Hyaluronan: from extracellular glue to pericellular cue

Advances in Skin Tissue Engineering and Regenerative Medicine

There are an estimated 500,000 patients treated with full-thickness wounds in the United States every year. Fire-related burn injuries are among the most common and devastating types of wounds that require advanced clinical treatment. Autologous split-thickness skin grafting is the clinical gold standard for the treatment of large burn wounds. However, skin grafting has several limitations, particularly in large burn wounds, where there may be a limited area of non-wounded skin to use for grafting. Non-cellular dermal substitutes have been developed but have their own challenges; they are expensive to produce, may require immunosuppression depending on design and allogenic cell inclusion. There is a need for more advanced treatments for devastating burns and wounds. This manuscript provides a brief overview of some recent advances in wound care, including the use of advanced biomaterials, cell-based therapies for wound healing, biological skin substitutes, biological scaffolds, spray on skin and skin bioprinting. Finally, we provide insight into the future of wound care and technological areas that need to be addressed to support the development and incorporation of these technologies.

Regulation of the E/I-balance by the neural matrisome

In the mammalian cortex a proper excitatory/inhibitory (E/I) balance is fundamental for cognitive functions. Especially γ-aminobutyric acid (GABA)-releasing interneurons regulate the activity of excitatory projection neurons which form the second main class of neurons in the cortex. During development, the maturation of fast-spiking parvalbumin-expressing interneurons goes along with the formation of net-like structures covering their soma and proximal dendrites. These so-called perineuronal nets (PNNs) represent a specialized form of the extracellular matrix (ECM, also designated as matrisome) that stabilize structural synapses but prevent the formation of new connections. Consequently, PNNs are highly involved in the regulation of the synaptic balance. Previous studies revealed that the formation of perineuronal nets is accompanied by an establishment of mature neuronal circuits and by a closure of critical windows of synaptic plasticity. Furthermore, it has been shown that PNNs differentially impinge the integrity of excitatory and inhibitory synapses. In various neurological and neuropsychiatric disorders alterations of PNNs were described and aroused more attention in the last years. The following review gives an update about the role of PNNs for the maturation of parvalbumin-expressing interneurons and summarizes recent findings about the impact of PNNs in different neurological and neuropsychiatric disorders like schizophrenia or epilepsy. A targeted manipulation of PNNs might provide an interesting new possibility to indirectly modulate the synaptic balance and the E/I ratio in pathological conditions.

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.

Absorption, metabolism, and functions of hyaluronic acid and its therapeutic prospects in combination with microorganisms: A review

Hyaluronic acid (HA) is key to the stability of the internal environment of tissues. HA content in tissues gradually decreases with age, causing age-related health problems. Exogenous HA supplements are used to prevent or treat these problems including skin dryness and wrinkles, intestinal imbalance, xerophthalmia, and arthritis after absorption. Moreover, some probiotics are able to promote endogenous HA synthesis and alleviate symptoms caused by HA loss, thus introducing potential preventative or therapeutic applications of HA and probiotics. Here, we review the oral absorption, metabolism, and biological function of HA as well as the potential role of probiotics and HA in increasing the efficacy of HA supplements.

Tissue Slice Culture and Analysis of Tumor-Associated Hyaluronan in Urothelial Carcinoma

Hyaluronan is a major component of the extracellular matrix in both normal and tumor tissue. Many solid cancers, including bladder cancer, are characterized by deregulated hyaluronan metabolism. It is postulated that the deregulated metabolism in cancer tissue is characterized by elevated hyaluronan synthesis and degradation. This results in the accumulation of small hyaluronan fragments in the tumor microenvironment which promotes cancer-related inflammation, stimulates tumor cell proliferation and angiogenesis, and contributes to immune-associated immune suppression. For a better understanding of the complex mechanisms of hyaluronan metabolism in cancer, it has been proposed to use precision-cut tissue slice cultures prepared using freshly excised cancer tissue. Here we describe the protocol for establishing tissue slice cultures and analysis of tumor-associated hyaluronan in human urothelial carcinoma.

Setting the stage for universal pharmacological targeting of the glycocalyx

All cells in the human body are covered by a complex meshwork of sugars as well as proteins and lipids to which these sugars are attached, collectively termed the glycocalyx. Over the past few decades, the glycocalyx has been implicated in a range of vital cellular processes in health and disease. Therefore, it has attracted considerable interest as a therapeutic target. Considering its omnipresence and its relevance for various areas of cell biology, the glycocalyx should be a versatile platform for therapeutic intervention, however, the full potential of the glycocalyx as therapeutic target is yet to unfold. This might be attributable to the fact that glycocalyx alterations are currently discussed mainly in the context of specific diseases. In this perspective review, we shift the attention away from a disease-centered view of the glycocalyx, focusing on changes in glycocalyx state. Furthermore, we survey important glycocalyx-targeted drugs currently available and finally discuss future steps. We hope that this approach will inspire a unified, holistic view of the glycocalyx in disease, helping to stimulate novel glycocalyx-targeted therapy strategies.

Antitumor Therapy Targeting the Tumor Microenvironment

The development and progression of tumors in human tissues extensively rely on its surrounding environment, that is, tumor microenvironment which includes a variety of cells, molecules, and blood vessels. These components are modified, organized, and integrated to support and facilitate the growth, invasion, and metabolism of tumor cells, suggesting them as potential therapeutic targets in anticancer treatment. An increasing number of pharmacological agents have been developed and clinically applied to target the oncogenic components in the tumor microenvironment, and in this review, we will summarize these pharmacological agents that directly or indirectly target the cellular or molecular components in the tumor microenvironment. However, difficulties and challenges still exist in this field, which will also be reported in this literature.

Importance of lactate dehydrogenase (LDH) and monocarboxylate transporters (MCTs) in cancer cells

Background

In most regions, cancer ranks the second most frequent cause of death following cardiovascular disorders.

Aim

In this article, we review the various aspects of glycolysis with a focus on types of MCTs and the importance of lactate in cancer cells.

Results and Discussion

Metabolic changes are one of the first and most important alterations in cancer cells. Cancer cells use different pathways to survive, energy generation, growth, and proliferation compared to normal cells. The increase in glycolysis, which produces substances such as lactate and pyruvate, has an important role in metastases and invasion of cancer cells. Two important cellular proteins that play a role in the production and transport of lactate include lactate dehydrogenase and monocarboxylate transporters (MCTs). These molecules by their various isoforms and different tissue distribution help to escape the immune system and expansion of cancer cells under different conditions.

Hyaluronic Acid as a Modern Approach in Anticancer Therapy-Review

Hyaluronic acid (HA) is a linear polysaccharide and crucial component of the extracellular matrix (ECM), maintaining tissue hydration and tension. Moreover, HA contributes to embryonic development, healing, inflammation, and cancerogenesis. This review summarizes new research on the metabolism and interactions of HA with its binding proteins, known as hyaladherins (CD44, RHAMM), revealing the molecular basis for its distinct biological function in the development of cancer. The presence of HA on the surface of tumor cells is a sign of an adverse prognosis. The involvement of HA in malignancy has been extensively investigated using cancer-free naked mole rats as a model. The HA metabolic components are examined for their potential impact on promoting or inhibiting tumor formation, proliferation, invasion, and metastatic spread. High molecular weight HA is associated with homeostasis and protective action due to its ability to preserve tissue integrity. In contrast, low molecular weight HA indicates a pathological condition in the tissue and plays a role in pro-oncogenic activity. A systematic approach might uncover processes related to cancer growth, establish novel prognostic indicators, and identify potential targets for treatment action.

