS

We compared the effect of SI-613, HA, and diclofenac sodium (DF-Na) on high molecular weight HA production by human synoviocytes.

RESULTS

SI-613 and exogenous HA induced the production of high molecular weight HA in synoviocytes from OA patients, whereas DF-Na had no effect. The molecular weight of newly produced HA was about 1000 kDa in the HA-treated synoviocytes and much higher than 2400 kDa in the SI-613-treated cells. The effect of the mixture of HA and DF-Na was similar to that of HA alone in that the molecular weight of newly produced HA was around 1000 kDa. SI-613 significantly suppressed hyaluronidase 2 (HYAL2) mRNA expression and significantly enhanced hyaluronan synthase 2 (HAS2) mRNA expression. HA had no effect on the expression levels of HYAL and HAS.

CONCLUSION

The present results clearly demonstrate that SI-613 induces the production of high molecular weight HA in synoviocytes from OA patients, suggesting the long-lasting analgesic and disease modifying effect of SI-613 for OA. Taken together with the anti-inflammatory and analgesic effects we recently reported for the intra-articular administration of SI-613 to experimental animal models, SI-613 holds great promise for the treatment of knee osteoarthritis.

Pharmacokinetics and four-week repeated-dose toxicity of hyaluronic acid and ketorolac combination following intra-articular administration in normal rats

Intra-articular (IA) injection of hyaluronic acid (HA) in combination with nonsteroidal anti-inflammatory drugs, such as ketorolac (KL), have been clinically investigated to provide more rapid and profound pain relief in patients with osteoarthritis. However, its safety, local tolerance, and potential for pharmacokinetic interaction have not been assessed. In this study, the pharmacokinetics and toxicity of a combination of HA and KL were evaluated in normal rats following four-week repeated-dose injection. Rats received HA or KL alone at 4 mg/kg or 16 mg/kg, respectively, or HA/KL combination at 4/4 mg/kg, 4/8 mg/kg, or 4/16 mg/kg on a weekly basis. The rats exhibited temporal, reversible changes in hematology, serum chemistry, and urinalysis caused primarily by KL treatment. No deleterious effects were observed on the joint following repeated IA HA/KL administration, which showed only minimal to mild levels of temporary inflammatory changes in synovial membrane. The plasma KL level following IA injection rose as fast as that of intra-muscular injection, with no alteration with the co-administered HA. In conclusion, repeated IA administration of HA/KL combination was tolerated well in normal rats, encouraging future studies of IA injection of HA/KL combination on osteoarthritis-induced animal models and even patients.

circRNA.33186 Contributes to the Pathogenesis of Osteoarthritis by Sponging miR-127-5p

Osteoarthritis (OA), the most prevalent age-related joint disorder, is characterized by chronic inflammation, progressive articular cartilage destruction, and subchondral bone sclerosis. Accumulating evidences indicate that circular RNAs (circRNAs) play a critical role in various diseases, but the function of circRNAs in OA remains largely unknown. Here we showed that circRNA.33186 was significantly upregulated in IL-1β)-treated chondrocytes and in cartilage tissues of a destabilized medial meniscus (DMM)-induced OA mouse model. Knockdown of circRNA.33186 increased anabolic factor (type II collagen) expression and decreased catabolic factor (MMP-13) expression. Knockdown of circRNA.33186 also promoted proliferation and inhibited apoptosis in IL-1β-treated chondrocytes. Silencing of circRNA.33186 in vivo markedly alleviated DMM-induced OA. Mechanistic study showed that circRNA.33186 directly binds to and inhibits miR-127-5p, thereby increasing MMP-13 expression, and contributes to OA pathogenesis. Taken together, our findings demonstrated a fundamental role of circRNA.33186 in OA progression and provide a potential drug target in OA therapy.

