Hyaluronic Acid Polymer Research Articles

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

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

MXene/polymer dot-decorated flexible sensor for cancer cell-responsive hydrogel with tunable elastic modulus, porosity, and conductivity

This study reports a facile strategy for cancer cell modulated mechanically and electronically tunable hydrogel based on MXene-immobilized hyaluronic acid polymer dot (M-PD). Elevated levels of reactive oxygen species (ROS), such as H2O2 in cancer cells cleave MXene owing to the oxygen-titanium affinity of Ti3C2Tx, altering the physico-mechanical, electrochemical, and fluorescence (FL) properties of the sensor. The H2O2-induced cleavage of M-PD in the hydrogel causes the quenched FL intensity by the Forster resonance energy transfer effect (FRET) to recover, alongside an increase in pore size, influencing shifts in hydrogen bonding and inducing viscoelastic changes in the flexible sensor. This caused physico-mechanical alterations in the sensor, modified the viscosity (G′ decreased by 98.7%), and enhanced the stretchability. Further, in vitro electrochemical impedance spectroscopy (EIS) highlighted the distinct results for cancer cells (B16F10: 8.10 kΩ, MDA-MB-231: 8.30 kΩ), and normal cells (CHO-K1: 3.40 kΩ), showcasing electrochemical differentiation between these cells. Additionally, the flexible M-PD hydrogel sensor exhibits high sensitivity, with detection limits of 2.58 cells/well (CHO-K1), 0.96 cells/well (B16F10), and 1.20 cells/well (MDA-MB-231). Finally, real-time cancer monitoring was achieved by integrating the M-PD hydrogel with a wireless setup on a smartphone.

Energy-based devices and hyaluronic acid filler, polymer filler, and threads: Cadaveric study.

The objective of this experiment was to investigate the thermal effects on hyaluronic acid fillers, PCL fillers, and PDO threads when exposed to controlled heat. This study aims to provide insights into how these materials respond to thermal energy, which is crucial for safe and effective cosmetic procedures involving combined modalities. Cadaveric tissue was utilized to simulate clinical conditions. Hyaluronic acid fillers were injected at approximately 1 mm and 5 mm thicknesses, with variations in G' value (high and low). PCL fillers were similarly injected in 1 mm and 5 mm thicknesses. PDO threads were also inserted. All materials were injected at a depth of 2 cm. A thermometer was used to measure heat penetration, and a multi-wavelength laser was applied to the tissue. The temperature was maintained at 60°C for 5 min to assess whether heat penetrated more than 3 cm in thickness. Observations were made regarding the heat distribution and any physical changes in the fillers and threads. In thick layers, heat accumulated above the PCL filler without penetrating deeper layers. In thin layers, heat penetration was observed. For the HA fillers, heat energy was not blocked, regardless of the G' value or thickness. For the threads, no significant heat blockage effect was observed. For all materials, no visual changes were detected in any of the materials due to temperature exposure. The findings suggest that the thickness and composition of fillers significantly influence heat penetration. Thick PCL fillers act as a thermal barrier, whereas thin PCL fillers allow deeper heat penetration. Hyaluronic acid fillers do not impede heat transfer, regardless of their physical properties. PDO threads do not exhibit any notable thermal resistance. These insights are essential for optimizing the safety and efficacy of combined filler and energy-based device treatments in esthetic medicine.

Remote Effect of Fascial Manipulation on Knee Pain: A Case Report

The study on the remote effect of fascial manipulation on knee pain presents a case report of a patient with knee pain who underwent a single session of fascial manipulation to reduce pain and improve daily activities. The report explains the anatomy of the knee joint and the potential causes of knee pain, including bony and soft tissue involvement. Fascial manipulation is a technique that involves applying mechanical force to areas of fascial dysfunction to stimulate the body’s natural inflammatory response. The therapy is based on applying physical friction to the densified connective tissue with an elbow or knuckle to raise the temperature and change the consistency of loose connective tissue rich in hyaluronic acid. The locations picked were proximal and distal to the problematic area, and no point was treated over the painful region, which is consistent with the notion of pain being caused by aberrant fascial tensions. Manipulation of the connective tissue is thought to cause mechanical stress and heat, resulting in less macromolecular crowding and defragmentation of the Hyaluronic Acid (HA) polymers and normalised fascial gliding across the connective tissue. Reduced discomfort and enhanced range of motion are two more regularly reported effects of Fascial Manipulation. The patient was urged to resume his everyday activities after each treatment session to favour typical physiological motions that would align collagen fibres along normal lines of force. The report concludes that fascial manipulation can be a beneficial technique for managing knee pain, and it can be complemented with exercises and stretches to improve outcomes.

