Molecular Weight Hyaluronic Acid Research Articles

Study on hyaluronic acid aquaphotomics-from one dimension to two dimension analysis.

Hyaluronic acid (HA) is widely used in cosmetics because of its unique hygroscopic properties. However, it is difficult to characterize the interactions between HA and water molecules in the skin. In this study, we developed a fast and nondestructive method for visualizing skin water species based on aquaphotomics to elucidate the mechanism by which HA affected water species. The first HA-water system was introduced to investigate the relationship between HA and water species based on near-infrared (NIR) spectroscopy and aquaphotomics. NIR-hyperspectral imaging was then applied to characterize the distribution of different water species in the skin. The HA-water system results indicated that oligo HA had hydration behaviors opposite to those of low molecular weight HA. NIR hyperspectral imaging results showed that the intensity and spatial distribution of each water species within the skin model can be directly characterized by upgrading aquaphotomics from one-dimensional to two-dimensional. Studies showed that HA tetrasaccharides and 600-700kDa HA could maintain the strength of skin water species. In summary, the visual representation of water species distribution enables rapid and nondestructive monitoring of macromolecule hydration with skin which could help cosmetics formulators to optimize their HA formulation to realize their best hygroscopic properties in the future.

Ion-Mediated Cross-Linking of Hyaluronic Acid into Hydrogels without Chemical Modification.

Hyaluronic acid (HA) is a biomedically relevant polymer widely explored as a component of hydrogels. The prevailing approaches for cross-linking HA into hydrogels require chemically modifying the polymer, which can increase processing steps and complicate biocompatibility. Herein, we demonstrate an alternative approach to cross-link HA that eliminates the need for chemical modifications by leveraging the interactions between metal cations and the negatively charged, ionizable functional groups on HA. We demonstrate that HA can be cross-linked with the bivalent metal cations Mn(II), Fe(II), Co(II), Ni(II), Cu(II), Zn(II), Pd(II), and notably Mg(II). Using Mg(II) as a model, we show that ion-HA hydrogel rheological properties can be tuned by altering the HA molecular weight and concentrations of ions, NaOH, and HA. Mg(II)-HA hydrogels showed the potential for self-healing and stimulus response. Our findings lay the groundwork for developing a new class of HA-based hydrogels for use in biomedical applications and beyond.

The Effect of the Molecular Weight of Hyaluronic Acid on the Rheological and Tribological Properties of the Base for Artificial Synovial Fluid Preparations

Abstract The synovial fluid is responsible for adequately lubricating, moisturizing, and nutritional human joints. This liquid should have appropriate viscoelastic properties and ensure a low coefficient of friction in biotribological systems. Many artificial synovial fluid preparations used in viscosupplementation treatments are based on hyaluronic acid. This work aimed to evaluate the influence of molecular weight on the functional properties of solutions based on hyaluronic acid. 1% solutions based on hyaluronic acid with five different molecular weights from 50,000 Da to 2 MDa were made. Rheological (viscosity, viscoelasticity), tribological (coefficient of friction, wear assessment), and wettability tests were carried out. Significant differences were observed in the rheological tests, where the viscosity strictly depends on the molecular weight of the hyaluronic acid. It has been shown that the molecular weight of HA has little effect on the coefficient of friction. On the other hand, the differences in the tribological wear are much more significant. The molecular weight of biopolymers is one of the essential parameters in developing new artificial synovial fluids. Using a higher molecular weight of hyaluronic acid increases viscosity and wettability, resulting in less tribological wear.

Stability Studies of a Tetraethyl Orthosilicate-Based Thixotropic Drug Delivery System.

