Analysis of CD44-hyaluronan interactions in an artificial membrane system: insights into the distinct binding properties of high and low molecular weight hyaluronan

Engineering hypoxia-specific core-shell nanotherapeutics: A sequential strategy for amplified multimodal synergistic breast cancer treatment

The reactive oxygen species (ROS)-based chemodynamic therapy (CDT) and sonodynamic therapy (SDT) have garnered significant interests in advanced tumor treatments. However, their therapeutic efficacy is severely hindered by tumor hypoxia and overexpressed antioxidant glutathione (GSH) in the tumor microenvironment (TME). Motivated by the concept of metal coordination-based nanomedicine, we proposed an innovative strategy for synergistic tumor therapy tailored to the TME. Herein, we developed a multifunctional targeted delivery nanosystem based on the tirapazamine (TPZ)-loaded BT@M/T@T(Cu)GH cascade nanoreactor to enhance the synergistic efficacy of CDT, SDT, chemotherapy (CT) and starvation therapy (ST) against breast cancer. The rationally designed nanoreactor was constructed through covalent conjugation of glucose oxidase (GOx) onto TPZ-loaded BT@M/T@T(Cu) nanoparticles, wherein the formed tannic acid/copper (Ⅱ) (T(Cu)) network served as the "nanovalve"for BT@M/T nanoparticles. Surface functionalization with hyaluronic acid (HA) enabled BT@M/T@T(Cu) nanoparticles to effectively target CD44-overexpressed 4T1 breast tumors via passive targeting and active targeting effect, while mitigating cytotoxicity toward normal cells/tissues. Following successful tumor accumulation, BT@M/T@T(Cu)GH nanoparticles underwent pH-dependent disassembly and released TPZ, Cu2+ and GOx, initiating a cascade of integrated therapeutic functions, including redox balance disruption, starvation, oxidative cytotoxicity, and hypoxia-activated chemotoxicity. When exposed to ultrasound (US) irradiation, BT@M/T@T(Cu)GH nanoparticles demonstrated sonosensitization capability, generating substantial singlet oxygen (1O2) through energy transfer processes. Owing to all these prominent features, the all-in-one nanomedicine exhibited significant apoptotic cell death and noteworthy tumor eradication in vivo, via synergistic combination of GOx-based ST, self-amplified CDT, hypoxia-activated CT, and US-activated SDT. Additionally, the administration of BT@M/T@T(Cu)GH had negligible effects on the normal growth. Taken together, this work establishes a versatile TiO2-based nanosystem integrating tumor targeting and multi-mode synergistic therapy of breast cancer, offering a novel strategy for highly effective and precise treatment of malignancies.

Design Strategies for Hyaluronic Acid-based Drug Delivery Systems in Cancer Immunotherapy

Despite its robust therapeutic potential, cancer immunotherapy has provided little progress towards improved survival rates for patients bearing immunologically refractory tumors. The implementation of advanced drug delivery systems represents a powerful means of improving cancer immunotherapy by relieving immunosuppression and promoting immune response; however, the overall impact of these systems on immunotherapy currently remains modest. Hyaluronic acid represents a widely used polymer in drug delivery; meanwhile, recent studies linking hyaluronic acid to the immune system make this polymer an attractive component in the design of next-generation cancer immunotherapies. Herein, we review our current understanding of the immunological properties of hyaluronic acid and discuss them in the context of bioactive functions and immune-related interactions with receptors, immune, and cancer cells. We analyze the potential of hyaluronic acid as a component in advanced drug delivery systems, highlighting strategies for the design of more effective vaccines and cancer chemo-immunotherapies. Finally, we discuss critical considerations to facilitate design and clinical translation to overcome existing challenges and maximize therapeutic potential.

Polydopamine-assisted ion-mediated hyaluronic acid grafting for effective construction of hemocompatible platform with cancer cell recognition

Surfaces capable of specific biomolecule recognition are essential for cancer theranostics, biosensing, and tissue engineering. However, current grafting methods, critical for dictating the recognition efficiency and biocompatibility of biomaterials, especially hydrophilic polymers, struggle to balance high grafting density with ease of implementation. In pursuit of a simple, effective, and versatile solution, we introduced a polydopamine (PDA)-assisted Ca2+-mediated grafting strategy using hyaluronic acid (HA) as a model material. By increasing the PDA amine group density through deposition time optimization and coiling HA conformation via Ca2+-mediation, the grafting density of aldehyde-bearing HA enhanced 13 folds and reached 2.4 ± 0.2 × 105 chains μm-2. After removement of Ca2+ ions, the dense HA grafting was highly stretched on PDA-coated substrates, close to the contour length of HA. Ca2+-mediated HA (CamHA) grafting was then implemented on versatile substrates with PDA assistance, demonstrating enhanced hemocompatibility by reducing protein adsorption and blood cell interference. Furthermore, the dense and stretched HA chains in CamHA enhanced interactions with CD44, enabling selective recognition of CD44-high cells under static and dynamic conditions. The PDA-assisted CamHA grafting presents a model system for studying the effects of regulated biomaterial grafting on biological functions, offering simplicity, versatility, and the flexibility to select diverse substrates, grafting materials, and targeting elements for customization in a range of biomedical applications.

Recent advances in the development of chitosan/hyaluronic acid-based hybrid materials for skin protection, regeneration, and healing: A review

Biomaterials play vital roles in regenerative medicine, specifically in tissue engineering applications. They promote angiogenesis and facilitate tissue creation and repair. The most difficult aspect of this field is acquiring smart biomaterials that possess qualities and functions that either surpass or are on par with those of synthetic products. The biocompatibility, biodegradability, film-forming capacity, and hydrophilic nature of the non-sulfated glycosaminoglycans (GAGs) (hyaluronic acid (HA) and chitosan (CS)) have attracted significant attention. In addition, CS and HA possess remarkable inherent biological capabilities, such as antimicrobial, antioxidant, and anti-inflammatory properties. This review provides a comprehensive overview of the recent progress made in designing and fabricating CS/HA-based hybrid materials for dermatology applications. Various formulations utilizing CS/HA have been developed, including hydrogels, microspheres, films, foams, membranes, and nanoparticles, based on the fabrication protocol (physical or chemical). Each formulation aims to enhance the materials' remarkable biological properties while also addressing their limited stability in water and mechanical strength. Additionally, this review gave a thorough outline of future suggestions for enhancing the mechanical strength of CS/HA wound dressings, along with methods to include biomolecules to make them more useful in skin biomedicine applications.

Chemoenzymatic synthesis with the Pasteurella hyaluronan synthase; production of a multitude of defined authentic, derivatized, and analog polymers

Hyaluronan (HA; [-3-GlcNAc-1-beta-4-GlcA-1-beta] n ), an essential matrix polysaccharide of vertebrates and the molecular camouflage coating in certain pathogens, is polymerized by "HA synthase" (HAS) enzymes. Three HAS classes have been identified with biotechnological utility, but only the Class II PmHAS from Pasteurella multocida Type A has been useful for preparation of very defined HA polymers in vitro. Two general chemoenzymatic strategies with different size products are possible: (1) repetitive step-wise extension reactions by sequential addition of a single monosaccharide from a donor UDP-sugar onto an acceptor (or "primer") comprised of a short glycosaminoglycan chain (e.g., HA di-, tri- or tetrasaccharide) or an artificial glucuronide yielding homogeneous oligosaccharides in the range of 2 to ~20 monosaccharide units (n = 1 to ~10), or (2) "one-pot" polymerization reactions employing acceptor-mediated synchronization with stoichiometric size control yielding quasi-monodisperse (i.e., polydispersity approaching 1; very narrow size distributions) polysaccharides in the range of ~7 kDa to ~2 MDa (n = ~17 to 5000). In either strategy, acceptors containing non-carbohydrate functionalities (e.g., biotin, fluorophores, amines) can add useful moieties to the reducing termini of HA chains at 100% efficiency. As a further structural diversification, PmHAS can utilize a variety of unnatural UDP-sugar analogs thus adding novel groups (e.g., trifluoroacetyl, alkyne, azide, sulfhydryl) along the HA backbone and/or at its nonreducing terminus. This review discusses the current understanding and recent advances in HA chemoenzymatic synthesis methods using PmHAS. This powerful toolbox has potential for creation of a multitude of HA-based probes, therapeutics, drug conjugates, coatings, and biomaterials.

