Recent advances and prospects of hyaluronan as a multifunctional therapeutic system

Design of a targeted dual drug delivery system for boosting the efficacy of photoimmunotherapy against melanoma proliferation and metastasis

INTRODUCTION

The combination of a photosensitizer and indoleamine-2,3 dioxygenase (IDO) inhibitor provides a promising photoimmunotherapy (PIT) strategy for melanoma treatment. A dual drug delivery system offers a potential approach for optimizing the inhibitory effects of PIT on melanoma proliferation and metastasis.

OBJECTIVE

To develop a dual drug delivery system based on PIT and to study its efficacy in inhibiting melanoma proliferation and metastasis.

METHODS

We constructed a multifunctional nano-porphyrin material (P18-APBA-HA) using the photosensitizer-purpurin 18 (P18), hyaluronic acid (HA), and 4-(aminomethyl) phenylboronic acid (APBA). The resulting P18-APBA-HA was inserted into a phospholipid membrane and the IDO inhibitor epacadostat (EPA) was loaded into the internal phase to prepare a dual drug delivery system (Lip\EPA\P18-APBA-HA). Moreover, we also investigated its physicochemical properties, targeting, anti-tumor immunity, and anti-tumor proliferation and metastasis effects.

RESULTS

The designed system utilized the pH sensitivity of borate ester to realize an enhanced-targeting strategy to facilitate the drug distribution in tumor lesions and efficient receptor-mediated cellular endocytosis. The intracellular release of EPA from Lip\EPA\P18-APBA-HA was triggered by thermal radiation, thereby inhibiting IDO activity in the tumor microenvironment, and promoting activation of the immune response. Intravenous administration of Lip\EPA\P18-APBA-HA effectively induced anti-tumor immunity by promoting dendritic cell maturation, cytotoxic T cell activation, and regulatory T cell suppression, and regulating cytokine secretion, to inhibit the proliferation of melanoma and lung metastasis.

CONCLUSION

The proposed nano-drug delivery system holds promise as offers a promising strategy to enhance the inhibitory effects of the combination of EPA and P18 on melanoma proliferation and metastasis.

Pain Management Strategies in Osteoarthritis

Pain is the major symptom of osteoarthritis (OA) and is an important factor in strategies to manage this disease. However, the current standard of care does not provide satisfactory pain relief for many patients. The pathophysiology of OA is complex, and its presentation as a clinical syndrome is associated with the pathologies of multiple joint tissues. Treatment options are generally classified as pharmacologic, nonpharmacologic, surgical, and complementary and/or alternative, typically used in combination to achieve optimal results. The goals of treatment are the alleviation of symptoms and improvement in functional status. Several studies are exploring various directions for OA pain management, including tissue regeneration techniques, personalized medicine, and targeted drug therapies. The aim of the present narrative review is to extensively describe all the treatments available in the current practice, further describing the most important innovative therapies. Advancements in understanding the molecular and genetic aspects of osteoarthritis may lead to more effective and tailored treatment approaches in the future.

A review of hyaluronic acid-based therapeutics for the treatment and management of arthritis

Hyaluronic acid (HA), a biodegradable, biocompatible and non-immunogenic therapeutic polymer is a key component of the cartilage extracellular matrix (ECM) and has been widely used to manage two major types of arthritis, osteoarthritis (OA) and rheumatoid arthritis (RA). OA joints are characterized by lower concentrations of depolymerized (low molecular weight) HA, resulting in reduced physiological viscoelasticity, while in RA, the associated immune cells are over-expressed with various cell surface receptors such as CD44. Due to HA's inherent viscoelastic property and its ability to target CD44, there has been a surge of interest in developing HA-based systems to deliver various bioactives (drugs and biologics) and manage arthritis. Considering therapeutic benefits of HA in arthritis management and potential advantages of novel delivery systems, bioactive delivery through HA-based systems is beginning to display improved outcomes over bioactive only treatment. The benefits include enhanced bioactive uptake due to receptor-mediated targeting, prolonged retention of bioactives in the synovium, reduced expressions of proinflammatory mediators, enhanced cartilage regeneration, reduced drug toxicity due to sustained release, and improved and cost-effective treatment. This review provides an underlying rationale to prepare and use HA-based bioactive delivery systems for arthritis applications. With special emphasis given to preclinical/clinical results, this article reviews various bioactive-loaded HA-based particulate carriers (organic and inorganic), gels, scaffolds and polymer-drug conjugates that have been reported to treat and manage OA and RA. Furthermore, the review identifies several key challenges and provides valuable suggestions to address them. Various developments, strategies and suggestions described in this review may guide the formulation scientists to optimize HA-based bioactive delivery systems as an effective approach to manage and treat arthritis effectively.

A chemo/chemodynamic nanoparticle based on hyaluronic acid induces ferroptosis and apoptosis for triple-negative breast cancer therapy

Triple-negative breast cancer (TNBC) poses a serious threat to women's life and health due to its high malignancy, strong invasiveness, and propensity for early recurrence and metastasis. Therefore, there is an urgent need to develop a highly effective and low-toxic TNBC treatment scheme to enhance the anti-cancer efficacy and prolong the survival of patients. In this work, we designed and synthesized a chemodynamic therapy (CDT) agent (HA-Fc-Mal). The chemo/chemodynamic (CT/CDT) nanoparticle (HCM@DOX) based on hyaluronic acid induces ferroptosis and apoptotic for TNBC therapy was constructed via self-assembled of HA-Fc-Mal and doxorubicin (DOX). HCM@DOX orderly realized the TNBC targeting, controlled DOX release, GSH depletion and induce ROS erupt. In vivo and in vitro experiments confirmed that HCM@DOX inhibited the growth of 4 T1 tumors through ferroptosis and apoptosis, and the tumor inhibition rate was as high as 81.87 %. In addition, HCM@DOX significantly inhibited lung metastasis and exhibited excellent biosafety. Overall, our findings offer a new strategy for TNBC therapy using a CT/CDT nanoparticle that induces ferroptosis and apoptosis.

pH-sensitive docetaxel-loaded chitosan/thiolated hyaluronic acid polymeric nanoparticles for colorectal cancer

Aim: This study aimed to develop and evaluate pH-sensitive docetaxel-loaded thiolated hyaluronic acid (HA-SH) nanoparticles (NPs) for targeted treatment of colon cancer. Materials & methods: HA-SH, synthesized via oxidation and subsequent covalent linkage to cysteamine, served as the precursor for developing HA-SH NPs through polyelectrolyte complexation involving chitosan and thiol-bearing HA. Results & conclusion: HA-SH NPs displayed favorable characteristics, with small particle sizes (184-270 nm), positive zeta potential (15.4-18.6 mV) and high entrapment efficiency (91.66-95.02%). In vitro, NPs demonstrated potent mucoadhesion and enhanced cytotoxicity compared with free docetaxel. In vivo assessments confirmed safety and biocompatibility, suggesting HA-SH NPs as promising pH-sensitive drug carriers with enhanced antitumor activity for colorectal cancer treatments.

