Hyaluronic Acid Concentration Research Articles

Hyaluronic Acid and Large Extracellular Vesicles (EVs) in Synovial Fluid and Plasma of Patients With End-Stage Arthritis: Positive Association of EVs to Joint Pain.

Hyaluronic acid (HA) in synovial fluid (SF) contributes to boundary lubrication with altered levels in osteoarthritis (OA) and rheumatoid arthritis (RA). SF extracellular vesicles (EVs) may participate in arthritis by affecting inflammation and cartilage degradation. It remains unknown whether HA and EVs display joint-specific alterations in arthritic SFs. We investigated the numbers and characteristics of HA-particles and large EVs in SF from knees and shoulders of 8 OA and 8 RA patients and 8 trauma controls, and in plasma from 10 healthy controls and 11 knee OA patients. The plasma and SF HA concentrations were determined with a sandwich-type enzyme-linked sorbent assay, and EVs and HA-particles were characterized from plasma and unprocessed and centrifuged SFs with confocal microscopy. The data were compared according to diagnosis, location, and preanalytical processing. The main findings were: (1) OA and RA SFs can be distinguished from trauma joints based on the distinctive profiles of HA-particles and large EVs, (2) there are differences in the SF HA and EV characteristics between shoulder and knee joints that could reflect their dissimilar mobility, weight-bearing, and shock absorption properties, (3) EV counts in SF and plasma can positively associate with pain parameters independent of age and body adiposity, and (4) low-speed centrifugation causes alterations in the features of HA-particles and EVs, complicating their examination in the original state. Arthritis and anatomical location can affect the characteristics of HA-particles and large EVs that may have potential as biomarkers and effectors in joint degradation and pain.

Effect of synergistic fermentation of Saccharomyces cerevisiae and Lactobacillus plantarum on thermal properties of hyaluronic acid-wheat starch system

Hyaluronic acid (HA), as a multifunctional hydrophilic polysaccharide, is potentially beneficial in improving the thermal stability of fermented modified starches, but relevant insights at the molecular level are lacking. The aim of this study was to investigate the effect of different levels (0 %, 3 %, 6 %, 9 %, 12 % and 15 %) of HA on the structural, thermal and pasting properties of wheat starch co-fermented with Saccharomyces cerevisiae and Lactobacillus plantarum. We found that the addition of HA increased the median particle size of fermented starch granules from 16.387 to 17.070 μm. Meanwhile, the crystallinity of fermented starch was negatively correlated with the HA content, decreasing from 14.70 % to 12.80 % (p < 0.05). Fourier transform infrared spectroscopy results confirmed that HA interacted with starch granules and water molecules mainly through hydrogen bonding. Thermal analyses showed that the thermal peak of the composite correlated with the HA concentration, reaching a maximum of 73.17 °C at 12 % HA. In addition, HA increases the pasting temperature, reduces the peak, breakdown and setback viscosities of starch. This study demonstrates the role of HA in improving the thermal stability of fermented starch, providing new insights for traditional fermented food research and the application of HA in food processing.

A quality by design approach to optimise disulfide-linked hyaluronic acid hydrogels

In this study, the disulfide-linked hyaluronic acid (HA) hydrogels were optimised for potential application as a scaffold in tissue engineering through the Quality by Design (QbD) approach. For this purpose, HA was first modified by incorporating the cysteine moiety into the HA backbone, which promoted the formation of disulfide cross-linked HA hydrogel at physiological pH. Utilising a Design of Experiments (DoE) methodology, the critical factors to achieve stable biomaterials, i.e. the degree of HA substitution, HA molecular weight, and coupling agent ratio, were explored. To establish a design space, the DoE was performed with 65 kDa, 138 kDa and 200 kDa HA and variable concentrations of coupling agent to optimise conditions to obtain HA hydrogel with improved rheological properties. Thus, HA hydrogel with a 12 % degree of modification, storage modulus of ≈2321 Pa and loss modulus of ≈15 Pa, was achieved with the optimum ratio of coupling agent. Furthermore, biocompatibility assessments in C28/I2 chondrocyte cells demonstrated the non-toxic nature of the hydrogel, underscoring its potential for tissue regeneration. Our findings highlight the efficacy of the QbD approach in designing HA hydrogels with tailored properties for biomedical applications.