Hyaluronan-Based Hydrogels for 3D Modeling of Tumor Tissues

Although routine two-dimensional (2D) cell culture techniques have advanced basic cancer research owing to their simplicity, cost-effectiveness, and reproducibility, they have limitations that necessitate the development of advanced three-dimensional (3D) tumor models that better recapitulate the tumor microenvironment. Various biomaterials have been used to establish these 3D models, enabling the study of cancer cell behavior within different matrices. Hyaluronic acid (HA), a key component of the extracellular matrix (ECM) in tumor tissues, has been widely studied and employed in the development of multiple cancer models. This review first examines the role of HA in tumors, including its function as an ECM component and regulator of signaling pathways that affect tumor progression. It then explores HA-based models for various cancers, focusing on HA as a central component of the 3D matrix and its mobilization within the matrix for targeted studies of cell behavior and drug testing. The tumor models discussed included those for breast cancer, glioblastoma, fibrosarcoma, gastric cancer, hepatocellular carcinoma, and melanoma. The review concludes with a discussion of future prospects for developing more robust and high-throughput HA-based models to more accurately mimic the tumor microenvironment and improve drug testing. Impact Statement This review underscores the transformative potential of hyaluronic acid (HA)-based hydrogels in developing advanced tumor models. By exploring HA's dual role as a critical extracellular matrix component and a regulator of cancer cell dynamics, we highlight its unique contributions to replicating the tumor microenvironment. The recent advancements in HA-based models provide new opportunities for more accurate studies of cancer cell behavior and drug responses. Looking ahead, these innovations pave the way for high-throughput, biomimetic platforms that could revolutionize drug testing and accelerate the discovery of effective cancer therapies.

Chemical modification of hyaluronan oligosaccharides differentially modulates hyaluronan-hyaladherin interactions

The glycosaminoglycan hyaluronan (HA) is a ubiquitous, nonsulfated polysaccharide with diverse biological roles mediated through its interactions with HA-binding proteins (HABPs). Most HABPs belong to the Link module superfamily, including the major HA receptor, CD44, and secreted protein TSG-6, which catalyzes the covalent transfer of heavy chains from inter-α-inhibitor onto HA. The structures of the HA-binding domains (HABDs) of CD44 (HABD_CD44) and TSG-6 (Link_TSG6) have been determined and their interactions with HA extensively characterized. The mechanisms of binding are different, with Link_TSG6 interacting with HA primarily via ionic and CH-π interactions, whereas HABD_CD44 binds solely via hydrogen bonds and van der Waals forces. Here, we exploit these differences to generate HA oligosaccharides, chemically modified at their reducing ends, that bind specifically and differentially to these target HABPs. Hexasaccharides (HA6AN) modified with 2- or 3-aminobenzoic acid (HA6-2AA, HA6-3AA) or 2-amino-4-methoxybenzoic acid (HA6-2A4MBA), had increased affinities for Link_TSG6 compared to unmodified HA6AN. These modifications did not increase the affinity for CD44_HABD. A model of HA6-2AA (derived from the solution dynamic 3D structure of HA4-2AA) was docked into the Link_TSG6 structure, providing evidence that the 2AA-carboxyl forms a salt bridge with Arginine-81. These modeling results informed a second series of chemical modifications for HA oligosaccharides, which again showed differential binding to the two proteins. Several modifications to HA4 and HA6 were found to convert the oligosaccharide into substrates for heavy chain transfer, whereas unmodified HA4 and HA6 are not. This study has generated valuable research tools to further understand HA biology.

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

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

Ultrasound-triggered three dimensional hyaluronic acid hydrogel promotes in vitro and in vivo reprogramming into induced pluripotent stem cells

Cellular reprogramming technologies have been developed with different physicochemical factors to improve the reprogramming efficiencies of induced pluripotent stem cells (iPSCs). Ultrasound is a clinically applied noncontact biophysical factor known for regulating various cellular behaviors but remains uninvestigated for cellular reprogramming. Here, we present a new reprogramming strategy using low-intensity ultrasound (LIUS) to improve cellular reprogramming of iPSCs in vitro and in vivo. Under 3D microenvironment conditions, increased LIUS stimulation shows enhanced cellular reprogramming of the iPSCs. The cellular reprogramming process facilitated by LIUS is accompanied by increased mesenchymal to epithelial transition and histone modification. LIUS stimulation transiently modulates the cytoskeletal rearrangement, along with increased membrane fluidity and mobility to increase HA/CD44 interactions. Furthermore, LIUS stimulation with HA hydrogel can be utilized in application of both human cells and in vivo environment, for enhanced reprogrammed cells into iPSCs. Thus, LIUS stimulation with a combinatorial 3D microenvironment system can improve cellular reprogramming in vitro and in vivo environments, which can be applied in various biomedical fields.

Naked mole-rat hyaluronan

Naked mole rats (NMRs) are renowned for their exceptional longevity and remarkable maintenance of health throughout their lifetime. Their subterranean lifestyle has led to adaptations that have resulted in elevated levels of a very high molecular weight hyaluronan in their tissues. Hyaluronan, a glycosaminoglycan, is a key component of the extracellular matrix, which plays a critical role in maintaining tissue structure and regulating cell signaling pathways. This phenomenon in NMRs is attributed to a higher processing and production capacity by some of their hyaluronan synthases, along with lower degradation by certain hyaluronidases. Furthermore, this adaptation indirectly confers several advantages to NMRs, such as the preservation of skin elasticity and youthful appearance, accelerated wound healing, protection against oxidative stress, and resistance to conditions such as cancer and arthritis, largely attributable to CD44 signaling and other intricate mechanisms. Thus, the main objective of this study was to conduct a comprehensive study of the distinctive features of NMR hyaluronan, particularly emphasizing the currently known molecular mechanisms that contribute to its beneficial properties. Furthermore, this research delves into the potential applications of NMR hyaluronan in both cosmetic and therapeutic fields, as well as the challenges involved.

Hyaluronic acid from bluefin tuna by-product: Structural analysis and pharmacological activities

The fishing and aquaculture industries generate a huge amount of waste during processing and preservation operations, especially those of tuna. Recovering these by-products is a major economic and environmental challenge for manufacturers seeking to produce new active biomolecules of interest. A new hyaluronic acid was extracted from bluefin tuna's vitreous humour to assess its antioxidant and pharmacological activities. The characterization by infrared spectroscopy (FT-IR), nuclear magnetic resonance ((1D1H) and 2D (1H COSY, 1H/13C HSQC)) and size exclusion chromatography (SEC/MALS/DRI/VD) revealed that the extracted polysaccharide was a hyaluronic acid with high uronic acid content (55.8 %) and a weight average molecular weight of 888 kDa. This polymer possesses significant anti-radical activity and ferrous chelating capacity. In addition, pharmacological evaluation of its anti-inflammatory and analgesic potential, using preclinical models, in comparison with reference drugs (Dexamethasone, diclofenac, and acetylsalicylate of lysine), revealed promising anti-inflammatory activity as well as interesting peripheral and central antinociceptive activity. Therefore, our new hyaluronic acid compound may therefore serve as a potential drug candidate for the treatment of pain sensation and inflammation of various pathological origins.

