Hyaluronic acid: separation and biological implications

Photo-Crosslinked Pro-Angiogenic Hydrogel Dressing for Wound Healing

Severe burns are one of the most devastating injuries, in which sustained inflammation and ischemia often delay the healing process. Pro-angiogenic growth factors such as vascular endothelial growth factor (VEGF) have been widely studied for promoting wound healing. However, the short half-life and instability of VEGF limit its clinical applications. In this study, we develop a photo-crosslinked hydrogel wound dressing from methacrylate hyaluronic acid (MeHA) bonded with a pro-angiogenic prominin-1-binding peptide (PR1P). The materials were extruded in wound bed and in situ formed a wound dressing via exposure to short-time ultraviolet radiation. The study shows that the PR1P-bonded hydrogel significantly improves VEGF recruitment, tubular formation, and cell migration in vitro. Swelling, Scanning Electron Microscope, and mechanical tests indicate the peptide does not affect the overall mechanical and physical properties of the hydrogels. For in vivo studies, the PR1P-bonded hydrogel dressing enhances neovascularization and accelerates wound closure in both deep second-degree burn and full-thickness excisional wound models. The Western blot assay shows such benefits can be related to the activation of the VEGF-Akt signaling pathway. These results suggest this photo-crosslinked hydrogel dressing efficiently promotes VEGF recruitment and angiogenesis in skin regeneration, indicating its potential for clinical applications in wound healing.

Separation and purification of hyaluronic acid by Fe3O4 nano and micro particles coated with chitosan and silica

Hyaluronic acid (HA), a glycosaminoglycan, is comprised of alternating units of D-glucuronic acid and N-acetylglucosamine. This compound harbors numerous biomedical applications, including its use in pharmaceuticals, wound healing, osteoarthritis treatment, and drug delivery. Its unique composition and exceptional features, such as its high water-absorbing and retaining capacity, have also led to its use in the cosmetics industry. The employment of this biopolymer has given rise to an escalation in the request for its manufacture. The present investigation has explored the correlation between hyaluronic acid and chitosan and silica for the purpose of separation. Consequently, Iron oxide magnetic nano particles and micro particles were produced via co-precipitation method and were layered with chitosan and silica to purify the hyaluronic acid from the fermentation broth that was generated by Streptococcus Zooepidemicus. The size distribution and zeta potentials of the two kinds of particles were gauged with the aid of a dynamic laser light scattering apparatus and zeta potential meter (Malvern, Zeta master) respectively. The confirmation of the chemical structure of the Fe3O4 nanoparticles and Fe3O4 particles conjugated with chitosan and silica was accomplished through the utilization of Fourier Transform Infrared Spectroscopy (FT-IR). Protein contamination was thoroughly characterized by means of sodium dodecyl-sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and Nanodrop 2000/2000c spectrophotometers protein estimation method. The maximum HA adsorption capacity, under optimal pH conditions of 4, was determined to be 87 mg/g, 112 mg/g, 51 mg/g, and 44 mg/g for Fe3O4 -chitosan nanoparticle, Fe3O4 -chitosan micro particle, Fe3O4 -silica microparticle, and Fe3O4 -silica nanoparticle, respectively.

Protective effect of Bifidobacterium animalis CGMCC25262 on HaCaT keratinocytes

Bifidobacteria are the most prevalent members of the intestinal microbiota in mammals and other animals, and they play a significant role in promoting gut health through their probiotic effects. Recently, the potential applications of Bifidobacteria have been extended to skin health. However, the beneficial mechanism of Bifidobacteria on the skin barrier remains unclear. In this study, keratinocyte HaCaT cells were used as models to evaluate the protective effects of the cell-free supernatant (CFS), heat-inactivated bacteria, and bacterial lysate of Bifidobacterium animalis CGMCC25262 on the skin barrier and inflammatory cytokines. The results showed that all the tested samples were able to upregulate the transcription levels of biomarker genes associated with the skin barrier, such as hyaluronic acid synthetase (HAS) and aquaporins (AQPs). Notably, the transcription of the hyaluronic acid synthetase gene-2 (HAS-2) is upregulated by 3~4 times, and AQP3 increased by 2.5 times when the keratinocyte HaCaT cells were co-incubated with 0.8 to 1% CFS. In particular, the expression level of Filaggrin (FLG) in HaCaT cells increased by 1.7 to 2.7 times when incubated with Bifidobacterial samples, reaching its peak at a concentration of 0.8% CFS. Moreover, B. animalis CGMCC25262 also decreased the expression of the proinflammatory cytokine RANTES to one-tenth compared to the levels observed in HaCaT cells induced with tumor necrosis factor alpha (TNF-α) and interferon gamma (IFN-γ). These results demonstrate the potential of B. animalis CGMCC25262 in protecting the skin barrier and reducing inflammatory response.