Methotrexate-loaded hyaluronan-modified liposomes integrated into dissolving microneedles for the treatment of psoriasis

Methotrexate (MTX) is a first-line drug in treating psoriasis because of its strong anti-proliferation and anti-inflammatory effects. However, systemic administration of MTX will lead to many side effects, such as gastrointestinal irritation, liver and kidney toxicity, etc. Herein, we developed liposome-loaded microneedles (MNs) system to improve transdermal efficiency, which was used to overcome the problems of low transdermal efficiency and poor therapeutic effect of traditional transdermal drug delivery methods. Hyaluronic acid (HA) was modified on the surface of MTX-loaded liposomes. The interaction of HA and CD44 could increase the adhesion of HA-MTX-Lipo to HaCaT cells, thereby promoting the apoptosis or death of HaCaT cells. Results indicated HA-MTX-Lipo MNs could inhibit the development of psoriasis and reduce the degree of skin erythema, scaling, and thickening. The mRNA levels of proinflammatory cytokines such as IL-17A, IL-23, and TNF-α were decreased. The epidermal thickness and proliferative cell-associated antigen Ki67 expression were also reduced. Specifically, the expression of mRNA levels of proinflammatory cytokines was down-regulated. The MNs transdermal delivery of HA-modified-MTX liposomes provided a promising method for treating psoriasis.

Design of synthetic peptide-based fluorescence probes for turn-on detection of hyaluronan

Herein, we designed and examined a series of fluorescent peptide-based probes for turn-on detection of hyaluronan (HA), a member of the glycosaminoglycan family. We utilized two kinds of synthetic HA-binding peptides as the binding unit for HA, and each peptide was coupled with three kinds of environment-sensitive fluorophores as the signaling unit. From the examination of the peptides, fluorophores, and the position and number of fluorophore modification, we found that X7 peptide (RYPISRPRKR) labelled with an aggregation-induced emission (AIE) fluorogen, tetraphenylethene (TPE), at the N-terminal (named TPE-X7) did function as a light-up probe for HA. The response of TPE-X7 was highly selective to higher molecular weight HA in comparison with lower ones, having the possible potential for the analysis of HA size. TPE-X7 was also applicable to the quantification of HA in synovial fluids.

Polysaccharides as a Hydrophilic Building Block of Amphiphilic Block Copolymers for the Conception of Nanocarriers

Polysaccharides are gaining increasing attention for their relevance in the production of sustainable materials. In the domain of biomaterials, polysaccharides play an important role as hydrophilic components in the design of amphiphilic block copolymers for the development of drug delivery systems, in particular nanocarriers due to their outstanding biocompatibility, biodegradability, and structural versatility. The presence of a reducing end in polysaccharide chains allows for the synthesis of polysaccharide-based block copolymers. Compared with polysaccharide-based graft copolymers, the structure of block copolymers can be more precisely controlled. In this review, the synthesis methods of polysaccharide-based amphiphilic block copolymers are discussed in detail, taking into consideration the structural characteristics of polysaccharides. Various synthetic approaches, including reductive amination, oxime ligation, and other chain-end modification reactions, are explored. This review also focuses on the advantages of polysaccharides as hydrophilic blocks in polymeric nanocarriers. The structure and unique properties of different polysaccharides such as cellulose, hyaluronic acid, chitosan, alginate, and dextran are described along with examples of their applications as hydrophilic segments in the synthesis of amphiphilic copolymers to construct nanocarriers for sustained drug delivery.

Hyaluronan nanogel co-loaded with chloroquine to enhance intracellular cisplatin delivery through lysosomal permeabilization and lysophagy inhibition

Hyaluronan (HA) has been widely used to construct nanocarriers for cancer-targeted drug delivery, due to its excellent biocompatibility and intrinsic affinity towards CD44 that is overexpressed in most cancer types. However, the HA-based nanocarriers are prone to trapping in lysosomes following the HA-mediated endocytosis, which limited the delivered drug to access its pharmacological action sites and subsequently compromised the therapeutic efficacy. To overcome this intracellular obstacle, here we demonstrated the co-loading of chloroquine (CQ) in HA nanogel could efficiently promote the intracellular delivery of cisplatin. The cisplatin coordination with HA generated the nanogel that could also co-encapsulate CQ (HA/Cis/CQ nanogel). Compared with cisplatin-loaded HA nanogel (HA/Cis), HA/Cis/CQ significantly promoted the lysosomal escape of cisplatin as well as enhanced tumor inhibition in the triple-negative breast cancer model. Mechanism studies suggested that co-delivery of CQ not only induced the lysosomal membrane permeabilization but also inhibited the lysophagy, which collectively contributed to the lysosomal instability and cisplatin escape. This HA/Cis/CQ nanogel elicited less toxicity compared with the combination of free Cis and CQ, thus suggesting a promising HA nanocarrier to boost the cisplatin delivery towards cancer-targeted therapy.

Recent Advances in Nanocarrier-based Approaches to Atopic Dermatitis and Emerging Trends in Drug Development and Design

Atopic dermatitis (AD), commonly known as Eczema, is a non-communicable skin condition that tends to become chronic. The deteriorating immunological abnormalities are marked by mild to severe erythema, severe itching, and recurrent eczematous lesions. Different pharmacological approaches are used to treat AD. The problem with commercial topical preparations lies in the limitation of skin atrophy, systemic side effects, and burning sensation that decreases patient compliance. The carrier-based system promises to eliminate these shortcomings; thus, a novel approach to treating AD is required. Liposomes, microemulsions, solid lipid nanoparticles (SLNs), nanoemulsions, etc., have been developed recently to address this ailment. Despite extensive research in the development method and various techniques, it has been challenging to demonstrate the commercial feasibility of these carrier- based systems, which illustrates a gap among the different research areas. Further, different soft wares and other tools have proliferated among biochemists as part of a cooperative approach to drug discovery. It is crucial in designing, developing, and analyzing processes in the pharmaceutical industry and is widely used to reduce costs, accelerate the development of biologically innovative active ingredients, and shorten the development time. This review sheds light on the compilation of extensive efforts to combat this disease, the product development processes, commercial products along with patents in this regard, numerous options for each step of computer-aided drug design, including in silico pharmacokinetics, pharmacodynamics, and toxicity screening or predictions that are important in finding the drug-like compounds.

The impact of different concentrations of hyaluronic acid on the pasting and microstructural properties of corn starch

Starch aging in starchy foods is a major problem affecting their quality. In order to improve the viscosity and textural properties of native starch gelatinization and retrogradation, this study investigated the effect of hyaluronic acid (HA) at different concentrations (2 %, 4 %, 6 % w/w) on the pasting and microstructure of corn starch (CS). The findings revealed that the addition of HA significantly enhanced the peak viscosity, solubility, and water-holding capacity of the CS-HA mixtures. Moreover, it reduced the pasting temperature, swelling force, and leaching of amylose. All the mixtures exhibited shear thinning and thixotropic properties. The CS-HA mixtures created a thicker pseudoplastic system with significantly enhanced shear stability. The structures of the mixtures were characterized using Fourier transform infrared spectroscopy and scanning electron microscopy. It was observed that HA effectively inhibited short-term retrogradation of starch, enhanced the interaction between CS and HA, and formed a dense honeycomb three-dimensional mesh structure. In conclusion, as a novel anionic hydrocolloid, HA holds great potential to improve the retrogradation properties of starch-based products.

Bioinspired synthesis of bioactive glass nanocomposites for hyaluronic acid delivery to bone and skin

In this study, we present nanocomposites of bioactive glass (BG) and hyaluronic acid (HA) (nano-BGHA) for effective delivery of HA to skin and bone. The synthesis of the nanocomposites has been carried out through the bio-inspired method, which is a modification of the traditional Stober's synthesis as it avoids using ethanol, ammonia, synthetic surfactants, or high-temperature calcination. This environmentally friendly, bio-inspired route allowed the synthesis of mesoporous nanocomposites with an average hydrodynamic radius of ∼190 nm and an average net surface charge of ∼-21 mV. Most nanocomposites are amorphous and bioactive in nature with over 70 % cellular viability for skin and bone cell lines even at high concentrations, along with high cellular uptake (90-100 %). Furthermore, the nanocomposites could penetrate skin cells in a transwell set-up and artificial human skin membrane (StratM®), thus depicting an attractive strategy for the delivery of HA to the skin. The purpose of the study is to develop nanocomposites of HA and BG that can have potential applications in non-invasive treatments that require the delivery of high molecular weight HA such as in the case of osteoarthritis, sports injury treatments, eye drops, wound healing, and some anticancer treatments, if further investigated. The presence of BG further enhances the range to bone-related applications. Additionally, the nanocomposites can have potential cosmeceutical applications where HA is abundantly used, for instance in moisturizers, dermal fillers, shampoos, anti-wrinkle creams, etc.