A review of the current state of natural biomaterials in wound healing applications

Skin, the largest biological organ, consists of three main parts: the epidermis, dermis, and subcutaneous tissue. Wounds are abnormal wounds in various forms, such as lacerations, burns, chronic wounds, diabetic wounds, acute wounds, and fractures. The wound healing process is dynamic, complex, and lengthy in four stages involving cells, macrophages, and growth factors. Wound dressing refers to a substance that covers the surface of a wound to prevent infection and secondary damage. Biomaterials applied in wound management have advanced significantly. Natural biomaterials are increasingly used due to their advantages including biomimicry of ECM, convenient accessibility, and involvement in native wound healing. However, there are still limitations such as low mechanical properties and expensive extraction methods. Therefore, their combination with synthetic biomaterials and/or adding bioactive agents has become an option for researchers in this field. In the present study, the stages of natural wound healing and the effect of biomaterials on its direction, type, and level will be investigated. Then, different types of polysaccharides and proteins were selected as desirable natural biomaterials, polymers as synthetic biomaterials with variable and suitable properties, and bioactive agents as effective additives. In the following, the structure of selected biomaterials, their extraction and production methods, their participation in wound healing, and quality control techniques of biomaterials-based wound dressings will be discussed.

Efficacy of hyaluronic acid in the treatment of nasal inflammatory diseases: a systematic review and meta-analysis

Background: Hyaluronic acid (HA), the main component of the extracellular matrix, has the ability to promote tissue repair and regulate inflammation. It is used in otolaryngology as an adjuvant treatment to alleviate postoperative nasal symptoms. However, there is currently insufficient evidence demonstrating the therapeutic efficacy of HA for patients with nasal inflammatory diseases (NIDs). Therefore, this study aimed to evaluate the efficacy and safety of topical HA in the treatment of NID patients without receiving surgery. Methods: In this meta-analysis, comprehensive searches were conducted in PubMed, Embase, the Cochrane Central Register of Controlled Trials, and Web of Science. Keywords searched included "hyaluronic acid," "sinusitis," "allergic rhinitis," "rhinitis," and "randomized controlled trials (RCTs)." The Cochrane Collaboration's "Risk of Bias Assessment" tool was used to assess the quality of the included trials, and the meta-analysis was performed using the RevMan 5.3 and STATA 15 statistical software. Results: A total of 11 articles and 825 participants were enrolled. For the primary outcomes, the pooled results revealed that HA significantly improves nasal obstruction (SMD, -0.53; 95% CI, -0.92 to -0.14; p = 0.008; and I2 = 79%) and rhinorrhea (SMD, -0.71; 95% CI, -1.27 to -0.15; p = 0.01; and I2 = 90%) in patients with NIDs. As for the secondary outcomes, the pooled results demonstrated that when compared with the control group, HA could significantly improve nasal endoscopic scores (p < 0.05), rhinitis scores (p < 0.05), rhinomanometry (p < 0.05), nasal neutrophils (p < 0.05), and mucociliary clearance (p < 0.05). However, no significant differences were observed between the two groups regarding nasal itching, sneezing, hyposmia, quality-of-life scores, and nasal eosinophils. For the risk of bias, 54.5% and 45.5% of trials had a low risk of bias in the randomization process and deviation of the intended intervention, respectively. Conclusion: In the present study, the results reveal that HA might ameliorate symptoms of patients with NIDs. However, more clinical trials with larger participant cohorts are required to confirm this result. Systematic review registration number: clinicaltrials.gov, identifier CRD42023414539.

Hyaluronan-arginine enhanced and dynamic interaction emerges from distinctive molecular signature due to electrostatics and side-chain specificity

Hyaluronan is a natural carbohydrate polymer with a negative charge that fosters gel-like conditions crucial for its cellular functions and industrial applications. As a recognized ligand for proteins, understanding their mutual interactions provides solid ground to tune hyaluronan's gel properties using biocompatible peptides. This work employs NMR and molecular dynamics simulations to identify molecular motifs relevant to hyaluronan-peptide interactions using arginine, lysine, and glycine oligopeptides. Arginine-rich peptides exhibit the strongest binding to hyaluronan according to chemical shift perturbation measurements, followed distantly by the similarly charged lysine. This difference highlights the significance of electrostatics and the peculiarities of the guanidinium side chain in arginine, capable of non-polar interactions that further stabilize the binding. Additional nuclear Overhauser effect measurements do not show stable interaction partners, precluding strong and well-defined complexes. Finally, molecular simulations support our findings and show an extended but significant interaction region, especially for arginine, responsible for the observed enhanced binding, which can also promote cross-linking of hyaluronan polymers. Our findings pave the way for optimizing biocompatible peptides to alter hyaluronan gels' properties efficiently and also explain why hyaluronan-protein interaction typically involves positively charged arginine-rich regions also capable of forming hydrogen bonds and non-polar interactions.

Recent advances of novel targeted drug delivery systems based on natural medicine monomers against hepatocellular carcinoma

Hepatocellular carcinoma (HCC), the most prevalent type of liver cancer, is often diagnosed at an advanced stage. Surgical interventions are often ineffective, leading HCC patients to rely on systemic chemotherapy. Unfortunately, commonly used chemotherapeutic drugs have limited efficacy and can adversely affect vital organs, causing significant physical and psychological distress for patients. Natural medicine monomers (NMMs) have shown promising efficacy and safety profiles in HCC treatment, garnering attention from researchers. In recent years, the development of novel targeted drug delivery systems (TDDS) combining NMMs with nanocarriers has emerged. These TDDS aim to concentrate drugs effectively in HCC cells by manipulating the characteristics of nanomedicines, leveraging receptor and ligand interactions, and utilizing endogenous stimulatory responses to promote specific nanomedicines distribution. This comprehensive review presents recent research on TDDS for HCC treatment using NMMs from three perspectives: passive TDDS, active TDDS, and stimuli-responsive drug delivery systems (SDDS). It consolidates the current state of research on TDDS for HCC treatment with NMMs and highlights the potential of these innovative approaches in improving treatment outcomes. Moreover, the review also identifies research gaps in the related fields to provide references for future targeted therapy research in HCC.

Alginate/hyaluronic acid-based systems as a new generation of wound dressings: A review

Skin is the largest organ of the human body, which acts as a protective barrier against pathogens. Therefore, a lot of research has been carried out on wound care and healing. Creating an ideal environment for wound healing and optimizing the local and systemic conditions of the patient play critical roles in successful wound care. Many products have been developed for improving the wound environment and providing a protected and moist area for fast healing. However, there is still high demand for new systems with high efficiency. The first generation of wound dressings merely covered the wound, while the subsequent/last generations covered it and aided in healing it in different ways. In modern wound dressings, the kind of used materials and their complexity play a crucial role in the healing process. These new systems support wound healing by lowering inflammation, exudate, slough, and bacteria. This study addresses a review of alginate/hyaluronic acid-based wound dressings developed so far as well as binary and ternary systems and their role in wound healing. Our review corroborates that these systems can open up a new horizon for wounds that do not respond to usual treatments and have a long curing period.

Nebulized hyaluronic acid improves nasal symptoms after orthognathic surgery: a randomized clinical trial

PURPOSE

After maxillary osteotomy in orthognathic surgery, patients report nasal breathing discomfort in early postoperative period. Topical hyaluronic acid (HA) has been proven to have beneficial effects on the upper airway tract mucosa. This prospective randomized controlled study was designed to analyze the effect on nasal obstruction of nebulized HA during the recovery process after maxillary osteotomy.