Diabetic foot ulcer: Challenges and future

Diabetic foot ulcers (DFUs) have become one of the important causes of mortality and morbidity in patients with diabetes, and they are also a common cause of hospitalization, which places a heavy burden on patients and society. The prevention and treatment of DFUs requires multidisciplinary management. By controlling various risk factors, such as blood glucose levels, blood pressure, lipid levels and smoking cessation, local management of DFUs should be strengthened, such as debridement, dressing, revascularization, stem cell decompression and oxygen therapy. If necessary, systemic anti-infection treatment should be administered. We reviewed the progress in the clinical practice of treating DFUs in recent years, such as revascularization, wound repair, offloading, stem cell transplantation, and anti-infection treatment. We also summarized and prospectively analyzed some new technologies and measurements used in the treatment of DFUs and noted the future challenges and directions for the development of DFU treatments.

Thermo-responsive palladium-ruthenium nanozyme synergistic photodynamic therapy for metastatic breast cancer management

Reactive oxygen species (ROS) have become an effective "weapon" for cancer therapy due to their strong oxidation and high anti-tumor activity. Photodynamic therapy (PDT) is one of the classical methods to induce reactive oxygen species. Therefore, an ultraminiature palladium ruthenium alloy (sPdRu) and Ru(II) were combined with thermally responsive phase change materials (PCMs). Polypyridyl-complex (RCE) co-encapsulation was performed to obtain thermally responsive nanoparticles (PdRu-RCE@PCMNPs) for multimodal synergistic anti-breast cancer therapy. On the one hand, the thermosensitive PCM protective layer can realize the slow release of sPdRu, and then catalyze the production of oxygen from tumor endogenous H₂O₂ to perform RCE-mediated PDT. At the same time, sPdRu further increased ROS levels through peroxidase (POD) activity. On the other hand, sPdRu has high photothermal conversion efficiency and can be effectively used for photothermal therapy and photodynamic therapy. Importantly, PdRu-RCE@PCM NPs not only can effectively inhibit primary tumor growth, but also can inhibit tumor metastasis. In addition, due to the effective accumulation of sPdRu and RCE, PdRu-RCE@PCM NPs also show excellent fluorescence and photothermal imaging capabilities of tumors, which can be used for tumor tracing and evaluation of treatment. Accordingly, PdRu-RCE@PCM NPs are useful in treating primary tumors and inhibiting tumor metastasis.

Beyond the Lab: What We Can Learn about Cancer from Wild and Domestic Animals

Cancer research has benefited immensely from the use of animal models. Several genetic tools accessible in rodent models have provided valuable insight into cellular and molecular mechanisms linked to cancer development or metastasis and various lines are available. However, at the same time, it is important to accompany these findings with those from alternative or non-model animals to offer new perspectives into the understanding of tumor development, prevention, and treatment. In this review, we first discuss animals characterized by little or no tumor development. Cancer incidence in small animals, such as the naked mole rat, blind mole rat and bats have been reported as almost negligible and tumor development may be inhibited by increased defense and repair mechanisms, altered cell cycle signaling and reduced rates of cell migration to avoid tumor microenvironments. On the other end of the size spectrum, large animals such as elephants and whales also appear to have low overall cancer rates, possibly due to gene replicates that are involved in apoptosis and therefore can inhibit uncontrolled cell cycle progression. While it is important to determine the mechanisms that lead to cancer protection in these animals, we can also take advantage of other animals that are highly susceptible to cancer, especially those which develop tumors similar to humans, such as carnivores or poultry. The use of such animals does not require the transplantation of malignant cancer cells or use of oncogenic substances as they spontaneously develop tumors of similar presentation and pathophysiology to those found in humans. For example, some tumor suppressor genes are highly conserved between humans and domestic species, and various tumors develop in similar ways or because of a common environment. These animals are therefore of great interest for broadening perspectives and techniques and for gathering information on the tumor mechanisms of certain types of cancer. Here we present a detailed review of alternative and/or non-model vertebrates, that can be used at different levels of cancer research to open new perspectives and fields of action.

Short communication: Photoperiod impacts ovarian extracellular matrix and metabolic gene expression in Siberian hamsters

Ovarian cyclicity is variable in adult Siberian hamsters (Phodopus sungorus), who respond to long breeding season photoperiods with follicle development and ovulation, while short photoperiods typical of the non-breeding season induce gonadal atrophy. Recent RNAseq results identified ovarian matrix components and regulators of metabolism as differentially regulated by photoperiod; however, the impact of photoperiod across a full cycle of ovarian regression and recrudescence had not been explored for additional regulators of ovarian metabolism and extracellular matrix components. We hypothesized that matrix and metabolism-related genes would be expressed differentially across photoperiods that mimic breeding and non-breeding season daylengths. Hamsters were housed in one of four photoperiod groups: long day (16 h of light per day: 8 h of dark; LD, controls), short day regressed (8 L:16D; SD, regressed), and females exposed to SD then transferred to LD to stimulate return of ovarian function for 2 (early recrudescence), or 8 (late recrudescence) weeks. Plasma leptin concentrations along with expression of ovarian versican and liver-receptor homolog-1/Nr582 mRNA decreased in SD compared to LD and late recrudescence, while vimentin mRNA expression peaked in early and late recrudescence. Ovarian expression of fibronectin and extracellular matrix protein-1 was low in LD ovaries and increased in regressed and recrudescing groups. Expression of hyaluronidase-2, nectin-2, liver-X receptors-α and-β, and adiponectin mRNA peaked in late recrudescence, with no changes noted for adiponectin receptor-1 and -2. The results offer a first look at the parallels between expression of these genes and the dynamic remodeling that occurs during ovarian regression and recrudescence.

Engineered hyaluronic acid-decorated niosomal nanoparticles for controlled and targeted delivery of epirubicin to treat breast cancer

Targeted drug delivery systems using nanocarriers offer a versatile platform for breast cancer treatment; however, a robust, CD44-targeted niosomal formulation has not been developed and deeply studied (both in vitro and in vivo) yet. Here, an optimized system of epirubicin (Epi)-loaded niosomal nanoparticles (Nio) coated with hyaluronic acid (HA) has been engineered for targeting breast cancer cells. The nanoformulation was first optimized (based on size, polydispersity index, and entrapment efficiency); then, we characterized the morphology, stability, and release behavior of the nanoparticles. Epirubicin release from the HA-coated system (Epi-Nio-HA) showed a 21% (acidic buffer) and 20% (neutral buffer) reduction in comparison with the non-coated group (Epi-Nio). The cytotoxicity and apoptosis results of 4T1 and SkBr3 cells showed an approximately 2-fold increase in the Epi-Nio-HA system over Epi-Nio and free epirubicin, which confirms the superiority of the engineered nanocarriers. Moreover, real-time PCR data demonstrated the down-regulation of the MMP-2, MMP-9, cyclin D, and cyclin E genes expression while caspase-3 and caspase-9 gene expression were up-regulated. Confocal microscopy and flow cytometry studies uncovered the cellular uptake mechanism of the Epi-Nio-HA system, which was CD44-mediated. Furthermore, in vivo studies indicated Epi-Nio-HA decreased mice breast tumor volume by 28% (compared to epirubicin) without side effects on the liver and kidney. Conclusively, our results indicated that the HA-functionalized niosomes provide a promising nanoplatform for efficient and targeted delivery of epirubicin to potentially treat breast cancer.

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.