Background/Objectives: This study assessed the effects of formulation components on the long-term stability of a previously described tetraethyl orthosilicate-based drug delivery system. Early stability studies of a product concept are crucial not only to provide information on the overall system stability and individual components' contributions to it, but also to identify opportunities for dosage form optimization and to define its use case. Methods: We assessed the time-dependent thixogel properties-specifically, mechanical strength, thixotropy, release of model drug, and dry substance-in both real-time and accelerated shelf-life determination set-ups. Results: Our findings indicate that the concentration and molecular weight of hyaluronic acid, one of the main constituents of the investigated thixotropic systems, are key determinants of formulation stability. We further showed that changes in both of these parameters reflect on the drug release properties and stiffness of the formulation and could inform subsequent product development based on several use cases. Conclusions: Overall, this study provides an understanding of some key factors that would need to be considered prior to and in the final product development process of thixogels in preparation for commercialization.

In vitro study of the gel cohesivity and persistence to hyaluronidase degradation of a novel stabilized composition of 26 mg/mL of high molecular weight HA

Aim: Hyaluronic acid (HA) is extensively used in injectable skin quality products due to its documented role in skin rejuvenation. The rapid in vivo degradation of HA by the enzyme hyaluronidase necessitates the development of advanced formulations to ensure the efficacy and longevity of the treatments. In this context, a novel 2.6% high molecular weight HA (H-HA)/3.2% sorbitol composition has been introduced, featuring stabilization through hydrogen bonds rather than traditional crosslinking. Methods: The stabilized composition was evaluated through two in vitro enzymatic degradation tests. In the first test, the efficiency on the gel degradation was followed by rheology and compared with two crosslinked HA products available on the market. In the second test, the effect on the gel structure of a less diluted hyaluronidase dose was followed by rheological and cohesivity measurements. Results: In vitro study demonstrates that, before its complete degradation into a liquid-like state, the stabilized composition exhibits high elasticity and cohesivity during the enzymatic degradation process, surpassing traditional crosslinked HA products. Conclusion: The stabilization provided by the sorbitol in the stabilized composition effectively enhances product properties and protects them during gel degradation. These attributes indicate significant potential for improved clinical outcomes in skin quality treatments.

A retrospective claims data analysis of health care utilization and cost among patients receiving multi-injection intraarticular hyaluronic acid.

With the rising costs for knee arthroplasty, therapies that allow patients to avoid or delay surgery following knee osteoarthritis (KOA) may help in reducing overall health care costs. Multiple intraarticular hyaluronic acid (HA) products are available on the market, varying by formulation, molecular weight, and number of injections, but clinical and economic benefits may differ by product. OBJECTIVES: To evaluate the all-cause and KOA-related health care resource utilization (HCRU) and costs among newly diagnosed patients with KOA treated with multi-injection HA. A retrospective cohort study using a large commercial claims database (Merative MarketScan database) to identify patients with KOA treated with high molecular weight (HMW) (n = 11,200), medium molecular weight (MMW) (n = 10,225), or low molecular weight (LMW) HAs (n = 8,473) between 2016 and 2019. KOA-related and all-cause HCRU and costs were compared within 12 months after the index HA treatment date. The association between outcomes and HA treatments was evaluated using a doubly robust method to adjust for confounding factors. HCRU and costs among the propensity score-weighted HA groups were compared using generalized linear models. HMW HA patients were found to have lower adjusted KOA-related medical costs by $265.37 (P < 0.001) and pharmacy costs by $19.90 (P < 0.001) compared with LMW HA patients, as well as lower all-cause total medical costs by $130.42 (P = 0.013) and pharmacy costs by $63.33 (P < 0.001). HMW HA patients also had a lower adjusted KOA-related medical cost by $205.74 (P < 0.001) and pharmacy cost by $14.39 (P < 0.001) compared with MMW HA patients, as well as lower all-cause medical by $1,195.66 (P < 0.001) and pharmacy by $196.99 (P < 0.001). Three-injection treatment patients (HMW HA, 84%; MMW HA, 82%) had high completion rate, compared with the 5-injection treatment cohort (LMW HA, 48%). HMW HA patients had statistically significantly lower adjusted all-cause and KOA-related medical and pharmacy costs at 1 year follow-up compared with MMW HA and LMW HA patients. It is unclear if this is related to differences in molecular weight or specific mechanism of actions.

