Hyaluronic Acid in the Third Millennium

Hyaluronic acid promotes heat-induced gelation of ginkgo seed proteins

This study aimed to investigate how varying concentrations (0.01-0.5 %, w/v) and molecular weights (50, 500, 1500 kDa) of hyaluronic acid (HA) affect the physicochemical properties of heat-induced ginkgo seed protein isolate (GSPI)-HA composite gel. Incorporating HA increased viscosity (up to 14 times) and charge (up to 23 %) of GSPI-HA aggregates, while reducing particle size (up to 31 %) and improving gel texture, particularly with high molecular weight HA. However, high concentrations (0.5 %, w/v) of HA weakened gel texture. Non-covalent bonds primarily drive the formation of a continuous gel network between HA and GSPI, resulting in small pores and enhanced hydration properties. With increasing HA molecular weight, non-covalent interactions between GSPI and HA increased, leading to improved gel thermal stability. Overall, the study suggests that manipulating the molecular weight and concentration of HA can enhance the gelling properties of GSPI, leading to the development of a diverse array of GSPI-HA composite gels with varied properties.

Injectable Salecan/hyaluronic acid-based hydrogels with antibacterial, rapid self-healing, pH-responsive and controllable drug release capability for infected wound repair

Designing materials for wound dressings with superior therapeutic benefits, self-healing and injectable characteristics is important in clinical practice. Herein, a new self-healing injectable hydrogel was prepared via thermal treatment and dynamic Schiff base reaction by mixing oxidized hyaluronic acid (OHA) and hydrazided Salecan (Sal-ADH). The versatility of the wound dressing was confirmed by studying the inherent rheological properties, high swelling rate, sustained-release behavior of the drug, pH/hyaluronidase-dependent biodegradation, in vitro antimicrobial as well as in vivo wound healing performance. The presence of the antimicrobial drug polyhexamethylene biguanide (PHMB) conferred good antimicrobial properties to the Sal-ADH/OHA/PHMB (SOP) hydrogel, which could effectively prevent wound infection (the width of the inhibition circle of SOP-0.20 hydrogel was 4.97 mm, 5.93 mm for Staphylococcus aureus and Escherichia coli, respectively). The findings suggested that SOP hydrogel exhibited remarkable self-healing and injectability properties, as well as excellent hemostasis and biocompatibility. In vivo experiments indicated that the application of SOP hydrogels would obviously accelerate wound healing and attenuate the inflammatory response while increasing collagen deposition and angiogenesis. Altogether, antibacterial SOP hydrogels with moderate mechanical properties, pH-responsive release, excellent injectability, exceptional self-healing ability and anti-inflammatory effects could expand potential applications of injectable hydrogels in the biomedical field.

Design and preparation of hydrogel microspheres for spinal cord injury repair

A severe disorder known as spinal cord damage causes both motor and sensory impairment in the limbs, significantly reducing the patients' quality of life. After a spinal cord injury, functional recovery and therapy have emerged as critical concerns. Hydrogel microspheres have garnered a lot of interest lately because of their enormous promise in the field of spinal cord injury rehabilitation. The material classification of hydrogel microspheres (natural and synthetic macromolecule polymers) and their synthesis methods are examined in this work. This work also covers the introduction of several kinds of hydrogel microspheres and their use as carriers in the realm of treating spinal cord injuries. Lastly, the study reviews the future prospects for hydrogel microspheres and highlights their limitations and problems. This paper can offer feasible ideas for researchers to advance the application of hydrogel microspheres in the field of spinal cord injury.

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.

Excipient-free nanotransformation of hydrophilic macromolecules using aqueous counter collision for enhanced bioavailability

The demand for sustainable, eco-friendly biopolymer transdermal delivery systems has increased owing to growing environmental awareness. In this study, we used aqueous counter collision (ACC), a nontoxic nanotransformation method, to convert high- and ultrahigh-molecular-weight hydrophilic macromolecules into their corresponding nanoparticles (NPs). Hyaluronic acid (HA) and crosslinked HA (CLHA) were chosen as the model compounds. Their NPs exhibited particle sizes in the range of 10-100 nm and negative zeta potentials (-20 to -30 mV). Transmission electron microscopy revealed that the NPs were nearly spherical with smooth surfaces. Fourier-transform infrared and proton nuclear magnetic resonance spectroscopy and agarose gel electrophoresis confirmed that the structures and molecular weights of HA and CLHA remained unaltered after ACC. However, the storage and loss moduli of HANPs and CLHANPs were significantly lower than those of HA and CLHA, respectively. Furthermore, the permeation of HANPs and CLHANPs in reconstructed human skin and human cadaver skin was visualized and quantified. HANPs and CLHANPs penetrated deeper into the skin, whereas HA and CLHA were mainly found in the stratum corneum. The total skin absorption (permeation and deposition) of HANPs and CLHANPs was approximately 2.952 and 5.572 times those of HA and CLHA, respectively. Furthermore, HANPs and CLHANPs exhibited resistance to enzyme and free radical degradation. Our findings reveal ACC as a promising, sustainable hydrophilic macromolecule delivery system compared with the chemical hydrolysis of HA.

Hyaluronan size and concentration: Effect on key biophysical and biochemical features

The effect of hyaluronan (HA) molecular weight (MW) and concentration (c) on key features of HA-formulations was systematically studied, in vitro, exploring the widest range/number of MW/c to date. Nine pharmaceutical-grade HA-samples (60-2500 kDa) were hydrodynamically characterized using Size-Exclusion-Chromatography-Triple-Detector-Array (SEC-TDA) also providing conformational data. HAs aqueous solutions (thirteen concentrations in the range 0.1-32 g/L) were tested for dynamic viscosity (η). η dependence on MW/c was analyzed providing mathematical correlations not only for the specific-zero-shear-viscosity, but also for the critical-shear-rate and the shear-thinning-extent. Besides confirming the dilute- and semi-dilute- c-regimes for the HAs, a third concentrated regime was evidenced for the 220-2500 kDa samples. Data on how MW affects the dependence of viscosity parameters on c and vice-versa were provided. The 60-90 kDa HAs proved stable to thermal sterilization and enzymatically catalyzed hydrolysis, while the 220-2500 kDa samples depolymerized to an extent depending, beyond concentration, on MW. HA size did not significantly affect fibroblasts behavior: under the conditions here tested, the HAs similarly sustained human-dermal-fibroblasts growth and wound-healing also showing comparable effect on collagen-I, elastin and hyaluronan-synthase-1 expression. Overall, results valuably contribute to the understanding of the HA MW/c impact on the rheological, stability and biochemical features of the final formulations also providing mathematical correlations allowing for their optimization towards specific performance.

Topical hADSCs-HA Gel Promotes Skin Regeneration and Angiogenesis in Pressure Ulcers by Paracrine Activating PPARβ/δ Pathway

Background

Pressure ulcer is common in the bedridden elderly with high mortality and lack of effective treatment. In this study, human-adipose-derived-stem-cells-hyaluronic acid gel (hADSCs-HA gel) was developed and applied topically to treat pressure ulcers, of which efficacy and paracrine mechanisms were investigated through in vivo and in vitro experiments.

Methods

Pressure ulcers were established on the backs of C57BL/6 mice and treated topically with hADSCs-HA gel, hADSCs, hyaluronic acid, and normal saline respectively. The rate of wound closure was observed continuously during the following 14 days and the wound samples were obtained for Western blot, histopathology, immunohistochemistry, and proteomic analysis. Human dermal fibroblasts (HDFs) and human venous endothelial cells (HUVECs) under normal or hypoxic conditions were treated with conditioned medium of human ADSCs (ADSC-CM), then CCK-8, scratch test, tube formation, and Western blot were conducted to evaluate the paracrine effects of hADSCs and to explore the underlying mechanism.

Results

The in vivo data demonstrated that hADSCs-HA gel significantly accelerated the healing of pressure ulcers by enhancing collagen expression, angiogenesis, and skin proliferation. The in vitro data revealed that hADSCs strengthened the proliferation and wound healing capabilities of HDFs and HUVECs, meanwhile promoted collagen secretion and tube formation through paracrine mode. ADSC-CM was also proved to exert protective effects on hypoxic HDFs and HUVECs. Besides, the results of proteomic analysis and Western blot elucidated that lipid metabolism and PPARβ/δ pathway mediated the healing effect of hADSCs-HA gel on pressure ulcers.

Conclusion

Our research showed that topical application of hADSCs-HA gel played an important role in dermal regeneration and angiogenesis. Therefore, hADSCs-HA gel exhibited the potential as a novel stem-cell-based therapeutic strategy of treating pressure ulcers in clinical practices.