Tailoring tumor-recognizable hyaluronic acid-lipid conjugates to enhance anticancer efficacies of surface-engineered natural killer cells

Natural killer (NK) cells have clinical advantages in adoptive cell therapy owing to their inherent anticancer efficacy and their ability to identify and eliminate malignant tumors. However, insufficient cancer-targeting ligands on NK cell surfaces often inhibit their immunotherapeutic performance, especially in immunosuppressive tumor microenvironment. To facilitate tumor recognition and subsequent anticancer function of NK cells, we developed hyaluronic acid (HA, ligands to target CD44 overexpressed onto cancer cells)-poly(ethylene glycol) (PEG, cytoplasmic penetration blocker)-Lipid (molecular anchor for NK cell membrane decoration through hydrophobic interaction) conjugates for biomaterial-mediated ex vivo NK cell surface engineering. Among these major compartments (i.e., Lipid, PEG and HA), optimization of lipid anchors (in terms of chemical structure and intrinsic amphiphilicity) is the most important design parameter to modulate hydrophobic interaction with dynamic NK cell membranes. Here, three different lipid types including 1,2-dimyristoyl-sn-glycero-3-phosphati-dylethanolamine (C14:0), 1,2-distearoyl-sn-glycero-3-phosphatidylethanolamine (DSPE, C18:0), and cholesterol were evaluated to maximize membrane coating efficacy and associated anticancer performance of surface-engineered NK cells (HALipid-NK cells). Our results demonstrated that NK cells coated with HA-PEG-DSPE conjugates exhibited significantly enhanced anticancer efficacies toward MDA-MB-231 breast cancer cells without an off-target effect on human fibroblasts specifically via increased NK cell membrane coating efficacy and prolonged surface duration of HA onto NK cell surfaces, thereby improving HA-CD44 recognition. These results suggest that our HALipid-NK cells with tumor-recognizable HA-PEG-DSPE conjugates could be further utilized in various cancer immunotherapies.

Clinical and Biochemical Implications of Hyaluronic Acid in Musculoskeletal Rehabilitation: A Comprehensive Review

Hyaluronic acid (HA) naturally occurs as a biopolymer in the human body, primarily in connective tissues like joints and skin. Functioning as a vital element of synovial fluid, it lubricates joints, facilitating fluid movement and diminishing bone friction to protect articular well-being. Its distinctive attributes encompass notable viscosity and water retention capacities, ensuring flexibility and absorbing shock during motion. Furthermore, HA has gained significant attention for its potential benefits in various medical applications, including rehabilitation. Ongoing research explores its properties and functions, especially its biomedical applications in several clinical trials, with a focus on its role in improving rehabilitation outcomes. But the clinical and biochemical implications of HA in musculoskeletal rehabilitation have yet to be fully explored. This review thoroughly investigates the properties and functions of HA while highlighting its biomedical applications in different clinical trials, with a special emphasis on its role in rehabilitation. The presented findings provide evidence that HA, as a natural substance, enhances the outcomes of musculoskeletal rehabilitation through its exceptional mechanical and biochemical effects.

Hyaluronic Acid Nanogels: A Promising Platform for Therapeutic and Theranostic Applications

Hyaluronic acid (HA) nanogels are a versatile class of nanomaterials with specific properties, such as biocompatibility, hygroscopicity, and biodegradability. HA nanogels exhibit excellent colloidal stability and high encapsulation capacity, making them promising tools for a wide range of biomedical applications. HA nanogels can be fabricated using various methods, including polyelectrolyte complexation, self-assembly, and chemical crosslinking. The fabrication parameters can be tailored to control the physicochemical properties of HA nanogels, such as size, shape, surface charge, and porosity, enabling the rational design of HA nanogels for specific applications. Stimulus-responsive nanogels are a type of HA nanogels that can respond to external stimuli, such as pH, temperature, enzyme, and redox potential. This property allows the controlled release of encapsulated therapeutic agents in response to specific physiological conditions. HA nanogels can be engineered to encapsulate a variety of therapeutic agents, such as conventional drugs, genes, and proteins. They can then be delivered to target tissues with high efficiency. HA nanogels are still under development, but they have the potential to become powerful tools for a wide range of theranostic or solely therapeutic applications, including anticancer therapy, gene therapy, drug delivery, and bioimaging.

Preparation of Cholesterol-Modified Hyaluronic Acid Nanogel-Based Hydrogel and the Inflammatory Evaluation Using Macrophage-like Cells

Nanogels are candidate biomaterials for tissue engineering and drug delivery. In the present study, a cholesterol-hyaluronic acid hydrogel was developed, and the pro-inflammatory response of macrophages to the hydrogel was investigated to determine its use in biomedical applications. Hyaluronic acid modified with cholesterol (modification rate: 0-15%) and maleimide (Chol-HA) was synthesized. The Chol-HA nanogel was formed through self-assembly via hydrophobic cholesterol interactions in aqueous solution. The Chol-HA hydrogel was formed through chemical crosslinking of the Chol-HA nanogel via a Michael addition reaction between the maleimide and thiol groups of 4arm-PEGSH. We found that the Chol-HA hydrogels with 5, 10, and 15% cholesterol inhibited the pro-inflammatory response of HiBiT-THP-1 cells, suggesting that the cholesterol contributed to the macrophage response. Furthermore, Interleukin 4 (IL-4) encapsulated in the hydrogel of the Chol-HA nanogel enhanced the inhibition of the inflammatory response in HiBiT-THP-1 cells. These results provide useful insights into the biomedical applications of hydrogels.

Components and physical properties of hydrogels modulate inflammatory response and cartilage repair

Collagen and hyaluronic acid are commonly applied in cartilage tissue engineering, yet there has been limited investigation into their inflammatory response, a crucial factor in articular cartilage repair. This study aimed to evaluate the impact of components and physical properties of hydrogels on inflammatory response and cartilage repair. Three kinds of hydrogels with comparable storage moduli at low frequencies were designed and fabricated, namely, methacrylic anhydride-modified hyaluronic acid hydrogel (HAMA), methacrylic anhydride-modified type I collagen hydrogel (CMA) and unmodified type I collagen hydrogel (Col). HAMA hydrogel was unfavorable for adhesion and spreading of BMSCs. Furthermore, HAMA hydrogel stimulated rapid migration and pro-inflammatory M1 polarization of macrophages, leading to persistent and intense inflammation, which was unfavorable for cartilage repair. CMA and Col hydrogels possessed the same component and facilitated the adhesion, spreading and proliferation of BMSCs. Compared with CMA hydrogel, Col hydrogel induced rapid migration and moderate M1 polarization of macrophages at the early stage of injury, which was mainly influenced by its fast dissolution rate, small pore size fiber network structure and rapid stress relaxation. In addition, the phenotype of macrophages timely transformed into anti-inflammatory M2 due to the properties of the collagen component, which shortened the duration of inflammation and enhanced cartilage repair. The results indicated that moderate macrophage activation adjusted by hydrogel components and physical properties was critical in modulating inflammation and cartilage regeneration.