The Potential of Intra-Articular Therapies in Managing Knee Osteoarthritis: A Systematic Review.

Knee osteoarthritis (KOA) is a common degenerative and progressive joint disorder that negatively influences patients' quality of life. Intra-articular therapies, such as hyaluronic acid (HA) and platelet-rich plasma (PRP), have garnered attention for their potential to manage osteoarthritis OA symptoms effectively. This systematic review aims to identify the effectiveness and safety of HA and PRP treatment modalities in treating KOA. A literature search was conducted across MEDLINE (PubMed), Web of Science Core Collection, and Science Direct Collection Elsevier. Twenty-three randomized controlled trials, cohort studies, and observational studies were included in the review. The selection criteria focused on studies published in English within the last 10 years, involving subjects with KOA treated with intra-articular injections of HA or PRP and reporting on pain, function, or overall treatment efficacy outcomes. The analysis showed that both HA and PRP significantly improve functionality and reduce pain in KOA patients. High molecular weight HA consistently reduced pain and improved joint mobility in various studies. PRP had better long-term outcomes when combined with HA, leading to greater pain reduction and functional improvement. Both therapies had generally favorable safety profiles, with only minor adverse events reported. However, there were potential biases identified across the studies, such as selection, performance, detection, and reporting biases, which impacted the reliability of the results. Intra-articular treatments with HA and PRP show promise in managing knee osteoarthritis, with personalized treatment plans and further research needed to confirm these findings.

Ultrasound-Assisted Preparation of Hyaluronic Acid-Based Nanocapsules with an Oil Core.

Liquid-core nanocapsules (NCs) coated with amphiphilic hyaluronic acid (AmHA) have been proposed for the preparation of drug and food formulations. Herein, we focused on the use of ultrasound techniques to (i) optimize the polysaccharide chain length with respect to the properties of NCs stabilized with AmHAs and (ii) form oil-core nanocapsules with a coating composed of AmHAs. The results indicate that sonication is a convenient and effective method that allows for a controlled reduction in HA molecular weight. The initial (H-HA) and degraded (L-HA) polysaccharides were then reacted with dodecylamine to obtain hydrophobic HA derivatives (HA-C12s). Then, NCs were prepared based on HA-C12s using ultrasound-assisted emulsification of glyceryl triacetate oil. The nanocapsules coated with L-HA-C12 showed greater stability compared to the longer-chain polysaccharide. Molecular dynamics (MD) simulations revealed that HA-C12 readily adsorbs at the water-oil interphase, adopting a more compact conformation compared to that in the aqueous phase. The dodecyl groups are immersed in the oil droplet, while the main polysaccharide chain remaining in the aqueous phase forms hydrogen bonds or water bridges with the polar part of the triglycerides, thus increasing the stability of the NC. Our research underscores the usefulness of ultrasound technology in preparing suitable formulations of bioactive substances.

Hyaluronic Acid Role in Biomaterials Prevascularization.

Tissue vascularization is a major bottleneck in tissue engineering. In this review, the state of the art on the intricate role of hyaluronic acid (HA) in angiogenesis is explored. HA plays a twofold role in angiogenesis. First, when released as a free polymer in the extracellular matrix (ECM), HA acts as a signaling molecule triggering multiple cascades that foster smooth muscle cell differentiation, migration, and proliferation thereby contributing to vessel wall thickening. Simultaneously, HA bound to the plasma membrane in the pericellular space functions as a polymer block, participating in vessel formation. Starting with the HA origins in native vascular tissues, the approaches aimed at achieving vascularization in vivo are reviewed. The significance of HA molecular weight (MW) in angiogenesis and the challenges associated with utilizing HA in vascular tissue engineering (VTE) are conscientiously addressed. The review finally focuses on a thorough examination and comparison of the diverse strategies adopted to harness the benefits of HA in the vascularization of bioengineered materials. By providing a nuanced perspective on the multifaceted role of HA in angiogenesis, this review contributes to the ongoing discourse in tissue engineering and advances the collective understanding of optimizing vascularization processes assisted by functional biomaterials.