Hyaluronic acid-mediated collagen intrafibrillar mineralization and enhancement of dentin remineralization

Non-collagenous proteins (NCPs) in the extracellular matrix (ECM) of bone and dentin are known to play a critical regulatory role in the induction of collagen fibril mineralization and are embedded in hyaluronic acid (HA), which acts as a water-retaining glycosaminoglycan and provides necessary biochemical and biomechanical cues. Our previous study demonstrated that HA could regulate the mineralization degree and mechanical properties of collagen fibrils, yet its kinetics dynamic mechanism on mineralization is under debate. Here, we further investigated the role of HA on collagen fibril mineralization and the possible mechanism. The HA modification can significantly promote intrafibrillar collagen mineralization by reducing the electronegativity of the collagen surface to enhance calcium ions (Ca2+) binding capacity to create a local higher supersaturation. In addition, the HA also provides additional nucleation sites and shortens the induction time of amorphous calcium phosphate (ACP)-mediated hydroxyapatite (HAP) crystallization, which benefits mineralization. The acceleration effect of HA on intrafibrillar collagen mineralization is also confirmed in collagen hydrogel and in vitro dentin remineralization. These findings offer a physicochemical view of the regulation effect of carbohydrate polymers in the body on biomineralization, the fine prospect for an ideal biomaterial to repair collagen-mineralized tissues.

Tapping on the Potential of Hyaluronic Acid: from Production to Application

The manufacture, purification, and applications of hyaluronic acid (HA) are discussed in this article. Concerning the growing need for affordable, high-quality HA, it is essential to consider diverse production techniques using renewable resources that pose little risk of cross-contamination. Many microorganisms can now be used to produce HA without limiting the availability of raw materials and in an environmentally friendly manner. The production of HA has been associated with Streptococci A and C, explicitly S. zooepidemicus and S. equi. Different fermentation techniques, including the continuous, batch, fed-batch, and repeated batch culture, have been explored to increase the formation of HA, particularly from S. zooepidemicus. The topic of current interest also involves a complex broth rich in metabolites and residual substrates, intensifying downstream processes to achieve high recovery rates and purity. Although there are already established methods for commercial HA production, the anticipated growth in trade and the diversification of application opportunities necessitate the development of new procedures to produce HA with escalated productivity, specified molecular weights, and purity. In this report, we have enacted the advancement of HA technical research by analyzing bacterial biomanufacturing elements, upstream and downstream methodologies, and commercial-scale HA scenarios.

Drug-Embedded Nanovesicles Assembled from Peptide-Decorated Hyaluronic Acid for Rheumatoid Arthritis Synergistic Therapy

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease that causes endless pain and poor quality of life in patients. Usage of a lubricant combined with anti-inflammatory therapy is considered a reasonable and effective approach for the treatment of RA. Herein, inspired by glycopeptides, a peptide-decorated hyaluronic acid was synthesized, and the grafted Fmoc-phenylalanine-phenylalanine-COOH (FmocFF) peptide self-assembled with β-sheet conformations could induce the folding of polymer molecular chains to form a vesicle structure in aqueous solution. The hydrophobic anti-inflammatory drug curcumin (Cur) could be embedded in the vesicle walls through π-π interactions with the FmocFF peptide. Furthermore, the inflammation suppression function of the Cur-loaded vesicles both in vitro and in vivo was demonstrated to be an effective treatment for RA therapy. This work proposes new insights into the folding and hierarchical assembly of glycopeptide mimics, providing an efficient approach for constructing intelligent platforms for drug delivery, disease therapy, and diagnostic applications.

The Extracellular Matrix: Its Composition, Function, Remodeling, and Role in Tumorigenesis

The extracellular matrix (ECM) is a ubiquitous member of the body and is key to the maintenance of tissue and organ integrity. Initially thought to be a bystander in many cellular processes, the extracellular matrix has been shown to have diverse components that regulate and activate many cellular processes and ultimately influence cell phenotype. Importantly, the ECM's composition, architecture, and stiffness/elasticity influence cellular phenotypes. Under normal conditions and during development, the synthesized ECM constantly undergoes degradation and remodeling processes via the action of matrix proteases that maintain tissue homeostasis. In many pathological conditions including fibrosis and cancer, ECM synthesis, remodeling, and degradation is dysregulated, causing its integrity to be altered. Both physical and chemical cues from the ECM are sensed via receptors including integrins and play key roles in driving cellular proliferation and differentiation and in the progression of various diseases such as cancers. Advances in 'omics' technologies have seen an increase in studies focusing on bidirectional cell-matrix interactions, and here, we highlight the emerging knowledge on the role played by the ECM during normal development and in pathological conditions. This review summarizes current ECM-targeted therapies that can modify ECM tumors to overcome drug resistance and better cancer treatment.