The Glycosaminoglycan Side Chains and Modular Core Proteins of Heparan Sulphate Proteoglycans and the Varied Ways They Provide Tissue Protection by Regulating Physiological Processes and Cellular Behaviour

This review examines the roles of HS-proteoglycans (HS-PGs) in general, and, in particular, perlecan and syndecan as representative examples and their interactive ligands, which regulate physiological processes and cellular behavior in health and disease. HS-PGs are essential for the functional properties of tissues both in development and in the extracellular matrix (ECM) remodeling that occurs in response to trauma or disease. HS-PGs interact with a biodiverse range of chemokines, chemokine receptors, protease inhibitors, and growth factors in immune regulation, inflammation, ECM stabilization, and tissue protection. Some cell regulatory proteoglycan receptors are dually modified hybrid HS/CS proteoglycans (betaglycan, CD47). Neurexins provide synaptic stabilization, plasticity, and specificity of interaction, promoting neurotransduction, neurogenesis, and differentiation. Ternary complexes of glypican-1 and Robbo-Slit neuroregulatory proteins direct axonogenesis and neural network formation. Specific neurexin-neuroligin complexes stabilize synaptic interactions and neural activity. Disruption in these interactions leads to neurological deficits in disorders of functional cognitive decline. Interactions with HS-PGs also promote or inhibit tumor development. Thus, HS-PGs have complex and diverse regulatory roles in the physiological processes that regulate cellular behavior and the functional properties of normal and pathological tissues. Specialized HS-PGs, such as the neurexins, pikachurin, and Eyes-shut, provide synaptic stabilization and specificity of neural transduction and also stabilize the axenome primary cilium of phototoreceptors and ribbon synapse interactions with bipolar neurons of retinal neural networks, which are essential in ocular vision. Pikachurin and Eyes-Shut interactions with an α-dystroglycan stabilize the photoreceptor synapse. Novel regulatory roles for HS-PGs controlling cell behavior and tissue function are expected to continue to be uncovered in this fascinating class of proteoglycan.

Hyaluronic Acid in Rheumatology

Hyaluronic acid (HA), also known as hyaluronan, is an anionic glycosaminoglycan widely distributed throughout various tissues of the human body. It stands out from other glycosaminoglycans as it lacks sulfation and can attain considerable size: the average human synovial HA molecule weighs about 7 million Dalton (Da), equivalent to roughly 20,000 disaccharide monomers; although some sources report a lower range of 3-4 million Da. In recent years, HA has garnered significant attention in the field of rheumatology due to its involvement in joint lubrication, cartilage maintenance, and modulation of inflammatory and/or immune responses. This review aims to provide a comprehensive overview of HA's involvement in rheumatology, covering its physiology, pharmacology, therapeutic applications, and potential future directions for enhancing patient outcomes. Nevertheless, the use of HA therapy in rheumatology remains controversial with conflicting evidence regarding its efficacy and safety. In conclusion, HA represents a promising therapeutic option to improve joint function and alleviate inflammation and pain.

Hyaluronic Acid-Based Bioconjugate Systems, Scaffolds, and Their Therapeutic Potential

In recent years, the development of hyaluronic acid or hyaluronan (HA) based scaffolds, medical devices, bioconjugate systems have expanded into a broad range of research and clinical applications. Research findings over the last two decades suggest that the abundance of HA in most mammalian tissues with distinctive biological roles and chemical simplicity for modifications have made it an attractive material with a rapidly growing global market. Besides its use as native forms, HA has received much interest on so-called "HA-bioconjugates" and "modified-HA systems". In this review, the importance of chemical modifications of HA, underlying rationale approaches, and various advancements of bioconjugate derivatives with their potential physicochemical, and pharmacological advantages are summarized. This review also highlights the current and emerging HA-based conjugates of small molecules, macromolecules, crosslinked systems, and surface coating strategies with their biological implications, including their potentials and key challenges discussed in detail.

CEMIP-mediated hyaluronan metabolism facilitates SCLC metastasis by activating TLR2/c-Src/ERK1/2 axis

Small-cell lung cancer (SCLC) is a highly metastatic and recalcitrant malignancy. Metastasis is the major cause of death in patients with SCLC but its mechanism remains poorly understood. An imbalance of hyaluronan catabolism in the extracellular matrix accelerates malignant progression in solid cancers due to the accumulation of low-molecular-weight HA. We previously found that CEMIP, a novel hyaluronidase, may act as a metastatic trigger in SCLC. In the present study, we found that both CEMIP and HA levels were higher in SCLC tissues than in paracancerous tissues from patient specimens and in vivo orthotopic models. Additionally, high expression of CEMIP was associated with lymphatic metastasis in patients with SCLC, and in vitro results showed that CEMIP expression was elevated in SCLC cells relative to human bronchial epithelial cells. Mechanistically, CEMIP facilitates the breakdown of HA and accumulation of LMW-HA. LMW-HA activates its receptor TLR2, and subsequently recruits c-Src to activate ERK1/2 signalling, thereby promoting F-actin rearrangement as well as migration and invasion of SCLC cells. In addition, the in vivo results verified that depletion of CEMIP attenuated HA levels and the expressions of TLR2, c-Src, and phosphorylation of ERK1/2, as well as liver and brain metastasis in SCLC xenografts. Furthermore, the application of the actin filament inhibitor latrunculin A significantly inhibited the liver and brain metastasis of SCLC in vivo. Collectively, our findings reveal the critical role of CEMIP-mediated HA degradation in SCLC metastasis and suggest its translational potential as an attractive target and a novel strategy for SCLC therapy.

Sustained Release Microneedles: Materials and Applications in Facial Rejuvenation

Wrinkled and loose skin resulting from collagen degradation along with fibers decreasing reflects the youth diminishing. Microneedles (MNs) have opened up new avenues for the development of painless and noninvasive transdermal drug delivery systems for facial rejuvenation. Encapsulated drugs or molecules are transmitted to targeted tissues via percutaneous microchannels, which eliminate potential gastric stimulation or first-pass metabolic effects, as well as boost patient compliance. Although MNs are considered effective and feasible therapeutic alternatives to metals, silicon, and polymers, traditional procedures with reduction processes continue to encounter methodological limitations. In recent years, promising additive manufacturing processes such as three-dimensional printing and two-photon polymerization manufacturing have been developed with the aim of overcoming the limitations by traditional processes to facilitate an efficient and economic production mode. This review summarizes the design, material selection, and manufacturing method for recently advanced MN systems. Furthermore, we also highlight specific polymeric or natural microneedle products, like hyaluronan, plant derivates, and vitamins, for esthetic applications in this review. Impact Statement In this review, the materials and manufactural routes of microneedles (MNs) are detailed. Moreover, similar to the diagnostic or therapeutic MNs, the feature of dispensation with training and ready-to-use is perfect for beautification and anti-aging, which necessitate repeated and long-term usage. Furthermore, the specific polymeric or natural products for esthetic applications of MNs are highlighted in this review.