Strontium ranelate-loaded human hair keratin-hyaluronic acid hydrogel accelerates wound repair with anti-inflammatory and antioxidant properties

Inflammation and reactive oxygen species (ROS) production often accompany the repair of severe skin wounds, and the management of wounds has always been a clinical challenge, so the design of a hydrogel wound dressing with antioxidant and anti-inflammatory properties is of significant importance. This work incorporated strontium ranelate (SrR) into the keratin/hyaluronic acid (K/HA) hydrogel, which could scavenge ROS and reduce inflammation. The optimized hydrogel exhibits large pore size (217.2 μm), high porosity (57 %), high swelling rate (1759.52 %), and an elastic modulus (3.41 kPa). In the in vitro study, incorporating SrR into hydrogel effectively inhibited oxidative damage in mouse fibroblasts (L929) and improved anti-inflammatory effect in RAW264.7 cells stimulated by lipopolysaccharide. The in vivo study showed that, compared with the control group, the expression of ROS, IL-6 and TNF - α in the K/HA/0.5 mM SrR group were significantly reduced to 31.6 %, 39.7 % and 61.1 %, respectively. The in vivo evaluation in a full-thickness wound defect model demonstrated that K/HA/0.5 mM SrR hydrogel promotes wound healing by attenuating ROS levels, reducing inflammation, and promoting microangiogenesis. In summary, the excellent ROS scavenging and anti-inflammatory properties of SrR make the K/HA/SrR hydrogel a promising and effective strategy for wound healing.

The Pathogenetic Role of RANK/RANKL/OPG Signaling in Osteoarthritis and Related Targeted Therapies

Background: Osteoarthritis (OA) is the most common degenerative joint disease and affects millions of people worldwide, particularly the elderly population. The pathophysiology of OA is complex and involves multiple factors. Methods: Several studies have emphasized the crucial role of inflammation in this process. The receptor activator of NF-κB ligand (RANKL), the receptor activator of NF-κB (RANK), and osteoprotegerin (OPG) trigger a signaling cascade that leads to the excessive production of RANKL in the serum. Conclusions: The aim of this narrative review is (i) to assess the role of the RANK/RANKL/OPG signaling pathway in the context of OA progression, focusing especially on the physiopathology and on all the mechanisms leading to the activation of the inflammatory cascade, and (ii) to evaluate all the potential therapeutic strategies currently available that restore balance to bone formation and resorption, reducing structural abnormalities and relieving pain in patients with OA.

Hydrogel Applications in the Diagnosis and Treatment of Glioblastoma

Glioblastoma multiforme (GBM), a common malignant neurological tumor, has boundaries indistinguishable from those of normal tissue, making complete surgical removal ineffective. The blood-brain barrier (BBB) further impedes the efficacy of radiotherapy and chemotherapy, leading to suboptimal treatment outcomes and a heightened probability of recurrence. Hydrogels offer multiple advantages for GBM diagnosis and treatment, including overcoming the BBB for improved drug delivery, controlled drug release for long-term efficacy, and enhanced relaxation properties of magnetic resonance imaging (MRI) contrast agents. Hydrogels, with their excellent biocompatibility and customizability, can mimic the in vivo microenvironment, support tumor cell culture, enable drug screening, and facilitate the study of tumor invasion and metastasis. This paper reviews the classification of hydrogels and recent research for the diagnosis and treatment of GBM, including their applications as cell culture platforms and drugs including imaging contrast agents carriers. The mechanisms of drug release from hydrogels and methods to monitor the activity of hydrogel-loaded drugs are also discussed. This review is intended to facilitate a more comprehensive understanding of the current state of GBM research. It offers insights into the design of integrated hydrogel-based GBM diagnosis and treatment with the objective of achieving the desired therapeutic effect and improving the prognosis of GBM.

Homologous cell membrane-based hydrogel creates spatiotemporal niches to improve outcomes of dysregulated chronic wound healing

The (M2M + TGF-β)@HAMA hydrogel dressing improves the outcomes of dysregulated chronic wound healing by protecting the open wound from repeated bacterial infections, reprogramming endogenous monocytes and M1 macrophages into an M2-phenotype, as well as enhancing fibroblastic proliferation and migration for matrix remodeling and granulation tissue formation.Image 1.

Antibacterial properties of photo-crosslinked chitosan/methacrylated hyaluronic acid nanoparticles loaded with bacitracin

The current treatments for wounds often fail to induce adequate healing, leaving wounds vulnerable to persistent infections and development of drug-resistant microbial biofilms. New natural-derived nanoparticles were studied to impair bacteria colonization and hinder the formation of biofilms in wounds. The nanoparticles were fabricated through polyelectrolyte complexation of chitosan (CS, polycation) and hyaluronic acid (HA, polyanion). UV-induced photo-crosslinking was used to enhance the stability of the nanoparticles. To achieve this, HA was methacrylated (HAMA, degree of modification of 20 %). Photo-crosslinked nanoparticles obtained from HAMA and CS had a diameter of 478 nm and a more homogeneous size distribution than nanoparticles assembled solely through complexation (742 nm). The nanoparticles were loaded with the antimicrobial agent bacitracin (BC), resulting in nanoparticles with a diameter of 332 nm. The encapsulation of BC was highly efficient (97 %). The BC-loaded nanoparticles showed significant antibacterial activity against gram-positive bacteria Staphylococcus aureus, Methicillin-resistant S. aureus and S. epidermidis. Photo-crosslinked HAMA/CS nanoparticles loaded with BC demonstrated inhibition of biofilm formation and a positive effect on the proliferation of mammalian cells (L929). These crosslinked nanoparticles have potential for the long-term treatment of wounds and controlled antibiotic delivery at the location of a lesion.

Hydrogels with Antioxidant Microparticles Systems Based on Hyaluronic Acid for Regenerative Wound Healing

This research focuses on the synthesis of hydrogels exhibiting enhanced antioxidant properties derived from hyaluronic acid (HA) and poly(ethylene brassylate-co-squaric acid) (PEBSA), a copolymacrolactone that have the ability to be used in drug delivery applications. Quercetin (Q), a bioflavonoid with strong antioxidant properties, is employed as a bioactive compound. The biomolecule is encapsulated in the polymeric network using different entrapment techniques, including the initial formation of a complex between PEBSA and Q, which is demonstrated through the dynamic light scattering technique. Fourier transform infrared spectroscopy (FT-IR) and rheological studies confirm the formation of the hydrogels, revealing the occurrence of physical interactions between the synthetic polymer and the polysaccharide. Moreover, the hydrogels demonstrate biocompatible properties after direct contact with the HDFa cell line and antioxidant properties, as revealed by DPPH tests.

Application of the Thermal Analysis of Frozen Aqueous Solutions to Assess the Miscibility of Hyaluronic Acid and Polymers Used for Dissolving Microneedles

Background: The combination of multiple polymers is anticipated to serve as a means to diversify the physical properties and functionalities of dissolving microneedles. The mixing state of components is considered as a crucial factor in determining their suitability. Objectives: The purpose of this study was to elucidate whether thermal analysis of frozen aqueous solutions can appropriately predict the miscibility of hyaluronic acid (HA) and other polymers used for dissolving microneedles prepared by a micromolding method. Methods: Aliquots of aqueous polymer solutions were applied for thermal analysis by heating the samples from -70 °C at 5 °C/min to obtain the transition temperature of amorphous polymers and/or the crystallization/melting peaks of polymers (e.g., polyethylene glycol (PEG)). Films and dissolving microneedles were prepared by air-drying of the aqueous polymer solutions to assess the polymer miscibility in the solids. Results: The frozen aqueous single-solute HA solutions exhibited a clear Tg' (the glass transition temperature of maximally freeze-concentrated solutes) at approximately -20 °C. The combination of HA with several polymers (e.g., dextran FP40, DEAE-dextran, dextran sulfate, and gelatin) showed a single Tg' transition at temperatures that shifted according to their mass ratio, which strongly suggested the mixing of the freeze-concentrated solutes. By contrast, the observation of two Tg' transitions in a scan strongly suggested the separation of HA and polyvinylpyrrolidone (PVP) or HA and polyacrylic acid (PAA) into different freeze-concentrated phases, each of which was rich in an amorphous polymer. The combination of HA and PEG exhibited the individual physical changes of the polymers. The polymer combinations that showed phase separation in the frozen solution formed opaque films and microneedles upon their preparation by air-drying. Coacervation occurring in certain polymer combinations was also suggested as a factor contributing to the formation of cloudy films. Conclusions: Freezing aqueous polymer solutions creates a highly concentrated polymer environment that mimics the matrix of dissolving microneedles prepared through air drying. This study demonstrated that thermal analysis of the frozen solution offers insights into the mixing state of condensed polymers, which can be useful for predicting the physical properties of microneedles.