The association between different molecular weights of hyaluronic acid and CHAD, HIF-1α, COL2A1 expression in chondrocyte cultures

The aim of the present study was to investigate the effects of three different formulations of hyaluronic acid (HA): Low molecular weight (MW) Sinovial One^®, medium MW Viscoplus^® and high MW Durolane^®, on chondrocyte proliferation and collagen type II (COL2A1), hypoxia-inducible factor 1α (HIF-1α) and chondroadherin (CHAD) expression in primary chondrocyte cultures. Standard primary chondrocyte cultures were established from osteochondral tissues surgically obtained from 6 patients with gonarthrosis. Cell morphology was evaluated using an inverted light microscope; cell proliferation was determined with a MTT assay and confirmed with acridine orange/propidium iodide staining. Levels of CHAD, COL2A1 and HIF-1α expression were assessed using specific TaqMan gene expression assays. The results demonstrated the positive effect of HA treatment on cell proliferation, which was independent from the MW. COL2A1 expression increased in the medium and high MW HA treated groups. It was observed that HIF-1α expression increased in the high MW treated group alone. CHAD expression increased only in the medium MW HA treated group. Evaluation of gene expression revealed that levels of expression increased as the duration of HA application increased, in the medium and high MW HA treated groups. In terms of increased viability and proliferation, a longer duration of HA application was more effective. Taken together, it may be concluded that the administration of medium and high MW HA may be a successful way of treating diseases affecting chondrocytes in a clinical setting.

Intra-articular injection of microRNA-140 (miRNA-140) alleviates osteoarthritis (OA) progression by modulating extracellular matrix (ECM) homeostasis in rats

OBJECTIVE

Disruptions of extracellular matrix (ECM) homeostasis are key events in the pathogenesis of osteoarthritis (OA). MicroRNA-140 (miRNA-140) is expressed specifically in cartilage and regulates ECM-degrading enzymes. Our objective in this study was to determine if intra-articular injection of miRNA-140 can attenuate OA progression in rats.

DESIGN

miRNA-140 levels in human normal and OA cartilage derived chondrocytes and synovial fluid were assessed by polymerase chain reaction (PCR). After primary human chondrocytes were transfected with miRNA-140 mimic or inhibitor, PCR and western blotting were performed to quantify Collagen II, MMP-13, and ADAMTS-5 expression. An OA model was induced surgically in rats, and subsequently treated with one single intra-articular injection of miRNA-140 agomir. At 4, 8, and 12 weeks after surgery, OA progression were evaluated macroscopically, histologically, and immunohistochemically in these rats.

RESULTS

miRNA-140 levels were significantly reduced in human OA cartilage derived chondrocytes and synovial fluid compared with normal chondrocytes and synovial fluid. Overexpressing miRNA-140 in primary human chondrocytes promoted Collagen II expression and inhibited MMP-13 and ADAMTS-5 expression. miRNA-140 levels in rat cartilage were significantly higher in the miRNA-140 agomir group than in the control group. Moreover, behavioural scores, chondrocyte numbers, cartilage thickness and Collagen II expression levels in cartilage were significantly higher, while pathological scores and MMP-13 and ADAMTS-5 expression levels were significantly lower in the miRNA-140 agomir group than in the control group.

CONCLUSION

Intra-articular injection of miRNA-140 can alleviate OA progression by modulating ECM homeostasis in rats, and may have potential as a new therapy for OA.

Comparison of Low-, Moderate-, and High-Molecular-Weight Hyaluronic Acid Injections in Delaying Time to Knee Surgery

BACKGROUND

We compared the effectiveness of low-molecular-weight (MW) hyaluronic acid (HA) injections (LMWHA), moderate-MW HA injections (MMWHA), and high-MW HA injections (HMWHA) for prevention or delay of knee surgery in patients with knee osteoarthritis.

METHODS

An observational cohort study using LifeLink Plus claims (2006-2015) was used. The primary outcome measure of the study included all surgical interventions of the knee. The secondary outcome measures were the following: (1) unicompartmental knee arthroplasty or total knee arthroplasty and (2) total knee arthroplasty only. A high-dimensional propensity score (hdPS) using 1:1 matching was used to adjust for confounding. The likelihood of each outcome was assessed using Cox proportional hazard models.

RESULTS

A cohort of 30,417 incident HA users with knee osteoarthritis met our inclusion-exclusion criteria. There was no difference in the likelihood of composite surgical events between LMWHA users (hazard ratio, 0.939; 95% confidence interval, 0.870-1.013) and MMWHA users (hazard ratio, 1.032; 95% confidence interval, 0.952-1.119) when compared with HMWHA users in a matched hdPS analysis. However, a significantly lower likelihood for all outcome measures was demonstrated in LMWHA and MMWHA users compared with HMWHA users when hdPS was not used.