Beneficial Effects of Hyaluronan-Based Hydrogel Implantation after Cortical Traumatic Injury

Traumatic brain injury (TBI) causes cell death mainly in the cerebral cortex. We have previously reported that transplantation of embryonic cortical neurons immediately after cortical injury allows the anatomical reconstruction of injured pathways and that a delay between cortical injury and cell transplantation can partially improve transplantation efficiency. Biomaterials supporting repair processes in combination with cell transplantation are in development. Hyaluronic acid (HA) hydrogel has attracted increasing interest in the field of tissue engineering due to its attractive biological properties. However, before combining the cell with the HA hydrogel for transplantation, it is important to know the effects of the implanted hydrogel alone. Here, we investigated the therapeutic effect of HA on host tissue after a cortical trauma. For this, we implanted HA hydrogel into the lesioned motor cortex of adult mice immediately or one week after a lesion. Our results show the vascularization of the implanted hydrogel. At one month after HA implantation, we observed a reduction in the glial scar around the lesion and the presence of the newly generated oligodendrocytes, immature and mature neurons within the hydrogel. Implanted hydrogel provides favorable environments for the survival and maturation of the newly generated neurons. Collectively, these results suggest a beneficial effect of biomaterial after a cortical traumatic injury.

A cell adhesion-promoting multi-network 3D printing bio-ink based on natural polysaccharide hydrogel

Due to its high biosafety, gellan gum (GG) hydrogel, a naturally occurring polysaccharide released by microorganisms, is frequently utilized in food and pharmaceuticals. In recent years, like GG, natural polysaccharide-based hydrogels have become increasingly popular in 3D-printed biomedical engineering because of their simplicity of processing, considerable shear thinning characteristic, and minimal pH dependence. To mitigate the negative effects of the GG's high biological inertia, poor cell adhesion, single cross-linked network, and high brittleness. Mesoporous silica nanospheres (MMSN) and Aldehyde-based methacrylated hyaluronic acid (AHAMA) were combined to sulfhydrated GG (TGG) to create a multi-network AHAMA/TGG/MMSN hydrogel in this study. For this composite hydrogel system, the multi-component offers several crosslinking networks: the double bond in AHAMA can be photocrosslinked by activating the photoinitiator, aldehyde groups on its side chain can create Schiff base bonds with MMSN, while TGG can self-curing at room temperature. The AHAMA/TGG/MMSN hydrogel, with a mass ratio of 2:6:1, exhibits good cell adhesion, high strength and elasticity, and great printability. We believe that this innovative multi-network hydrogel has potential uses in tissue regeneration and biomedical engineering.

Application of Hydrogels as Sustained-Release Drug Carriers in Bone Defect Repair

Large bone defects resulting from trauma, infection and tumors are usually difficult for the body's repair mechanisms to heal spontaneously. Generally, various types of bones and orthopedic implants are adopted to enhance bone repair and regeneration in the clinic. Due to the limitations of traditional treatments, bone defect repair is still a compelling challenge for orthopedic surgeons. In recent years, bone tissue engineering has become a potential option for bone repair and regeneration. Amidst the various scaffolds for bone tissue engineering applications, hydrogels are considered a new type of non-toxic, non-irritating and biocompatible materials, which are widely used in the biomedicine field currently. Some studies have demonstrated that hydrogels can provide a three-dimensional network structure similar to a natural extracellular matrix for tissue regeneration and can be used to transport cells, biofactors, nutrients and drugs. Therefore, hydrogels may have the potential to be multifunctional sustained-release drug carriers in the treatment of bone defects. The recent applications of different types of hydrogels in bone defect repair were briefly reviewed in this paper.

Opposing Roles of IGFBP-3 and Heparanase in Regulating A549 Lung Cancer Cell Survival

In this study, we examined the roles of heparanase and IGFBP-3 in regulating A549 and H1299 non-small-cell lung cancer (NSCLC) survival. We found that H1299 cells, known to be p53-null with no expression of IGFBP-3, had higher heparanase levels and activity and higher levels of heparan sulfate (HS) in the media compared to the media of A549 cells. Inhibiting heparanase activity or its expression using siRNA had no effect on the levels of IGFBP-3 in the media of A549 cells, reduced the levels of soluble HS fragments, and led to decreased interactions between IGFBP-3 and HS in the media. HS competed with HA for binding to IGFBP-3 or IGFBP-3 peptide (²¹⁵-KKGFYKKKQCRPSKGRKR-²³²) but not the mutant peptide (K228AR230A). HS abolished the cytotoxic effects of IGFBP-3 but not upon blocking HA-CD44 signaling with the anti-CD44 antibody (5F12). Blocking HA-CD44 signaling decreased the levels of heparanase in the media of both A549 and H1299 cell lines and increased p53 activity and the levels of IGFBP-3 in A549 cell media. Knockdown of p53 led to increased heparanase levels and reduced IGFBP-3 levels in A549 cell media while knockdown of IGFBP-3 in A549 cells blocked p53 activity and increased heparanase levels in the media.

Atomic-Resolution Experimental Structural Biology and Molecular Dynamics Simulations of Hyaluronan and Its Complexes

This review summarizes the atomic-resolution structural biology of hyaluronan and its complexes available in the Protein Data Bank, as well as published studies of atomic-resolution explicit-solvent molecular dynamics simulations on these and other hyaluronan and hyaluronan-containing systems. Advances in accurate molecular mechanics force fields, simulation methods and software, and computer hardware have supported a recent flourish in such simulations, such that the simulation publications now outnumber the structural biology publications by an order of magnitude. In addition to supplementing the experimental structural biology with computed dynamic and thermodynamic information, the molecular dynamics studies provide a wealth of atomic-resolution information on hyaluronan-containing systems for which there is no atomic-resolution structural biology either available or possible. Examples of these summarized in this review include hyaluronan pairing with other hyaluronan molecules and glycosaminoglycans, with ions, with proteins and peptides, with lipids, and with drugs and drug-like molecules. Despite limitations imposed by present-day computing resources on system size and simulation timescale, atomic-resolution explicit-solvent molecular dynamics simulations have been able to contribute significant insight into hyaluronan's flexibility and capacity for intra- and intermolecular non-covalent interactions.

P-glycoprotein and cancer: what do we currently know?

Acquired resistance during cancer treatment is unfortunately a frequent event. There are several reasons for this, including the ability of the ATP-binding cassette transporters (ABC transporters), which are integral membrane proteins, to export chemotherapeutic molecules from the interior of the tumor cells. One important member of this family is the protein known as Permeability Glycoprotein (P-Glycoprotein, P-gp or ABCB1). Its clinical relevance relies mainly on the fact that the inhibition of P-gp and other ABC transporters could result in the reversal of the multidrug resistance (MDR) phenotype in some patients. Recently, other roles apart from being a key player in MDR, have emerged for P-gp. Therefore, this review discusses the relationship between P-gp and MDR, in addition to the possible role of this protein as a biomarker in cancer.

Construction and Evaluation of Hyaluronic Acid-Coated Flurbiprofen-Layered Double Hydroxide Ocular Drug Delivery System