Manufacturing Process of Hyaluronic Acid Dermal Fillers

Hyaluronic acid (HA) fillers are extensively utilized in aesthetic medicine due to their biocompatibility, reversibility, and effectiveness in enhancing skin hydration, volume, and overall appearance. These fillers are predominantly produced through microbial fermentation, followed by a critical cross-linking process that enhances their longevity by resisting enzymatic degradation. This review provides a thorough examination of the manufacturing processes that differentiate HA fillers, with particular attention to the distinctions between biphasic and monophasic variants. Unlike previous studies, this review emphasizes the specific cross-linking techniques and their substantial impact on the fillers' rheological properties, such as elasticity and cohesiveness, which are crucial to their clinical performance and patient outcomes. Additionally, the review offers a comprehensive comparison of HA fillers with non-HA alternatives, including calcium hydroxylapatite, poly-l-lactic acid, and polymethyl methacrylate, highlighting the unique advantages and potential complications associated with each type. By presenting novel insights into the latest advancements and challenges in filler technology, this review aims to provide clinicians with a deeper understanding of filler properties, thereby guiding them in making informed decisions to optimize patient safety and aesthetic results.

Targeting inflammation with hyaluronic acid-based micro- and nanotechnology: A disease-oriented review

Inflammation is a pivotal immune response in numerous diseases and presents therapeutic challenges. Traditional anti-inflammatory drugs and emerging cytokine inhibitors encounter obstacles such as limited bioavailability, poor tissue distribution, and adverse effects. Hyaluronic acid (HA), a versatile biopolymer, is widely employed to deliver therapeutic agents, including anti-inflammatory drugs, genes, and cell therapies owing to its unique properties, such as hydrophilicity, biodegradability, and safety. HA interacts with cell receptors to initiate processes such as angiogenesis, cell proliferation, and immune regulation. HA-based drug delivery systems offer dual strategies for effective inflammation management, capitalizing on passive and active mechanisms. This synergy permits the mitigation of inflammation by lowering the doses of anti-inflammatory drugs and their off-target adverse effects. A diverse array of micro- and nanotechnology techniques enable the fabrication of tailored HA-engineered systems, including hydrogels, microgels, nanogels, microneedles, nanofibers, and 3D-printed scaffolds, for diverse formulations and administration routes. This review explores recent insights into HA pharmacology in inflammatory conditions, material design, and fabrication methods, as well as its applications across a spectrum of inflammatory diseases, such as atherosclerosis, psoriasis, dermatitis, wound healing, rheumatoid arthritis, osteoarthritis, inflammatory bowel disease, and colitis, highlighting its potential for clinical translation.

Influence of Anticoagulants and Heparin Contaminants on the Suitability of MMP-9 as a Blood-Derived Biomarker

In contrast to other common anticoagulants such as citrate and low-molecular-weight heparin (LMWH), high-molecular-weight heparin (HMWH) induces the expression of matrix metalloproteinase (MMP)-9, which is also measured as a biomarker for stroke in blood samples. Mechanistically, HMWH-stimulated T cells produce cytokines that induce monocytic MMP-9 expression. Here, the influence of further anticoagulants (Fondaparinux, Hirudin, and Alteplase) and the heparin-contaminating glycosaminoglycans (GAG) hyaluronic acid (HA), dermatan sulfate (DS), chondroitin sulfate (CS), and over-sulfated CS (OSCS) on MMP-9 was analyzed to assess its suitability as a biomarker under various conditions. Therefore, starved Jurkat T cells were stimulated with anticoagulants/contaminants. Subsequently, starved monocytic THP-1 cells were incubated with the conditioned Jurkat supernatant, and MMP-9 mRNA levels were monitored (quantitative (q)PCR). Jurkat-derived mediators secreted in response to anticoagulants/contaminants were also assessed (proteome profiler array). The supernatants of HMWH-, Hirudin-, CS-, and OSCS-treated Jurkat cells comprised combinations of activating mediators and led to a significant (in the case of OSCS, dramatic) MMP-9 induction in THP-1. HA induced MMP-9 only in high concentrations, while LMWH, Fondaparinux, Alteplase, and DS had no effect. This indicates that depending on molecular weight and charge (but independent of anticoagulant activity), anticoagulants/contaminants provoke the expression of T-cell-derived cytokines/chemokines that induce monocytic MMP-9 expression, thus potentially impairing the diagnostic validity of MMP-9.

Polymers as Efficient Non-Viral Gene Delivery Vectors: The Role of the Chemical and Physical Architecture of Macromolecules

Gene therapy is the technique of inserting foreign genetic elements into host cells to achieve a therapeutic effect. Although gene therapy was initially formulated as a potential remedy for specific genetic problems, it currently offers solutions for many diseases with varying inheritance patterns and acquired diseases. There are two major groups of vectors for gene therapy: viral vector gene therapy and non-viral vector gene therapy. This review examines the role of a macromolecule's chemical and physical architecture in non-viral gene delivery, including their design and synthesis. Polymers can boost circulation, improve delivery, and control cargo release through various methods. The prominent examples discussed include poly-L-lysine, polyethyleneimine, comb polymers, brush polymers, and star polymers, as well as hydrogels and natural polymers and their modifications. While significant progress has been made, challenges still exist in gene stabilization, targeting specificity, and cellular uptake. Overcoming cytotoxicity, improving delivery efficiency, and utilizing natural polymers and hybrid systems are vital factors for prospects. This comprehensive review provides an illuminating overview of the field, guiding the way toward innovative non-viral-based gene delivery solutions.

Advances in Microbial Exopolysaccharides: Present and Future Applications

Microbial exopolysaccharides (EPSs) are receiving growing interest today, owing to their diversity in chemical structure and source, multiple functions, and immense potential applications in many food and non-food industries. Their health-promoting benefits for humans deserve particular attention because of their various biological activities and physiological functions. The aim of this paper is to provide a comprehensive review of microbial EPSs, covering (1) their chemical and biochemical diversity, including composition, biosynthesis, and bacterial sources belonging mainly to lactic acid bacteria (LAB) or probiotics; (2) their technological and analytical aspects, especially their production mode and characterization; (3) their biological and physiological aspects based on their activities and functions; and (4) their current and future uses in medical and pharmaceutical fields, particularly for their prebiotic, anticancer, and immunobiotic properties, as well as their applications in other industrial and agricultural sectors.

Delivery of Nitric Oxide by Chondroitin Sulfate C Increases the Rate of Wound Healing through Immune Modulation

Chronic wounds impact 2.5% of the United States population and will continue to be a major clinical challenge due to increases in population age, chronic disease diagnoses, and antibiotic-resistant infection. Nitric oxide (NO) is an endogenous signaling molecule that represents an attractive, simple therapeutic for chronic wound treatment due to its innate antibacterial and immunomodulatory function. Unfortunately, modulating inflammation for extended periods by low levels of NO is not possible with NO gas. Herein, we report the utility of a NO-releasing glycosaminoglycan biopolymer (GAG) for promoting wound healing. GAGs are naturally occurring biopolymers that are immunomodulatory and known to be involved in the native wound healing process. Thus, the combination of NO and GAG biopolymers represents an attractive wound therapeutic due to these known independent roles. The influence and contribution of chondroitin sulfate C (CSC) modified to facilitate controlled and targeted delivery of NO (CSC-HEDA/NO) was evaluated using in vitro cell proliferation and migration assays and an in vivo wound model.

Predictors of Satisfaction in Patients with Knee Osteoarthritis Treated with a Single Injection of Mannitol-Modified Crosslinked Hyaluronate Derivative

Background/Objectives: There is a gap between the very positive opinion of patients and doctors regarding knee viscosupplementation (VS) and the contrasting results of controlled studies. The objective of this study was to evaluate the overall satisfaction and predictors of satisfaction with VS in patients with knee osteoarthritis treated with VS. Methods: Post-hoc analysis of a cross-sectional study in patients with knee OA treated with one injection of a mannitol-modified cross-linked HA (HANOX-M-XL). The primary outcome was satisfaction, self-assessed semi-quantitatively by the patients. Demographics, radiological features, comorbidities, OA and comorbidities treatments, and lifestyle associated with satisfaction were studied in bivariate and multivariate analysis. Results: 89 patients (124 knees) were analyzed. A total of 88.7% were satisfied with the treatment. Satisfaction was correlated with duration of effectiveness (DoE) and negatively correlated with BMI. Satisfaction was higher in active versus sedentary patients, in tibiofemoral involvement, in Kellgren-Lawrence grade 1-3 versus 4, and in subjects not requiring intraarticular corticosteroid (IACS) concomitantly to VS. Satisfied subjects were older than dissatisfied ones. In multivariate analysis, older age, K-L grade < 4, absence of IACS, and longer DoE were associated with higher rates of satisfaction. Conclusions: We identified several predictive factors of patient satisfaction after VS of the knee. Alongside these objective factors, there are probably subjective factors linked to patient beliefs, fears, and expectations impacting satisfaction.