Accurate prediction of hyaluronic acid concentration under temperature perturbations using near-infrared spectroscopy and deep learning

Accurate prediction of the concentration of a large number of hyaluronic acid (HA) samples under temperature perturbations can facilitate the rapid determination of HA’s appropriate applications. Near-infrared (NIR) spectroscopy analysis combined with deep learning presents an effective solution to this challenge, with current research in this area being scarce. Initially, we introduced a novel feature fusion method based on an intersection strategy and used two-dimensional correlation spectroscopy (2DCOS) and Aquaphotomics to interpret the interaction information in HA solutions reflected by the fused features. Subsequently, we created an innovative, multi-strategy improved Walrus Optimization Algorithm (MIWaOA) for parameter optimization of the deep extreme learning machine (DELM). The final constructed MIWaOA-DELM model demonstrated superior performance compared to partial least squares (PLS), extreme learning machine (ELM), DELM, and WaOA-DELM models. The results of this study can provide a reference for the quantitative analysis of biomacromolecules in complex systems.

Collagen short nanofiber-embedded chondroitin sulfate–hyaluronic acid nanocomposite: A cartilage-mimicking in situ-forming hydrogel with fine-tuned properties

In situ-forming hydrogels that possess the ability to be injected in a less invasive manner and mimic the biochemical composition and microarchitecture of the native cartilage extracellular matrix are desired for cartilage tissue engineering. Besides, gelation time and stiffness of the hydrogel are two interdependent factors that affect cells' distribution and fate and hence need to be optimized. This study presented a bioinspired in situ-forming hydrogel composite of hyaluronic acid (HA), chondroitin sulfate (CS), and collagen short nanofiber (CSNF). HA and CS were functionalized with aldehyde and amine groups to form a gel through a Schiff-base reaction. CSNF was fabricated via electrospinning, followed by fragmentation by ultrasonics. Gelation time (11–360 s) and compressive modulus (1.4–16.2 kPa) were obtained by varying the concentrations of CS, HA, CSNFs, and CSNFs length. The biodegradability and biocompatibility of the hydrogels with varying gelation and stiffness were also assessed in vitro and in vivo. At three weeks, the assessment of hydrogels' chondrogenic differentiation also yields varying levels of chondrogenic differentiation. The subcutaneous implantation of the hydrogels in a mouse model indicated no severe inflammation. Results demonstrated that the injectable CS/HA@CSNF hydrogel was a promising hydrogel for tissue engineering and cartilage regeneration.

Association between skin lymphangiogenesis parameters and arterial hypertension status in patients: An observational study.

Recent studies have indicated that the skin lymphatic system and interstitium may play a role in the pathophysiology of arterial hypertension (AH). We aimed to determine whether the set of pathway parameters described previously in rodents would allow for the distinction between hypertensive and normotensive patients. Molecular and histopathological parameters from the skin and blood of patients with AH (AH group, n = 53), resistant AH (RAH group, n = 32) and control (C group, n = 45) were used, and a statistical multivariate bootstrap methodology combining partial least squares-discriminant analysis (PLS-DA) and selectivity ratio (SR) were applied. The C vs RAH model presented the best prediction performance (AUC test = 0.90) and had a sensitivity and specificity of 73.68% and 83.33%, respectively. However, the parameters selected for the C vs AH group model were the most important for the pathway described in the rodent model, i.e., greater density of the skin lymphatic vessels (D2-40 expression) and greater number of macrophages (CD68 expression), higher expression of the messenger ribonucleic acid (mRNA) of nuclear factor of activated T cells 5 (NFAT5), vascular endothelial growth factor C (VEGFC) and podoplanin (PDPN) in the skin, greater concentration of hyaluronic acid (HA) in the skin, and lower serum concentration of VEGF-C. Our study suggests that the NFAT5/VEGF-C/lymphangiogenesis pathway, previously described in rodent studies, may also be present in human HA. Further experiments are needed to confirm our findings.

Chin reinforcement using the hyaluronic acid injectable filler VYC-20L and VYC-25L.