Overview of 37 Tear Substitutes in Europe Based on Various Physicochemical Parameters.

Dry eye disease (DED) is one of the most prevalent eye conditions worldwide, with artificial tears serving as a primary treatment option. Despite their wide availability on the European market, there is a lack of established classifications based on their physicochemical properties. The aim of our study was therefore (i) to develop an analytical method that measures the concentration and the molecular weight (MW) of the hyaluronic acid (HA) in commercialized products, and (ii) to propose an overview based on their various physicochemical parameters. The intrinsic viscosity and MW of the HA, as well as osmolarity, pH, rheological profile, and viscosity, were measured or determined. A specific method was developed to measure the average intrinsic viscosity and HA content using a liquid size-exclusion chromatography system. The MW was determined using the Mark-Houwink equation. Thirty-seven products commercialized in Europe were analyzed, with 21 of them containing HA. The HA MW was lowest (300kDa) for Thealose®, Thealoz Duo® Gel, and Hyabak®, and highest (1300kDa) for Vismed® Multi, Vismed® Gel, and Neovis® Gel. The pH values varied between 5.94 for Treovis® and 8.06 for Systane® Ultra. Osmolarity ranged between 148 mOsm/L and 325 mOsm/L for Neovis® and Treovis®, respectively. Viscosity was highly variable, ranging from 0.38 mPas·s for Hylolipid® to 337.47 mPas·s for Thealoz® Duo Gel. Finally, rheological profile analysis revealed different shear-thinning behaviors. While the perfect eye drop does not exist, a multitude of options are available to choose from. This study improves our understanding of the major tear substitutes available on the European market based on several physicochemical properties. A better understanding and awareness of these parameters is crucial in order to offer the best treatment for patients with DED.

Hyaluronic Acid Influences Amino Acid Metabolism via Differential L‐Type Amino Acid Transporter 1 Expression in the U87‐Malignant Glioma Cell Line

The glioblastoma (GBM) tumor microenvironment is heterogeneous, complex, and being increasingly understood as a significant contributor to tumor progression. In brain tumors, the extracellular matrix contains a large concentration of hyaluronic acid (HA) that makes it important to study its role in cancer progression. In particular, abnormal accumulation of HA is observed in gliomas and is often associated with poor prognosis. In addition, HA is a polymer and its molecular weight (MW) distribution may influence tumor cell activity. Herein, the influence of the MW of HA on tumor cell metabolism is evaluated. A 2D cell culture approach is used to expose the U87‐MG (medium glucose [MG]) cell line to different HA MWs (10, 60, and 500 kDa) and glucose concentrations (0, 5.5, and 25 mm). Notably, it is found that HA influences GBM amino acid metabolism via reduction in LAT1 transporter protein expression. Also an influence on mitochondrial respiration levels and a difference in the accumulation of some key products of cell metabolic activity (lactic acid, glutamic acid, and succinic acid) are reported. Overall, in these results, it is indicated that HA MW can influence GBM metabolic state, with implications for cell invasion and tumor progression.

Identification and Characterization of a Highly Active Hyaluronan Lyase from Enterobacter asburiae.

Hyaluronic acid (HA) is a well-known functional marine polysaccharide. The utilization and derivative development of HA are of great interest. Hyaluronan lyase has wide application prospects in the production of HA oligosaccharides and lower molecular weight HA. In this study, a strain of Enterobacter asburiae CGJ001 with high hyaluronan lyase activity was screened from industrial wastewater. This strain exhibited an impressive enzyme activity of 40,576 U/mL after being incubated for 14 h. Whole genome sequencing analysis revealed that E. asburiae CGJ001 contained a cluster of genes involved in HA degradation, transport, and metabolism. A newly identified enzyme responsible for glycosaminoglycan degradation was designated as HylEP0006. A strain of E. coli BL21(DE3)/pET-22b(+)-hylEP0006 was successfully constructed. HylEP0006 exhibited optimal degradation at 40 °C and pH 7.0, showing a high activity of 950,168.3 U/mg. HylEP0006 showed specific activity against HA. The minimum degradation fragment of HylEP0006 was hyaluronan tetrasaccharides, and HylEP0006 could efficiently degrade HA into unsaturated disaccharides (HA2), with HA2 as the final product. These characteristics indicate that HylEP0006 has a potential application prospect for the extraction and utilization of hyaluronic acid.