Targeting LAYN inhibits colorectal cancer metastasis and tumor-associated macrophage infiltration induced by hyaluronan oligosaccharides

The accumulation of hyaluronan oligosaccharides (oHA) in colorectal cancer (CRC) is closely related to tumor metastasis, but the underlying mechanism remains unclear. In this study, we first described that LAYN, a novel HA receptor, was upregulated in CRC tissue. Aberrant LAYN expression correlated with CRC metastasis and poor prognosis and positively correlated with tumor-associated macrophage (TAM) infiltration and M2 macrophage polarization in the tumor environment. Both in vitro and in vivo studies demonstrated that LAYN is activated by oHA and subsequently induces CRC metastasis and macrophage infiltration. Mechanistic studies demonstrated that oHA activates LAYN by binding to the 60-68th amino acid region of the extracellular segment. oHA-induced LAYN activation promoted metastasis and CCL20 secretion through the NF-kB pathway in CRC cells. Furthermore, targeting LAYN using a blocking antibody prevented oHA-mediated tumor metastasis, TAM infiltration and M2 polarization. This study revealed the LAYN activation mechanism and identified a potential target for the treatment of CRC tumor exhibiting high oHA levels.

IBD disease-modifying therapies: insights from emerging therapeutics

Inflammatory bowel disease (IBD) pathogenesis is associated with gut mucosal inflammation, epithelial damage, and dysbiosis leading to a dysregulated gut mucosal barrier. However, the extent and underlying mechanisms remain largely unknown. Current treatment regimens have focused mainly on treating IBD symptoms; however, such treatment strategies do not address mucosal epithelial repair, barrier homeostasis, or intestinal dysbiosis. Although attempts have been made to identify new therapeutic modalities to enhance gut barrier functions, these are at an early developmental stage and have not been wholly successful. We review conventional therapies, the possible relevant role of gut barrier-protecting agents, and biomaterial strategies relating to combination therapies that may pave the way towards developing new therapeutic approaches for IBD.

Smart Phototheranostics based on Carbon Nanohorns for Precise Imaging-Guided Post-PDT toward Residual Tumor Cells after Initial Phototherapy

As promising photonic material, phototheranostics can be activated in the laser irradiation range of tumor with sensitivity and spatiotemporal precision. However, it is difficult to completely eradicate solid tumors due to their irregularity and limited laser irradiation area. Herein, multi-stimulus responsive HA-Ce6@SWNHs were constructed with single-walled carbon nanohorns (SWNHs) and chlorine e6 (Ce6) modified hyaluronic acid (HA) via non-covalent binding. This SWNHs-based phototheranostics not only exhibited water dispersion but also could target tumor and be activated by near-infrared light for photodynamic therapy (PDT) and photothermal therapy (PTT). Additionally, HA-Ce6@SWNHs could be degraded by hyaluronidase in residual tumor cells, causing HA-Ce6 to fall off the SWNHs surfaces to restore autofluorescence, thus precisely guiding the programmed photodynamic treatments for residual tumor cells after the initial phototherapy. Thus, this work provides a rationally designed multiple-stimulus-response strategy to develop smart SWNHs-based phototheranostics for precise PDT/PTT and post-treatment imaging-guided PDT of residual tumor cells.

Multifunctional hydrogels based on chitosan, hyaluronic acid and other biological macromolecules for the treatment of inflammatory bowel disease: A review

Hydrogel is a three-dimensional network polymer material rich in water. It is widely used in the biomedical field because of its unique physical and chemical properties and good biocompatibility. In recent years, the incidence of inflammatory bowel disease (IBD) has gradually increased, and the disadvantages caused by traditional drug treatment of IBD have emerged. Therefore, there is an urgent need for new treatments to alleviate IBD. Hydrogel has become a potential therapeutic platform. However, there is a lack of comprehensive review of functional hydrogels for IBD treatment. This paper first summarizes the pathological changes in IBD sites. Then, the action mechanisms of hydrogels prepared from chitosan, sodium alginate, hyaluronic acid, functionalized polyethylene glycol, cellulose, pectin, and γ-polyglutamic acid on IBD were described from aspects of drug delivery, peptide and protein delivery, biologic therapies, loading probiotics, etc. In addition, the advanced functions of IBD treatment hydrogels were summarized, with emphasis on adhesion, synergistic therapy, pH sensitivity, particle size, and temperature sensitivity. Finally, the future development direction of IBD treatment hydrogels has been prospected.

Polysaccharide-based nanocarriers for efficient transvascular drug delivery

Polysaccharide-based nanocarriers (PBNs) are the focus of extensive investigation because of their biocompatibility, low cost, wide availability, and chemical versatility, which allow a wide range of anticancer agents to be loaded within the nanocarriers. Similar to other nanocarriers, most PBNs are designed to extravasate out of tumor vessels, depending on the enhanced permeability and retention (EPR) effect. However, the EPR effect is compromised in some tumors due to the heterogeneity of tumor structures. Transvascular transport efficacy is decreased by complex blood vessels and condensed tumor stroma. The limited extravasation impedes efficient drug delivery into tumor parenchyma, and thus affects the subsequent tumor accumulation, which hinders the therapeutic effect of PBNs. Therefore, overcoming the biological barriers that restrict extravasation from tumor vessels is of great importance in PBN design. Many strategies have been developed to enhance the EPR effect that involve nanocarrier property regulation and tumor structure remodeling. Moreover, some researchers have proposed active transcytosis pathways that are complementary to the paracellular EPR effect to increase the transvascular extravasation efficiency of PBNs. In this review, we summarize the recent advances in the design of PBNs with enhanced transvascular transport to enable optimization of PBNs in the extravasation of the drug delivery process. We also discuss the obstacles and challenges that need to be addressed to clarify the transendothemial mechanism of PBNs and the potential interactions between extravasation and other drug delivery steps.

Hyaluronan-Cyclodextrin Conjugates as Doxorubicin Delivery Systems

In the last years, nanoparticles based on cyclodextrins have been widely investigated for the delivery of anticancer drugs. In this work, we synthesized nanoparticles with a hyaluronic acid backbone functionalized with cyclodextrins under green conditions. We functionalized hyaluronic acid with two different molecular weights (about 11 kDa and 45 kDa) to compare their behavior as doxorubicin delivery systems. We found that the new hyaluronan-cyclodextrin conjugates increased the water solubility of doxorubicin. Moreover, we tested the antiproliferative activity of doxorubicin in the presence of the new cyclodextrin polymers in SK-N-SH and SK-N-SH-PMA (over-expressing CD44 receptor) cancer cells. We found that hyaluronan-cyclodextrin conjugates improved the uptake and antiproliferative activity of doxorubicin in the SK-N-SH-PMA compared to the SK-N-SH cell line at the ratio 8/1 doxorubicin/polymer. Notably, the system based on hyaluronan (45 kDa) was more effective as a drug carrier and significantly reduced the IC₅₀ value of doxorubicin by about 56%. We also found that hyaluronic acid polymers determined an improved antiproliferative activity of doxorubicin (IC₅₀ values are on average reduced by about 70% of free DOXO) in both cell lines at the ratio 16/1 doxorubicin/polymer.

Application of decellularized vascular matrix in small-diameter vascular grafts

Coronary artery bypass grafting (CABG) remains the most common procedure used in cardiovascular surgery for the treatment of severe coronary atherosclerotic heart disease. In coronary artery bypass grafting, small-diameter vascular grafts can potentially replace the vessels of the patient. The complete retention of the extracellular matrix, superior biocompatibility, and non-immunogenicity of the decellularized vascular matrix are unique advantages of small-diameter tissue-engineered vascular grafts. However, after vascular implantation, the decellularized vascular matrix is also subject to thrombosis and neoplastic endothelial hyperplasia, the two major problems that hinder its clinical application. The keys to improving the long-term patency of the decellularized matrix as vascular grafts include facilitating early endothelialization and avoiding intravascular thrombosis. This review article sequentially introduces six aspects of the decellularized vascular matrix as follows: design criteria of vascular grafts, components of the decellularized vascular matrix, the changing sources of the decellularized vascular matrix, the advantages and shortcomings of decellularization technologies, modification methods and the commercialization progress as well as the application prospects in small-diameter vascular grafts.