In this study, flurbiprofen (FB) was selected as the model drug, and hyaluronic acid-coated flurbiprofen-layered double hydroxide ophthalmic drug delivery system (HA-FB-LDH) was designed and prepared. In this system, the model drug flurbiprofen was intercalated in layered double hydroxide and coated with hyaluronic acid (HA), so as to prolong the corneal residence time and increase the corneal permeability of the drug. Layered double hydroxide (LDH) was prepared by alcohol-water coprecipitation method. Through single factor investigation, the optimum preparation conditions were obtained as follows: The Mg/Al ratio was 2:1, the reaction pH was 11.0, the hydrothermal reaction time was 24 h, and the hydrothermal reaction temperature was 100°C. Under these conditions, the particle size of LDH was 116.4 ± 0.8 nm, the potential was 42.2 ± 1.2 mV, and a relatively regular crystal structure could be had. Then FB was intercalated into the LDH layer to prepare flurbiprofen-layered double hydroxide (FB-LDH). In the end, HA-FB-LDH was prepared by the stirring-ultrasonic method, in which through prescription screening, the molecular weight of HA was 200-400 kDa and the concentration of HA solution was 1.25 mg·mL ^-1, the final particle size of HA-FB-LDH was 185.8 ± 3.3 nm, and potential of - 31.4 ± 0.7 mV. The successful loading of FB and the coating of HA were verified by XRD, FTIR, TGA, TEM, and other characterization methods. The results of in vitro stability experiment indicated that the coating of HA could significantly enhance the stability of LDH in the presence of electrolytes. The in vitro release results suggested that the cumulative release amounts of FB-LDH and HA-FB-LDH within 12 h were 92.99 ± 0.37% and 74.82 ± 0.29% respectively, showing a certain sustained release effect. At the same time, the release mechanism of FB-LDH was preliminarily explored by in vitro release experiment, which proved that the release mechanism of FB-LDH was mainly ion exchange. The results of in vivo ocular irritation experiments demonstrated that the ophthalmic preparation studied in this paper was safe and non-irritating. The results of tear pharmacokinetics in rabbits showed that the area under the curve(AUC), the average residence time (MRT), and the highest concentration (C_max) in tears in the HA-FB-LDH group were 4.43, 4.48, and 2.27 times higher than those in eye drops group separately. Furthermore, the AUC of the HA-FB-LDH group was 1.48 times higher than that of the FB-LDH group. The above results suggested that HA-FB-LDH could improve the precorneal residence time. The results of aqueous humor pharmacokinetics in rabbits indicated that the AUC, MRT, and maximum concentration (C_max) in aqueous humor in the HA-FB-LDH group were 6.88, 2.15, and 4.08 times of those in the eye drop group respectively. Additionally, the AUC and MRT of the HA-FB-LDH group were 1.55 and 1.63 times those of the FB-LDH group separately. These mentioned findings verified that HA-FB-LDH could enhance the corneal permeability of the drug. The fluorescent substance-fluoresce isothiocyanate (FITC) was substituted for FB intercalation in LDH for in vitro tissue imaging study of rabbits, whose results stated clearly that FITC-LDH and HA-FITC-LDH could both prolong the precorneal residence time of drugs, and HA-FITC-LDH could increase the corneal permeability of the drug to a certain extent. To sum up, HA-FB-LDH, which can overcome the shortcomings of low bioavailability of traditional eye drops to a certain degree, is a safe and effective ophthalmic drug delivery system.

Risk Factors, Hyaluronidase Expression, and Clinical Immunogenicity of Recombinant Human Hyaluronidase PH20, an Enzyme Enabling Subcutaneous Drug Administration

Multiple FDA-approved and clinical-development stage therapeutics include recombinant human hyaluronidase PH20 (rHuPH20) to facilitate subcutaneous administration. As rHuPH20-reactive antibodies potentially interact with endogenous PH20, we investigated rHuPH20 immunogenicity risk through hyaluronidase tissue expression, predicted B cell epitopes, CD4+ T cell stimulation indices and related these to observed clinical immunogenicity profiles from 18 clinical studies. Endogenous hyaluronidase PH20 expression in humans/mice was assessed by reverse transcriptase-polymerase chain reaction (RT-PCR), quantitative RT-PCR, and deep RNA-Seq. rHuPH20 potential T cell epitopes were evaluated in silico and confirmed in vitro. Potential B cell epitopes were predicted for rHuPH20 sequence in silico, and binding of polyclonal antibodies from various species tested on a rHuPH20 peptide microarray. Clinical immunogenicity data were collected from 2643 subjects. From 57 human adult and fetal tissues previously screened by RT-PCR, 22 tissue types were analyzed by deep RNA-Seq. Hyaluronidase PH20 messenger RNA expression was detected in adult human testes. In silico analyses of the rHuPH20 sequence revealed nine T cell epitope clusters with immunogenic potential, one cluster was homologous to human leukocyte antigen. rHuPH20 induced T cell activation in 6-10% of peripheral blood mononuclear cell donors. Fifteen epitopes in the rHuPH20 sequence had the potential to cross-react with B cells. The cumulative treatment-induced incidence of anti-rHuPH20 antibodies across clinical studies was 8.8%. Hyaluronidase PH20 expression occurs primarily in adult testes. Low CD4+ T cell activation and B cell cross-reactivity by rHuPH20 suggest weak rHuPH20 immunogenicity potential. Restricted expression patterns of endogenous PH20 indicate low immunogenicity risk of subcutaneous rHuPH20.

Key Role of Hyaluronan Metabolism for the Development of Brain Metastases in Triple-Negative Breast Cancer

Breast cancer (BC) is the second-most common cause of brain metastases (BM) and BCBM patients have a reduced quality of life and a poor prognosis. Hyaluronan (HA), and in particular the hyaluronidase Hyal-1, has been already linked to the development of BCBM, and therefore presents an interesting opportunity to develop new effective therapeutic options. HA metabolism was further discovered by the CRISPR/Cas9-mediated knockout of HYAL1 and the shRNA-mediated down-regulation of HA-receptor CD44 in the brain-seeking triple-negative breast cancer (TNBC) cell line MDA-MB-231-BR. Therefore, the impact of Hyal-1 on adhesion, disruption, and invasion through the brain endothelium, both in vitro and in vivo, was studied. Our analysis points out a key role of Hyal-1 and low-molecular-weight HA (LMW-HA) in the formation of a pericellular HA-coat in BC cells, which in turn promotes tumor cell adhesion, disruption, and migration through the brain endothelium in vitro as well as the extent of BM in vivo. CD44 knockdown in MDA-MB-231-BR significantly reduced the pericellular HA-coat on these cells, and, consequently, tumor cell adhesion and invasion through the brain endothelium. Thus, the interaction between Hyal-1-generated LMW-HA fragments and the HA-receptor CD44 might represent a potential target for future therapeutic options in BC patients with a high risk of cerebral metastases formation.

CEMIP, a Promising Biomarker That Promotes the Progression and Metastasis of Colorectal and Other Types of Cancer

Simple Summary

CEMIP (cell migration-inducing and hyaluronan-binding protein) has been implicated in the pathogenesis of numerous diseases, including colorectal and other forms of cancer. The molecular functions of CEMIP are currently under investigation and include the degradation of the extracellular matrix component hyaluronic acid (HA), as well as the regulation of a number of signaling pathways. In this review, we survey our current understanding of how CEMIP contributes to tumor growth and metastasis, focusing particularly on colorectal cancer, for which it serves as a promising biomarker.

Abstract

Originally discovered as a hypothetical protein with unknown function, CEMIP (cell migration-inducing and hyaluronan-binding protein) has been implicated in the pathogenesis of numerous diseases, including deafness, arthritis, atherosclerosis, idiopathic pulmonary fibrosis, and cancer. Although a comprehensive definition of its molecular functions is still in progress, major functions ascribed to CEMIP include the depolymerization of the extracellular matrix component hyaluronic acid (HA) and the regulation of a number of signaling pathways. CEMIP is a promising biomarker for colorectal cancer. Its expression is associated with poor prognosis for patients suffering from colorectal and other types of cancer and functionally contributes to tumor progression and metastasis. Here, we review our current understanding of how CEMIP is able to foster the process of tumor growth and metastasis, focusing particularly on colorectal cancer. Studies in cancer cells suggest that CEMIP exerts its pro-tumorigenic and pro-metastatic activities through stimulating migration and invasion, suppressing cell death and promoting survival, degrading HA, regulating pro-metastatic signaling pathways, inducing the epithelial–mesenchymal transition (EMT) program, and contributing to the metabolic reprogramming and pre-metastatic conditioning of future metastatic microenvironments. There is also increasing evidence indicating that CEMIP may be expressed in cells within the tumor microenvironment that promote tumorigenesis and metastasis formation, although this remains in an early stage of investigation. CEMIP expression and activity can be therapeutically targeted at a number of levels, and preliminary findings in animal models show encouraging results in terms of reduced tumor growth and metastasis, as well as combating therapy resistance. Taken together, CEMIP represents an exciting new player in the progression of colorectal and other types of cancer that holds promise as a therapeutic target and biomarker.