CONCLUSION

There was no significant difference in the likelihood of surgical interventions between LMWHA, MMWHA, and HMWHA users after accounting for empirically derived confounders.

Changes in Knee Joint Space Width in Treatment with a New Hyaluronic-Based Hydrogel

Objective: Our purpose was to assess the effect of a new hyaluronic acid-based (Hymovis®) injections on joint space width narrowing in patients diagnosed with knee osteoarthritis.

Methods: A prospective clinical trial was conducted in the Department of Orthopedics and Traumatology II from the Clinical County Hospital, Tîrgu Mureș, Romania. Thirty-five patients diagnosed with idiopathic knee osteoarthritis received two intraarticular injections with hyaluronic acid-based hydrogel (24 mg of hyaluronic acid/3 ml) at one-week interval. Anteroposterior radiographs were obtained before the injections, at six and twelve months after. Minimum joint space width was measured by two senior orthopaedics surgeons at each follow up. Each radiograph was measured again by the same evaluators two weeks apart.

Results: Thirty-one patients were present at the final follow-up. A minor reduction in mean weight was noticed (from 82.2 kg ± 16.2 kg to 80.9 kg ± 16.0, p > 0.398) without any correlation with joint space width narrowing. There were no major changes at the first follow up (6 months) regarding joint space narrowing. A reduction in joint space width was observed however at 12 months varying from 4.4 mm (SD ± 1.64, range 1.8-7.1) at the first assessment to 4.3 mm (SD ± 1.26, range 0.0-6.8) at the final follow-up but with no statistical difference (p=0.237).

Conclusion: No significant modification in joint space width at the final follow-up secondarily proved that two injections of Hymovis® may slow down narrowing in the knee joint space over a one-year period.

The Disease-Modifying Effects of Hyaluronan in the Osteoarthritic Disease State

Hyaluronic acid (HA) has been a treatment modality for patients with knee osteoarthritis (OA) for many years now. Since HA was first introduced for the treatment of painful knee OA, much has been elucidated regarding both the etiology of this disease and the mechanisms by which HA may mitigate joint pain and tissue destruction. The objectives of this article are to (1) describe the etiology and pathophysiology of OA including both what is known about the genetics and biochemistry, (2) describe the role of HA on disease progression, (3) detail the antinociceptive and anti-inflammatory actions of HA in OA, and (4) present evidence of disease-modifying effects of HA in the preservation and restoration of the extracellular matrix. These data support that HA is not only just a simple device used for viscosupplementation but also a biologically active molecule that can affect the physiology of articular cartilage.

The effect of sodium hyaluronate-chondroitin sulfate combined solution on cartilage formation in osteochondral defects of the rabbit knee: an experimental study

Objective

In focal cartilage lesions, multipotent mesenchymal stem cells in bone marrow are aimed to be moved into the defect area using subchondral drilling or microfracture method. However, repaired tissue insufficiently fills the defect area or cannot meet natural hyaline tissue functions, due to fibrous structure. We investigated the effect of a combined solution of sodium hyaluronate + chondroitin sulfate (HA+CS) administered intra-articularly after subchondral drilling on newly formed cartilage in rabbits with focal osteochondral defects.

Materials and methods

A total of 32 New Zealand White mature rabbits, whose weights ranged from 2.5 to 3 kg, were randomly divided into four groups. Full-thickness osteochondral defect was formed in the left-knee medial femur condyles of all rabbits. Subchondral drilling was then performed. The following treatment protocol was administered intra-articularly on knee joints on days 7, 14, and 21 after surgery: group 1, 0.3 mL combined solution of HA+CS (20 mg CS combined with 16 mg HA/mL); group 2, 0.3 mL HA (16 mg/mL); group 3, 0.3 mL CS (20 mg/mL); and group 4 (control group), 0.3 mL saline solution. In the sixth week, all animals were killed and then evaluated histopathologically and biochemically.

Results

There was significant articular cartilage formation in the HA+CS group compared to the HA, CS, and control groups. Hyaline cartilage formation was observed only in the HA+CS group. Cartilage-surface continuity and smoothness were significantly higher in the HA+CS and HA groups compared to the other groups. Normal cartilage mineralization was found to be significantly higher in the HA+CS group compared to the other groups. Increased levels of VEGFA and IL-1β in synovial fluid were observed in the HA+CS group.