The chin is an essential element of the facial unit and influences how people perceive facial aesthetic appeal. Hyaluronic acid (HA) gel injections are tried-and-true therapies for regenerative therapies with a record of success in efficacy and safety. To determine the best type of concentration of HA and way of injection for deep and superficial planes of chin. VYC-20L and VYC-25L (Juvederm Voluma XC® Juvéderm Volux®; Allergan plc) are 20- and 25-mg/mL HA gels with lidocaine, respectively, were injected with cannulas and needles on the bone, respectively. Chin reinforced respecting the measures with good contouring. No serious complications. Patient was satisfied with results. We advise using VYC 20L superficially above the muscle or with a cannula for injection, and we recommend using VYC 25L in the supraperiosteal plane.

Abstract B052: Hyaluronic acid influences amino acid metabolism in glioblastoma's U87-MG cell line in a 2D culture via LAT1 transporter expression

Abstract Glioblastoma (GBM) is one of the deadliest forms of brain cancer with high inter and intra tumor heterogeneity and altered metabolism pathways. GBM’s microenvironment is highly complex and plays a key role in determining overall tumor growth and patient survival. Hyaluronic acid (HA) is one of the key components of this tumor microenvironment and is often associated with poor prognosis. HA is present in the form of polymeric chain units, and it is highly likely that the resulting molecular weight (MW) distribution influences how a tumor cell behaves. Through this study, we highlight this differential influence of HA MWs on GBM’s energy metabolism. GBM’s U87-MG cell lines were grown in an adherent culture with media supplemented with different MWs of HA (10, 60 and 500 kDa) and glucose concentrations (0 mM: glucose starved, 5.5 mM: normoglycemic and 25 mM: hyperglycemic). LC-MS analysis on supernatant media coupled with numerical analysis highlighted an interesting influence of HA on GBM’s amino acid metabolism via reduction in LAT1 transporter protein expression. The results also indicated a differential influence on mitochondrial respiration levels with changing ATP demands and a difference in the accumulation of some key products of cell fermentation (lactic acid, glutamic acid, and succinic acid). Overall, these results highlight the differential influence of HA MWs on the metabolic state of GBM. Citation Format: Ashwin A. Bale, Rohit Bhargava, Brendan Harley. Hyaluronic acid influences amino acid metabolism in glioblastoma's U87-MG cell line in a 2D culture via LAT1 transporter expression [abstract]. In: Proceedings of the AACR Special Conference on Brain Cancer; 2023 Oct 19-22; Minneapolis, Minnesota. Philadelphia (PA): AACR; Cancer Res 2024;84(5 Suppl_1):Abstract nr B052.

Histological and Molecular Assessment of Anti-inflammatory Effect of Different Concentrations of Hyaluronic Acid Injected in Inflamed Rabbit’s Tempromandibular Joint

Histological and Molecular Assessment of Anti-inflammatory Effect of Different Concentrations of Hyaluronic Acid Injected in Inflamed Rabbit’s Tempromandibular Joint

Immature mandarin orange extract increases the amount of hyaluronic acid in human skin fibroblast and keratinocytes.

Immature mandarin orange is thinned in order to maturation of orange. To use immature mandarin orange as a cosmetic functional material, we investigated the seasonal fluctuation changes in hesperidin and narirutin levels of immature mandarin oranges, and the effects on human skin cells. The contents of hesperidin from Aoshima, Otsu, and Shonan gold, is higher at about a month after flowering. Shonan gold has higher content of narirutin to compere that of Aoshima and Otsu. We found the addition of immature mandarin orange extracts to the human skin fibroblasts and keratinocytes, gene expression level of hyaluronic acid synthase and the hyaluronic acid contents in the medium are higher than that of the control. It was suggested that hesperidin in immature mandarin orange enhances the ability of skin cells to produce hyaluronic acid. Our findings indicate that the immature mandarin orange is a characteristic material on cosmetics and functional foods.