Correlation of cell mechanics with the resistance to malignant transformation in naked mole rat fibroblasts

Naked mole rats (NMRs) demonstrate exceptional longevity and resistance to cancer. Using a biochemical approach, it was previously shown that the treatment of mouse fibroblast cells with RasV12 oncogene and SV40 Large T antigen (viral oncoprotein) led to malignant transformations of cells. In contrast, NMR fibroblasts were resistant to malignant transformations upon this treatment. Here we demonstrate that atomic force microscopy (AFM) can provide information which is in agreement with the above finding, and further, adds unique information about the physical properties of cells that is impossible to obtain by other existing techniques. AFM indentation data were collected from individual cells and subsequently processed through the brush model to obtain information about the mechanics of the cell body (absolute values of the effective Young's moduli). Furthermore, information about the physical properties of the pericellular layer surrounding the cells was obtained. We found a statistically significant decrease in the rigidity of mouse cells after the treatment, whereas there was no significant change found in the rigidity of NMR cells upon the treatment. We also found that the treatment caused a substantial increase in a long part of the pericellular layer in NMR cells only (the long brush was defined as having a size of >10 microns). The mouse cells and smaller brush did not show statistically significant changes upon treatment. The observed change in cell mechanics is in agreement with the frequently observed decrease in cell rigidity during progression towards cancer. The change in the pericellular layer due to the malignant transformation of fibroblast cells has practically not been studied, though it was shown that the removal of part of the pericellular layer of NMR fibroblasts made the cells susceptible to malignant transformation. Although it is plausible to speculate that the observed increase in the long part of the brush layer of NMR cells might help cells to resist malignant transformations, the significance of the observed change in the pericellular layer is yet to be understood. As of now, we can conclude that changes in cell mechanics might be used as an indication of the resistance of NMR cells to malignant transformations.

Deregulated hyaluronan metabolism in the tumor microenvironment drives cancer inflammation and tumor-associated immune suppression

Hyaluronan (HA) is known to be a prominent component of the extracellular matrix in tumors, and many solid cancers are characterized by aberrant HA metabolism resulting in increased production in tumor tissue. HA has been implicated in regulating a variety of cellular functions in tumor cells and tumor-associated stromal cells, suggesting that altered HA metabolism can influence tumor growth and malignancy at multiple levels. Importantly, increased HA production in cancer is associated with enhanced HA degradation due to high levels of expression and activity of hyaluronidases (Hyal). Understanding the complex molecular and cellular mechanisms involved in abnormal HA metabolism and catabolism in solid cancers could have important implications for the design of future cancer therapeutic approaches. It appears that extensive crosstalk between immune cells and HA-enriched stroma contributes to tumor growth and progression in several ways. Specifically, the interaction of tumor-recruited Hyal2-expressing myeloid-derived suppressor cells (MDSCs) of bone marrow origin with HA-producing cancer-associated fibroblasts and epithelial tumor cells results in enhanced HA degradation and accumulation of small pro-inflammatory HA fragments, which further drives cancer-related inflammation. In addition, hyaluronan-enriched stroma supports the transition of tumor-recruited Hyal2⁺MDSCs to the PD-L1⁺ tumor-associated macrophages leading to the formation of an immunosuppressive and tolerogenic tumor microenvironment. In this review, we aim to discuss the contribution of tumor-associated HA to cancer inflammation, angiogenesis, and tumor-associated immune suppression. We also highlight the recent findings related to the enhanced HA degradation in the tumor microenvironment.

Targeted Depletion of Hyaluronic Acid Mitigates Murine Breast Cancer Growth

Hyaluronic acid (HA) is highly elevated in breast cancers compared to normal breast tissue and is associated with increased tumor aggressiveness and poor prognosis. HA interacts with cell-trafficking CD44 receptors to promote tumor cell migration and proliferation and regulates both pro- and anti-inflammatory cytokine production through tumor-associated macrophages. The highly negative charge of HA enables its uptake of vast amounts of water that greatly increases the tumor interstitial fluidic pressure, which, combined with the presence of other extracellular matrix components such as collagen, results in tumor stroma with abnormal vasculature, hypoxia, and increased drug resistance. Thus, the degradation of HA in breast cancer may attenuate growth and improve permeability to anticancer agents. Previous methods to deplete tumor HA have resulted in significant off-tumor effects due to the systemic use of mammalian hyaluronidases. To overcome this, we developed a hyaluronidase-secreting Salmonella typhimurium (YS-HAse) that specifically and preferentially colonizes tumors to deplete HA. We show that the systemic administration of YS-HAse in immunocompetent murine models of breast cancer enhances tumor perfusion, controls tumor growth, and restructures the tumor immune contexture. These studies highlight the utility of YS-HAse as a novel microbial-based therapeutic that may also be combined with existing therapeutic approaches.

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.

Dicarboxylated hyaluronate: Synthesis of a new, highly functionalized and biocompatible derivative

Sequential periodate-chlorite oxidation of sodium hyaluronate to 2,3-dicarboxylated hyaluronate (DCH), a novel biocompatible and highly functionalized derivative bearing additional pair of COOH groups at C2 and C3 carbons of oxidized ᴅ-glucuronic acid units, is investigated. The impact of various reaction parameters (time, oxidizer concentration, and molar amount) on DCH's composition, molecular weight, degree of oxidation, and cytotoxicity are investigated to guide the synthesis of DCH derivatives of desired properties. Subsequently, fully (99%) and partially (70%) oxidized DCH derivatives were compared to untreated sodium hyaluronate in terms of anticancer drug cisplatin loading efficacy, carrier capacity, drug release rates, and cytotoxicity towards healthy and cancerous cell lines. DCH derivatives were found to be superior in every aspect, having nearly twice the carrier capacity, significantly slower release rates, and higher efficacy. DCH is thus a highly interesting hyaluronate derivative with an adjustable degree of oxidation, molecular weight, and great potential for further modifications.

Application of Nano-Inspired Scaffolds-Based Biopolymer Hydrogel for Bone and Periodontal Tissue Regeneration

This review’s objectives are to provide an overview of the various kinds of biopolymer hydrogels that are currently used for bone tissue and periodontal tissue regeneration, to list the advantages and disadvantages of using them, to assess how well they might be used for nanoscale fabrication and biofunctionalization, and to describe their production processes and processes for functionalization with active biomolecules. They are applied in conjunction with other materials (such as microparticles (MPs) and nanoparticles (NPs)) and other novel techniques to replicate physiological bone generation more faithfully. Enhancing the biocompatibility of hydrogels created from blends of natural and synthetic biopolymers can result in the creation of the best scaffold match to the extracellular matrix (ECM) for bone and periodontal tissue regeneration. Additionally, adding various nanoparticles can increase the scaffold hydrogel stability and provide a number of biological effects. In this review, the research study of polysaccharide hydrogel as a scaffold will be critical in creating valuable materials for effective bone tissue regeneration, with a future impact predicted in repairing bone defects.