4-Methylumbeliferone Treatment at a Dose of 1.2 g/kg/Day Is Safe for Long-Term Usage in Rats

4-methylumbelliferone (4MU) has been suggested as a potential therapeutic agent for a wide range of neurological diseases. The current study aimed to evaluate the physiological changes and potential side effects after 10 weeks of 4MU treatment at a dose of 1.2 g/kg/day in healthy rats, and after 2 months of a wash-out period. Our findings revealed downregulation of hyaluronan (HA) and chondroitin sulphate proteoglycans throughout the body, significantly increased bile acids in blood samples in weeks 4 and 7 of the 4MU treatment, as well as increased blood sugars and proteins a few weeks after 4MU administration, and significantly increased interleukins IL10, IL12p70 and IFN gamma after 10 weeks of 4MU treatment. These effects, however, were reversed and no significant difference was observed between control treated and 4MU-treated animals after a 9-week wash-out period.

Improvements in Human Keratinocytes and Antimicrobial Effect Mediated by Cell-Free Supernatants Derived from Probiotics

The skin acts as a physical and physiological barrier, thereby protecting the body from various environmental components and stimuli. Cell-free supernatants (CFS) derived from probiotics can improve skin functions and retain moisture. In this study, to assess the efficacy of CFS derived from Ligilactobacillus salivarius and Limosilactobacillus fermentum, we investigated the barrier strengthening and moisturizing effects of CFS in keratinocytes along with their antibacterial effects. We also determined the adhesive effects of probiotics on colorectal cells. To confirm improvements in moisturization and barrier function mediated by CFS in keratinocytes, hyaluronic acid (HA) production, and mRNA expression of HA synthases (HAS)2, HAS3, and FLG were measured. The results showed that CFS from L. salivarius MG242 and L. fermentum MG901 increased the expression of these genes along with the production of HA (2.40- and 1.95-fold of control). Additionally, CFS derived from L. salivarius MG242 and L. fermentum MG901 inhibited the growth of S. aureus and E. coli, thereby demonstrating inhibitory effects against harmful pathogens observed on the skin. These results indicate that the use of CFS derived from L. salivarius MG242 and L. fermentum MG901 may increase moisturization in the skin and improve barrier function of keratinocytes along with elimination of potential pathogens.

Hyaluronic Acid: Known for Almost a Century, but Still in Vogue

Hyaluronic acid (HA) has a special position among glycosaminoglycans. As a major component of the extracellular matrix (ECM). This simple, unbranched polysaccharide is involved in the regulation of various biological cell processes, whether under physiological conditions or in cases of cell damage. This review summarizes the history of this molecule's study, its distinctive metabolic pathway in the body, its unique properties, and current information regarding its interaction partners. Our main goal, however, is to intensively investigate whether this relatively simple polymer may find applications in protecting against ionizing radiation (IR) or for therapy in cases of radiation-induced damage. After exposure to IR, acute and belated damage develops in each tissue depending upon the dose received and the cellular composition of a given organ. A common feature of all organ damage is a distinct change in composition and structure of the ECM. In particular, the important role of HA was shown in lung tissue and the variability of this flexible molecule in the complex mechanism of radiation-induced lung injuries. Moreover, HA is also involved in intermediating cell behavior during morphogenesis and in tissue repair during inflammation, injury, and would healing. The possibility of using the HA polymer to affect or treat radiation tissue damage may point to the missing gaps in the responsible mechanisms in the onset of this disease. Therefore, in this article, we will also focus on obtaining answers from current knowledge and the results of studies as to whether hyaluronic acid can also find application in radiation science.

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

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

Advantages of Hyaluronic Acid and Its Combination with Other Bioactive Ingredients in Cosmeceuticals

This study proposes a review on hyaluronic acid (HA) known as hyaluronan or hyaluronate and its derivates and their application in cosmetic formulations. HA is a glycosaminoglycan constituted from two disaccharides (N-acetylglucosamine and D-glucuronic acid), isolated initially from the vitreous humour of the eye, and subsequently discovered in different tissues or fluids (especially in the articular cartilage and the synovial fluid). It is ubiquitous in vertebrates, including humans, and it is involved in diverse biological processes, such as cell differentiation, embryological development, inflammation, wound healing, etc. HA has many qualities that recommend it over other substances used in skin regeneration, with moisturizing and anti-ageing effects. HA molecular weight influences its penetration into the skin and its biological activity. Considering that, nowadays, hyaluronic acid has a wide use and a multitude of applications (in ophthalmology, arthrology, pneumology, rhinology, aesthetic medicine, oncology, nutrition, and cosmetics), the present study describes the main aspects related to its use in cosmetology. The biological effect of HA on the skin level and its potential adverse effects are discussed. Some available cosmetic products containing HA have been identified from the brand portfolio of most known manufacturers and their composition was evaluated. Further, additional biological effects due to the other active ingredients (plant extracts, vitamins, amino acids, peptides, proteins, saccharides, probiotics, etc.) are presented, as well as a description of their possible toxic effects.