Conclusion

After subchondral drilling, intra-articular HA-CS combination therapy is a good choice to promote better quality new cartilage-tissue formation in the treatment of focal osteochondral defects.

Preparation and Characterization of Hyaluronic Acid-Polycaprolactone Copolymer Micelles for the Drug Delivery of Radioactive Iodine-131 Labeled Lipiodol

Micelles, with the structure of amphiphilic molecules including a hydrophilic head and a hydrophobic tail, are recently developed as nanocarriers for the delivery of drugs with poor solubility. In addition, micelles have shown many advantages, such as enhanced permeation and retention (EPR) effects, prolonged circulation times, and increased endocytosis through surface modification. In this study, we measured the critical micelle concentrations, diameters, stability, and cytotoxicity and the cell uptake of micelles against hepatic cells with two kinds of hydrophilic materials: PEG-PCL and HA-g-PCL. We used ¹³¹I as a radioactive tracer to evaluate the stability, drug delivery, and cell uptake activity of the micelles. The results showed that HA-g-PCL micelles exhibited higher drug encapsulation efficiency and stability in aqueous solutions. In addition, the ¹³¹I-lipiodol loaded HA-g-PCL micelles had better affinity and higher cytotoxicity compared to HepG2 cells.

Prospective Evaluation of Intra-Articular Sodium Hyaluronate Injection in the Ankle

Viscosupplementation by injection of hyaluronic acid into the ankle can be used to provide pain relief and to delay the need for surgery in patients with osteoarthritis of the ankle. In the present investigation, we prospectively evaluated 50 consecutive patients (25 males and 25 females) undergoing a 3-injection protocol of sodium hyaluronate viscosupplementation in the ankle from January 2014 to January 2015. The Foot and Ankle Outcomes Score was used to compare the patients' pre- and post-treatment opinions about their ankle problems. The mean pretreatment Foot and Ankle Outcomes Score was 48 ± 6.3 (range 25 to 84) and the 6-month post-treatment score was 78 ± 5.8 (range 48 to 100). This difference was statistically significant (p = .003). From our findings in the present prospective cohort study, we have concluded that intra-articular injection of sodium hyaluronate viscosupplementation is a useful conservative therapy for osteoarthritis of the ankle.

THE EUROPEAN SOCIETY FOR CLINICAL AND ECONOMIC ASPECTS OF OSTEOPOROSIS AND OSTEOARTHRITIS (ESCEO) ALGORITHM FOR THE MANAGEMENT OF KNEE OSTEOARTHRITIS IS APPLICABLE TO RUSSIAN CLINICAL PRACTICE: A CONSENSUS STATEMENT OF LEADING RUSSIAN AND ESCEO OSTEOARTHRITIS EXPERTS

The European Society for Clinical and Economic Aspects of Osteoporosis and Osteoarthritis (ESCEO) treatment algorithm for the management of knee osteoarthritis (OA), published in December 2014, provides practical guidance for the prioritization of interventions. This current paper represents an assessment and endorsement of the algorithm by Russian experts in OA for use in Russian clinical practice, with the aim of providing easy-to-follow advice on how to establish a treatment flow in patients with knee OA, in support of the clinicians’ individualized assessment of the patient. Medications recommended by the ESCEO algorithm are available in Russia. In step 1, background maintenance therapy with symptomatic slow-acting drugs for osteoarthritis (SYSADOA) is advised, for which high-quality evidence is provided only for the formulations of patented crystalline glucosamine sulphate (pCGS) (Rottapharm/Meda) and prescription chondroitin sulfate. Paracetamol may be added for rescue analgesia only, due to limited efficacy and increasing safety signals. Topical non-steroidal anti-inflammatory drugs (NSAIDs) may provide additional symptomatic treatment with the same degree of efficacy as oral NSAIDs but without the systemic safety concerns. To be effective, topical NSAIDs must have high bioavailability, and among NSAIDs molecules like etofenamate have high absorption and bioavailability alongside evidence for accumulation in synovial tissues. Oral NSAIDs maintain a central role in step 2 advanced management of persistent symptoms. However, oral NSAIDs are highly heterogeneous in terms of gastrointestinal and cardiovascular safety profile, and patient stratification with careful treatment selection is advocated to maximize the risk: benefit ratio. Intra-articular hyaluronic acid as a next step provides sustained clinical benefit with effects lasting up to 6 months after a short-course of weekly injections. As a last step before surgery, the slow titration of sustained-release tramadol, a weak opioid, affords sustained analgesia with improved tolerability.