Heparinized Gelatin-Based Hydrogels for Differentiation of Induced Pluripotent Stem Cells

Chemically defined hydrogels are increasingly utilized to define the effects of extracellular matrix (ECM) components on cellular fate determination of human embryonic and induced pluripotent stem cell (hESC and hiPSCs). In particular, hydrogels cross-linked by orthogonal click chemistry, including thiol-norbornene photopolymerization and inverse electron demand Diels–Alder (iEDDA) reactions, are explored for 3D culture of hESC/hiPSCs owing to the specificity, efficiency, cytocompatibility, and modularity of the cross-linking reactions. In this work, we exploited the modularity of thiol-norbornene photopolymerization to create a biomimetic hydrogel platform for 3D culture and differentiation of hiPSCs. A cell-adhesive, protease-labile, and cross-linkable gelatin derivative, gelatin-norbornene (GelNB), was used as the backbone polymer for constructing hiPSC-laden biomimetic hydrogels. GelNB was further heparinized via the iEDDA click reaction using tetrazine-modified heparin (HepTz), creating GelNB-Hep. GelNB or GelNB-Hep was modularly cross-linked with either inert macromer poly(ethylene glycol)-tetra-thiol (PEG4SH) or another bioactive macromer-thiolated hyaluronic acid (THA). The formulations of these hydrogels were modularly tuned to afford biomimetic matrices with similar elastic moduli but varying bioactive components, enabling the understanding of each bioactive component on supporting hiPSC growth and ectodermal, mesodermal, and endodermal fate commitment under identical soluble differentiation cues.

Transcriptomics and proteomics analysis to explore the mechanism of Yishen Tongluo formula repairing sperm DNA damage in rats

The sperm DNA fragmentation index (DFI) is an objective indicator of male fertility. Currently, effective treatments for high sperm DFI are limited and traditional Chinese medicine (TCM) has certain advantages in this aspect. Yishen Tongluo formula (YSTL), a TCM formula, has been found to reduce DFI in patients. To better understand the mechanisms underlying its activity, we used transcriptomics and proteomics to analyse the potential target gene YSTL repairing tripterygium glycosides (TGs)-mediated sperm DNA damage in rats, followed by validation analyses using RT-qPCR and western blotting, which showed that relative to the control group, DFI was markedly elevated in the TGs group, but markedly lower in the YSTL group relative to the TGs group. KEGG pathway analysis of 119 differentially expressed genes and 158 DEPs identified using trend analysis revealed that they were enriched for apoptosis and base excision repair at the transcriptomic level and for microRNAs in cancer and complement and coagulation cascades at the proteomic level. Ttr and Pnpla2 were identified as potential target genes for YSTL. Our data show that YSTL can protect rat sperm DNA from TGs-induced damage, which may be related to apoptosis, DNA repair and other pathways, and the possible target genes are Ttr and Pnpla2.

Hyaluronic Acid-Enwrapped Polyoxometalate Complex for Synergistic Near Infrared-II Photothermal/Chemo-Therapy and Chemodynamic Therapy

To enhance the efficacy of tumor therapy, the collection of functional components into a targeting system shows advantages over most homogeneous materials in inducing apoptosis of cancer cells. The security and targeting of therapeutic agents also require the effect combination of additional components. However, the construction of multifunctional composites in a simple system with intelligent cooperative responsiveness remains a challenge. Herein, a reduced polyanionic cluster (rP₂W₁₈) bearing the absorption at the near infrared (NIR) II region is used as a core carrier to bind the positively charged doxorubicin hydrochloride (DOX) through ionic interaction. To reduce the physiological toxicity, hyaluronic acid grafting β-cyclodextrin side chains is used to cover the ionic complex through host-guest inclusion to DOX. When the nanocomposite is activated by local laser exposure, the final three-component therapeutic agent is demonstrated to present targeted photothermal conversion capability and chemodynamic activity together with chemotherapy. With the controlled release of DOX under the stimulation of mild acidity in the tumor region and photothermal effect, the exposed rP₂W₁₈ is aroused by hydrogen peroxide overexpressed in a tumor microenvironment to produce toxic reactive oxygen species, ¹O₂. This work presents an opportunity for the development of a nanocomposite in NIR-II photothermal/chemo-therapy and chemodynamic synergistic therapy.

The Extracellular Matrix: A Key Accomplice of Cancer Stem Cell Migration, Metastasis Formation, and Drug Resistance in PDAC

Pancreatic ductal adenocarcinoma (PDAC) is rich in dense fibrotic stroma that are composed of extracellular matrix (ECM) proteins. A disruption of the balance between ECM synthesis and secretion and the altered expression of matrix remodeling enzymes lead to abnormal ECM dynamics in PDAC. This pathological ECM promotes cancer growth, survival, invasion, and alters the behavior of fibroblasts and immune cells leading to metastasis formation and chemotherapy resistance, which contribute to the high lethality of PDAC. Additionally, recent evidence highlights that ECM, as a major structural component of the tumor microenvironment, is a highly dynamic structure in which ECM proteins establish a physical and biochemical niche for cancer stem cells (CSCs). CSCs are characterized by self-renewal, tumor initiation, and resistance to chemotherapeutics. In this review, we will discuss the effects of the ECM on tumor biological behavior and its molecular impact on the fundamental signaling pathways in PDAC. We will also provide an overview of how the different ECM components are able to modulate CSCs properties and finally discuss the current and ongoing therapeutic strategies targeting the ECM. Given the many challenges facing current targeted therapies for PDAC, a better understanding of molecular events involving the interplay of ECM and CSC will be key in identifying more effective therapeutic strategies to eliminate CSCs and ultimately to improve survival in patients that are suffering from this deadly disease.

Hyaluronic Acid: A Valid Therapeutic Option for Early Management of Genitourinary Syndrome of Menopause in Cancer Survivors?

Genitourinary syndrome of menopause (GSM) is a chronic condition affecting a large number of women, with a major impact on their urogenital health and sexual function. It occurs at midlife because estrogen levels decline with menopause enhancing aging-related changes of the functional anatomy of the urogenital system. Unfortunately, GSM may occur early in the lifespan of women or be exacerbated following anticancer treatments, such as chemotherapy, ionizing radiation, or surgical removal of reproductive organs. Symptoms of GSM are often under-reported by women, under-estimated and under-diagnosed by health care providers (HCPs), and subsequently under-treated, despite their profound negative impact on the quality of life. The mainstay of vaginal treatments is local estrogen therapy (LET) ensuring an effective management of moderate to severe symptomatic GSM. However, LET is generally contraindicated in women with a history of hormone receptor positive cancer, due to the fear of increased recurrence or possible interference with endocrine adjuvant therapies. Among non-hormonal treatments, hyaluronic acid-based moisturizers have shown promising clinical results both in healthy women and in cancer patients or survivors. Its strong water-binding properties provide lubricating and moisturizing effects, which contribute to maintaining a proper level of hydration and viscoelasticity in several body parts, including the urinary tract and genital tissues. Hyaluronic acid-based moisturizers are effective, safe, and well tolerated; therefore, they may represent a valid option for the early management of GSM-associated symptoms in every woman with a history of cancer who is unable or unwilling to undergo hormone-based therapies. Hence, the aim of this review was to provide an overview of GSM etiology and treatment in women with natural or iatrogenic menopause, with a focus on the use of hyaluronic acid as a prophylactic treatment in the context of an integrated management protocol for cancer patients.

Concurrent Overexpression of Two Hyaluronidases, KIAA1199 and TMEM2, Strongly Predicts Shorter Survival After Resection in Pancreatic Ductal Adenocarcinoma

OBJECTIVES

Pancreatic ductal adenocarcinoma (PDAC) is characterized by accelerated hyaluronan metabolism. Our previous studies have shown increased expression of 2 newly identified hyaluronidases, KIAA1199 and transmembrane protein 2 (TMEM2), in PDAC. However, the relationship between these 2 hyaluronidases is unknown. In the present study, we investigated the correlation between KIAA1199 and TMEM2 expression in PDAC.