Fast one-step acrylate functionalization of hyaluronic acid via Williamson ether synthesis

The synthetic route presented for acrylate-modified hyaluronic acid (HA-A-BEA) offers a simple and efficient process, reducing reaction time and purification steps while retaining biocompatibility. This study demonstrates the ability of HA-A-BEA to form tunable hydrogels via versatile techniques suitable for biomedical applications.

Evaluation of enteral and parenteral hyaluronic acid in induced ischemic skin flaps in rats: a double-blinded and randomized study

PURPOSE

To evaluate exogenous hyaluronic acid (HA) derived from bacterial fermentation through enteral and parenteral routes in ischemic skin flaps induced in rats, using clinical and histological exams; and interleukins (IL) as tissue inflammatory biomarkers.

METHODS

Sixty-four male adults Wistar rats with ischemic skin flaps on the dorsum were randomized into four groups, based on the treatment protocol: subcutaneous administration of saline solution (0.9%) (GI); oral administration of distilled water (GII); subcutaneous administration of HA (0.3%) (GIII); and oral administration of HA (1%) (GIV). Flaps of all groups were comparable regarding clinical and macroscopic evaluation, histological examination, pro-inflammatory cytokines (IL-1β, IL-6, and tumor necrosis factor-α) and anti-inflammatory cytokine IL-10.

RESULTS

A lower percentage of necrosis was identified in flaps treated with subcutaneous administration of HA (0.3%). The pro- and anti-inflammatory cytokines, epidermis thickness, blood vessels, and inflammatory cells showed statistically significant inter-group and intra-group differences (p < 0.05).

CONCLUSIONS

High molecular HA (1,400 ~ 2,000 kDa) administrated by subcutaneous or oral route exhibited beneficial effects in ischemic skin flaps of rats. However, subcutaneous administration of HA (0.3%) showed better results in terms of the percentage of necrosis and epithelialization.

Development of dissolving microneedles loaded with fucoidan for enhanced anti-aging activity: An in vivo study in mice animal model

Skin aging occurs naturally as essential skin components gradually decline, leading to issues such as fine lines, wrinkles, and pigmentation. Fucoidan, a natural bioactive compound, holds potential for addressing these age-related concerns. However, its hydrophilic nature and substantial molecular weight hinder its absorption into the skin. In this study, we utilized polyvinyl pyrrolidone K30 (PVP) and polyvinyl alcohol (PVA) as polymers to fabricate dissolving microneedles loaded with fucoidan (DMN-F). The DMN-F formulations were examined for physical characteristics, stability, permeability, toxicity, and efficacy in animal models. These formulations exhibited consistent polymer blends with a conical structure and uniform cone-shaped design. Microneedle structure and penetration capability gradually decreased with increasing fucoidan concentration, with storage recommended at approximately 33 % relative humidity (RH). Ex vivo studies showed that DMN-F efficiently delivered up to 95.03 ± 2.36 % of the total fucoidan concentration into the skin. In vivo investigations revealed that DMN-F effectively reduced wrinkles, improved skin elasticity, maintained moisture levels, and increased epidermal thickness. Histological images provided additional evidence of DMN-F's positive effects on these aging parameters. The results confirm that the DMN-F formulation effectively delivers fucoidan into the skin, allowing it to treat and mitigate signs of aging.

Redox-sensitive hydrogel based on hyaluronic acid with selenocystamine cross-linking for the delivery of Limosilactobacillus reuteri in a DSS-induced colitis mouse model

Disrupted gut microbiota homeostasis is an important cause of inflammatory colitis. Studies have shown that effective supplementation with probiotics can maintain microbial homeostasis and alleviate colitis. Here, to increase the viability of probiotics in the harsh gastrointestinal environments and enable targeted delivery, a redox-sensitive selenium hyaluronic acid (HA-Se) hydrogel encapsulating probiotics was developed. HA was modified with selenocystamine dihydrochloride and crosslinked by an amide reaction to generate a redox-sensitive hydrogel with stable mechanical properties, a low hemolysis rate and satisfactory biocompatibility. The HA-Se hydrogel exhibited suitable sensitivity to 10 mM GSH or 100 μM H2O2. The encapsulation of Limosilactobacillus reuteri (LR) in the HA-Se hydrogel (HA-Se-LR) significantly increased the survival rate of the probiotics in simulated gastric and intestinal fluid. HA-Se-LR administration increased the survival rate of mice with dextran sulfate sodium (DSS)-induced colitis, significantly alleviated oxidative stress and inflammation, and increased the effect of LR on microbiota α diversity. These results indicate that the HA-Se hydrogel constructed in this study can be used as a delivery platform to treat colitis, expanding the targeted applications of the natural polymer HA in disease treatment and the administration of probiotics as drugs to alleviate disease symptoms.

Significantly Enhanced Improvement in Dryness, Roughness, Fine Lines and Radiance Following Daily Use of a Novel Multi-Weight Hyaluronic Acid Plus Antioxidant Complex-Based Lotion Compared to a Single-Weight HA Plus Ceramide-Based Lotion

Objective

Hyaluronic acid (HA) has become a commonly used ingredient in topical moisturizing products; however, limitations of delivery of HA to only the surface of skin have hindered leveraging the full capacity of HA for skin rejuvenation. Here, we aimed to evaluate the clinical benefits of a multi-weight HA plus antioxidant complex-based lotion with SPF 30 compared to a single-weight HA plus ceramide-based lotion with SPF 30.

Methods

A double-blind comparative study was conducted on 70 female subjects, aged 25 to 65 years with mild-to-moderate facial dryness and visible fine lines and wrinkles, divided evenly into two groups (n=35 per group). Clinical grading of the face, including dryness, roughness, and fine lines, was assessed after once-daily application for up to eight weeks.

Results

Daily use of the multi-weight HA plus antioxidant lotion demonstrated significant improvements in all clinical grading assessments (dryness, roughness, and fine lines) as early as Week 2 compared to baseline. Statistically significant improvements in visible dryness, roughness, and fine lines were greater for the multi-weight HA plus antioxidant lotion compared to the single-weight HA plus ceramide-based lotion.

Limitations

The overall small sample size.

Conclusion

This study showed the enhanced improvement in dryness, roughness, and fine lines following daily utilization of a novel multi-weight HA plus antioxidant complex-based lotion compared to a single-weight HA plus ceramide-based lotion. These improvements may be attributed to the ability of multi-weight HAs to moisturize the skin surface and penetrate the upper surface layers of the skin, combined with the added benefits of key antioxidants.

ViSCNOVAS: A Novel Classification System for Hyaluronic Acid-Based Gels in Orthobiologic Products and Regenerative Medicine

Hyaluronic acid (HA), a naturally occurring polysaccharide, holds immense potential in regenerative medicine due to its diverse biological functions and clinical applications, particularly in gel formulations. This paper presents a comprehensive exploration of HA, encompassing its origins, molecular characteristics, and therapeutic roles in gel-based interventions. Initially identified in bovine vitreous humor, HA has since been found in various tissues and fluids across vertebrate organisms and bacterial sources, exhibiting consistent physicochemical properties. The synthesis of HA by diverse cell types underscores its integral role in the extracellular matrix and its relevance to tissue homeostasis and repair. Clinical applications of HA, particularly in addressing musculoskeletal ailments such as osteoarthritis, are examined, highlighting its efficacy and safety in promoting tissue regeneration and pain relief. Building upon this foundation, a novel classification system for HA-based interventions is proposed, aiming to standardize treatment protocols and optimize patient outcomes. The ViSCNOVAS classification system refers to viscosity, storage, chain, number, origin, volume, amount, and size. This classification is specifically designed for HA-based orthobiologic products used in regenerative medicine, including orthopedics, sports medicine, aesthetics, cosmetic dermatology, and wound healing. It aims to provide clinicians with a structured framework for personalized treatment strategies. Future directions in HA research are also discussed, emphasizing the need for further validation and refinement of the proposed classification system to advance the field of regenerative medicine. Overall, this manuscript elucidates the biological functions of hyaluronic acid and its potential in clinical practice while advocating for standardization to enhance patient care in various regenerative applications.

Evaluation of mango residues to produce hyaluronic acid by Streptococcus zooepidemicus

Mango processing generates significant amounts of residues (35-65%) that may represent environmental problems owed to improper disposal. The use of mango byproducts as substrates to produce hyaluronic acid (HA) is an attractive alternative to reduce the cost of substrate. In this study, we evaluated the potential of hydrolyzates from mango peels and seeds to produce HA by Streptococcus equi. subsp. zooepidemicus. The physicochemical characterization of mango residues showed that the seeds contain a higher amount of holocellulose (cellulose and hemicellulose), which amounts 54.2% (w/w) whereas it only represents 15.5% (w/w) in the peels. Mango peels, however, are composed mainly of hot water-extractives (62% w/w, that include sucrose, fructose, glucose and organic acids). A higher concentration of monosaccharides (39.8 g/L) was obtained from the enzymatic hydrolysis (with Macerex) of peels as compared to seeds (24.8 g/L with Celuzyme). From mango peels, hydrolyzates were obtained 0.6 g/L HA, while 0.9 g/L HA were obtained with hydrolyzates from mango seeds. These results demonstrate that mango byproducts have the potential to be used for production of HA.