Fluorescent nanodiamond - hyaluronate conjugates for target-specific molecular imaging

Despite wide investigation on molecular imaging contrast agents, there are still strong unmet medical needs to enhance their signal-to background ratio, brightness, photostability, and biocompatibility with multimodal imaging capability. Here, we assessed the feasibility of fluorescent nanodiamonds (FNDs) as carbon based photostable and biocompatible materials for molecular imaging applications. Because FNDs have negatively charged nitrogen vacancy (NV) centers, they can emit bright red light. FNDs were conjugated to hyaluronate (HA) for target-specific molecular imaging. HA is a biocompatible, biodegradable, and linear polysaccharide with abundant HA receptors in the liver, enabling liver targeted molecular imaging. In vitro cell viability tests revealed the biocompatibility of HA-FND conjugates and the competitive cellular uptake test confirmed their target-specific intracellular delivery to HepG2 cells with HA receptors. In addition, in vivo fluorescence lifetime (FLT) assessment revealed the imaging capability of FNDs and HA-FND conjugates. After that, we could confirm the statistically significant liver-targeted delivery of HA-FND conjugates by in vivo imaging system (IVIS) analysis and ex vivo biodistribution tests in various organs. The renal clearance test and histological analysis corroborated the in vivo biocompatibility and safety of HA-FND conjugates. All these results demonstrated the feasibility of HA-FND conjugates for further molecular imaging applications.

Bacterial exopolysaccharides: Chemical structures, gene clusters and genetic engineering

In recent decades, the composition, structure, biosynthesis, and function of bacterial extracellular polysaccharides (EPS) have been extensively studied. EPS are synthesized through different biosynthetic pathways. The genes responsible for EPS synthesis are usually clustered on the genome or large plasmids of bacteria. Generally, different EPS synthesis gene clusters direct the synthesis of EPS with different chemical structures and biological activities. A better understanding of the gene functions involved in EPS biosynthesis is critical for the production of EPS with special biological activities. Genetic engineering methods are usually used to study EPS synthesis related genes. This review organizes the available information on EPS, including their structures, synthesis of related genes, and highlights the research progress of modifying EPS gene clusters through gene-editing methods.

Use of Hyaluronic Acid (HA) in Chronic Airway Diseases

Hyaluronic acid (HA) is a key component of the extracellular matrix of the lungs. A unique attribute of HA is its water-retaining properties, so HA has a major role in the regulation of fluid balance in the lung interstitium. Hyaluronic acid has been widely used in the treatment of eyes, ears, joints and skin disorders, but in the last years, it has been also proposed in the treatment of certain lung diseases, including airway diseases, due to its anti-inflammatory and water-binding capacities. Hyaluronic acid aerosol decreases the severity of elastase-induced emphysema in murine models, prevents bronchoconstriction in asthmatics and improves some functional parameters in chronic obstructive pulmonary disease (COPD) patients. Due to the protection of HA against bronchoconstriction and its hydration properties, inhaled HA would increase the volume of airway surface liquid, resulting in mucus hydration, increased mucous transport and less mucous plugging of the airways. In addition, it has been seen in human studies that the treatment with nebulised HA improves the tolerability of nebulised hypertonic saline (even at 6% or 7% of concentration), which has been demonstrated to be an effective treatment in bronchial secretion management in patients with cystic fibrosis and bronchiectasis. Our objective is to review the role of HA treatment in the management of chronic airway diseases.

Biocompatibility of Materials for Biomedical Engineering

In the tissue engineering research field, nanobiomaterials highlight the impact of novel bioactive materials in both current applications and their potentials in future progress for tissue engineering and regenerative medicine. Tissue engineering is a well-investigated and challenging biomedical field, with promising perspectives to improve and support quality of life for the patient. To assess the response of those extracellular matrices (ECMs), induced by biomedical materials, this review will focus on cell response to natural biomaterials for biocompatibility.

Serum levels of hyaluronic acid are associated with COPD severity and predict survival

Hyaluronic acid (HA) and its degradation products play an important role in lung pathophysiology and airway remodelling in chronic obstructive pulmonary disease (COPD).We investigated if HA and its degrading enzyme hyaluronidase (HYAL)-1 are associated with COPD severity and outcome.Serum HA was assessed in a discovery cohort of 80 COPD patients at stable state and exacerbations. HA, HYAL-1 and HYAL-1 enzymatic activity were evaluated at stable state, exacerbations and 4 weeks after exacerbations in 638 COPD patients from the PROMISE validation cohort.In the discovery cohort, serum HA was higher at exacerbations compared with the stable state (p=0.015). In the validation cohort, HA was higher at moderate and severe exacerbations than at baseline (p<0.001), and remained higher after 4 weeks (p<0.001). HA was strongly predictive for overall survival since it was associated with time to death (p<0.001) independently of adjusted Charlson score, annual exacerbation rate and BODE (body mass, airflow obstruction, dyspnoea, exercise capacity) index. Serum HYAL-1 was increased at moderate (p=0.004) and severe (p=0.003) exacerbations, but decreased after 4 weeks (p<0.001). HYAL-1 enzymatic activity at stable state was inversely correlated with FEV₁ % pred (p=0.034) and survival time (p=0.017).Serum HA is associated with COPD severity and predicts overall survival. Degradation of HA is associated with airflow limitation and impairment of lung function.