METHODS

Patients were randomized to control and treatment groups. The postoperative treatment differed only for additional nebulized HA provided to the treatment group. The level of nasal obstruction, and its impact on quality of life, was assessed every 3 days for the first 15 days postoperatively using a questionnaire. Demographic and other variables (maxillary osteotomy type and surgical movements) were analyzed. Differences in quantitative data were tested using Student's t-test, the Mann-Whitney U test, and mixed repeated measures ANOVA.

RESULTS

Twenty-four subjects were included in each group; differences in age, sex, type of maxillary osteotomy, and movements were non-statistically significative. At the beginning of treatment (T0), the two groups had comparable questionnaire scores regarding nasal breathing discomfort (p >0.05), whereas statistically significant differences were found at days 3, 6, 9, and 12 (p <0.05). A significant decrease in nasal breathing discomfort over time was observed in both groups, with trends that differed between the two, indicating faster improvement in the treatment group.

CONCLUSION

Nebulized HA can be a useful additional treatment in early postoperative period after orthognathic surgery. Patients reported more rapid improvement of nasal respiratory symptoms, indicating a potential role for HA in reducing recovery time and patient discomfort after maxillary surgery.

Disabled-2: a protein up-regulated by high molecular weight hyaluronan has both tumor promoting and tumor suppressor roles in ovarian cancer

Although the pro-tumorigenic functions of hyaluronan (HA) are well documented there is limited information on the effects and targets of different molecular weight HA. Here, we investigated the effects of 27 kDa, 183 kDa and 1000 kDa HA on ES-2 ovarian cancer cells overexpressing the stem cell associated protein, Notch3. 1000 kDA HA promoted spheroid formation in ES-2 cells mixed with ES-2 overexpressing Notch3 (1:3). We report disabled-2 (DAB2) as a novel protein regulated by 1000 kDa HA and further investigated its role in ovarian cancer. DAB2 was downregulated in ovarian cancer compared to normal tissues but increased in metastatic ovarian tumors compared to primary tumors. High DAB2 expression was associated with poor patient outcome and positively correlated with HA synthesis enzyme HAS2, HA receptor CD44 and EMT and macrophage markers. Stromal DAB2 immunostaining was significantly increased in matched ovarian cancer tissues at relapse compared to diagnosis and associated with reduced survival. The proportion of DAB2 positive macrophages was significantly increased in metastatic ovarian cancer tissues compared to primary cancers. However, DAB2 overexpression significantly reduced invasion by both A2780 and OVCAR3 cells in vivo. Our research identifies a novel relationship between HA signalling, Notch3 and DAB2. We highlight a complex relationship of both pro-tumorigenic and tumor suppressive functions of DAB2 in ovarian cancer. Our findings highlight that DAB2 has a direct tumor suppressive role on ovarian cancer cells. The pro-tumorigenic role of DAB2 may be mediated by tumour associated macrophages and requires further investigation.

Markers of dental pulp stem cells in in vivo developmental context

Teeth and their associated tissues contain several populations of mesenchymal stem cells, one of which is represented by dental pulp stem cells (DPSCs). These cells have mainly been characterised in vitro and numerous positive and negati ve markers for these cells have been suggested. To investigate the presence and localization of these molecules during development, forming dental pulp was examined using the mouse first mandibular molar as a model. The stages corresponding to postnatal (P) days 0, 7, 14, and 21 were investigated. The expression was monitored using customised PCR Arrays. Additionally, in situ localization of the key trio of markers (Cd73, Cd90, Cd105 coded by genes Nt5e, Thy1, Eng) was performed at prenatal and postnatal stages using immunohistochemistry. The expression panel of 24 genes assigned as in vitro markers of DPSCs or mesenchymal stem cells (MSCs) revealed their developmental dynamics during formation of dental pulp mesenchyme. Among the positive markers, Vcam1, Fgf2, Nes were identified as increasing and Cd44, Cd59b, Mcam, Alcam as decreasing between perinatal vs. postnatal stages towards adulthood. Within the panel of negative DPSC markers, Cd14, Itgb2, Ptprc displayed increased and Cd24a decreased levels at later stages of pulp formation. Within the key trio of markers, Nt5e did not show any significant expression difference within the investigated period. Thy1 displayed a strong decrease between P0 and P7 while Eng increased between these stages. In situ localization of Cd73, Cd90 and Cd105 showed them overlap in differentiated odontoblasts and in the sub-odontoblastic layer that is speculated to host odontoblast progenitors. The highly prevalent expression of particularly Cd73 and Cd90 opens the question of potential multiple functions of these molecules. The results from this study add to the in vitro based knowledge by showing dynamics in the expression of DPSC/MSC markers during dental pulp formation in an in vivo context and thus with respect to the natural environment important for commitment of stem cells.

Effect of natural polymer materials on skin healing based on internal wound microenvironment: a review

The concept of wound microenvironment has been discussed for a long time. However, the mechanism of the internal microenvironment is relatively little studied. Here, we present a systematic discussion on the mechanism of natural polymer materials such as chitosan, cellulose, collagen and hyaluronic acid through their effects on the internal wound microenvironment and regulation of wound healing, in order to more comprehensively explain the concept of wound microenvironment and provide a reference for further innovative clinical for the preparation and application of wound healing agents.

CD44 Modulates Cell Migration and Invasion in Ewing Sarcoma Cells

The chimeric EWSR1::FLI1 transcription factor is the main oncogenic event in Ewing sarcoma. Recently, it has been proposed that EWSR1::FLI1 levels can fluctuate in Ewing sarcoma cells, giving rise to two cell populations. EWSR1::FLI1^low cells present a migratory and invasive phenotype, while EWSR1::FLI1^high cells are more proliferative. In this work, we described how the CD44 standard isoform (CD44s), a transmembrane protein involved in cell adhesion and migration, is overexpressed in the EWSR1::FLI1^low phenotype. The functional characterization of CD44s (proliferation, clonogenicity, migration, and invasion ability) was performed in three doxycycline-inducible Ewing sarcoma cell models (A673, MHH-ES1, and CADO-ES1). As a result, CD44s expression reduced cell proliferation in all the cell lines tested without affecting clonogenicity. Additionally, CD44s increased cell migration in A673 and MHH-ES1, without effects in CADO-ES1. As hyaluronan is the main ligand of CD44s, its effect on migration ability was also assessed, showing that high molecular weight hyaluronic acid (HMW-HA) blocked cell migration while low molecular weight hyaluronic acid (LMW-HA) increased it. Invasion ability was correlated with CD44 expression in A673 and MHH-ES1 cell lines. CD44s, upregulated upon EWSR1::FLI1 knockdown, regulates cell migration and invasion in Ewing sarcoma cells.

The role of high molecular weight hyaluronic acid in mucoadhesion on an ocular surface model

Hyaluronic acid (HA) is frequently formulated in eye drops to improve the stability of the tear film by hydration and lubrication. Mucoadhesion is related to the ocular residence time and therefore to the effectiveness of the eye drops. The ocular residence time of the HA formulation is correlated with the ability of HA to create specific strong interactions in the ocular surface with the mucus layer, mainly composed of a mixture of secreted mucins (MUC; gel forming MUC5AC and MUC2) and shed membrane-bound soluble mucins (MUC1, MUC4, and MUC16). Dry eye disease (DED) is a multifactorial pathology of the preocular tear film with possible damage to the ocular surface classified in two types: (1) aqueous-deficient dry eye and (2) evaporative dry eye, caused by a decrease in goblet cell density that reduces MUC expression and/or by meibomian gland dysfunction, that results in a drop in the lipidic fraction of the tear film. In this work, the binding affinity between HA and MUC2 has been evaluated with three complementary approaches because the secreted MUCs play a pivotal role in the viscoelastic properties of the tear film: 1. Rheological analysis, measuring the mucoadhesive index and the complex viscosity in relation to MM (Molecular Mass) and concentration; 2. Fluorescence analysis, using a fluorescent hydrophobic probe, to investigate the conformational change of MUC2 during the interaction with the HA polymer; 3. Surface plasmon resonance analysis, used to measure the affinity between MUC2 (immobilized on the surface of a sensor chip) and the HA polymers that flowed on it at the molecular level. For all these tests, the mucoadhesive performance of the natural HA linearly increases with the MM, whereas cross-linked HA and other emollient and gelling agents (formulated in artificial tears) do not show the same mucoadhesive properties (with the exception of xanthan gum). The mucoadhesive performance of high MM HA has also been confirmed in conditions that simulate the pathological condition of the tear film during DED by decreasing the MUC2 or oleic acid concentration. Physico-chemical analysis of a series of marketed artificial tears confirms the linear correlation between the MM of the HA used in the products and the mucoadhesive index measured on the ocular surface model.