Effects of vitamin D supplementation on liver fibrogenic factors, vitamin D receptor and liver fibrogenic microRNAs in metabolic dysfunction-associated steatotic liver disease (MASLD) patients: an exploratory randomized clinical trial

Background and aimsMetabolic dysfunction-associated steatotic liver disease (MASLD) is a global metabolic problem which can lead to irreversible liver fibrosis. It has been shown that vitamin D and its receptors contribute to fibrogenic pathways in the liver. However, the effect of vitamin D supplementation on liver fibrosis related factors have not been examined. This double blinded placebo controlled clinical trial was designed to investigate the effects on vitamin D supplementation on serum levels of VDR, fibrogenic factors and fibrogenic MicroRNAs in MASLD patients.MethodsForty six MASLD patients after block matching for sex and BMI were randomly assigned to receive 4000 IU/d vitamin D or placebo for 12 weeks. Weight, height and waist circumference were measured. Serum fibrogenic microRNAs, laminin, collagen type IV, hyaluronic acid, vitamin D, VDR, PTH, blood fasting glucose, serum fasting insulin, lipid profile, ALT and AST were determined at the baseline and at the end of the trial. Insulin resistance and insulin sensitivity were calculated using the HOMA-IR and QUICKI equation.ResultsSupplementation with vitamin D for 12 weeks led to the significant increases in serum 25(OH) vitamin D, VDR and HDL-C compared to placebo (P < 0.001, P = 0.008 and P < 0.001). There were significant decreases in ALT, AST, FBS and LDL-C levels in the vitamin D group as compared to the placebo (P < 0.05). Laminin and hyaluronic acid concentrations were significantly decreased in the vitamin D group as compared to the placebo group, by -10.6 and − 28.7 ng/mL, respectively. Supplementation with vitamin D for 12 weeks resulted in a significant lower MiR-21 and MiR-122 gene expressions compared to the placebo group (P = 0.01 and P < 0.001, respectively).DiscussionAs the first randomized controlled trial on the effect of vitamin D supplementation on serum levels of VDR, fibrogenic factors and fibrogenic MicroRNAs in MASLD patients, we found a significant reduction in some liver fibrogenic factors, in liver transaminases and corresponding changes in some fibrosis-related MiRs and some metabolic factors. Further clinical trials with larger sample sizes and direct measures of liver fibrosis are needed to confirm these findings.Trial registration number(available at: http://www.irct.ir, identifier: IRCT201405251485N13), Registration date: 14-03-2017.

Mediastinal angiosarcoma mimicking constrictive pericarditis and aortic dissection: a case report

BackgroundAngiosarcomas are soft-tissue sarcomas of endothelial cells that can arise from any site in the body. Primary mediastinal angiosarcoma is rare, with an extremely poor prognosis and currently no established treatment. Mediastinal angiosarcoma is often detected as a tumor mass in the heart, lung, aorta, or pulmonary artery. However, in cases where no tumor mass is found, a definitive diagnosis is difficult without tissue biopsy, as the condition shows various, non-specific clinical findings.Case presentationA 49-year-old man had an episode of syncope while walking. Cardiac catheterization and computed tomography suggested constrictive pericarditis, aortic dissection, and coronary artery disease. Scheduled total arch replacement and coronary artery bypass grafting could not be completed because intraoperative findings indicated the presence of a malignant tumor. Only pericardiectomy was performed. Hyaluronic acid concentration in the pleural fluid was high. The diagnosis of mediastinal angiosarcoma was confirmed postoperatively.ConclusionsMediastinal angiosarcoma might mimic multiple diseases within a single case. Hyaluronic acid concentration in the pleural fluid may be a useful indicator for mediastinal angiosarcoma diagnosis.

Inorganic Phosphate-Induced Extracellular Vesicles from Vascular Smooth Muscle Cells Contain Elevated Levels of Hyaluronic Acid, Which Enhance Their Interaction with Very Small Superparamagnetic Iron Oxide Particles.