Sample Delivery Media for Serial Crystallography

X-ray crystallographic methods can be used to visualize macromolecules at high resolution. This provides an understanding of molecular mechanisms and an insight into drug development and rational engineering of enzymes used in the industry. Although conventional synchrotron-based X-ray crystallography remains a powerful tool for understanding molecular function, it has experimental limitations, including radiation damage, cryogenic temperature, and static structural information. Serial femtosecond crystallography (SFX) using X-ray free electron laser (XFEL) and serial millisecond crystallography (SMX) using synchrotron X-ray have recently gained attention as research methods for visualizing macromolecules at room temperature without causing or reducing radiation damage, respectively. These techniques provide more biologically relevant structures than traditional X-ray crystallography at cryogenic temperatures using a single crystal. Serial femtosecond crystallography techniques visualize the dynamics of macromolecules through time-resolved experiments. In serial crystallography (SX), one of the most important aspects is the delivery of crystal samples efficiently, reliably, and continuously to an X-ray interaction point. A viscous delivery medium, such as a carrier matrix, dramatically reduces sample consumption, contributing to the success of SX experiments. This review discusses the preparation and criteria for the selection and development of a sample delivery medium and its application for SX.

Efficient Degradation of High-Molecular-Weight Hyaluronic Acid by a Combination of Ultrasound, Hydrogen Peroxide, and Copper Ion

Hyaluronic acid (HA) was depolymerized by a combination of ultrasound, hydrogen peroxide and copper ion. The structures of high-molecular-weight hyaluronic acid (HMW-HA) and low-molecular-weight hyaluronic acid (LMW-HA) were determined by Fourier transform infrared (FTIR) spectroscopy, circular dichroism (CD) spectroscopy, and UV-VIS absorption spectroscopy. The degradations of HMW-HA using a physical method, a chemical method, and a combination of physical and chemical method were compared. The results show that HA can be effectively degraded by a combinatorial method involving ultrasound, hydrogen peroxide, and copper ion. Under the degradation conditions of 50 mM H₂O₂, 5.0 μM CuCl₂, 160 W, pH 4.0, and reaction at 50 °C for 30 min, the content of glucuronic acid was 36.56%, and the yield of LMW-HA was 81.71%. The FTIR, CD, and UV-VIS absorption spectra of HA did not change with the decrease in molecular weight, indicating that the structure of HA remained intact during the degradation.

Combination of urea-crosslinked hyaluronic acid and sodium ascorbyl phosphate for the treatment of inflammatory lung diseases: An in vitro study

This in vitro study evaluated, for the first time, the safety and the biological activity of a novel urea-crosslinked hyaluronic acid component and sodium ascorbyl phosphate (HA-CL - SAP), singularly and/or in combination, intended for the treatment of inflammatory lung diseases. The aim was to understand if the combination HA-CL - SAP had an enhanced activity with respect to the combination native hyaluronic acid (HA) - SAP and the single SAP, HA and HA-CL components. Sample solutions displayed pH, osmolality and viscosity values suitable for lung delivery and showed to be not toxic on epithelial Calu-3 cells at the concentrations used in this study. The HA-CL - SAP displayed the most significant reduction in interleukin-6 (IL-6) and reactive oxygen species (ROS) levels, due to the combined action of HA-CL and SAP. Moreover, this combination showed improved cellular healing (wound closure) with respect to HA - SAP, SAP and HA, although at a lower rate than HA-CL alone. These preliminary results showed that the combination HA-CL - SAP could be suitable to reduce inflammation and oxidative stress in lung disorders like acute respiratory distress syndrome, asthma, emphysema and chronic obstructive pulmonary disease, where inflammation is prominent.

Instillation of hyaluronan reverses acid instillation injury to the mammalian blood gas barrier

Acid (HCl) aspiration during anesthesia may lead to acute lung injury. There is no effective therapy. We hypothesized that HCl instilled intratracheally in C57BL/6 mice results in the formation of low-molecular weight hyaluronan (L-HA), which activates RhoA and Rho kinase (ROCK), causing airway hyperresponsiveness (AHR) and increased permeability. Furthermore, instillation of high-molecular weight hyaluronan (H-HA; Yabro) will reverse lung injury. We instilled HCl in C57BL/6 wild-type (WT), myeloperoxidase gene-deficient (MPO^-/-) mice, and CD44 gene-deficient (CD44^-/-) mice. WT mice were also instilled intranasally with H-HA (Yabro) at 1 and 23 h post-HCl. All measurements were performed at 1, 5, or 24 h post-HCl. Instillation of HCl in WT but not in CD44^-/- resulted in increased inflammation, AHR, lung injury, and L-HA in the bronchoalveolar lavage fluid (BALF) 24 h post-HCl; L-HA levels and lung injury were significantly lower in HCl-instilled MPO^-/- mice. Isolated perfused lungs of HCl instilled WT but not of CD44^-/- mice had elevated values of the filtration coefficient ( K_f). Addition of L-HA on the apical surface of human primary bronchial epithelial cell monolayer decreased barrier resistance ( R_T). H-HA significantly mitigated inflammation, AHR, and pulmonary vascular leakage at 24 h after HCl instillation and mitigated the increase of K_f and R_T, as well as ROCK2 phosphorylation. Increased H- and L-HA levels were found in the BALF of mechanically ventilated patients but not in healthy volunteers. HCl instillation-induced lung injury is mediated by the L-HA-CD44-RhoA-ROCK2 signaling pathway, and H-HA is a potential novel therapeutic agent for acid aspiration-induced lung injury.