Hyaluronic Acid-Mediated Phenolic Compound Nanodelivery for Cancer Therapy

Phenolic compounds are bioactive phytochemicals showing a wide range of pharmacological activities, including anti-inflammatory, antioxidant, immunomodulatory, and anticancer effects. Moreover, they are associated with fewer side effects compared to most currently used antitumor drugs. Combinations of phenolic compounds with commonly used drugs have been largely studied as an approach aimed at enhancing the efficacy of anticancer drugs and reducing their deleterious systemic effects. In addition, some of these compounds are reported to reduce tumor cell drug resistance by modulating different signaling pathways. However, often, their application is limited due to their chemical instability, low water solubility, or scarce bioavailability. Nanoformulations, including polyphenols in combination or not with anticancer drugs, represent a suitable strategy to enhance their stability and bioavailability and, thus, improve their therapeutic activity. In recent years, the development of hyaluronic acid-based systems for specific drug delivery to cancer cells has represented a pursued therapeutic strategy. This is related to the fact that this natural polysaccharide binds to the CD44 receptor that is overexpressed in most solid cancers, thus allowing its efficient internalization in tumor cells. Moreover, it is characterized by high biodegradability, biocompatibility, and low toxicity. Here, we will focus on and critically analyze the results obtained in recent studies regarding the use of hyaluronic acid for the targeted delivery of bioactive phenolic compounds to cancer cells of different origins, alone or in combination with drugs.

Comprehensive review on biosynthesis of hyaluronic acid with different molecular weights and its biomedical applications

Hyaluronic acid (HA), an anionic and nonsulfated glycosaminoglycan, is the main structural component of various tissues and plays an important role in various biological processes. Given the promising properties of HA, such as high cellular compatibility, moisture retention, antiaging, proper interaction with cells, and CD44 targeting, HA can be widely used extensively in drug delivery, tissue engineering, wound healing, and cancer therapy. HA can obtain from animal tissues and microbial fermentation, but its applications depend on its molecular weight. Microbial fermentation is a common method for HA production on an industrial scale and S. zooepidemicus is the most frequently used strain in HA production. Culture conditions including pH, temperature, agitation rate, aeration speed, shear stress, dissolved oxygen, and bioreactor type significantly affect HA biosynthesis properties. In this review all the HA production methods and purification techniques to improve its physicochemical and biological properties for various biomedical applications are discussed in details. In addition, we showed that how HA molecular weight can significantly affect its properties and applications.

Hyaluronan and Reactive Oxygen Species Signaling—Novel Cues from the Matrix?

Hyaluronan (HA) is a naturally occurring non-sulfated glycosaminoglycan (GAG) localized to the cell surface and the tissue extracellular matrix (ECM). It is composed of disaccharides containing glucuronic acid and N-acetylglucosamine, is synthesized by the HA synthase (HAS) enzymes and is degraded by hyaluronidase (HYAL) or reactive oxygen and nitrogen species (ROS/RNS) actions. HA is deposited as a high molecular weight (HMW) polymer and degraded to low molecular weight (LMW) fragments and oligosaccharides. HA affects biological functions by interacting with HA-binding proteins (hyaladherins). HMW HA is anti-inflammatory, immunosuppressive, and antiangiogenic, whereas LMW HA has pro-inflammatory, pro-angiogenetic, and oncogenic effects. ROS/RNS naturally degrade HMW HA, albeit at enhanced levels during tissue injury and inflammatory processes. Thus, the degradation of endothelial glycocalyx HA by increased ROS challenges vascular integrity and can initiate several disease progressions. Conversely, HA exerts a vital role in wound healing through ROS-mediated HA modifications, which affect the innate immune system. The normal turnover of HA protects against matrix rigidification. Insufficient turnover leads to increased tissue rigidity, leading to tissue dysfunction. Both endogenous and exogenous HMW HA have a scavenging capacity against ROS. The interactions of ROS/RNS with HA are more complex than presently perceived and present an important research topic.

Hyaluronan in the Cancer Cells Microenvironment

The presence of the glycosaminoglycan hyaluronan in the extracellular matrix of tissues is the result of the cooperative synthesis of several resident cells, that is, macrophages and tumor and stromal cells. Any change in hyaluronan concentration or dimension leads to a modification in stiffness and cellular response through receptors on the plasma membrane. Hyaluronan has an effect on all cancer cell behaviors, such as evasion of apoptosis, limitless replicative potential, sustained angiogenesis, and metastasis. It is noteworthy that hyaluronan metabolism can be dramatically altered by growth factors and matrikines during inflammation, as well as by the metabolic homeostasis of cells. The regulation of HA deposition and its dimensions are pivotal for tumor progression and cancer patient prognosis. Nevertheless, because of all the factors involved, modulating hyaluronan metabolism could be tough. Several commercial drugs have already been described as potential or effective modulators; however, deeper investigations are needed to study their possible side effects. Moreover, other matrix molecules could be identified and targeted as upstream regulators of synthetic or degrading enzymes. Finally, co-cultures of cancer, fibroblasts, and immune cells could reveal potential new targets among secreted factors.

Role of Hyaluronic Acid in Selected Malignant Neoplasms in Women

Hyaluronic acid (HA) is a significant glycosaminoglycan component of the extracellular matrix, playing an essential role in cell localization and proliferation. However, high levels of HA may also correlate with multidrug resistance of tumor cells, an increased tendency to metastasize, or cancer progression, and thus represent a very unfavorable prognosis for cancer patients. The purpose of this review article is to summarize the results of studies describing the relationship between HA, the main ligand of the CD44 receptor, or other components of the HA signaling pathway. In addition, we review the course of selected female malignancies, i.e., breast, cervical, endometrial, and ovarian cancer, with the main focus on the mechanisms oriented to CD44. We also analyze reports on the beneficial use of HA-containing preparations in adjuvant therapy among patients with these types of cancer. Data from the literature suggest that HA and its family members may be critical prognostic biomarkers of selected malignancies among women. Nevertheless, the results of the available studies are inconclusive, and the actual clinical significance of HA expression analysis is still quite enigmatic. In our opinion, the HA-CD44 signaling pathway should be an attractive target for future research related to targeted therapy in gynecological cancers.

Renewable marine polysaccharides for microenvironment-responsive wound healing

Marine polysaccharides (MPs) are an eco-friendly and renewable resource with a distinctive set of biological functions and are regarded as biological materials that can be in contact with tissues and body fluids for an extended time and promote tissue or organ regeneration. Skin tissue is easily invaded by the external environment due to its softness and large surface area. However, the body's natural physiological healing process is often too slow or suffers from the incomplete restoration of skin structure and function. Functional wound dressings are crucial for skin tissue engineering. Herein, popular MPs from different sources are summarized systematically. In particular, the structure-effectiveness of MP-based wound dressings and the physiological remodeling process of different wounds are reviewed in detail. Finally, the prospect of MP-based smart wound dressings is stated in conjunction with the wound microenvironment and provides new opportunities for high-value biomedical applications of MPs.