Patients with chronic kidney disease (CKD) have a high prevalence of hyperphosphatemia, where uremic toxins like inorganic phosphate (Pi) induce a cardiovascular remodeling. Related disorders like atherosclerosis bear the risk of increased morbidity and mortality. We previously found that Pi stimulates the synthesis and sulfation of the negatively charged glycosaminoglycans (GAGs) heparan sulfate and chondroitin sulfate in vascular smooth muscle cells (VSMC). Similar GAG alterations were detected in VSMC-derived exosome-like extracellular vesicles (EV). These EV showed a strong interaction with very small superparamagnetic iron oxide particles (VSOP), which are used as imaging probes for experimental magnetic resonance imaging (MRI). Hyaluronic acid (HA) represents another negatively charged GAG which is supposed to function as binding motif for VSOP as well. We investigated the effects of Pi on the amounts of HA in cells and EV and studied the HA-dependent interaction between VSOP with cells and EV. Rat VSMC were treated with elevated concentrations of Pi. CKD in rats was induced by adenine feeding. EV were isolated from culture supernatants and rat plasma. We investigated the role of HA in binding VSOP to cells and EV via cell-binding studies, proton relaxometry, and analysis of cellular signaling, genes, proteins, and HA contents. Due to elevated HA contents, VSMC and EV showed an increased interaction with VSOP after Pi stimulation. Amongst others, Pi induced hyaluronan synthase (HAS)2 expression and activation of the Wnt pathway in VSMC. An alternative upregulation of HA by iloprost and an siRNA-mediated knockdown of HAS2 confirmed the importance of HA in cells and EV for VSOP binding. The in vitro-derived data were validated by analyses of plasma-derived EV from uremic rats. In conclusion, the inorganic uremic toxin Pi induces HA synthesis in cells and EV, which leads to an increased interaction with VSOP. HA might therefore be a potential molecular target structure for improved detection of pathologic tissue changes secondary to CKD like atherosclerosis or cardiomyopathy using EV, VSOP and MRI.

Fabrication of multifunctional silk nanofibril/hyaluronic acid scaffold for spinal cord repair

Bioactive scaffolds accurately mimicking the structure and composition of the extracellular matrix have garnered significant interest in tissue engineering. In this study, we developed a platform utilizing natural silk nanofibrils, hyaluronic acid, and basic fibroblast growth factor for the purpose of promoting spinal cord regeneration by creating an optimal microenvironment. The bioactive scaffold exhibited notable characteristics such as high porosity and hydrophilicity, attributed to its unique nanostructure, high connectivity, and polysaccharide composition. Furthermore, the pore size of the scaffold can be adjusted within the range of 90 μm to 120 μm by varying the content of hyaluronic acid. In vitro, human umbilical vein endothelial cells were seeded into the scaffold, demonstrating enhanced cell viability. The scaffold facilitated cell proliferation and migration. In vivo experiments on rats indicated that the scaffold had a beneficial impact on spinal cord regeneration, creating a conducive environment for motor function recovery of the rats. This effect may be attributed to the scaffold's ability to stimulate axon growth and neuronal survival, as well as inhibit the formation of glial scars, as evidenced by the decreased expression of growth associated protein-43, microtubule-associated protein 2, and neurofilament-200. This study presents a promising method to develop a feasible bioscaffold for the treatment of spinal cord injury.

Comparison of Hyaluronidase-Mediated Degradation Kinetics of Commercially Available Hyaluronic Acid Fillers In Vitro.

Hyaluronic acid (HA)-based fillers are degradable with hyaluronidase, which allows for better management of adverse effects and reversal of suboptimal treatment outcomes. To compare the enzymatic degradation kinetics of 16 commercially available HA-based fillers, representing 6 manufacturing technologies. In this nonclinical study, a recently developed in vitro multidose hyaluronidase administration protocol was used to induce degradation of HA-based fillers, which allowed for real-time evaluation of viscoelastic properties at near static conditions. Each filler was exposed to repeated doses of hyaluronidase at intervals of 5 minutes to reach the degradation threshold of G' ≤ 30 Pa. Noticeable differences in degradation characteristics were observed based on the design and technology of different filler classes. Vycross fillers were the most difficult to degrade and the Cohesive Polydensified Matrix filler was the least difficult to degrade. Preserved Network Technology products demonstrated proportional increases in gel degradation time and enzyme volume required for degradation across the individual RHA products and indication categories. No obvious relationship was observed between gel degradation characteristics and the individual parameters of HA concentration, HA chain length, or the degree of modification of each filler when analyzed separately; however, a general correlation was identified with certain physicochemical properties. Manufacturing technology was the most important factor influencing the reversibility of an HA product. An understanding of the differential degradation profiles of commercially available fillers will allow clinicians to select products that offer a higher margin of safety due to their preferential reversibility.