Efficient biomaterials for tissue engineering of female reproductive organs

Current investigations on the bioengineering of female reproductive tissues have created new hopes for the women suffering from reproductive organ failure including congenital anomaly of the female reproductive tract or serious injuries. There are many surgically restore forms that constitute congenital anomaly, however, to date, there is no treatment except surgical treatment of transplantation for patients who are suffering from anomaly or dysfunction organs like vagina and uterus. Restoring and maintaining the normal function of ovary and uterus require the establishment of biological substitutes that can cover the roles of structural support for cells and passage of secreting molecules. As in the case of constructing other functional organs, reproductive organ manufacturing also needs biological matrices which can provide an appropriate condition for attachment, growth, proliferation and signaling of various kinds of grafted cells. Among the organs, uterus needs special features such as plasticity due to their amazing changes in volume when they are in the state of pregnancy. Although numerous natural and synthetic biomaterials are still at the experimental stage, some biomaterials have already been evaluated their efficacy for the reconstruction of female reproductive tissues. In this review, all the biomaterials cited in recent literature that have ever been used and that have a potential for the tissue engineering of female reproductive organs were reviewed, especially focused on bioengineered ovary and uterus.

Long-term, feeder-free maintenance of human embryonic stem cells by mussel-inspired adhesive heparin and collagen type I

For practical applications of human embryonic stem cells (hESCs) in regenerative medicine, hESCs should be cultured on a large scale, and at the same time their properties have to be maintained in a controllable manner. Here, we report a chemically defined, scalable culture platform involving co-immobilization of heparin-catechol (HepC) and collagen type-1 (Col) for the long-term maintenance (>18 passages) of hESCs in a feeder-free condition. This platform utilizes a wet-adhesive, mussel-inspired heparin-catechol conjugate as a key component. We hypothesized that the heparin's affinity toward a wide range of proteins, might support undifferentiated in vitro growth of hESC. In fact, on the HepC-coated substrate, most hESC clumps were adhered (∼78% at passage 2 (P2)) and expressed pluripotency markers (Fig. 2). Although HepC alone wasn't able to support long-term maintenance of hESCs in a feeder-free system due to decrease in the adhesion rate of hESCs on HepC coating (∼ 44% at P4) during the repeated passaging processes, we found that when collagen type I was co-immobilized in the process of HepC coating, the long-term maintenance (passage 18 or more) of hESCs could be achieved with 100% adhesion efficiency (Fig. 4). One remarkable observation is that hESCs on collagen type-I underwent spontaneous differentiation after P6 (Fig. 3), which implied co-immobilized HepC played a role to suppress differentiation of hESCs. This study suggests that unlike the previous studies using proteins, peptides, or synthetic polymers, a polysaccharide, heparin, can be used as a cost-effective component for chemically defined, feeder-free culture of hESC.

STATEMENT OF SIGNIFICANCE

Towards practical applications of human embryonic stem cells (hESCs) in regenerative medicine, hESCs should be cultured on a large scale, and their pluripotent property has to be maintained in a controllable manner. To address these issues, studies that develop chemically defined culture substrates have been explored to replace the widely used, complex, and undefined culture materials represented by Matrigel. Most reports have focused on utilizing proteins, peptides and/or synthetic polymers. However, there have not yet been studies on using polysaccharides as two-dimensional coating materials to potentially replace Matrigel coating. Here, we report that heparin is an effective polysaccharide for the feeder-free, two dimensional culture of hESCs. Our study implies that use of polysaccharides or a polysaccharide/ECM combination can be a new, alternative design principle for hESC culture systems.

Characterisation of separated end hyaluronan oligosaccharides from leech hyaluronidase and evaluation of angiogenesis

Hyaluronan oligosaccharides (o-HAs), especially saturated o-HAs, have attracted intensive attention due to their potential applications in medical treatments. In this study, the hydrolysis process of leech hyaluronidase (LHase) towards the hyaluronan was investigated by HPLC and HPLC/ESI-MS. The proportions of hyaluronan tetrasaccharide (HA4) with hexasaccharide (HA6), end products, were illustrated to have a relationship with the amount of LHase. Higher yield of HA4 was achieved with higher activity of LHase. After optimisation of the packing resin and operation parameters (balanced pH, elution concentration, elution volume and elution flow rate), the highly pure HA4 and HA6 were efficiently separated and prepared by combining ion exchange Q-Sepharose Fast Flow and size exclusion column chromatography. Compared with o-HAs (average Mr of 4000 Da), HA4 and HA6 were demonstrated to show higher activity for promoting angiogenesis, which was similar with the corresponding HA4 and HA6 produced by bovine testicular hyaluronidase. The pure HA4 and HA6 that prepared from LHase will attract intensive studies and be used in potential applications in near future.