The state of CD44 activation in cancer progression and therapeutic targeting

CD44, a non-kinase transmembrane glycoprotein, is ubiquitously expressed on various types of cells, especially cancer stem cells (CSCs), and has been implicated in cancer onset and aggressiveness. The major ligand for the CD44, hyaluronan (HA), binds to and interacts with CD44, which in turn triggers downstream signaling cascades, thereby promoting cellular behaviors such as proliferation, motility, invasiveness and chemoresistance. The CD44-HA interaction is cell-specific and strongly affected by the state of CD44 activation. Therefore, the binding of HA to CD44 is essential for the activation of CD44 during which the detailed regulatory mechanism needs to be clarified. Different CD44 activation states distribute in human carcinoma and normal tissue; however, whether CD44 activation is a critical requirement for tumor initiation, progression and notorious CSC properties remains to be clarified. A deeper understanding of the regulation of CD44 activation may facilitate the development of novel targeted drugs in the future. Here, we review the current findings concerning the states of CD44 activation on the cell surface, the underlying regulatory mechanisms of CD44 activation, the known role for CD44 activation in tumor progression and CSC hallmarks, as well as the potential of HA-coated nanoparticle for targeting activated CD44 for cancer therapy.

Hyaluronic Acid-Coated Bovine Milk Exosomes for Achieving Tumor-Specific Intracellular Delivery of miRNA-204

Cell type-specific drug delivery is a straightforward strategy to achieve targeted cancer therapy and reduce side effects. Hyaluronic acid (HA), an U.S. Food and Drug Administration (FDA)-approved biocompatible carbohydrate polymer, has been extensively employed as a targeting ligand for a drug delivery system due to its natural ability to bind to tumor cells overexpressing cluster of differentiation 44 (CD44) receptors. Here, we report the preparation and antitumor efficacy of HA-coated bovine milk exosomes (HA-mExo) for tumor-specific delivery of microRNA-204-5p mimics (miR-204). The exosome-based delivery formulation was prepared with miR-204 encapsulated inside the lumen and HA displayed outside the membrane. The resultant formulation of HA-mExo-miR204 was able to specifically target CD44-positive cancer cells, with a concomitant increase in the intracellular uptake of miR-204. Compared to the uncoated mExo-miR204 formulation, HA-mExo-miR204 showed significantly increased antitumor efficacy both in vitro and in vivo. Importantly, HA-mExo-miR204 showed excellent biocompatibility and did not cause significant systemic toxicity. Given that both HA and bovine milk exosomes are low-cost and highly accessible biogenic materials with broad biomedical applications, HA-decorated bovine milk exosomes can be proven to be a practical drug delivery system of RNA drugs for targeted cancer therapy.

Hyaluronan Brush-like Copolymers Promote CD44 Declustering in Breast Cancer Cells

We report on the synthesis of hyaluronan (HA) brush-like copolymers and their application as antagonists of tumorigenic CD44-HA interactions. HA (4.8 kDa, ca. 24 saccharides) was grafted on 2-hydrohyethyl methacrylate (HEMA) by end-on oxime ligation. The obtained copolymers were compared with low and high molecular weight HA in terms of hydrolysis kinetics in the presence of hyaluronidase (isothermal titration calorimetry) and interactions with CD44 (surface plasmon resonance). The results evidenced that the high molecular weight HA and HA-g-HEMA have a much higher affinity to CD44 than low molecular weight HA. Additionally, slower enzymatic degradation was observed for the copolymer, making it an excellent candidate for active targeting of tumorigenic CD44-HA interactions. We, therefore, investigated the effect of the copolymer on cancer cell lines with different expression of CD44 and observed an efficient declustering of CD44 that is usually associated with reduction of metastasis and drug resistance.

Macrophage-Targeted Sonodynamic/Photothermal Synergistic Therapy for Preventing Atherosclerotic Plaque Progression Using CuS/TiO2 Heterostructured Nanosheets

Sonodynamic therapy (SDT) and photothermal therapy (PTT) are two effective strategies for the treatment of atherosclerotic plaques. However, the low yield of reactive oxygen species (ROS) of conventional organic sonosensitizers and the low biosafety of hyperthermia limit the therapeutic efficacy of SDT and PTT. Herein, we report copper sulfide/titanium oxide heterostructure nanosheets modified with hyaluronic acid (HA) and PEG (HA-HNSs) for low-intensity sonodynamic and mild-photothermal synergistic therapy for early atherosclerotic plaques. CuS/TiO₂ heterostructure nanosheets (HNSs) show high electron-hole separation efficiency and superior sonodynamic performance, because it has high surface energy crystal facets as well as a narrow band. Moreover, HNSs exhibit intense absorbance in the NIR-II region, which endows the nanosheets with excellent photothermal performance. With a further modification of HA, HA-HNSs can selectively target intraplaque proinflammatory macrophages through CD44-HA interaction. Because SDT reduces the expression of heat shock protein 90 and PTT facilitates the sonocatalytic process, the combination of SDT and PTT based on HA-HNSs could synergistically induce proinflammatory macrophage apoptosis. More importantly, the synergistic therapy prevents the progression of early atherosclerotic plaque by removing lesional macrophages and mitigating inflammation. Taken together, this work provides a macrophage-targeting sonodynamic/photothermal synergistic therapy, which is an effective translational clinical intervention for early atherosclerotic plaques.

Proteoglycans in Toll-like receptor responses and innate immunity

The extracellular matrix (ECM) is an active and dynamic feature of tissues that not only provides gross structure but also plays key roles in cellular responses. The ever-changing microenvironment responds dynamically to cellular and external signals, and in turn influences cell fate, tissue development, and response to environmental injury or microbial invasion. It is therefore paramount to understand how the ECM components interact with each other, the environment and cells, and how they mediate their effects. Among the ECM components that have recently garnered increased attention, proteoglycans (PGs) deserve special note. Recent evidence strongly suggests that they play a crucial role both in health maintenance and disease development. In particular, proteoglycans dictate whether homeostasis or cell death will result from a given injury, by triggering and modulating activation of the innate immune system, via a conserved array of receptors that recognize exogenous (infectious) or endogenous (tissue damage) molecular patterns. Innate immune activation by proteoglycans has important implications for the understanding of cell-matrix interactions in health and disease. In this review, we will summarize the current state of knowledge of innate immune signaling by proteoglycans, discuss the implications, and explore future directions to define progress in this area of extracellular matrix biology.

Facile calcium ion-regulated grafting of dense and highly stretched hyaluronan for selective mediation of cancer cells rolling under high-speed flow

The development of materials that selectively mediate the rolling of cancer cells is important for the high-throughput enrichment of high-speed cancer cells. Here we constructed a dense and stretched low molecular weight hyaluronic acid (HA_9.6k)-modified surface to selectively promote the rolling of CD44-high cancer cells. The HA surface (calcium ion-regulated HA_9.6k surface, Ca-rHA) was fabricated via a calcium ion-regulated method, where calcium ion incorporation induced the shrink of HA_9.6k chains to achieve the highest reported grafting density of about 2.73 ± 0.20 × 10⁴ HA chains μm^-2. Upon the removal of calcium ions, the dense HA_9.6k chains switched to a highly stretched conformation. The high density and flexibility of Ca-rHA bearing abundant binding sites enhanced the rolling of CD44-high cancer cells and reduced the velocity of cells from 1389 µm s^-1 to 99 µm s^-1 (7%), comparable to that of the physiological rolling event and outperforming traditional grafting-to HA and E-selectin, without causing phenotypic changes. When processing complex samples under high-speed flow, Ca-rHA selectively mediated the rolling of cancer cells and enriched their ratio to peripheral blood mononuclear cells from 1:1 to 15:1. As the only reported artificial biomaterial capable of selectively mediating the rolling of cancer cells under a physiological high-speed flow, Ca-rHA holds promise in enriching intact cells for downstream analysis in the clinics by encouraging the surface-cell contacts. STATEMENT OF SIGNIFICANCE: The development of materials that selectively mediate the rolling of cancer cells is important for the high-throughput enrichment of cancer cells rolling under high-speed flow, yet is less reported. To selectively promote the rolling of cancer stem cell marker CD44-high cancer cells, a surface with dense and stretched low molecular weight hyaluronic acid (HA_9.6k) was constructed. With Ca²⁺ regulation, HA_9.6k chains shrank to achieve the highest reported grafting density of 2.73 ± 0.20 × 10⁴ chains μm^-2 and further switched to a highly stretched conformation after the removal of Ca²⁺ ions. As the only reported artificial biomaterial capable of selectively mediating the rolling of cancer cells under a physiological high-speed flow, this Ca²⁺-regulated HA_9.6k surface holds promise in enriching intact cells for downstream analysis in the clinics.