Application frequency - key indicator for the efficiency of severe dry eye disease treatment - evidence for the importance of molecular weight of hyaluronan in lubricating agents

PURPOSE

Lubricant eye drops are the main therapeutic resource for dry eye disease (DED), with each drop representing the equivalent of ocular surface disease treatment. Thus, any reduction in the frequency of eye drop application reflects a degree of therapeutic success. Considering also the socioeconomic burden of DED, we investigated eye drop application frequency (DF) as a parameter to potentially track the success of therapy in severe DED. Hyaluronan (HA)-containing eye drops have become the first choice for tear substitution in many countries, and recent data indicate that the average molecular weight (Mw) of HA determines the therapeutic efficacy of such eye drops. This post-hoc subgroup analysis of a previously published multicentre prospective randomized open-label study, HYLAN M, is set out to compare the effects of very high Mw HA (hylan A) eye drops to comparator eye drops, containing lower Mw HA (control).

METHODS

Patients with severe DED (n = 47), recruited as part of the larger HYLAN M prospective, multicentre, open-label study, were randomized into two groups: hylan A and control group. In the hylan A group, 24 patients replaced their HA-containing eye drops with eye drops containing 0.15% hylan A, whereas the 23 control patients continued to use comparator HA eye drops. The DF was recorded daily by all participants over 8 weeks, and other subjective and objective parameters of DED were assessed at the time of inclusion (baseline), as well as at week 4 and 8.

RESULTS

There was a significant decrease in DF in the hylan A users between the baseline and week 4 (p = 0.004), remaining stable until week 8. Indeed, in contrast to the baseline, the hylan A group had a significantly lower DF than the control group at weeks 4 (p = 0.018) and 8 (p = 0.008). Likewise, the ocular surface disease index (OSDI) improved significantly between the time of inclusion and week 4 (p < 0.001) in hylan A users, remaining stable until week 8. The OSDI was similar in both groups at the baseline but it was significantly lower in the hylan A group than in the control group at week 4 (p = 0.002), remaining lower at week 8. Such a decrease in the DF and OSDI was not witnessed in the control group at any time point. The objective parameters assessed did not differ significantly within or between the two groups.

CONCLUSION

When treating severe DED, the DF can be significantly reduced by using very high Mw HA (3 MDa) lubricant eye drops, which better alleviate DED symptoms and decrease the OSDI scores. These drops not only provide an attractive and comfortable alternative for patients with severe DED but also offer the possibility of reducing the disease's socioeconomic burden, both for affected individuals and society as a whole.

A mosquito proboscis-inspired cambered microneedle patch for ophthalmic regional anaesthesia

INTRODUCTION

One of the methods for pain management involves the use of local anesthesia, which numbs sensations in specific body regions while maintaining consciousness.

OBJECTIVES

Considering the certain limitations (e.g., pain, the requirement of skilled professionals, or slow passive diffusion) of conventional delivery methods of local anesthetics, developing alternative strategies that offer minimally invasive yet therapeutically effective delivery systems is of great concern for ophthalmic regional anesthesia.

METHODS AND RESULTS

In this study, a rapidly dissolving cambered microneedle (MNs) patch, composed of poly(vinylpyrrolidone) (PVP) and hyaluronic acid (HA) and served as a delivery system for lidocaine (Lido) in local anesthesia, was developed taking inspiration from the mosquito proboscis's ability to extract blood unnoticed. The lidocaine-containing MNs patch (MNs@Lido) consisted of 25 microneedles with a four-pronged cone structure (height: 500 μm, base width: 275 μm), arranged in a concentric circle pattern on the patch, and displays excellent dissolubility for effective drug delivery of Lido. After confirming good cytocompatibility, MNs@Lido was found to possess adequate rigidity to penetrate the cornea without causing any subsequent injury, and the created corneal pinhole channels completely self-healed within 24 h. Interestingly, MNs@Lido exhibited effective analgesic effects for local anesthesia on both heel skin and eyeball, with the sustained anesthetic effect lasting for at least 30 min.

CONCLUSIONS

These findings indicate that the mosquito proboscis-inspired cambered MNs patch provides rapid and painless local anesthesia, overcoming the limitations of conventional delivery methods of local anesthetics, thus opening up new possibilities in the treatment of ophthalmic diseases.

Laponite-Modified Biopolymers as a Conformable Substrate for Optoelectronic Devices

Biopolymers such as carboxymethyl cellulose and hyaluronic acid are alternative substrates for conformable organic light-emitting diodes (OLEDs). However, drawbacks such as mechanical stress susceptibility can hinder the device's performance under stretched conditions. To overcome these limitations, herein, we developed a nanocomposite based on CMC/HA (carboxymethyl cellulose/hyaluronic acid) and synthetic Laponite, intending to improve the mechanical strength without compromising the film flexibility and transparency (transmittance >80%; 380-700 nm) as substrates for conformable OLEDs. From XRD, FTIR, CP-MAS NMR, and TGA/DTG characterization techniques, it was possible to conclude the presence of Laponite randomly dispersed between the polymer chains. CMC/HA with 5% (w/w) Laponite, CMC/HA 5, presented a higher tensile strength (370.6 MPa) and comparable Young's modulus (51.0 ± 1.2 MPa) in comparison to the nanocomposites and pristine films, indicating a better candidate for the device's substrates. To produce the OLED, the multilayer structure ITO/MoO3/NPB/TCTA:Ir(ppy)3/TPBi:Ir(ppy)3/BPhen/LiF was deposited onto the CMC/HA 5 substrate. The OLEDs fabricated using CMC/HA 5 substrates showed higher luminance (12 kcd/m2) and irradiance (0.9 mW/cm2) values when compared with those based on commercial bacterial cellulose. However, the same device presented a lower efficiency (3.2 cd/A) due to a higher current density. Moreover, the OLED fabricated onto the Laponite-modified biopolymer presented reproducible behavior when submitted to continuous bending stress. Thus, CMC/HA 5 demonstrates potential as a transparent conductor substrate for biopolymer-based OLEDs with comparable performance to commercial bacterial cellulose features.

The downregulation of genes encoding muscle proteins have a potential role in the development of scrotal hernia in pigs

BACKGROUND

Testicular descent is a physiological process regulated by many factors. Eventually, disturbances in the embryological/fetal development path facilitate the occurrence of scrotal hernia, a congenital malformation characterized by the presence of intestinal portions within the scrotal sac due to the abnormal expansion of the inguinal ring. In pigs, some genes have been related to this anomaly, but the genetic mechanisms involved remain unclear. This study aimed to investigate the expression profile of a set of genes potentially involved with the manifestation of scrotal hernia in the inguinal ring tissue.

METHODS AND RESULTS

Tissue samples from the inguinal ring/canal of normal and scrotal hernia-affected male pigs with approximately 30 days of age were used. Relative expression analysis was performed using qPCR to confirm the expression profile of 17 candidate genes previously identified in an RNA-Seq study. Among them, the Myosin heavy chain 1 (MYH1), Desmin (DES), and Troponin 1 (TNNI1) genes were differentially expressed between groups and had reduced levels of expression in the affected animals. These genes encode proteins involved in the formation of muscle tissue, which seems to be important for increasing the resistance of the inguinal ring to the abdominal pressure, which is essential to avoid the occurrence of scrotal hernia.

CONCLUSIONS

The downregulation of muscular candidate genes in the inguinal tissue clarifies the genetic mechanisms involved with this anomaly in its primary site, providing useful information for developing strategies to control this malformation in pigs and other mammals.

Endogenous Hyaluronan Promotes Intestinal Homeostasis and Protects against Murine Necrotizing Enterocolitis

Necrotizing enterocolitis (NEC) is a complex, multifactorial gastrointestinal disorder predominantly affecting preterm infants. The pathogenesis of this condition involves a complex interplay between intestinal barrier dysfunction, microbial dysbiosis, and an altered immune response. This study investigates the potential role of endogenous hyaluronan (HA) in both the early phases of intestinal development and in the context of NEC-like intestinal injury. We treated neonatal CD-1 mouse pups with PEP1, a peptide inhibiting HA receptor interactions, from postnatal days 8 to 12. We evaluated postnatal intestinal developmental indicators, such as villi length, crypt depth, epithelial cell proliferation, crypt fission, and differentiation of goblet and Paneth cells, in PEP1-treated animals compared with those treated with scrambled peptide. PEP1 treatment significantly impaired intestinal development, as evidenced by reductions in villi length, crypt depth, and epithelial cell proliferation, along with a decrease in crypt fission activity. These deficits in PEP1-treated animals correlated with increased susceptibility to NEC-like injuries, including higher mortality rates, and worsened histological intestinal injury. These findings highlight the role of endogenous HA in supporting intestinal development and protecting against NEC.