Hyaluronic acid in the management of osteoarthritis: injection therapies innovations

Osteoarthritis (OA) is a chronic degenerative joint disease characterized by pain and progressive functional limitation. Viscosupplementation with intra-articular (IA) hyaluronic acid (HA) could be a treatment option in OA, however recommendations made in different international guidelines for the non-surgical management of OA are not always concordant with regard to the role of IA injection therapies. Results from a recent Italian Consensus Conference underline how IA-HA to treat OA represents a widely used therapy in Italy. Specifically high molecular weight HA, cross-linked HA, and mobile reticulum HA are considered very useful to treat the OA joints from a great number of expert in Italy. These kinds of HA could reduce the NSAIDs intake, furthermore high-molecular weight and mobile reticulum HA are considered to be able to delay or avoid a joint prosthetic implant. This mini review highlights the results obtained from the Italian Consensus Conference "Appropriateness of clinical and organizational criteria for intra-articular injection therapies in osteoarthritis" and give further indication about innovation in IA-HA therapies.

Intra-articular Hyaluronic Acid in Treating Knee Osteoarthritis: a PRISMA-Compliant Systematic Review of Overlapping Meta-analysis

Numerous meta-analyses have been conducted aiming to compare hyaluronic acid (HA) and placebo in treating knee osteoarthritis (OA). Nevertheless, the conclusions of these meta-analyses are not in consistency. The purpose of the present study was to perform a systematic review of overlapping meta-analyses investigating the efficacy and safety of HA for Knee OA and to provide treatment recommendations through the best evidence. A systematic review was conducted based on the PRISMA guidelines. The meta-analyses and/or systematic reviews that compared HA and placebo for knee OA were identified. AMSTAR instrument was used to evaluate the methodological quality of individual study. The information of heterogeneity within each variable was fetched for the individual studies. Which meta-analyses can provide best evidence was determined according to Jadad algorithm. Twelve meta-analyses met the eligibility requirements. The Jadad decision making tool suggests that the highest quality review should be selected. As a result, a high-quality Cochrane review was included. The present systematic review of overlapping meta-analyses demonstrates that HA is an effective intervention in treating knee OA without increased risk of adverse events. Therefore, the present conclusions may help decision makers interpret and choose among discordant meta-analyses.

Extracellular vesicles — new tool for joint repair and regeneration

Cell-derived extracellular vesicles (EVs), present in synovial fluid and cartilage extracellular matrix (ECM), are involved in joint development and in the regulation of joint homeostasis. Although the exact function of EVs in these processes remains incompletely defined, the knowledge already acquired in this field suggests a role for these EVs as biomarkers of joint disease, and as a new tool to restore joint homeostasis and enhance articular tissue regeneration. In addition to direct injection of therapeutic EVs into the target site, surface coating of scaffolds and embedding of EVs in hydrogels might also lead to novel therapeutic possibilities. Based on the existing literature of EVs in synovial fluid and articular tissues, and investigation of the molecular factors (including microRNAs) active in joint homeostasis (or during its disturbance), we postulate novel perspectives for the implementation of EVs as a regenerative medicine approach in joint repair.