Hyaluronic Acid Receptor-Mediated Nanomedicines and Targeted Therapy.

Hyaluronic acid (HA) is a naturally occurring polysaccharide found in the extracellular matrix with broad applications in disease treatment. HA possesses good biocompatibility, biodegradability, and the ability to interact with various cell surface receptors. Its wide range of molecular weights and modifiable chemical groups make it an effective drug carrier for drug delivery. Additionally, the overexpression of specific receptors for HA on cell surfaces in many disease states enhances the accumulation of drugs at pathological sites through receptor binding. In this review, the modification of HA with drugs, major receptor proteins, and the latest advances in receptor-targeted nano drug delivery systems (DDS) for the treatment of tumors and inflammatory diseases are summarized. Furthermore, the functions of HA with varying molecular weights of HA in vivo and the selection of drug delivery methods for different diseases are discussed.

Nitrilotriacetic Acid Functionalized Microgels for Efficient Immobilization of Hyaluronan Synthase.

Enzymes play a vital role in synthesizing complex biological molecules like hyaluronic acid (HA). Immobilizing enzymes on support materials is essential for their efficient use and reuse in multiple cycles. Microgels, composed of cross-linked, highly swollen polymer networks, are ideal for enzyme uptake owing to their high porosity. This study demonstrates the immobilization of His6-tagged hyaluronan synthase from Pasteurella multocida (PmHAS) onto nitrilotriacetic acid functionalized microgels using different bivalent ions (Ni2+, Co2+, Mn2+, Mg2+, and Fe2+) via metal affinity binding. The results indicate that using Ni2+ yields the microgels with the highest enzyme uptake and HA formation. The immobilized PmHAS enables repetitive enzymatic production, producing high molecular weight HAs with decreasing dispersities in each step. Furthermore, the highest reported yield of HA with high molecular weight for immobilized PmHAS is achieved. This system establishes a foundation for continuous HA formation, with future works potentially enhancing PmHAS stability through protein engineering.

The interplay between hyaluronic acid and stem cell secretome boosts pulmonary differentiation in 3D biomimetic microenvironments

Mesenchymal stem cells (MCSs) secretome provide MSC-like therapeutic effects in preclinical models of lung injury, circumventing safety concerns with the use of live cells. Secretome consists of Extracellular Vesicles (EVs), including populations of nano- to micro-sized particles (exosomes and microvesicles) delimited by a phospholipidic bilayer. However, its poor stability and bioavailability severely limit its application. The role of Hyaluronic acid (HA) as potential carrier in biomedical applications has been widely demonstrated. Here, we investigated the interplay between HA and MSCs- secretome blends and their ability to exert a bioactive effect on pulmonary differentiation in a 3D microenvironment mimicking lung niche. To this aim, the physical-chemical properties of HA/Secre blends have been characterized at low, medium and high HA Molecular Weights (MWs), by means of SEM/TEM, DLS, confocal microscopy and FTIR. Collectively physical-chemical properties highlight the interplay between the HA and the EVs. In 3D matrices, HA/Secre blends showed to promote differentiation in pulmonary lineage, improved as the MW of the HA in the blends decreased. Finally, HA/Secre blends' ability to cross an artificial mucus has been demonstrated. Overall, this work provides new insights for the development of future devices for the therapy of respiratory diseases that are still unmet.