Degradable Biocompatible Porous Microtube Scaffold for Extended Donor Cell Survival and Activity

Cell therapy has significant therapeutic potential but is often limited by poor donor cell retention and viability at the host implantation site. Biomaterials can improve cell retention by providing cells with increased cell-cell and cell-matrix contacts and materials that allow three-dimensional cell culture to better recapitulate native cell morphology and function. In this study, we engineered a scaffold that allows for cell encapsulation and sustained three-dimensional cell culture. Since cell therapy is largely driven by paracrine secretions, the material was fabricated by electrospinning to have a large internal surface area, micrometer-thin walls, and nanoscale surface pores to allow for nutrient exchange without early cell permeation. The material is degradable, which allows for less invasive removal of the implant. Here, a biodegradable poly(lactic-co-glycolic acid) (PLGA) microtube array membrane was fabricated. In vitro testing showed that the material supported the culture of human dermal fibroblasts for at least 21 days, with paracrine secretion of pro-angiogenic FGF2. In vivo xenotransplantation of human cells in an immunocompetent mouse showed that donor cells could be maintained for more than one month and the material showed no obvious toxicity. Analysis of gene expression and tissue histology surrounding the implant showed that the material produced muted inflammatory and immune responses compared to a permanent implant and increased markers of angiogenesis.

The role of hyaluronan in renal cell carcinoma

Renal cell carcinoma (RCC) is associated with high mortality rates worldwide and survival among RCC patients has not improved significantly in the past few years. A better understanding of the pathogenesis of RCC can enable the development of more effective therapeutic strategies against RCC. Hyaluronan (HA) is a glycosaminoglycan located in the extracellular matrix (ECM) that has several roles in biology, medicine, and physiological processes, such as tissue homeostasis and angiogenesis. Dysregulated HA and its receptors play important roles in fundamental cellular and molecular biology processes such as cell signaling, immune modulation, tumor progression and angiogenesis. There is emerging evidence that alterations in the production of HA regulate RCC development, thereby acting as important biomarkers as well as specific therapeutic targets. Therefore, targeting HA or combining it with other therapies are promising therapeutic strategies. In this Review, we summarize the available data on the role of abnormal regulation of HA and speculate on its potential as a therapeutic target against RCC.

Hyaluronic acid in the treatment of dry eye disease

Dry eye disease (DED) is a highly prevalent and debilitating condition affecting several hundred million people worldwide. Hyaluronic acid (HA) is a naturally occurring glycosaminoglycan commonly used in the treatment of DED. This review aims to critically evaluate the literature on the safety and efficacy of artificial tears containing HA used in DED treatment. Literature searches were conducted in PubMed, including MEDLINE, and in Embase via Ovid with the search term: "(hyaluronic acid OR hyaluronan OR hyaluronate) AND (dry eye OR sicca)". A total of 53 clinical trials are included in this review, including eight placebo-controlled trials. Hyaluronic acid concentrations ranged from 0.1% to 0.4%. Studies lasted up to 3 months. A broad spectrum of DED types and severities was represented in the reviewed literature. No major complications or adverse events were reported. Artificial tears containing 0.1% to 0.4% HA were effective at improving both signs and symptoms of DED. Two major gaps in the literature have been identified: 1. no study investigated the ideal drop frequency for HA-containing eyedrops, and 2. insufficient evidence was presented to recommend any specific HA formulation over another. Future investigations assessing the optimal drop frequency for different concentrations and molecular weights of HA, different drop formulations, including tonicity, and accounting for DED severity and aetiology are essential for an evidence-based, individualized approach to DED treatment.

Glial cell line-derived neurotrophic factor and brain-derived neurotrophic factor regulate the interaction between astrocytes and Schwann cells at the trigeminal root entry zone

The trigeminal root entry zone is the zone at which the myelination switches from peripheral Schwann cells to central oligodendrocytes. Its special anatomical and physiological structure renders it susceptible to nerve injury. The etiology of most primary trigeminal neuralgia is closely related to microvascular compression of the trigeminal root entry zone. This study aimed to develop an efficient in vitro model mimicking the glial environment of trigeminal root entry zone as a tool to investigate the effects of glial cell line-derived neurotrophic factor and brain-derived neurotrophic factor on the structural and functional integrity of trigeminal root entry zone and modulation of cellular interactions. Primary astrocytes and Schwann cells isolated from trigeminal root entry zone of postnatal rats were inoculated into a two-well silicon culture insert to mimic the trigeminal root entry zone microenvironment and treated with glial cell line-derived neurotrophic factor and brain-derived neurotrophic factor. In monoculture, glial cell line-derived neurotrophic factor promoted the migration of Schwann cells, but it did not have effects on the migration of astrocytes. In the co-culture system, glial cell line-derived neurotrophic factor promoted the bidirectional migration of astrocytes and Schwann cells. Brain-derived neurotrophic factor markedly promoted the activation and migration of astrocytes. However, in the co-culture system, brain-derived neurotrophic factor inhibited the migration of astrocytes and Schwann cells to a certain degree. These findings suggest that glial cell line-derived neurotrophic factor and brain-derived neurotrophic factor are involved in the regulation of the astrocyte-Schwann cell interaction in the co-culture system derived from the trigeminal root entry zone. This system can be used as a cell model to study the mechanism of glial dysregulation associated with trigeminal nerve injury and possible therapeutic interventions.

HYDRHA: Hydrogels of hyaluronic acid. New biomedical approaches in cancer, neurodegenerative diseases, and tissue engineering

In the last decade, hyaluronic acid (HA) has attracted an ever-growing interest in the biomedical engineering field as a biocompatible, biodegradable, and chemically versatile molecule. In fact, HA is a major component of the extracellular matrix (ECM) and is essential for the maintenance of cellular homeostasis and crosstalk. Innovative experimental strategies in vitro and in vivo using three-dimensional (3D) HA systems have been increasingly reported in studies of diseases, replacement of tissue and organ damage, repairing wounds, and encapsulating stem cells for tissue regeneration. The present work aims to give an overview and comparison of recent work carried out on HA systems showing advantages, limitations, and their complementarity, for a comprehensive characterization of their use. A special attention is paid to the use of HA in three important areas: cancer, diseases of the central nervous system (CNS), and tissue regeneration, discussing the most innovative experimental strategies. Finally, perspectives within and beyond these research fields are discussed.

Interactions between Nitric Oxide and Hyaluronan Implicate the Migration of Breast Cancer Cells

Nitric oxide (^•NO) is one of the prominent free radicals, playing a pivotal role in breast cancer progression. Hyaluronic acid (HA) plays an essential role in neutralizing free radicals in tumor tissues. However, its interactions with nitric oxide have not been thoroughly investigated. Hence, this study attempts to understand the mechanism of these interactions and the different effects on the intracellular ^•NO levels and migration of breast cancer cells. The affinity of HA to scavenge ^•NO was investigated alongside the accompanying changes in specific physico-chemical properties and the further effects on the ^•NO-induced attachment and migration of the breast cancer cell lines, MDA-MB-231 and HCC1806. The reaction of the nitrogen dioxide radical, formed via ^•NO/O₂ interactions, with HA initiated a series of oxidative reactions, which, in the presence of ^•NO, induce the fragmentation of the polymeric chains. Furthermore, these interactions were found to hinder the NO-induced migration of cancer cells. However, the NO-induced HA modification/fragmentation was inhibited in the presence of hemin, a NO-scavenging compound. Collectively, these results help toward understanding the involvement of HA in the ^•NO-induced cell migration and suggest the possible modification of HA, used as one of the main materials in different biomedical applications.