METHODS

Using quantitative real-time reverse transcription polymerase chain reaction, we analyzed KIAA1199 and TMEM2 mRNA expression in 11 PDAC cell lines and frozen tissues from 12 patients with PDAC. We used immunohistochemistry to investigate expression patterns of KIAA1199 and TMEM2 in archival tissues obtained from 92 patients with PDAC who underwent surgical resection. We compared survival between 4 groups according to expression patterns of KIAA1199 and TMEM2.

RESULTS

We found a significantly positive correlation between KIAA1199 and TMEM2 mRNA in PDAC cell lines and tissues. Immunohistochemical analysis found that median overall survival was 30.2 months in patients with low expression of KIAA1199 and TMEM2 and 12.5 months in those with high expression of both. Patients with high expression of KIAA1199 and TMEM2 had significantly shorter survival than other patient groups.

CONCLUSIONS

Concurrent overexpression of these 2 hyaluronidases could be a strong prognostic marker in PDAC.

3'UTR shortening of HAS2 promotes hyaluronan hyper-synthesis and bioenergetic dysfunction in pulmonary hypertension

Pulmonary hypertension (PH) comprises a diverse group of disorders that share a common pathway of pulmonary vascular remodeling leading to right ventricular failure. Development of anti-remodeling strategies is an emerging frontier in PH therapeutics that requires a greater understanding of the interactions between vascular wall cells and their extracellular matrices. The ubiquitous matrix glycan, hyaluronan (HA), is markedly elevated in lungs from patients and experimental models with PH. Herein, we identified HA synthase-2 (HAS2) in the pulmonary artery smooth muscle cell (PASMC) layer as a predominant locus of HA dysregulation. HA upregulation involves depletion of NUDT21, a master regulator of alternative polyadenylation, resulting in 3'UTR shortening and hyper-expression of HAS2. The ensuing increase of HAS2 and hyper-synthesis of HA promoted bioenergetic dysfunction of PASMC characterized by impaired mitochondrial oxidative capacity and a glycolytic shift. The resulting HA accumulation stimulated pro-remodeling phenotypes such as cell proliferation, migration, apoptosis-resistance, and stimulated pulmonary artery contractility. Transgenic mice, mimicking HAS2 hyper-synthesis in smooth muscle cells, developed spontaneous PH, whereas targeted deletion of HAS2 prevented experimental PH. Pharmacological blockade of HAS2 restored normal bioenergetics in PASMC, ameliorated cell remodeling phenotypes, and reversed experimental PH in vivo. In summary, our results uncover a novel mechanism of HA hyper-synthesis and downstream effects on pulmonary vascular cell metabolism and remodeling.

A mechanically adaptive hydrogel neural interface based on silk fibroin for high-efficiency neural activity recording

A flexible non-transient electrical platform that can realize bidirectional neural communication from living tissues is of great interest in neuroscience to better understand basic neuroscience and the nondrug therapy of diseases or disorders. The development of soft, biocompatible, and conductive neural interface with mechanical coupling and efficient electrical exchange is a new trend but remains a challenge. Herein, we designed a multifunctional neural electrical communication platform in the form of a mechanically compliant, electrically conductive, and biocompatible hydrogel electrode. Silk fibroin (SF) obtained from Bombyx Mori cocoons was compounded with aldehyde-hyaluronic acid (HA-CHO) with a dynamic network to delay or interrupt the β-sheet-induced hardening of SF chains, resulting in the fabrication of a hydrogel matrix that is mechanically matched to biological tissues. Moreover, the incorporation of functionalized carbon nanotubes (CNTs) facilitated interaction and dispersion and enabled the formation of a hydrogel electrode with a high-current percolation network, thus contributing toward improving the electrical properties in terms of conductivity, impedance, and charge storage capabilities. These advances allow high-efficiency stimulation and the recording of neural signals during in vivo implantation. Overall, a wide range of animal experiments demonstrate that the platform exhibits minimal foreign body responses, thus showing it to be a promising electrophysiology interface for potential applications in neuroscience.

Design of ROS-Responsive Hyaluronic Acid-Methotrexate Conjugates for Synergistic Chemo-Photothermal Therapy for Cancer

Combining chemotherapy with photothermal therapy (PTT) for cancer treatment could overcome the inherent limitations of both single-modality chemotherapy and PTT. However, the obstacle of accurate drug delivery to tumor sites based on chemo-photothermal remains challenging. This article describes development of a reactive oxygen species (ROS)-responsive hyaluronic acid-based nanoparticle to overcome these drawbacks. Herein, HA-TK-MTX (HTM) was synthesized by a ROS-responsive cleaved thioketal moiety linker (TK) of methotrexate (MTX) and hyaluronic acid (HA). Through hydrophobic interaction and π-π stacking interaction, a photothermal agent IR780 was integrated into the HTM, and the IR780/HTM nanoparticles (IHTM NPs) were obtained. The IHTM NPs show high photostability, excellent photothermal performance, remarkable tumor-targeting ability, and ROS sensibility. Due to the accurate drug delivery ability and superior chemo-photothermal treatment effect of IHTM NPs, the tumor inhibition rate reached 70.95% for 4T1 tumor-bearing mice. This work serves as a precedent for the chemo-photothermal therapy of cancer by rationally designing ROS-responsive nanoparticles.

Small fragments of hyaluronan are increased in individuals with obesity and contribute to low-grade inflammation through TLR-mediated activation of innate immune cells

Background and aim

Extracellular matrix (ECM) components released during excessive fat mass expansion are considered potential endogenous danger/alarm signals contributing to innate immune system activation. The aim of the current study was to specifically measure plasma levels of low molecular weight (LMW) hyaluronan (HA) and to evaluate its role as pro-inflammatory damage-associated molecular pattern (DAMP) on leukocyte response in the context of human obesity.

Subjects and methods

Participants were selected according to their body mass index (BMI, kg/m²) as non-obese (BMI < 29.9, n = 18) and obese (BMI > 29.9, n = 33). Plasma samples were size-dependent fractionated using ion-exchange chromatography to specifically obtain LMW HA fractions that were subsequently quantified by ELISA. Cell incubation experiments with synthetic HA molecules were performed on freshly Ficoll-isolated neutrophils (PMN) and peripheral blood monocytes (PBMC). Leukocyte and adipose tissue gene expression was assessed by real-time PCR and NF-κB activation by western blot. Plasma cytokine levels were measured by fluorescent bead-based (Luminex) immunoassay.

Results

We observed a statistically significant increase in the circulating levels of HA fragments of LMW in individuals with obesity which were consistent with significant up-regulated expression of the LMW HA synthesizing enzyme hyaluronan synthase-1 (HAS-1) in obese adipose tissue. Gene expression assessment of HA receptors revealed up-regulated levels for TLR2 in both obese PMN and PBMC. Synthetic HA molecules of different sizes were tested on leukocytes from healthy donors. LMW HA fragments (15–40 kDa) and not those from intermediate molecular sizes (75–350 kDa) induced a significant up-regulation of the expression of major pro-inflammatory cytokines such as IL-1β, MCP-1 and IL-8 in PBMC. Importantly, LMW HA was able to induce the phosphorylation of IKK α/β complex supporting its pro-inflammatory role through NF-κB activation.

Conclusion

Circulating LMW HA molecules are elevated in obesity and may play an important role in triggering low-grade inflammation and the development of metabolic complications.