Influence of initial glucose and lactic acid concentration on hyaluronic acid production by Streptococcus zooepidemicus: Kinetic and modeling

Hyaluronic acid (HA) is a molecule of significant commercial value with applications in the pharmaceutical, cosmetic, and medical industries. It is typically produced through microbial fermentation. However, the efficiency of this type of process can be affected by inhibition phenomena due to the substrate or the product. In this sense, the effect of different initial concentrations of glucose (9.3–59.9 g/L) and lactic acid (10.7–56.0 g/L) was studied in the present investigation to determine their effect on the growth of Streptococcus zooepidemicus and HA production in batch fermentation. The maximum HA concentration obtained was 3.3 g/L from 59.9 g/L glucose, while productivity, yield, and specific rate of HA formation were higher at 31.9 g/L glucose. The biomass produced followed a stepwise pattern with increasing glucose, although the specific growth rate decreased after reaching 39.1 g/L glucose. The initial presence of lactic acid (LA) hurt fermentation, decreasing the amount of biomass and HA produced; the inhibitory effect of LA was more pronounced at 19.4 g/L and above, decreasing productivities, yields, and specific rates. Compared to experimental data, the proposed mathematical model described satisfactorily (R2 > 0.9) the dynamics of the fermentation process at different culture conditions.

The roles of autophagy in the treatment of diabetic nephropathy with rapamycin.

Rapamycin is known to induce autophagy, promote cell survival and inhibit the progression of diabetic nephropathy (DN). The aim of this study was to examine the role of autophagy in the treatment of DN with rapamycin to provide the basis for the DN treatment with rapamycin. Human mesangial cells (HMC) were cultured in a constant temperature incubator with 5% CO2, at 37°C and saturated humidity. Cells were divided into 5 groups and the 5-ethynyl-2-deoxyuridine (EdU) cell proliferation assay was used to determine cell proliferation. Flow cytometry was used to determine cell apoptosis, while GFP-RFP-LC3 showed autophagy flow. Western blot was employed to detect the expression of autophagy-related proteins LC3-II/LC3-I and P62. Enzyme-linked immunosorbent assay (ELISA) was used to determine the contents of type IV collagen fiber (Col4), hyaluronic acid (HA) and laminin (LA) in the extracellular matrix (ECM). Cell proliferation was the lowest in the hyperglycemic group. Additionally, the hyperglycemic group displayed the lowest number of autolysosomes compared to other groups. In contrast, the rapamycin group exhibited the highest number of autolysosomes. The LC3-II/LC3-I ratio was also the lowest in the hyperglycemic group, measuring 0.53 (0.50-0.58), while the expression level of P62 was significantly higher in that group at 0.98 (0.95-1.01) compared to other groups. Upon the introduction of rapamycin, the LC3-II/LC3-I ratio was significantly increased at 2.21 (1.95-2.21), and P62 was significantly decreased 0.38 (0.38-0.39) compared to the hyperglycemic group. Both changes were statistically significant, with p-values of 0.034 and 0.010, respectively. Enzyme-linked immunosorbent assay was employed to detect Col4, HA and LA content. The study findings demonstrated significantly higher levels of glucose in the hyperglycemic group in comparison to other groups. In contrast, the rapamycin group exhibited significantly lower levels of glucose than the hyperglycemic group, yet the difference was not statistically significant. Hyperglycemic can inhibit the autophagic activity of HMC, promote cell apoptosis, enhance ECM accumulation, and facilitate the DN progression. In contrast, rapamycin can elicit autophagy, decrease mesangial matrix proliferation, and therefore impede DN progression.

In Vitro Evaluation of Soft Contact Lens Wettability With a Nonmodified Commercial Videokeratoscope.