New Hyaluronic Acid from Plant Origin to Improve Joint Protection—An In Vitro Study

Background: In recent decades, hyaluronic acid (HA) has attracted great attention as a new treatment option for osteoarthritis. Classical therapies are not able to stop the cartilage degeneration process nor do they favor tissue repair. Nowadays, it is accepted that high molecular weight HA can reduce inflammation by promoting tissue regeneration; therefore, the aim of this study was to verify the efficacy of a new high molecular weight HA of plant origin (called GreenIuronic®) in maintaining joint homeostasis and preventing the harmful processes of osteoarthritis. Methods: The bioavailability of GreenIuronic® was investigated in a 3D intestinal barrier model that mimics human oral intake while excluding damage to the intestinal barrier. Furthermore, the chemical significance and biological properties of GreenIuronic® were investigated in conditions that simulate osteoarthritis. Results: Our data demonstrated that GreenIuronic® crosses the intestinal barrier without side effects as it has a chemical–biological profile, which could be responsible for many specific chondrocyte functions. Furthermore, in the osteoarthritis model, GreenIuronic® can modulate the molecular mechanism responsible for preventing and restoring the degradation of cartilage. Conclusion: According to our results, this new form of HA appears to be well absorbed and distributed to chondrocytes, preserving their biological activities. Therefore, the oral administration of GreenIuronic® in humans can be considered a valid strategy to obtain beneficial therapeutic effects during osteoarthritis.

Glycosaminoglycan-Based Hydrogel Delivery System Regulates the Wound Microenvironment to Rescue Chronic Wound Healing

Chronic wounds cannot proceed through the normal, orderly, and timely sequence of repair. The adverse cycle between excess reactive oxide species (ROS) and a persistent inflammatory response is an important mechanism of impaired wound healing. Herein, by combining the intrinsic bioactivities of natural polysaccharides and natural drugs, a glycosaminoglycan-based hydrogel delivery system is proposed to regulate the wound microenvironment. Dynamic supramolecular cross-linking enables the hydrogel to easily encapsulate the drug and fully fill the wound area. As the backbone of the hydrogel, heparin captures inflammatory chemokines at the wound site, while hyaluronic acid mimics the function of ECM. The hydrophobic drug curcumin has been ingeniously encapsulated in the hydrogel through micellization, thereby exerting good ROS scavenging ability and anti-inflammatory activity. Evaluations in diabetic mice showed that this antioxidant and anti-inflammatory hydrogel was effective in reducing the influx of immune cells at the wound site and in down-regulating the inflammatory response. Accelerated wound healing was also observed, as evidenced by faster re-epithelialization and better ECM remodeling. The proposed hydrogel can regulate the microenvironment of wounds from multiple aspects and thereby achieve regression of wound repair, which may provide a new therapeutic strategy for chronic wounds.

Hyaluronic Acid: Its Versatile Use in Ocular Drug Delivery with a Specific Focus on Hyaluronic Acid-Based Polyelectrolyte Complexes

Extensive research is currently being conducted into novel ocular drug delivery systems (ODDS) that are capable of surpassing the limitations associated with conventional intraocular anterior and posterior segment treatments. Nanoformulations, including those synthesised from the natural, hydrophilic glycosaminoglycan, hyaluronic acid (HA), have gained significant traction due to their enhanced intraocular permeation, longer retention times, high physiological stability, inherent biocompatibility, and biodegradability. However, conventional nanoformulation preparation methods often require large volumes of organic solvent, chemical cross-linkers, and surfactants, which can pose significant toxicity risks. We present a comprehensive, critical review of the use of HA in the field of ophthalmology and ocular drug delivery, with a discussion of the physicochemical and biological properties of HA that render it a suitable excipient for drug delivery to both the anterior and posterior segments of the eye. The pivotal focus of this review is a discussion of the formation of HA-based nanoparticles via polyelectrolyte complexation, a mild method of preparation driven primarily by electrostatic interaction between opposing polyelectrolytes. To the best of our knowledge, despite the growing number of publications centred around the development of HA-based polyelectrolyte complexes (HA-PECs) for ocular drug delivery, no review articles have been published in this area. This review aims to bridge the identified gap in the literature by (1) reviewing recent advances in the area of HA-PECs for anterior and posterior ODD, (2) describing the mechanism and thermodynamics of polyelectrolyte complexation, and (3) critically evaluating the intrinsic and extrinsic formulation parameters that must be considered when designing HA-PECs for ocular application.

Application of biomolecules modification strategies on PEEK and its composites for osteogenesis and antibacterial properties

As orthopedic and dental implants, polyetheretherketone (PEEK) is expected to be a common substitute material of titanium (Ti) and its alloys due to its good biocompatibility, chemical stability, and elastic modulus close to that of bone tissue. It could avoid metal allergy and bone resorption caused by the stress shielding effect of Ti implants, widely studied in the medical field. However, the lack of biological activity is not conducive to the clinical application of PEEK implants. Therefore, the surface modification of PEEK has increasingly become one of the research hotspots. Researchers have explored various biomolecules modification methods to effectively enhance the osteogenic and antibacterial activities of PEEK and its composites. Therefore, this review mainly summarizes the recent research of PEEK modified by biomolecules and discusses the further research directions to promote the clinical transformation of PEEK implants.

Fractone Stem Cell Niche Components Provide Intuitive Clues in the Design of New Therapeutic Procedures/Biomatrices for Neural Repair

The aim of this study was to illustrate recent developments in neural repair utilizing hyaluronan as a carrier of olfactory bulb stem cells and in new bioscaffolds to promote neural repair. Hyaluronan interacts with brain hyalectan proteoglycans in protective structures around neurons in perineuronal nets, which also have roles in the synaptic plasticity and development of neuronal cognitive properties. Specialist stem cell niches termed fractones located in the sub-ventricular and sub-granular regions of the dentate gyrus of the hippocampus migrate to the olfactory bulb, which acts as a reserve of neuroprogenitor cells in the adult brain. The extracellular matrix associated with the fractone stem cell niche contains hyaluronan, perlecan and laminin α5, which regulate the quiescent recycling of stem cells and also provide a means of escaping to undergo the proliferation and differentiation to a pluripotent migratory progenitor cell type that can participate in repair processes in neural tissues. Significant improvement in the repair of spinal cord injury and brain trauma has been reported using this approach. FGF-2 sequestered by perlecan in the neuroprogenitor niche environment aids in these processes. Therapeutic procedures have been developed using olfactory ensheathing stem cells and hyaluronan as a carrier to promote neural repair processes. Now that recombinant perlecan domain I and domain V are available, strategies may also be expected in the near future using these to further promote neural repair strategies.

Metallopolysaccharide-Based Smart Nanotheranostic for Imaging-Guided Precise Phototherapy and Sequential Enzyme-Activated Ferroptosis

Phototheranostic offers a regional-focused tumor treatment upon photoirradiation. However, it is difficult to completely eradicate solid tumors using a conventional phototheranostic owing to the residual tumor cells outside the laser irradiation range. Herein, we fabricated a metallopolysaccharide-based smart nanotheranostic (Fe-^dHA) via a nanoassembly-driven method, in which Fe³⁺ ions were coordinated to dopamine-modified biopolysaccharide hyaluronic acid (^dHA). Taking advantage of the structural backbone and intrinsic dual-information-related functions of HA as well as the bi-functional Fe(III)-coordination centers, Fe-^dHA can efficiently target tumor cells for phototheranostic. Additionally, it can be activated by endogenous overexpressed hyaluronidase to achieve sequential ferroptosis in tumor cells. The precise imaging and effective tumor inhibition using this metallopolysaccharide-based nanotheranostic were significantly demonstrated in vivo and in vitro. Thus, this rationally designed Fe-^dHA provided a simple metallopolysaccharide strategy to develop an "all-in-one" smart nanotheranostic to synergize different therapeutic modalities for improving cancer therapy.