Identification of hyaluronic acid in seized samples by Hypercarb chromatography-high resolution mass spectrometry.

Hyaluronic acid (HA) has been commonly used to treat osteoarthritis and joint injuries in horses and dogs since the 1970s. HA is a polysaccharide made up of alternating N-acetyl-d-glucosamine and d-glucuronic acid residues, with polymeric molecules achieving molecular weights as high as 20 MDa. High molecular weight HA forms a viscous hydrogel when dissolved in water, making HA solutions distinct from most other pharmaceutical preparations. Clear viscous solutions are often encountered during stable and kennel inspections, but in the absence of an analytical method, it is not possible to identify if these substances contain HA or other unknown compounds. This paper presents a simple method for the identification of HA in seized materials based on chemical hydrolysis followed by Hypercarb chromatography and MS/MS analysis.

Profhilo® Structura, Current Status and Future Perspectives: A Practical Review.

Hyaluronic acid (HA)-based injectables continue to grow in popularity and are used worldwide to improve facial changes associated with aging. Profhilo® Structura (IBSA Farmaceutici Italia, Lodi, Italy) is a novel HA-based product that uses nano hybrid complex of hyaluronic acid (NAHYCO)® technology to create hybrid cooperative complexes consisting of high and low molecular weight HA. Profhilo® Structura's high concentration (45 mg of total HA) and rheological properties (ie, viscosity [resistance to flow] and elasticity [stickiness]) have been specially formulated to restore facial adipose tissue. Because of their early involvement in the facial aging process, the superficial medial and lateral-temporal cheek fat compartments are good candidates for treatment. However, recommendations and guidelines are necessary to ensure that treatment is safe and effective. Three experts were invited to IBSA Farmaceutici Italia Srl to discuss clinical rationale, optimal injection techniques, and clinical outcomes for treating the superficial medial and lateral-temporal cheek fat compartments with Profhilo® Structura. These techniques were developed using patients presenting with either initial hypotrophy of fat compartments within the preauricular area (ie, sinkers) or jowl sagging due to hypotrophy within the preauricular and zygomatic areas (ie, saggers). Targeting these areas using the optimal injection site can maximize product diffusion and minimize the risk for vascular compromise. Targeting these areas also leads to lateral tightening and lipolifting effects due to adipose tissue restoration. The experts agreed that Profhilo® Structura is currently the first and only HA-based injectable treatment that can integrate and restore the adipose tissue in these affected fat compartments.

Late-Onset Reactions after Hyaluronic Acid Dermal Fillers: A Consensus Recommendation on Etiology, Prevention and Management.

Hyaluronic acid (HA) dermal fillers, generally considered low-risk, can lead to rare late-onset reactions (LORs) manifesting between 3 and 4 months postinjection, occasionally even as early as 24h postinjection. The Complication Assessment and Risk Evaluation (CARE) board was established to review these reactions. In this publication, the authors aims to explore the etiological hypotheses underlying LORs, associated risk factors, prevention, and management approaches suggested by the CARE board. The CARE board identified three etiological hypotheses contributing to LORs. Firstly, the physicochemical structure of the filler, particularly low molecular weight HA, which may trigger an immune response. Secondly, infection, potentially introduced during injection or by dormant biofilm activation. Lastly, an imbalance in the host immune system, caused by factors like autoimmune diseases or viral infections, may lead to extended foreign body reactions, delayed type IV hypersensitivity, or adjuvant-based reactions. Based on these hypotheses, the board categorized various risk factors as patient-related (e.g., recent dental treatment, current medical status, active autoimmune disease), product-related (e.g., molecular weight), and procedure-related (e.g., aseptic technique and trauma). To reduce the risk of LORs, the CARE board recommends diligent patient selection, including comprehensive medical history assessment and informed consent. Practitioners should maintain an effective aseptic technique, and choose an appropriate product and injection depth for the anatomical location. Post-procedure, patients should receive education on proper filler care. Management of LORs depends on the suspected etiology, and the CARE board has proposed an algorithm to determine the most appropriate treatment. Hyaluronidase is recommended for noninflammatory reactions in the absence of active infection, while watchful waiting and/or steroid treatment may be preferred for inflammatory reactions. Hyaluronidase is not recommended as a first-line treatment for infections, which require drainage, bacterial culture, and antibiotic treatment. However, the board emphasizes the need for individualized evaluation and treatment in all cases.