To evaluate a new in vitro technique for measuring soft contact lens wettability using a nonmodified commercial videokeratoscope, the Medmont E300. To this end, the capability of different artificial tears containing hyaluronic acid (HA) to improve soft contact lens wettability in vitro was investigated. An experimental in vitro study was conducted to assess the wetting properties of three artificial tears containing different concentrations of HA (0.1%, 0.2%, and 0.3%) on soft contact lenses. A saline solution was used as the control. For each solution, 15 hydrogel (Ocufilcon D) contact lenses and 15 silicone-hydrogel (Somofilcon A) contact lenses were evaluated. The in vitro wettability of the lenses was measured using the Medmont E300 with a self-developed technique, which involved measuring the tear film surface quality (TFSQ) mean, TFSQ area, TFSQ central, and TFSQ inferior. Compared with the saline solution, all the concentration of HA (0.1%, 0.2%, and 0.3%) improved the in vitro wettability of both soft contact lenses by decreasing their TFSQ mean and TFSQ area ( P <0.05). Regression models revealed an exponential relationship between contact lens wettability and the concentration of HA for both soft contact lenses ( R >0.5, P <0.05). Furthermore, the hydrogel contact lens presented a wetter surface than the silicone-hydrogel contact lens ( P <0.05). The measurement of in vitro wettability of soft contact lenses with a nonmodified Medmont E300 seems to be a useful technique to evaluate the wetting properties of contact lens products.

Clinical Perspectives on the Injectability of Cross-Linked Hyaluronic Acid Dermal Fillers: A Standardized Methodology for Commercial Product Benchmarking with Inter-Injector Assessments.

The injectability of cross-linked hyaluronic acid (HA) dermal fillers is influenced by polymer concentration, polymer cross-linking type and degree, the presence of lidocaine or other functional excipients, types of syringes, and injection techniques. Finished product injectability constitutes a critical quality attribute for clinical injectors, as it strongly influences product applicability and ease of use in aesthetic medicine. While injectable product extrusion force specifications are provided by the respective device manufacturers, the qualitative informative value of such datasets is low for injectors wishing to compare product brands and technologies from an injectability standpoint. Therefore, the present study comparatively assessed 28 cross-linked HA dermal fillers (JUVÉDERM®, Restylane®, BELOTERO®, TEOSYAL RHA®, and STYLAGE® brands) using various injectability benchmarking setups for enhanced clinical-oriented relevance. Manual product injections were performed by three specialized and experienced clinicians, whereas automatic product extrusion was performed using a Texture Analyzer instrument. The various hydrogel products were injected into ex vivo human skin and into SimSkin® cutaneous equivalents to appropriately account for injection-related counterpressure. The injectability results revealed important variability between and within product brands, with a strong influence of the local anesthetic lidocaine, HA contents, and needle gauge size. Critical appraisals of the investigated products were performed, notably from manufacturing process-based and clinical ease of application-based standpoints, centered on respective experimental injectability quality levels. Generally, it was confirmed that each HA-based dermal filler product requires specific expertise for optimal injection, mainly due to differing viscoelastic characteristics and injectability attributes. Overall, the present study set forth evidence-based and clinical-oriented rationale elements confirming the importance for injectors to work with injectable products with which they are experienced and comfortable to optimize clinical results.

Evaluation of Antioxidants’ Ability to Enhance Hyaluronic Acid-Based Topical Moisturizers

Introduction: Hyaluronic acid (HA) is a unique molecule with multiple biological activities. In skin, HA plays an essential role as a humectant, capable of binding up to 1000 times its mass with water, leading to both skin moisturization and extracellular matrix rigidity. HA concentration and synthesis decreases significantly in aging skin, due to exogenous and endogenous factors, including photoaging and HA metabolism, respectively. A key driver for HA degradation and decrease in concentration is mediated via the induction of reactive oxygen species (ROS) and other free radicals. In this study, we evaluate antioxidant ingredients essential in the development of next-generation multi-weight HA-based topical formulations aimed at leveraging hyaluronic acid’s ability to maximize anti-aging properties. Methods: Two antioxidants, glycine saponin and glycyrrhetinic acid, were evaluated for stimulation of endogenous HA production and inhibition of endogenous hyaluronidase activity in an in vitro and cell-free assay. Results: The antioxidant glycine saponin induced endogenous HA synthesis in keratinocytes, while the antioxidant glycyrrhetinic acid demonstrated an approximately 54% reduction of hyaluronidase activity for the HA-degrading enzyme HYAL1. Conclusion: This study demonstrates the ability of two antioxidants (glycine saponin and glycyrrhetinic acid, essential in the development of the next generation of multi-weight HA plus antioxidant complex-based topical skin formulations) to limit the signs of aging skin, addressing limitations of many currently available topical HA-based formulations.