The role of hyaluronan in the pathobiology and treatment of respiratory disease

Hyaluronan, a ubiquitous naturally occurring glycosaminoglycan, is a major component of the extracellular matrix, where it participates in biological processes that include water homeostasis, cell-matrix signaling, tissue healing, inflammation, angiogenesis, and cell proliferation and migration. There are emerging data that hyaluronan and its degradation products have an important role in the pathobiology of the respiratory tract. We review the role of hyaluronan in respiratory diseases and present evidence from published literature and from clinical practice supporting hyaluronan as a novel treatment for respiratory diseases. Preliminary data show that aerosolized exogenous hyaluronan has beneficial activity against airway inflammation, protects against bronchial hyperreactivity and remodeling, and disrupts the biofilm associated with chronic infection. This suggests a role in airway diseases with a predominant inflammatory component such as rhinosinusitis, asthma, chronic obstructive pulmonary disease, cystic fibrosis, and primary ciliary dyskinesia. The potential for hyaluronan to complement conventional therapy will become clearer when data are available from controlled trials in larger patient populations.

Polysaccharide–porphyrin–fullerene supramolecular conjugates as photo-driven DNA cleavage reagents

Water-soluble polysaccharide–porphyrin–fullerene supramolecular conjugates were constructed, showing the capability of completely cleaving closed supercoiled DNA to nicked DNA.

Hollow hydroxyapatite/polyelectrolyte hybrid microparticles with controllable size, wall thickness and drug delivery properties

Hollow hydroxyapatite/polyelectrolyte microparticles with controllable size, wall thickness and drug delivery properties have been fabricated via the green hydrothermal method and the LbL self-assembly technique.

Current research on hyaluronic acid-drug bioconjugates

Hyaluronic acid (HA) is a mucopolysaccharide acid composed of repeating disaccharide units of D-glucuronic acid and N-acetyl-D-glucosamine. Based on numerous characteristics such as viscoelastic properties, water-binding ability, biocompatibility and non-immunogenicity, HA has been approved by FDA for biological and medical applications. In addition, multifarious receptors of HA like CD44, RHAMM and TSG6 are over-expressed on the surface of malignant cells, which play important roles in targeting ability. Bioconjugates linking drugs to HA could improve solubility, prolong half-life, provide active targeting capability and then increase the bioavailability of these coupled drugs by pro-drug strategy. Therefore, a large number of HA-drug bioconjugates have been studied. The purpose of this review was to summarize these HA-drug bioconjugates and further discuss synthetic methods and the relevant application in pharmaceuticals.

Involvement of hyaluronan synthesis in ovarian follicle growth in rats

Most of the previous studies on ovarian hyaluronan (HA) have focused on mature antral follicles or corpora lutea, but scarcely on small preantral follicles. Moreover, the origin of follicular HA is unknown. To clarify the localization of HA and its synthases in small growing follicles, involvement of HA in follicle growth, and gonadotropin regulation of HA synthase (Has) gene expression, in this study, perinatal, immature, and adult ovaries of Wistar-Imamichi rats were examined histologically and biochemically and byin vitrofollicle culture. HA was detected in the extracellular matrix of granulosa and theca cell layers of primary follicles and more advanced follicles. Ovarian HA accumulation ontogenetically started in the sex cords of perinatal rats, and its primary site shifted to the intrafollicular region of primary follicles within 5 days of birth. TheHas1–3mRNAs were expressed in the ovaries of perinatal, prepubertal, and adult rats, and the expression levels ofHas1andHas2genes were modulated during the estrous cycle in adult rats and following administration of exogenous gonadotropins in immature acyclic rats. TheHas1andHas2mRNAs were predominantly localized in the theca and granulosa cell layers of growing follicles respectively. Treatments with chemicals known to reduce ovarian HA synthesis induced follicular atresia. More directly, the addition ofStreptomyceshyaluronidase, which specifically degrades HA, induced the arrest of follicle growth in anin vitroculture system. These results indicate that gonadotropin-regulated HA synthesis is involved in normal follicle growth.