Development of novel iron(III) crosslinked bioinks comprising carboxymethyl cellulose, xanthan gum, and hyaluronic acid for soft tissue engineering applications

The advent of three-dimensional (3D) bioprinting offers a feasible approach to construct complex structures for soft tissue regeneration. Carboxymethyl cellulose (CMC) has been emerging as a very promising biomaterial for 3D bioprinting. However, due to the inability to maintain the post-printed stability, CMC needs to be physically blended and/or chemically crosslinked with other polymers. In this context, this study presents the combination of CMC with xanthan gum (XG) and hyaluronic acid (HA) to formulate a multicomponent bioink, leveraging the printability of CMC and XG, as well as the cellular support properties of HA. The ionic crosslinking of printed constructs with iron(III) via the metal-ion coordination between ferric cations and carboxylate groups of the three polymers was introduced to induce improved mechanical strength and long-term stability. Moreover, immortalized human epidermal keratinocytes (HaCaT) and human foreskin fibroblasts (HFF) encapsulated within iron-crosslinked printed hydrogels exhibited excellent cell viability (more than 95%) and preserved morphology. Overall, the presented study highlights that the combination of these three biopolymers and the ionic crosslinking with ferric ions is a valuable strategy to be considered for the development of new and advanced hydrogel-based bioinks for soft tissue engineering applications.

Hyaluronic acid impacts hematological endpoints and spleen histological features in African catfish (Clarias gariepinus)

Since its identification in the vitreous humour of the eye and laboratory biosynthesis, hyaluronic acid (HA) has been a vital component in several pharmaceutical, nutritional, medicinal, and cosmetic uses. However, little is known about its potential toxicological impacts on aquatic inhabitants. Herein, we investigated the hematological response of Clarias gariepinus to nominal doses of HA. To achieve this objective, 72 adult fish were randomly and evenly distributed into four groups: control, low-dose (0.5 mg/l HA), medium-dose (10 mg/l HA), and high-dose (100 mg/l HA) groups for two weeks each during both the exposure and recovery periods. The findings confirmed presence of anemia, neutrophilia, leucopoenia, lymphopenia, and eosinophilia at the end of exposure to HA. In addition, poikilocytosis and a variety of cytomorphological disturbances were observed. Dose-dependent histological alterations in spleen morphology were observed in the exposed groups. After HA removal from the aquarium for 2 weeks, the groups exposed to the two highest doses still exhibited a notable decline in red blood cell count, hemoglobin concentration, mean corpuscular hemoglobin concentration, and an increase in mean corpuscular volume. Additionally, there was a significant rise in neutrophils, eosinophils, cell alterations, and nuclear abnormalities percentages, along with a decrease in monocytes, coupled with a dose-dependent decrease in lymphocytes. Furthermore, only the highest dose of HA in the recovered groups continued to cause a significant increase in white blood cells. White blood cells remained lower, and the proportion of apoptotic RBCs remained higher in the high-dose group. The persistence of most of the haematological and histological disorders even after recovery period indicates a failure of physiological compensatory mechanisms to overcome the HA-associated problems or insufficient duration of recovery. Thus, these findings encourage the inclusion of this new hazardous agent in the biomonitoring program and provide a specific pattern of hematological profile in HA-challenged fish. Further experiments are highly warranted to explore other toxicological hazards of HA using dose/time window protocols.

A structure-functionality insight into the bioactivity of microbial polysaccharides toward biomedical applications: A review

Microbial polysaccharides (MPs) are biopolymers secreted by microorganisms such as bacteria and fungi during their metabolic processes. Compared to polysaccharides derived from plants and animals, MPs have advantages such as wide sources, high production efficiency, and less susceptibility to natural environmental influences. The most attractive feature of MPs lies in their diverse biological activities, such as antioxidative, anti-tumor, antibacterial, and immunomodulatory activities, which have demonstrated immense potential for applications in functional foods, cosmetics, and biomedicine. These bioactivities are precisely regulated by their sophisticated molecular structure. However, the mechanisms underlying this precise regulation are not yet fully understood and continue to evolve. This article presents a comprehensive review of the most representative species of MPs, including their fermentation and purification processes and their biomedical applications in recent years. In particular, this work presents an in-depth analysis into the structure-activity relationships of MPs across multiple molecular levels. Additionally, this review discusses the challenges and prospects of investigating the structure-activity relationships, providing valuable insights into the broad and high-value utilization of MPs.

A review on revolutionizing ophthalmic therapy: Unveiling the potential of chitosan, hyaluronic acid, cellulose, cyclodextrin, and poloxamer in eye disease treatments

Ocular disorders, encompassing both common ailments like dry eye syndrome and more severe situations for instance age-related macular degeneration, present significant challenges to effective treatment due to the intricate architecture and physiological barriers of the eye. Polysaccharides are emerging as potential solutions for drug delivery to the eyes due to their compatibility with living organisms, natural biodegradability, and adhesive properties. In this review, we explore not only the recent advancements in polysaccharide-based technologies and their transformative potential in treating ocular illnesses, offering renewed optimism for both patients and professionals but also anatomy of the eye and the significant obstacles hindering drug transportation, followed by an investigation into various drug administration methods and their ability to overcome ocular-specific challenges. Our focus lies on biological adhesive polymers, including chitosan, hyaluronic acid, cellulose, cyclodextrin, and poloxamer, known for their adhesive characteristics enhancing drug retention on ocular surfaces and increasing bioavailability. A detailed analysis of material designs used in ophthalmic formulations, such as gels, lenses, eye drops, nanofibers, microneedles, microspheres, and nanoparticles, their advantages and limitations, the potential of formulations in improving therapeutic outcomes for various eye conditions. Moreover, we underscore the discovery of novel polysaccharides and their potential uses in ocular drug delivery.

Hyaluronic acid/PEO electrospun tube reduces tendon adhesion to levels comparable to native tendons - An in vitro and in vivo study

A major problem after tendon injury is adhesion formation to the surrounding tissue leading to a limited range of motion. A viable strategy to reduce adhesion extent is the use of physical barriers that limit the contact between the tendon and the adjacent tissue. The purpose of this study was to fabricate an electrospun bilayered tube of hyaluronic acid/polyethylene oxide (HA/PEO) and biodegradable DegraPol® (DP) to improve the anti-adhesive effect of the implant in a rabbit Achilles tendon full laceration model compared to a pure DP tube. Additionally, the attachment of rabbit tenocytes on pure DP and HA/PEO containing scaffolds was tested and Scanning Electron Microscopy, Fourier-transform Infrared Spectroscopy, Differential Scanning Calorimetry, Water Contact Angle measurements, and testing of mechanical properties were used to characterize the scaffolds. In vivo assessment after three weeks showed that the implant containing a second HA/PEO layer significantly reduced adhesion extent reaching levels comparable to native tendons, compared with a pure DP implant that reduced adhesion formation only by 20 %. Tenocytes were able to attach to and migrate into every scaffold, but cell number was reduced over two weeks. Implants containing HA/PEO showed better mechanical properties than pure DP tubes and with the ability to entirely reduce adhesion extent makes this implant a promising candidate for clinical application in tendon repair.

Hyaluronidase inhibitor delphinidin inhibits cancer metastasis

Cancer remains a formidable global health challenge, with metastasis being a key contributor to its lethality. Abundant high molecular mass hyaluronic acid, a major non-protein component of extracellular matrix, protects naked mole rats from cancer and reduces cancer incidence in mice. Hyaluronidase plays a critical role in degrading hyaluronic acid and is frequently overexpressed in metastatic cancer. Here we investigated the potential of targeting hyaluronidases to reduce metastasis. A high throughput screen identified delphinidin, a natural plant compound found in fruits and vegetables, as a potent hyaluronidase inhibitor. Delphinidin-mediated inhibition of hyaluronidase activity led to an increase in high molecular weight hyaluronic acid in cell culture and in mouse tissues, and reduced migration and invasion behavior of breast, prostate, and melanoma cancer cells. Moreover, delphinidin treatment suppressed melanoma metastasis in mice. Our study provides a proof of principle that inhibition of hyaluronidase activity suppresses cancer cell migration, invasion and metastasis. Furthermore, we identified a natural compound delphinidin as a potential anticancer therapeutic. Thus, we have identified a path for clinical translation of the cancer resistance mechanism identified in the naked mole rat.