Recent progress in the early detection of cancer based on CD44 biomarker; nano-biosensing approaches

CD44 is a cell matrix adhesion molecule overexpressed on the cell surfaces of the major cancers. CD44 as a cancer-related biomarker has an essential role in the invasion and metastasis of cancer. The detection and quantification of CD44 can provide essential information useful for clinical cancer diagnosis. In this regard, biosensors with sensitive and specific properties, give prominence to the development of CD44 detection platforms. To date, various aptamer-based sensitive-enhancers together with nanoparticles (NPs) have been combined into the biosensors systems to provide an innovative biosensing method (aptasensors/nano-aptasensors) with substantially improved detection limit. This review article discusses the recent advances in the field of biosensors, nanobiosensors, and aptasensors for the quantitative determination of CD44 and the detection of CD44-expressing cancer cells.

Influence of Hyaluronan Density on the Behavior of Breast Cancer Cells with Different CD44 Expression

Molecular gradients are common in biosystems and play an essential role in physiological and pathological processes. During carcinogenesis, for example, hyaluronan (HA) homeostasis is dysregulated by cancer cells and the altered synthesis and degradation processes result in the formation of HA gradients within the tumor microenvironment. Herein, a platform is developed to study the biological role of HA gradient in breast cancer cells. Cells with different aggressiveness and expression of CD44-the main HA receptor usually overexpressed in breast cancers, are selected for this study. The developed platform is compatible with several imaging modalities and allows assessment of cell density, morphology, CD44 expression, and cell motility in a function of HA density. Using high-throughput analysis, it is shown that cells that do not express CD44 do not change along the gradient, while CD44 positive cells respond differently to the HA gradient depending on the level of CD44 expression and HA density. This different response is associated with the activation of different signaling pathways by the CD44-HA interactions.

CD44-Targeted Carriers: The Role of Molecular Weight of Hyaluronic Acid in the Uptake of Hyaluronic Acid-Based Nanoparticles

Nanotechnology offers advanced biomedical tools for diagnosis and drug delivery, stressing the value of investigating the mechanisms by which nanocarriers interact with the biological environment. Herein, the cellular response to CD44-targeted nanoparticles (NPs) was investigated. CD44, the main hyaluronic acid (HA) receptor, is widely exploited as a target for therapeutic purposes. HA NPs were produced by microfluidic platform starting from HA with different molecular weights (Mw, 280, 540, 820 kDa) by polyelectrolyte complexation with chitosan (CS). Thanks to microfluidic technology, HA/CS NPs with the same physical features were produced, and only the effects of HA Mw on CD44-overexpressing cells (human mesenchymal stem cells, hMSCs) were studied. This work provides evidence of the HA/CS NPs biocompatibility regardless the HA Mw and reveals the effect of low Mw HA in improving the cell proliferation. Special attention was paid to the endocytic mechanisms used by HA/CS NPs to enter hMSCs. The results show the notable role of CD44 and the pronounced effect of HA Mw in the NPs’ internalization. HA/CS NPs uptake occurs via different endocytic pathways simultaneously, and most notably, NPs with 280 kDa HA were internalized by clathrin-mediated endocytosis. Instead, NPs with 820 kDa HA revealed a greater contribution of caveolae and cytoskeleton components.

Endogenously-Produced Hyaluronan and Its Potential to Regulate the Development of Peritoneal Adhesions

Formation of peritoneal adhesions (PA) is one of the major complications following intra-abdominal surgery. It is primarily caused by activation of the mesothelial layer and underlying tissues in the peritoneal membrane resulting in the transition of mesothelial cells (MCs) and fibroblasts to a pro-fibrotic phenotype. Pro-fibrotic transition of MCs—mesothelial-to-mesenchymal transition (MMT), and fibroblasts activation to myofibroblasts are interconnected to changes in cellular metabolism and culminate in the deposition of extracellular matrix (ECM) in the form of fibrotic tissue between injured sides in the abdominal cavity. However, ECM is not only a mechanical scaffold of the newly synthetized tissue but reciprocally affects fibrosis development. Hyaluronan (HA), an important component of ECM, is a non-sulfated glycosaminoglycan consisting of N-acetyl-D-glucosamine (GlcNAc) and D-glucuronic acid (GlcUA) that can affect the majority of processes involved in PA formation. This review considers the role of endogenously produced HA in the context of different fibrosis-related pathologies and its overlap in the development of PA.

CD44: A Multifunctional Mediator of Cancer Progression

CD44, a non-kinase cell surface transmembrane glycoprotein, has been widely implicated as a cancer stem cell (CSC) marker in several cancers. Cells overexpressing CD44 possess several CSC traits, such as self-renewal and epithelial-mesenchymal transition (EMT) capability, as well as a resistance to chemo- and radiotherapy. The CD44 gene regularly undergoes alternative splicing, resulting in the standard (CD44s) and variant (CD44v) isoforms. The interaction of such isoforms with ligands, particularly hyaluronic acid (HA), osteopontin (OPN) and matrix metalloproteinases (MMPs), drive numerous cancer-associated signalling. However, there are contradictory results regarding whether high or low CD44 expression is associated with worsening clinicopathological features, such as a higher tumour histological grade, advanced tumour stage and poorer survival rates. Nonetheless, high CD44 expression significantly contributes to enhanced tumourigenic mechanisms, such as cell proliferation, metastasis, invasion, migration and stemness; hence, CD44 is an important clinical target. This review summarises current research regarding the different CD44 isoform structures and their roles and functions in supporting tumourigenesis and discusses CD44 expression regulation, CD44-signalling pathways and interactions involved in cancer development. The clinical significance and prognostic value of CD44 and the potential of CD44 as a therapeutic target in cancer are also addressed.

Hyaluronan-coated nanoparticles for active tumor targeting: Influence of polysaccharide molecular weight on cell uptake

Here we aimed to correlate different molecular weights of hyaluronic acid (HA), 200, 800 and 1437 kDa, used to decorate poly(lactic-co-glycolic acid) (PLGA)-based nanoparticles (NPs), to their cell uptakes. NP internalization kinetics in CD44-overexpressing breast carcinoma cells were quantified, using healthy fibroblast cells as reference. Actually, NP uptake and selectivity by tumor cells were maximized for NPs HA 800 kDa, while being minimum for NPs HA1400 kDa. This unexpected result could be explained considering that the interaction between NPs and tumor cells is dictated by rearrangement and conformation of that segment of HA chain that actually protrudes from the NPs. Overall, results obtained in this work point at how HA molecular weight, is pivotal project parameter in NP formulation to promote active targeting in the CD44 overexpressing cancer cells.