Injectable hydrogel with immobilized BMP-2 mimetic peptide for local bone regeneration

Osteoporosis is a disease characterized by a decrease in bone mineral density, thereby increasing the risk of sustaining a fragility fracture. Most medical therapies are systemic and do not restore bone in areas of need, leading to undesirable side effects. Injectable hydrogels can locally deliver therapeutics with spatial precision, and this study reports the development of an injectable hydrogel containing a peptide mimic of bone morphogenetic protein-2 (BMP-2). To create injectable hydrogels, hyaluronic acid was modified with norbornene (HANor) or tetrazine (HATet) which upon mixing click into covalently crosslinked Nor-Tet hydrogels. By modifying HANor macromers with methacrylates (Me), thiolated BMP-2 mimetic peptides were immobilized to HANor via a Michael addition reaction, and coupling was confirmed with 1H NMR spectroscopy. BMP-2 peptides presented in soluble and immobilized form increased alkaline phosphatase (ALP) expression in MSCs cultured on 2D and encapsulated in 3D Nor-Tet hydrogels. Injection of bioactive Nor-Tet hydrogels into hollow intramedullary canals of Lewis rat femurs showed a local increase in trabecular bone density as determined by micro-CT imaging. The presented work shows that injectable hydrogels with immobilized BMP-2 peptides are a promising biomaterial for the local regeneration of bone tissue and for the potential local treatment of osteoporosis.

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.

Hyaluronic Acid–Stabilized Fe3O4 Nanoparticles for Promoting In Vivo Magnetic Resonance Imaging of Tumors

The use of iron oxide (Fe3O4) nanoparticles as novel contrast agents for magnetic resonance imaging (MRI) has attracted great interest due to their high r2 relaxivity. However, both poor colloidal stability and lack of effective targeting ability have impeded their further expansion in the clinics. Here, we reported the creation of hyaluronic acid (HA)-stabilized Fe3O4 nanoparticles prepared by a hydrothermal co-precipitation method and followed by electrostatic adsorption of HA onto the nanoparticle surface. The water-soluble HA functions not only as a stabilizer but also as a targeting ligand with high affinity for the CD44 receptor overexpressed in many tumors. The resulting HA-stabilized Fe3O4 nanoparticles have an estimated size of sub-20 nm as observed by transmission electron microscopy (TEM) imaging and exhibited long-term colloidal stability in aqueous solution. We found that the nanoparticles are hemocompatible and cytocompatible under certain concentrations. As verified by quantifying the cellular uptake, the Fe3O4@HA nanoparticles were able to target a model cell line (HeLa cells) overexpressing the CD44 receptor through an active pathway. In addition, we showed that the nanoparticles can be used as effective contrast agents for MRI both in vitro in HeLa cells and in vivo in a xenografted HeLa tumor model in rodents. We believe that our findings shed important light on the use of active targeting ligands to improve the contrast of lesion for tumor-specific MRI in the nano-based diagnosis systems.

Gold Nanostar@Polyaniline Theranostic Agent with High Photothermal Conversion Efficiency for Photoacoustic Imaging-Guided Anticancer Phototherapy at a Low Dosage

Due to the strong and tunable photothermal effect, metallic nanoparticles are of enormous interest in light-activated biomedical applications, such as photoacoustic imaging (PAI) and photothermal therapy (PTT). However, the photothermal conversion efficiency (PCE) of existing metallic photothermal agents is still unsatisfactory. Herein, we develop an efficient photothermal theranostic agent based on a gold nanostar@polyaniline core-shell nanocomposite with high PCE for PAI-guided PTT at a low dosage. After optimizing the relative composition of polyaniline (PANI) and gold nanostars (AuNSs), this nanocomposite eventually empowers an outstanding PCE of up to 78.6%, which is much better than AuNSs or PANI alone and most of the existing photothermal theranostic agents. Besides, the nanocomposite can act as a targeted probe for tumors by hyaluronic acid (HA) modification without compromising the photothermal performance. The obtained nanoprobes named AuNSPHs exhibit promising biocompatibility and great performance of PAI-guided PTT to treat triple-negative breast cancer both in vitro and in vivo. More importantly, a single injection of AuNSPHs significantly suppresses tumor growth with a low dosage of Au (0.095 mg/kg), which is attributed to the high PCE of AuNSPHs. Taking advantage of the exhilarating photothermal conversion ability, this theranostic agent can safely potentiate the antitumor therapeutic efficacy of laser-induced ablation and holds great potential for future medical applications.

A quartz crystal microbalance method to quantify the size of hyaluronan and other glycosaminoglycans on surfaces

Hyaluronan (HA) is a major component of peri- and extra-cellular matrices and plays important roles in many biological processes such as cell adhesion, proliferation and migration. The abundance, size distribution and presentation of HA dictate its biological effects and are also useful indicators of pathologies and disease progression. Methods to assess the molecular mass of free-floating HA and other glycosaminoglycans (GAGs) are well established. In many biological and technological settings, however, GAGs are displayed on surfaces, and methods to obtain the size of surface-attached GAGs are lacking. Here, we present a method to size HA that is end-attached to surfaces. The method is based on the quartz crystal microbalance with dissipation monitoring (QCM-D) and exploits that the softness and thickness of films of grafted HA increase with HA size. These two quantities are sensitively reflected by the ratio of the dissipation shift (ΔD) and the negative frequency shift (- Δf) measured by QCM-D upon the formation of HA films. Using a series of size-defined HA preparations, ranging in size from ~ 2 kDa tetrasaccharides to ~ 1 MDa polysaccharides, we establish a monotonic yet non-linear standard curve of the ΔD/ - Δf ratio as a function of HA size, which reflects the distinct conformations adopted by grafted HA chains depending on their size and surface coverage. We demonstrate that the standard curve can be used to determine the mean size of HA, as well as other GAGs, such as chondroitin sulfate and heparan sulfate, of preparations of previously unknown size in the range from 1 to 500 kDa, with a resolution of better than 10%. For polydisperse samples, our analysis shows that the process of surface-grafting preferentially selects smaller GAG chains, and thus reduces the average size of GAGs that are immobilised on surfaces comparative to the original solution sample. Our results establish a quantitative method to size HA and other GAGs grafted on surfaces, and also highlight the importance of sizing GAGs directly on surfaces. The method should be useful for the development and quality control of GAG-based surface coatings in a wide range of research areas, from molecular interaction analysis to biomaterials coatings.

Novel Brain-Stiffness-Mimicking Matrix Gel Enables Comprehensive Invasion Analysis of 3D Cultured GBM Cells

Glioblastoma (GBM) is the most common malignant primary brain tumor in adults, which is fast growing and tends to invade surrounding normal brain tissues. Uncovering the molecular and cellular mechanisms of GBM high invasion potential is of great importance for the treatment and prognostic prediction. However, the commonly used two-dimensional (2D) cell culture and analysis system suffers from lack of the heterogeneity and in vivo property of brain tissues. Here, we established a three-dimensional (3D) cell culture-based analysis system that could better recapitulate the heterogeneity of GBM and mimic the in vivo conditions in the brain. The GBM cell lines, DBTRG and U251, were cultured by hanging drop culture into the GBM multicellular spheroids, which were embedded in the optimized 3D brain-stiffness-mimicking matrix gel (0.5 mg/ml Collagen Ⅰ + 3 mg/ml Matrigel+ 3.3 mg/ml Hyaluronic Acid (HA)). The biochemical composition of the optimized matrix gel is similar to that of the brain microenvironment, and the elastic modulus is close to that of the brain tissue. The dynamics of the GBM spheroids was examined using high-content imaging for 60 h, and four metrics including invasion distance, invasion area, single-cell invasion velocity, and directionality were employed to quantify the invasion capacity. The result showed that DBTRG cells possess higher invasion capacity than U251 cells, which was consistent with the results of the classic transwell test. Transcriptome analysis of both cell lines was performed to explore the underlying molecular mechanisms. Our novel brain-stiffness-mimicking matrix gel enables comprehensive invasion analysis of the 3D cultured GBM cells and provides a model basis for in-depth exploration of the mechanisms regulating GBM invasion including the interaction between GBM cells and brain stroma.