Determination of sodium hyaluronate in pharmaceutical formulations by HPLC-UV

A liquid chromatography (HPLC) method with UV detection was developed for determination of sodium hyaluronate in pharmaceutical formulation. Sodium hyaluronate is a polymer of disaccharides, composed of d-glucuronic acid and d-N-acetylglucosamine, linked via alternating β-1, 4 and β-1, 3 glycosidic bonds. Being a polymer compound it lacks a UV absorbing chromophore. In the absence of a UV absorbing chromophore and highly polar nature of compound, the analysis becomes a major challenge. To overcome these problems a novel method for the determination of sodium hyaluronate was developed and validated based on size exclusion liquid chromatography (SEC) with UV detection. An isocratic mobile phase consisting of buffer 0.05 M potassium dihydrogen phosphate, pH adjusted to 7.0 using potassium hydroxide (10%) was used. Chromatography was carried out at 25 °C on a BioSep SEC S2000, 300 mm×7.8 mm column. The detection was carried out using variable wavelength UV-vis detector set at 205 nm. The compounds were eluted isocratically at a steady flow rate of 1.0 mL/min. Sodium hyaluronate retention time was about 4.9 min with an asymmetry factor of 1.93. A calibration curve was obtained from 1 to 38 g/mL (r>0.9998). Within-day % RSD was 1.0 and between-day % RSD was 1.10. Specificity/selectivity experiments revealed the absence of interference from excipients, recovery from spiked samples for sodium hyaluronate was 99-102. The developed method was applied to the determination of sodium hyaluronate in pharmaceutical drug substance and product.

Proteolytic activity from chicken intestine and pancreas: extraction, partial characterization and application for hyaluronic acid separation from chicken comb

BACKGROUND

The potential utilization of viscera and combs, by-products from the chicken-processing industry, was investigated. Chicken combs have been reported to consist of hyaluronic acid (HA) bound to protein. Thus proteases extracted from broiler viscera were applied to digest combs to separate HA, a high-value ingredient widely used in pharmaceutical and medical products.

RESULTS

The highest activity of crude protease extracted from chicken intestine and pancreas was 0.35 U mg(-1) enzyme at 60 °C and pH 7.5. pH stability of the enzyme was attained from pH 6 to 8, while its thermal stability declined from 30 to 50 °C, with complete activity loss occurring after 30 min at temperatures above 60 °C. Therefore the optimal conditions for broiler comb digestion by crude protease in this study were chosen as pH 7.5 and 50 °C. The results showed that the yield of crude enzyme-extracted HA was lower (P < 0.05) than that obtained by commercial papain digestion. Similar identity of extracted HA and HA standard was verified by cellulose acetate electrophoresis and Fourier transform infrared spectroscopy.

CONCLUSION

The crude enzyme extract from chicken intestine and pancreas had high proteolytic activity and could be used successfully to separate HA from broiler combs. The method provides an appropriate means to add value to poultry-processing waste.

Agarose and polyacrylamide gel electrophoresis methods for molecular mass analysis of 5- to 500-kDa hyaluronan

Agarose and polyacrylamide gel electrophoresis systems for the molecular mass-dependent separation of hyaluronan (HA) in the size range of approximately 5-500 kDa were investigated. For agarose-based systems, the suitability of different agarose types, agarose concentrations, and buffer systems was determined. Using chemoenzymatically synthesized HA standards of low polydispersity, the molecular mass range was determined for each gel composition over which the relationship between HA mobility and logarithm of the molecular mass was linear. Excellent linear calibration was obtained for HA molecular mass as low as approximately 9 kDa in agarose gels. For higher resolution separation, and for extension to molecular masses as low as approximately 5 kDa, gradient polyacrylamide gels were superior. Densitometric scanning of stained gels allowed analysis of the range of molecular masses present in a sample as well as calculation of weight-average and number-average values. The methods were validated for polydisperse HA samples with viscosity-average molecular masses of 112, 59, 37, and 22 kDa at sample loads of 0.5 μg (for polyacrylamide) to 2.5 μg (for agarose). Use of the methods for electrophoretic mobility shift assays was demonstrated for binding of the HA-binding region of aggrecan (recombinant human aggrecan G1-IGD-G2 domains) to a 150-kDa HA standard.

Long acting hyaluronate--exendin 4 conjugate for the treatment of type 2 diabetes

Despite clinical exploitation of exendin 4 for the treatment of type 2 diabetes, the significantly short half-life requiring twice a day injection has limited the wide applications. In this work, a protocol for the synthesis of long acting hyaluronate (HA) - exendin 4 conjugate was successfully developed using Michael addition chemistry between vinyl sulfone modified HA (HA-VS) and thiolated exendin 4. The exendin 4 content could be controlled in the range of 5-30 molecules per single HA chain with a bioconjugation efficiency higher than 90%. The conjugation of exendin 4 with HA resulted in about 20 times improved in vitro serum stability maintaining the hypoglycemic and gluco-regulatory bioactivities of exendin 4. HA - exendin 4 conjugates showed excellent glucose-lowering capabilities in type 2 db/db mice demonstrating protracted hypoglycemic effect up to 3 days after a single subcutaneous injection. Furthermore, insulin immunohistochemical analysis of islets in db/db mice confirmed the improved insulinotropic activity of HA - exendin 4 conjugates. The HA - exendin 4 conjugates will be investigated further as a twice a week injection dosage form for clinical applications.