Chemical Modification of Hyaluronan and Their Biomedical Applications

Hyaluronan, the extracellular matrix glycosaminoglycan, is an important structural component of many tissues playing a critical role in a variety of biological contexts. This makes hyaluronan, which can be biotechnologically produced in large scale, an attractive starting polymer for chemical modifications. This review provides a broad overview of different synthesis strategies used for modulating the biological as well as material properties of this polysaccharide. We discuss current advances and challenges of derivatization reactions targeting the primary and secondary hydroxyl groups or carboxylic acid groups and the N-acetyl groups after deamidation. In addition, we give examples for approaches using hyaluronan as biomedical polymer matrix and consequences of chemical modifications on the interaction of hyaluronan with cells via receptor-mediated signaling. Collectively, hyaluronan derivatives play a significant role in biomedical research and applications indicating the great promise for future innovative therapies.

Modulation of Gut Barrier Functions in Ulcerative Colitis by Hyaluronic Acid System

The active stages of intestinal inflammation and the pathogenesis of ulcerative colitis are associated with superficial mucosal damage and intermittent wounding that leads to epithelial barrier defects and increased permeability. The standard therapeutic interventions for colitis have focused mainly on maintaining the remission levels of the disease. Nonetheless, such treatment strategies (using anti-inflammatory, immunomodulatory agents) do not address colitis' root cause, especially the mucosal damage and dysregulated intestinal barrier functions. Restoration of barrier functionality by mucosal healing or physical barrier protecting strategies shall be considered as an initial event in the disease suppression and progression. Herein, a biphasic hyaluronan (HA) enema suspension, naïve-HA systems that protect the dysregulated gut epithelium by decreasing the inflammation, permeability, and helping in maintaining the epithelial barrier integrity in the dextran sodium sulfate-induced colitis mice model is reported. Furthermore, HA-based system modulates intestinal epithelial junctional proteins and regulatory signaling pathways, resulting in attenuation of inflammation and mucosal protection. The results suggest that HA-based system can be delivered as an enema to act as a barrier protecting system for managing distal colonic inflammatory diseases, including colitis.

Gellan gum modified hyaluronic acid hydrogel as viscosupplement with lubrication maintenance and enzymatic resistance

Osteoarthritis (OA) is a common disease caused by damage to articular cartilage and underlying bone tissues. Early OA can be treated by intra-articular injection of viscosupplements to restore the lost...

Laser-Assisted Fabrication of Injectable Nanofibrous Cell Carriers

The use of injectable biomaterials for cell delivery is a rapidly expanding field which may revolutionize the medical treatments by making them less invasive. However, creating desirable cell carriers poses significant challenges to the clinical implementation of cell-based therapeutics. At the same time, no method has been developed to produce injectable microscaffolds (MSs) from electrospun materials. Here the fabrication of injectable electrospun nanofibers is reported on, which retain their fibrous structure to mimic the extracellular matrix. The laser-assisted micro-scaffold fabrication has produced tens of thousands of MSs in a short time. An efficient attachment of cells to the surface and their proliferation is observed, creating cell-populated MSs. The cytocompatibility assays proved their biocompatibility, safety, and potential as cell carriers. Ex vivo results with the use of bone and cartilage tissues proved that NaOH hydrolyzed and chitosan functionalized MSs are compatible with living tissues and readily populated with cells. Injectability studies of MSs showed a high injectability rate, while at the same time, the force needed to eject the load is no higher than 25 N. In the future, the produced MSs may be studied more in-depth as cell carriers in minimally invasive cell therapies and 3D bioprinting applications.

Hyaluronan: A Neuroimmune Modulator in the Microbiota-Gut Axis

The commensal microbiota plays a fundamental role in maintaining host gut homeostasis by controlling several metabolic, neuronal and immune functions. Conversely, changes in the gut microenvironment may alter the saprophytic microbial community and function, hampering the positive relationship with the host. In this bidirectional interplay between the gut microbiota and the host, hyaluronan (HA), an unbranched glycosaminoglycan component of the extracellular matrix, has a multifaceted role. HA is fundamental for bacterial metabolism and influences bacterial adhesiveness to the mucosal layer and diffusion across the epithelial barrier. In the host, HA may be produced and distributed in different cellular components within the gut microenvironment, playing a role in the modulation of immune and neuronal responses. This review covers the more recent studies highlighting the relevance of HA as a putative modulator of the communication between luminal bacteria and the host gut neuro-immune axis both in health and disease conditions, such as inflammatory bowel disease and ischemia/reperfusion injury.

Hyaluronan Functions in Wound Repair That Are Captured to Fuel Breast Cancer Progression

Signaling from an actively remodeling extracellular matrix (ECM) has emerged as a critical factor in regulating both the repair of tissue injuries and the progression of diseases such as metastatic cancer. Hyaluronan (HA) is a major component of the ECM that normally functions in tissue injury to sequentially promote then suppress inflammation and fibrosis, a duality in which is featured, and regulated in, wound repair. These essential response-to-injury functions of HA in the microenvironment are hijacked by tumor cells for invasion and avoidance of immune detection. In this review, we first discuss the numerous size-dependent functions of HA and emphasize the multifunctional nature of two of its receptors (CD44 and RHAMM) in regulating the signaling duality of HA in excisional wound healing. This is followed by a discussion of how HA metabolism is de-regulated in malignant progression and how targeting HA might be used to better manage breast cancer progression.

Modulation of hyaluronan signaling as a therapeutic target in human disease

The extracellular matrix is an active participant, modulator and mediator of the cell, tissue, organ and organismal response to injury. Recent research has highlighted the role of hyaluronan, an abundant glycosaminoglycan constituent of the extracellular matrix, in many fundamental biological processes underpinning homeostasis and disease development. From this basis, emerging studies have demonstrated the therapeutic potential of strategies which target hyaluronan synthesis, biology and signaling, with significant promise as therapeutics for a variety of inflammatory and immune diseases. This review summarizes the state of the art in this field and discusses challenges and opportunities in what could emerge as a new class of therapeutic agents, that we term "matrix biologics".

Hyaluronidases and hyaluronate lyases: From humans to bacteriophages

Hyaluronan is a non-sulfated negatively-charged linear polymer distributed in most parts of the human body, where it is located around cells in the extracellular matrix of connective tissues and plays an essential role in the organization of tissue architecture. Moreover, hyaluronan is involved in many biological processes and used in many clinical, cosmetic, pharmaceutic, and biotechnological applications worldwide. As interest in hyaluronan applications increases, so does interest in hyaluronidases and hyaluronate lyases, as these enzymes play a major part in hyaluronan degradation. Many hyaluronidases and hyaluronate lyases produced by eukaryotic cells, bacteria, and bacteriophages have so far been described and annotated, and their ability to cleave hyaluronan has been experimentally proven. These enzymes belong to several carbohydrate-active enzyme families, share very low sequence identity, and differ in their cleaving mechanisms and in their structural and functional properties. This review presents a summary of annotated and characterized hyaluronidases and hyaluronate lyases isolated from different sources belonging to distinct protein families, with a main focus on the binding and catalytic residues of the discussed enzymes in the context of their biochemical properties. In addition, the application potential of individual groups of hyaluronidases and hyaluronate lyases is evaluated.