Comparison of Two Hyaluronic Acid Preparations for the Treatment of Rizoarthrosis

Osteoarthritis of the trapeziometacarpal joint (TOA) or rizoarthrosis is a pathology particularly prevalent in post-menopausal women. It can be symptomatic, with associated pain, or asymptomatic, and in this latter case it is diagnosed by radiographical examination. TOA, when symptomatic, strongly affects quality of life. The treatment of TOA involves both pharmacological and non-pharmacological treatment (including local application of heat, ultrasound and splints). The major treatments, recommended by the European League Against Rheumatism consists of corticosteroids for pain control and hyaluronic acid (HA) for amelioration of functional capacity. The present study aimed at comparing the efficacy and tolerance of intra articular injections of two HA preparations, high-low molecular weight HA (HL) (Sinovial® HL) and high molecular weight HA (HMW) (Sinovial® Mini), in patients with TOA. The observational and retrospective study involved overall 125 subjects, ageing from 45 to 85 years, who had clinical symptoms of TOA lasting at least 6 months. The patients received HL (66 subjects) or HMW (59 subjects) in two injections at baseline and after 15 days. The subjects were followed for 6 months, and the outcome measurements included pain control (through VAS scale) functional hand capacity, using the Duruoz Hand Index (DHI) and the change of the duration of morning stiffness, using the Italian version of the Health Assessment Questionnaire (HAQ). HL was found superior to HMW in all the three parameters examined, with a quicker and stronger pain relief, recovery of hand function as well as in self-assessment by the subjects. Both treatments were associated with very modest side effects. In conclusion, our data show the efficacy of HL and HMW for the treatment of TOA and the superiority of HL to HMW. Although these data are observational and retrospective, they pose the basis for future prospective studies focused on the use of HL and HMW in TOA.

Local injection therapy with hyaluronic acid preparations: in focus of rheumatologists and orthopedic traumatologists

Hyaluronic acid (HA) is an effective and safe medication for local injection therapy (LIT) widely used in the treatment of osteoarthritis (OA) of large joints. The therapeutic effect of HA is determined both by the replacement of the lubricating function of natural hyaluronate (viscosupplementation), which leads to an improvement in the biomechanical parameters of the joint, and by the biological effects that unfold when interacting with cellular receptors (CD44, RHAMM, etc.), resulting in an anti-inflammatory, anti-nociceptive and anabolic effect of HA. HA therapy has a reliable evidence base. According to a number of clinical studies and meta-analyses, LIT with HA – reduces pain intensity by 28–54 % and improves the function of the affected joint by 9–32 % compared to baseline over a 12-24 week observation period. Repeated administration of HA can delay the need for orthopedic surgery. HA extremely rarely causes serious adverse events and can also be prescribed to patients with concomitant diseases. The use of HA for the treatment of OA is included in Russian and several foreign clinical guidelines (in particular OARSI and ESCEO). A new direction in LIT for OA is therapy with combined (hybrid) HA preparations containing high molecular weight (HMW) and low molecular weight (LMW) fractions. A new HA preparation has appeared in our country, which is a stabilized, highly purified hydrogel containing 80 % HMW HA (molecular weight – 30,000 kDa) with transverse "crosslinking" BDDE (innovative ECHATM technology) and 20 % "uncluttered" linear HA (molecular weight – 1500 kDa). This product is characterized by favorable rheological parameters, which guarantee a long-term improvement in the biomechanics of the affected joint and a rapid onset of biological effects, reduction in pain and inflammation and activation of the synthesis of natural hyaluronate.