Synovial fluid pretreatment with hyaluronidase facilitates isolation of CD44+ extracellular vesicles

Extracellular vesicles (EVs) in synovial fluid (SF) are gaining increased recognition as important factors in joint homeostasis, joint regeneration, and as biomarkers of joint disease. A limited number of studies have investigated EVs in SF samples of patients with joint disease, but knowledge on the role of EVs in healthy joints is lacking. In addition, no standardized protocol is available for isolation of EVs from SF. Based on the high viscosity of SF caused by high concentrations of hyaluronic acid (HA) - a prominent extracellular matrix component - it was hypothesized that EV recovery could be optimized by pretreatment with hyaluronidase (HYase). Therefore, the efficiency of EV isolation from healthy equine SF samples was tested by performing sequential ultracentrifugation steps (10,000g, 100,000g and 200,000g) in the presence or absence of HYase. Quantitative EV analysis using high-resolution flow cytometry showed an efficient recovery of EVs after 100,000g ultracentrifugation, with an increased yield of CD44+ EVs when SF samples were pretreated with HYase. Morphological analysis of SF-derived EVs with cryo-transmission-electron microscopy did not indicate damage by high-speed ultracentrifugation and revealed that most EVs are spherical with a diameter of 20-200 nm. Further protein characterization by Western blotting revealed that healthy SF-derived EVs contain CD9, Annexin-1, and CD90/Thy1.1. Taken together, these data suggest that EV isolation protocols for body fluids that contain relatively high amounts of HA, such as SF, could benefit from treatment of the fluid with HYase prior to ultracentrifugation. This method facilitates recovery and detection of CD44+ EVs within the HA-rich extracellular matrix. Furthermore, based on the findings presented here, it is recommended to sediment SF-derived EVs with at least 100,000g for optimal EV recovery.

Pre-injection of hyaluronic acid does not affect the systemic effects of intra-articular depot betamethasone injection at the knee joint

Intra-articular injection (IAI) of both hyaluronic acid (HA) and depot-steroid preparations had the advantage of quick and prolonged favorable effects on pain relief among patients with symptomatic osteoarthritis of the knee (OAK). The effect of IAI of HA on the systemic effects of the intra-articular steroids had not been investigated. Non-selected patients attending the rheumatology clinic with symptomatic OAK who failed NSAIDS and physical therapy were offered an IAI of HA at the knee joint followed 20 min later by an IAI of 1 ml of Celestone Chronodose at the same joint (group 1). Morning serum levels of cortisol were obtained just prior to the IAI and 1, 2 and 8 days later. Demographic, clinical, and laboratory parameters were obtained also from all the patients. Age- and sex-matched group of patients from the same clinic were recruited as a control group (group 2). Mean baseline serum cortisol levels in group 1 was 381 ± 154 mmol/l vs. 376 ± 119 in group 2 (p = 0.954). Morning serum cortisol levels at day 1 and day 2 were 24 ± 6 and 22 ± 6 mmol/l, respectively, in group 1 patients vs. 27 ± 5.8 (p = 0.214) and 25 ± 5.6 mmol/l (p = 0.200), respectively, in group 2. These levels were significantly lower than baseline levels in each group. Morning serum cortisol levels at day 8 in group 1 and group 2 were 349 ± 128 and 314 ± 99 mmol/l, respectively (p = 0.419). Pre-injection of HA at the knee joint did not affect the systemic effect on the hypothalamic-pituitary-adrenal axis of IAI of Celestone Chronodose.

Altered microRNA expression profile in synovial fluid from patients with knee osteoarthritis with treatment of hyaluronic acid

OBJECTIVE

The aim of this study was to investigate the microRNA (miRNA) expression pattern in synovial fluid from patients with knee osteoarthritis (OA) after treatment with intra-articular injection of hyaluronan (HA).

METHODS

Twelve OA patients were enrolled in accordance with the Kellgren-Lawrence classification of knee OA. All patients received intra-articular injection of HA once a week for 5 weeks and were evaluated with the Western Ontario and McMaster Universities (WOMAC) index at baseline. TaqMan miRNA assay profiling was performed on synovial fluid RNAs extracted from OA patients pre-injection and after 5 weeks of treatment with HA. Validation was performed using independent samples, including ten healthy controls and ten matched OA patients.

RESULTS

Forty-three miRNAs (21 overexpressed miRNAs and 22 underexpressed miRNAs) were differentially expressed in OA patients before and after treatment with HA (P < 0.05, false discovery rate corrected). Further bioinformatics prediction by mirPath indicated that the differential miRNA signatures in synovial fluid extracted from the OA patients demonstrated primarily upregulation of the PI3K-Akt signaling pathway, mitogen-activated protein kinase signaling pathway, regulation of autophagy, mRNA surveillance pathway, and B cell receptor signaling pathway. In addition, TaqMan real-time reverse transcription polymerase chain reaction was performed for validation on miR-146a, miR-155, let-7a, miR-181a, miR-454, and let-7b, which were significantly changed in abundance, using an independent cohort of ten healthy controls and ten OA patients as compared with those with intra-articular injection of HA.