Urinary hyaluronidase activity is closely related to vasopressinergic system following an oral water load in men: a potential role in blood pressure regulation and early stages of hypertension development

Introduction

Blood pressure (BP) regulation is a complex process involving several factors, among which water-sodium balance holds a prominent place. Arginin-vasopressin (AVP), a key player in water metabolism, has been evoked in hypertension development since the 1980s, but, to date, the matter is still controversial. Hyaluronic acid metabolism has been reported to be involved in renal water management, and AVP appears to increase hyaluronidase activity resulting in decreased high-molecular-weight hyaluronan content in the renal interstitium, facilitating water reabsorption in collecting ducts. Hence, our aim was to evaluate urinary hyaluronidase activity in response to an oral water load in hypertensive patients (HT, n=21) compared to normotensive subjects with (NT+, n=36) and without (NT-, n=29) a family history of hypertension, and to study its association with BP and AVP system activation, expressed by serum copeptin levels and urine Aquaporin 2 (AQP2)/creatinine ratio.

Methods

Eighty-six Caucasian men were studied. Water load test consisted in oral administration of 15-20 ml of water/kg body weight over 40-45 min. BP, heart rate, serum copeptin, urine hyaluronidase activity and AQP2 were monitored for 4 hours.

Results

In response to water drinking, BP raised in all groups with a peak at 20-40 min. Baseline levels of serum copeptin, urinary hyaluronidase activity and AQP2/creatinine ratio were similar among groups and all decreased after water load, reaching their nadir at 120 min and then gradually recovering to baseline values. Significantly, a blunted reduction in serum copeptin, urinary hyaluronidase activity and AQP2/creatinine ratio was observed in NT+ compared to NT- subjects. A strong positive correlation was also found between urinary hyaluronidase activity and AQP2/creatinine ratio, and, although limited to the NT- group, both parameters were positively associated with systolic BP.

Discussion

Our results demonstrate for the first time the existence in men of a close association between urinary hyaluronidase activity and vasopressinergic system and suggest that NT+ subjects have a reduced ability to respond to water loading possibly contributing to the blood volume expansion involved in early-stage hypertension. Considering these data, AVP could play a central role in BP regulation by affecting water metabolism through both hyaluronidase activity and AQP2 channel expression.

Material-specific binding peptides empower sustainable innovations in plant health, biocatalysis, medicine and microplastic quantification

Material-binding peptides (MBPs) have emerged as a diverse and innovation-enabling class of peptides in applications such as plant-/human health, immobilization of catalysts, bioactive coatings, accelerated polymer degradation and analytics for micro-/nanoplastics quantification. Progress has been fuelled by recent advancements in protein engineering methodologies and advances in computational and analytical methodologies, which allow the design of, for instance, material-specific MBPs with fine-tuned binding strength for numerous demands in material science applications. A genetic or chemical conjugation of second (biological, chemical or physical property-changing) functionality to MBPs empowers the design of advanced (hybrid) materials, bioactive coatings and analytical tools. In this review, we provide a comprehensive overview comprising naturally occurring MBPs and their function in nature, binding properties of short man-made MBPs (<20 amino acids) mainly obtained from phage-display libraries, and medium-sized binding peptides (20-100 amino acids) that have been reported to bind to metals, polymers or other industrially produced materials. The goal of this review is to provide an in-depth understanding of molecular interactions between materials and material-specific binding peptides, and thereby empower the use of MBPs in material science applications. Protein engineering methodologies and selected examples to tailor MBPs toward applications in agriculture with a focus on plant health, biocatalysis, medicine and environmental monitoring serve as examples of the transformative power of MBPs for various industrial applications. An emphasis will be given to MBPs' role in detecting and quantifying microplastics in high throughput, distinguishing microplastics from other environmental particles, and thereby assisting to close an analytical gap in food safety and monitoring of environmental plastic pollution. In essence, this review aims to provide an overview among researchers from diverse disciplines in respect to material-(specific) binding of MBPs, protein engineering methodologies to tailor their properties to application demands, re-engineering for material science applications using MBPs, and thereby inspire researchers to employ MBPs in their research.

In-vitro effects of different hyaluronic acids on periodontal biofilm-immune cell interaction

Introduction

Recent studies have demonstrated a positive role of hyaluronic acid (HA) on periodontal clinical outcomes. This in-vitro study aimed to investigate the impact of four different HAs on interactions between periodontal biofilm and immune cells.

Methods

The four HAs included: high-molecular-weight HA (HHA, non-cross-linked), low-molecular-weight HA (LHA), oligomers HA (OHA), and cross-linked high-molecular-weight HA (CHA). Serial experiments were conducted to verify the influence of HAs on: (i) 12-species periodontal biofilm (formation and pre-existing); (ii) expression of inflammatory cytokines and HA receptors in monocytic (MONO-MAC-6) cells and periodontal ligament fibroblasts (PDLF) with or without exposure to periodontal biofilms; (iii) generation of reactive oxygen species (ROS) in MONO-MAC-6 cells and PDLF with presence of biofilm and HA.

Results

The results indicated that HHA and CHA reduced the bacterial counts in a newly formed (4-h) biofilm and in a pre-existing five-day-old biofilm. Without biofilm challenge, OHA triggered inflammatory reaction by increasing IL-1β and IL-10 levels in MONO-MAC cells and IL-8 in PDLF in a time-dependent manner, whereas CHA suppressed this response by inhibiting the expression of IL-10 in MONO-MAC cells and IL-8 in PDLF. Under biofilm challenge, HA decreased the expression of IL-1β (most decreasing HHA) and increased IL-10 levels in MONO-MAC-6 cells in a molecular weight dependent manner (most increasing CHA). The interaction between HA and both cells may occur via ICAM-1 receptor. Biofilm stimulus increased ROS levels in MONO-MAC-6 cells and PDLF, but only HHA slightly suppressed the high generation of ROS induced by biofilm stimulation in both cells.

Conclusion

Overall, these results indicate that OHA induces inflammation, while HHA and CHA exhibit anti-biofilm, primarily anti-inflammatory, and antioxidant properties in the periodontal environment.

Janus structure hydrogels: recent advances in synthetic strategies, biomedical microstructure and (bio)applications

Janus structure hydrogels (JSHs) are novel materials. Their primary fabrication methods and various applications have been widely reported. JSHs are primarily composed of Janus particles (JNPs) and polysaccharide components. They exhibit two distinct physical or chemical properties, generating intriguing characteristics due to their asymmetric structure. Normally, one side (adhesive interface) is predominantly constituted of polysaccharide components, primarily serving excellent adhesion. On the other side (functional surface), they integrate diverse functionalities, concurrently performing a plethora of synergistic functions. In the biomedical field, JSHs are widely applied in anti-adhesion, drug delivery, wound healing, and other areas. It also exhibits functions in seawater desalination and motion sensing. Thus, JSHs hold broad prospects for applications, and they possess significant research value in nanotechnology, environmental science, healthcare, and other fields. Additionally, this article proposes the challenges and future work facing these fields.

Tunable and fast-cured hyaluronic acid hydrogel inspired on catechol architecture for enhanced adhesion property

Hyaluronic acid-based hydrogels have been broadly used in medical applications due to their remarkable properties such as biocompatibility, biodegradability, super hydroscopicity, non-immunogenic effect, etc. However, the inherent weak and hydrophilic polysaccharide structure of pure hyaluronic acid (HA) hydrogels has limited their potential use in muco-adhesiveness, wound dressing, and 3D printing. In this research, we developed in-situ forming of catechol-modified HA hydrogels with improved mechanical properties involving blue-light curing crosslinking reaction. The effect of catechol structure on the physicochemical properties of HA hydrogels was evaluated by varying the content (0-40 %). The as-synthesized hydrogel demonstrated rapid prototyping, excellent wetting adhesiveness, and good biocompatibility. Furthermore, an optimized hydrogel precursor solution was used as a blue light-cured bio-ink with high efficiency and good precision and successfully prototyped a microstructure that mimicked the human hepatic lobule by using DLP 3D printing method. This catechol-modified HA hydrogel with tunable physicochemical and rapid prototyping properties has excellent potential in biomedical engineering.

Advances of biological macromolecules hemostatic materials: A review

Achieving hemostasis is a necessary intervention to rapidly and effectively control bleeding. Conventional hemostatic materials currently used in clinical practice may aggravate the damage at the bleeding site due to factors such as poor adhesion and poor adaptation. Compared to most traditional hemostatic materials, polymer-based hemostatic materials have better biocompatibility and offer several advantages. They provide a more effective method of stopping bleeding and avoiding additional damage to the body in case of excessive blood loss. Various hemostatic materials with greater functionality have been developed in recent years for different organs using diverse design strategies. This article reviews the latest advances in the development of polymeric hemostatic materials. We introduce the coagulation cascade reaction after bleeding and then discuss the hemostatic mechanisms and advantages and disadvantages of various polymer materials, including natural, synthetic, and composite polymer hemostatic materials. We further focus on the design strategies, properties, and characterization of hemostatic materials, along with their applications in different organs. Finally, challenges and prospects for the application of hemostatic polymeric materials are summarized and discussed. We believe that this review can provide a reference for related research on hemostatic materials, contributing to the further development of polymer hemostatic materials.