Natural Presentation of Glycosaminoglycans in Synthetic Matrices for 3D Angiogenesis Models

Glycosaminoglycans (GAGs) are long, linear polysaccharides that occur in the extracellular matrix of higher organisms and are either covalently attached to protein cores, as proteoglycans or in free form. Dependent on their chemical composition and structure, GAGs orchestrate a wide range of essential functions in tissue homeostasis. Accordingly, GAG-based biomaterials play a major role in tissue engineering. Current biomaterials exploit crosslinks between chemically modified GAG chains. Due to modifications along the GAG chains, they are limited in their GAG-protein interactions and accessibility to dissect the biochemical and biophysical properties that govern GAG functions. Herein, a natural presentation of GAGs is achieved by a terminal immobilization of GAGs to a polyethylene glycol (PEG) hydrogel. A physicochemical characterization showed that different end-thiolated GAGs can be incorporated within physiological concentration ranges, while the mechanical properties of the hydrogel are exclusively tunable by the PEG polymer concentration. The functional utility of this approach was illustrated in a 3D cell culture application. Immobilization of end-thiolated hyaluronan enhanced the formation of capillary-like sprouts originating from embedded endothelial cell spheroids. Taken together, the presented PEG/GAG hydrogels create a native microenvironment with fine-tunable mechanobiochemical properties and are an effective tool for studying and employing the bioactivity of GAGs.

Advances in Hyaluronic-Acid-Based (Nano)Devices for Cancer Therapy

Cancer is the main cause of fatality all over the world with a considerable growth rate. Many biologically active nanoplatforms are exploited for tumor treatment. Of nanodevices, hyaluronic acid (HA)-based systems have shown to be promising candidates for cancer therapy due to their high biocompatibility and cell internalization. Herein, surface functionalization of different nanoparticles (NPs), e.g., organic- and inorganic-based NPs, is highlighted. Subsequently, HA-based nanostructures and their applications in cancer therapy are presented.

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".

Glycosaminoglycans: Sweet as Sugar Targets for Topical Skin Anti-Aging

Glycosaminoglycans (GAGs) are long, linear polysaccharides comprised of repeating disaccharide units with pleiotropic biological functions, with the non-sulfated GAG hyaluronic acid (HA), and sulfated GAGs dermatan sulfate, chondroitin sulfate, heparan sulfate, keratan sulfate, and to a lesser extent heparin all being expressed in skin. Their ability to regulate keratinocyte proliferation and differentiation, inflammatory processes and extracellular matrix composition and quality demonstrates their critical role in regulating skin physiology. Similarly, the water-binding properties of GAGs and structural qualities, particularly for HA, are crucial for maintaining proper skin form and hydration. The biological importance of GAGs, as well as extensive evidence that their properties and functions are altered in both chronological and extrinsic skin aging, makes them highly promising targets to improve cosmetic skin quality. Within the present review, we examine the cutaneous biological activity of GAGs alongside the protein complexes they form called proteoglycans and summarize the age-related changes of these molecules in skin. We also examine current topical interventional approaches to modulate GAGs for improved skin quality such as direct exogenous administration of GAGs, with a particular interest in strategies targeted at potentiating GAG levels in skin through either attenuating GAG degradation or increasing GAG production.

Drug delivery carriers with therapeutic functions

Design of micro- or nanocarriers for drug delivery has primarily been focused on properties such as hydrophobicity, biodegradability, size, shape, surface charge, and toxicity, so that they can achieve optimal delivery with respect to drug loading, release kinetics, biodistribution, cellular uptake, and biocompatibility. Incorporation of stimulus-sensitive moieties into the carriers would lead to "smart" delivery systems. A further evolution would be to endow the carrier with a therapeutic function such that it no longer serves as a mere passive entity to release the drug at the target tissue but can be viewed as a therapeutic agent in itself. In this review, we will discuss recent and ongoing efforts over the past decade to design therapeutic drug carriers that confer a biological benefit, including ROS scavenging or generating, pro- or anti-inflammatory, and immuno-evasive properties, to enhance the overall therapeutic efficacy of the delivery systems.

Immunologic Roles of Hyaluronan in Dermal Wound Healing

Hyaluronic acid (HA), a glycosaminoglycan ubiquitous in the skin, has come into the limelight in recent years for its role in facilitating dermal wound healing. Specifically, HA's length of linearly repeating disaccharides-in other words, its molecular weight (MW)-determines its effects. High molecular weight (HMW)-HA serves an immunosuppressive and anti-inflammatory role, whereas low molecular weight (LMW)-HA contributes to immunostimulation and thus inflammation. During the inflammatory stage of tissue repair, direct and indirect interactions between HA and the innate and adaptive immune systems are of particular interest for their long-lasting impact on wound repair. This review seeks to synthesize the literature on wound healing with a focus on HA's involvement in the immune subsystems.

Characterization of a hyaluronic acid and folic acid-based hydrogel for cisplatin delivery: Antineoplastic effect in human ovarian cancer cells in vitro

We successfully prepared and characterized a hyaluronic acid- and folic acid-based hydrogel for the delivery of cisplatin (GEL-CIS) with the aim to induce specific and efficient incorporation of CIS into ovarian cancer (OC) cells, improve its antineoplastic effect and avoid CIS-resistance. The slow and controlled release of the drug from the polymeric network and its swelling degree at physiologic pH suggested its suitability for CIS delivery in OC. We compared here the effects of pure CIS to that of GEL-CIS on human OC cell lines, either wild type or CIS-resistant, in basal conditions and in the presence of macrophage-derived conditioned medium, mimicking the action of tumor-associated macrophages in vivo. GEL-CIS inhibited OC cell growth and migration more efficiently than pure CIS and modulated the expression of proteins involved in the Epithelial Mesenchymal Transition, a process playing a key role in OC metastatic spread and resistance to CIS.

Role of the interactions of soft hyaluronan nanomaterials with CD44 and supported bilayer membranes in the cellular uptake

Increasing valence by acting on nanomaterial morphology can enhance the ability of a ligand to specifically bind to targeted cells. Herein, we investigated cell internalization of soft hyaluronic acid (HA) nanoplatelets (NPs) that exhibit a typical hexagonal shape, flat surfaces and high aspect ratio (Γ≈12 to 20), as characterized by atomic force microscopy in hydrated conditions. Fluorescence imaging revealed that internalization of HA-NPs by a T24 tumor cell line and by macrophages was higher than native polysaccharide in a dose-dependent and time-dependent manners. The ability of HA-NPs to efficiently compete with native HA assessed using Bio-layer interferometry showed that NPs had a stronger interaction with recombinant CD44 receptor compared to native HA. The results were discussed regarding physical properties of the NPs and the implication of multivalent interactions in HA binding to CD44. Experiments conducted on supported bilayer membranes with different compositions showed that non-specific interactions of NPs with lipid membranes were negligible. Our findings provide insights into intracellular drug delivery using soft HA-NPs through receptor-mediated multivalent interactions.

Tunable layer-by-layer films containing hyaluronic acid and their interactions with CD44

We report on the development of layer-by-layer (LbL) constructs whose viscoelastic properties and bioactivity can be finely tuned by using polyanions of different size and/or crosslinking. As a polyanion we used hyaluronic acid (HA) - a multi-signaling biomolecule whose bioactivity depends on its molecular weight. We investigated the interplay between the mechanical properties of the LbL systems built using HA of different sizes and the specific HA-mediated biochemical interactions. We characterized the assembled materials and their interactions with CD44, the main HA receptor, by Quartz Crystal Microbalance with Dissipation (QCM-D), Surface Plasmon Resonance (SPR) and Atomic Force Microscopy (AFM). We observed that the presence of CD44 resulted in the disruption of the non-crosslinked multilayers, while crosslinked films remain stable and bind CD44 in a HA molecular weight and charge specific fashion.