CONCLUSION

Our results demonstrated that dysregulation in miRNAs in synovial fluid from OA patients and their affected biologic cellular processes might play important role in OA pathogenesis and HA-mediated therapeutics.

Unraveling the confusion behind hyaluronic acid efficacy in the treatment of symptomatic knee osteoarthritis

Hyaluronic acid (HA) is a commonly prescribed treatment for knee pain resulting from osteoarthritis (OA). Although numerous HA products have been approved for use by the US Food and Drug Administration, the efficacy of HA injections for knee OA remains disputed with meta-analyses and societal clinical guidelines drawing disparate conclusions. The American Academy of Orthopaedic Surgeons (AAOS) recently published a best-evidence systematic review and concluded that available data did not support the routine use of HA for knee OA. The purpose of the current article is to highlight issues that confound interpretation of meta-analyses on HA for knee OA, to provide realistic estimates of the true efficacy of HA injections in knee OA, and to provide commentary on the methods and conclusions from the AAOS systematic review. In general, the clinical benefit of HA is underestimated using conventional meta-analytic techniques. When accounting for differential control group effects in HA studies, it can be reasonably concluded that HA injections may be beneficial to an appreciable number of patients with knee OA. In addition, the systematic review methodology used by AAOS was questionable due to exclusion of numerous relevant studies and inclusion of studies that used HAs not approved for use in the US, both of which underestimated the true efficacy of HA injections. Overall, the efficacy of HA injections for knee OA is likely better than previously reported. Future clinical trials and meta-analyses should account for differential control group effects in order to avoid the continued confusion surrounding HA injection efficacy.

Novel hyaluronic acid-methotrexate conjugate suppresses joint inflammation in the rat knee: efficacy and safety evaluation in two rat arthritis models

Background

Methotrexate (MTX) is one of the most widely used medications to treat rheumatoid arthritis (RA), and recent studies have also suggested the potential benefit of the drug for the treatment of osteoarthritis (OA) of the knee. MTX is commonly administered in oral formulations, but is often associated with systemic adverse reactions. In an attempt to address this issue, we have shown previously that a conjugate of hyaluronic acid (HA) and MTX exhibits potential as a drug candidate for intra-articular treatment of inflammatory arthritis. In this study, we compare the efficacy and safety of an optimized HA-MTX conjugate, DK226, with that of MTX in inflammatory arthritis rat models.

Methods

In vitro activity of DK226 was assessed in human fibroblast-like synoviocytes (HFLS) and a synovial sarcoma cell line, SW982. Release of MTX from DK226 was investigated after incubation with rabbit synovial tissue homogenate or synovial fluid. In vivo efficacy of DK226 was evaluated in antigen-induced arthritis (AIA) and collagen-induced arthritis (CIA) in the rat knee. Pharmacokinetics and hematological toxicity after treatment with oral MTX or an intra-articular injection of DK226 were compared in AIA.

Results

Proliferation of HFLS and SW982 cells was inhibited by DK226, and the inhibitory activity was reversed by cotreatment with excess HA or anti-CD44 antibody. MTX was released from DK226 by incubation with rabbit synovial tissue homogenate or synovial fluid at pH 4.0, but not at pH 7.4. AIA was ameliorated by intra-articular DK226, but not by HA, as potently as oral MTX. Hematological toxicity was induced by oral MTX, but not by DK226. The maximum plasma concentration of MTX after oral MTX was 40 times higher than the concentration of MTX after an intra-articular injection of DK226. Knee swelling in AIA was inhibited by intra-articular injections of DK226, but not by free MTX or a mixture of HA and MTX. In CIA, an injection of DK226 into the right knee joint significantly reduced swelling and synovial inflammation of the treated knee joint, but had no effect on the untreated contralateral knee joint.

Conclusions

DK226 exerted anti-arthritic effects in two different models of arthritis. The conjugate had a wider therapeutic window than oral MTX, and could be a future drug for treatment of arthritic disorders, including inflammatory OA.