The bioengineering application of hyaluronic acid in tissue regeneration and repair

The multifaceted role of hyaluronic acid (HA) across diverse biomedical disciplines underscores its versatility in tissue regeneration and repair. HA hydrogels employ different crosslinking including chemical (chitosan, collagen), photo- initiation (riboflavin, LAP), enzymatic (HRP/H2O2), and physical interactions (hydrogen bonds, metal coordination). In biophysics and biochemistry, HA's signaling pathways, primarily through CD44 and RHAMM receptors, modulate cell behavior (cell migration; internalization of HA), inflammation, and wound healing. Particularly, smaller HA fragments stimulate inflammatory responses through toll-like receptors, impacting macrophages and cytokine expression. HA's implications in oncology highlight its involvement in tumor progression, metastasis, and treatment. Elevated HA in tumor stroma impacts apoptosis resistance and promotes tumor growth, presenting potential therapeutic targets to halt tumor progression. In orthopedics, HA's presence in synovial fluid aids in osteoarthritis management, as its supplementation alleviates pain, enhances synovial fluid's viscoelastic properties, and promotes cartilage integrity. In ophthalmology, HA's application in dry eye syndrome addresses symptoms by moisturizing the eyes, replenishing tear film deficiencies, and facilitating wound healing. Intravitreal injections and hydrogel-based systems offer versatile approaches for drug delivery and vitreous humor replacement. For skin regeneration and wound healing, HA hydrogel dressings exhibit exceptional properties by promoting moist wound healing and facilitating tissue repair. Integration of advanced regenerative tools like stem cells and solubilized amnion membranes into HA-based systems accelerates wound closure and tissue recovery. Overall, HA's unique properties and interactions render it a promising candidate across diverse biomedical domains, showcasing immense potentials in tissue regeneration and therapeutic interventions. Nevertheless, many detailed cellular and molecular mechanisms of HA and its applications remain unexplored and warrant further investigation.

Tunnel technique and subepithelial connective tissue graft, with or without cross-linked hyaluronic acid, in the treatment of multiple gingival recessions: 12-month outcomes of a randomized clinical trial

BACKGROUND

This study evaluated the influence of the adjunctive application of a cross-linked hyaluronic acid (HA) in the treatment of multiple gingival recessions, using a modified coronally advanced tunnel (MCAT) technique and subepithelial connective tissue graft (SCTG) (MCAT+SCTG±HA).

METHODS

A randomized, split-mouth, double-masked comparison of the effects of MCAT+HA+SCTG (test) versus MCAT+SCTG (control) in the treatment of multiple, contralateral gingival recessions with clinical, esthetic, and histological evaluations was carried out. All samples were stained with hematoxylin and eosin, Masson's trichrome, Verhoeff-Van Gieson, and Alcian blue stain for semiquantitative evaluation. The primary outcome variable was 12-month mean root coverage (MRC).

RESULTS

Twenty-four patients with 266 gingival recessions received both control and test treatments (133 recessions per group). 12-month MRC of the MCAT+HA+SCTG group was not significantly different from the MCAT+SCTG group with 84.32%±  34.46% and 85.71%±  36.43%, respectively (p = 0.991). Both treatment modes produced favorable esthetic outcomes (root coverage esthetic score [RES] 9.51±  1.01 tests vs. 9.26±  1.10 controls, p = 0.7292). However, the application of HA improved soft tissue texture (p = 0.0091). The remaining end point measures did not differ significantly between groups. Histological evaluation showed a significantly greater number of elastic fibers and a moderate increase in collagen fiber density in biopsy samples taken from the test sides when compared to the control sides (p = 0.0419 and p = 0.300, respectively).

CONCLUSIONS

MCAT+SCTG is an effective procedure in the treatment of multiple recession Type 1 (RT1) and RT2 recessions. There were no statistically significant differences in evaluated clinical treatment outcomes in the MCAT+HA+SCTG group compared to the MCAT+SCTG group within a period of 12 months. The application of HA increased collagen and elastic fiber density.

Dual Functionalization of Hyaluronan Dermal Fillers with Vitamin B3: Efficient Combination of Bio-Stimulation Properties with Hydrogel System Resilience Enhancement

Hyaluronic acid (HA) hydrogels are commonly used for facial dermal filling and for alternative medical aesthetic purposes. High diversity exists in commercial formulations, notably for the optimization of finished product stability, functionality, and performance. Polyvalent ingredients such as calcium hydroxylapatite (CaHA) or vitamin B3 (niacinamide) are notably used as bio-stimulants to improve skin quality attributes at the administration site. The aim of the present study was to perform multi-parametric characterization of two novel cross-linked dermal filler formulas (HAR-1 "Instant Refine" and HAR-3 "Maxi Lift") for elucidation of the various functional impacts of vitamin B3 incorporation. Therefore, the HAR products were firstly comparatively characterized in terms of in vitro rheology, cohesivity, injectability, and resistance to chemical or enzymatic degradation (exposition to H2O2, AAPH, hyaluronidases, or xanthine oxidase). Then, the HAR products were assessed for cytocompatibility and in vitro bio-stimulation attributes in a primary dermal fibroblast model. The results showed enhanced resilience of the cohesive HAR hydrogels as compared to JUVÉDERM® VOLBELLA® and VOLUMA® reference products in a controlled degradation assay panel. Furthermore, significant induction of total collagen synthesis in primary dermal fibroblast cultures was recorded for HAR-1 and HAR-3, denoting intrinsic bio-stimulatory effects comparable or superior to those of the Radiesse® and Sculptra™ reference products. Original results of high translational relevance were generated herein using robust and orthogonal experimental methodologies (hydrogel degradation, functional benchmarking) and study designs. Overall, the reported results confirmed the dual functionalization role of vitamin B3 in cross-linked HA dermal fillers, with a significant enhancement of hydrogel system stability attributes and the deployment of potent bio-stimulatory capacities.

A Mechanically Resilient Soft Hydrogel Improves Drug Delivery for Treating Post-Traumatic Osteoarthritis in Physically Active Joints

Intra-articular delivery of disease-modifying osteoarthritis drugs (DMOADs) is likely to be most effective in early post-traumatic osteoarthritis (PTOA) when symptoms are minimal and patients are physically active. DMOAD delivery systems therefore must withstand repeated mechanical loading without affecting the drug release kinetics. Although soft materials are preferred for DMOAD delivery, mechanical loading can compromise their structural integrity and disrupt drug release. Here, we report a mechanically resilient soft hydrogel that rapidly self-heals under conditions resembling human running while maintaining sustained release of the cathepsin-K inhibitor L-006235 used as a proof-of-concept DMOAD. Notably, this hydrogel outperformed a previously reported hydrogel designed for intra-articular drug delivery, used as a control in our study, which neither recovered nor maintained drug release under mechanical loading. Upon injection into mouse knee joints, the hydrogel showed consistent release kinetics of the encapsulated agent in both treadmill-running and non-running mice. In a mouse model of aggressive PTOA exacerbated by treadmill running, L-006235 hydrogel markedly reduced cartilage degeneration. To our knowledge, this is the first hydrogel proven to withstand human running conditions and enable sustained DMOAD delivery in physically active joints, and the first study demonstrating reduced disease progression in a severe PTOA model under rigorous physical activity, highlighting the hydrogel's potential for PTOA treatment in active patients.

The rheology of injectable hyaluronic acid hydrogels used as facial fillers: A review

Injectable hyaluronic acid (HA) hydrogels have been popularized in facial aesthetics as they provide a long-lasting effect, low risk of complications, allergenicity tests are not required before application and can be easily removed by the action of hyaluronidases. On the other hand, the development of these systems requires in-depth studies of chemical mechanisms involved in hydrogel formation. Ideal dermal fillers should temporarily fluidize during extrusion through the needle and quickly recover their original shape after application. Hydrogels with more elastic properties, for example, are difficult to inject while viscous materials are too liquid. A balance between both properties should be achieved. Each region of the face requires products with distinct rheological properties. High G' dermal fillers are preferable for deeper wrinkles whereas the counterpart with lower values of G' is more indicated in superficial wrinkles or lip augmentation. Factors such as molecular weight and concentration of HA, pH, type and concentration of the crosslinking agent, particle size, crosslinking reaction time and crosslinking agent/polysaccharide ratio should be modulated to achieve specific rheological properties. In this review, the effect of each variable is discussed in detail to guide the rational development of new dermal fillers.