Cancer intra and extracellular microenvironment-responsive electrical signal of touchable conductive hydrogel

A wireless-integrated tumor microenvironment-responsive sensor designed from diselenide-functionalized carbon dot (dsCD) and hyaluronic acid polymer dot (PD(HA)) loaded in a mineralized conductive hydrogel (dsCD-PD(HA) Hydrogel) for detecting cellular reactive oxygen species (ROS) and pH detection. The manufactured ROS/pH responsive conductive hydrogel efficiently differentiated between cancer cells and normal cells in response to cellular factors through changes in fluorescence, electrical and mechanical response. Tumor microenvironment acidity and high ROS concentrations caused fluorescence recovery via boronate ester and diselenide bond cleavage alongside a change in electrical resistivity from 78.9 kΩ (pH 7.4) to 38.8 kΩ (0.1 mM H2O2/pH 6.8) due to disintegration of molecular interaction in the sensor. In vitro electrochemical analysis revealed different ΔR/R0 bending profiles between cancer (26.2 % and 25.9 % for HeLa and PC-3, respectively) and normal cells (17.9 %), alongside the optical performance demonstrating higher regain of fluorescence of cancer cells (HeLa and PC-3) compared to the normal cells (CHO-K1). Additionally, the dsCD-PD(HA) Hydrogel demonstrated favorable biocompatibility and in vitro ROS scavenging, with selective targeting of cancer cells. A wireless sensing platform was developed by connecting the dsCD-PD(HA) Hydrogel sensor to a smartphone, showing a precise signal during detection via resistance or electro-mechanical signals.

Bile Acid-Targeted Hyaluronic Acid Nanoparticles for Enhanced Oral Absorption of Deferoxamine.

Patients with β-thalassemia and sickle cell disease often rely on blood transfusions which can lead to hemochromatosis and chronic oxidative stress in cells and tissues. Deferoxamine (DFO) is clinically approved to treat hemochromatosis but is suboptimal to patients due to its poor pharmacokinetics which requires long-term infusion regimens. Although the oral route is preferable, DFO has limited oral bioavailability. Studies have shown that hyaluronic acid (HA) and bile acid (BA) can enhance the oral absorption of poorly absorbed drugs. To improve upon the oral delivery of DFO, we report on the synthesis and characterization of HA (MW 15 kD) conjugated to two types of BA, deoxycholic acid (DOCA) and taurocholic acid (TCA), and DFO. The resulting seven polymeric conjugates all formed self-assembled nanoparticles. The degree of BA and DFO conjugation to the HA polymer was confirmed at each step through nuclear magnetic resonance, Fourier transform infrared spectroscopy, and UV-Vis spectroscopy. The best formulations for further in vitro testing were determined based on physicochemical characterizations and included HA-DFO, TCA9-HA-DFO, and DOCA9-HA-DFO. Results from in vitro assays revealed that TCA9-HA-DFO enhanced the permeation of DFO the most and was also less cytotoxic to cells compared to the free drug DFO. In addition, ferritin reduction studies indicated that the conjugation of DFO to TCA9-HA did not compromise its chelation efficiency at equivalent free DFO concentrations. This research provides supportive data for the idea that TCA conjugated to HA may enhance the oral absorption of DFO, improve its cytocompatibility, and maintain its iron chelation efficiency.

Granular Hydrogels Improve Myogenic Invasion and Repair after Volumetric Muscle Loss.

Skeletal muscle injuries including volumetric muscle loss (VML) lead to excessive tissue scarring and permanent functional disability. Despite its high prevalence, there is currently no effective treatment for VML. Bioengineering interventions such as biomaterials that fill the VML defect to support cell and tissue growth are a promising therapeutic strategy. However, traditional biomaterials developed for this purpose lack the pore features needed to support cell infiltration. The present study investigates for the first time, the impact of granular hydrogels on muscle repair - hypothesizing that their flowability will permit conformable filling of the defect site and their inherent porosity will support the invasion of native myogenic cells, leading to effective muscle repair. Small and large microparticle fragments are prepared from photocurable hyaluronic acid polymer via extrusion fragmentation and facile size sorting. In assembled granular hydrogels, particle size and degree of packing significantly influence pore features, rheological behavior, and injectability. Using a mouse model of VML, it is demonstrated that, in contrast to bulk hydrogels, granular hydrogels support early-stage (satellite cell invasion) and late-stage (myofiber regeneration) muscle repair processes. Together, these results highlight the promising potential of injectable and porous granular hydrogels in supporting endogenous repair after severe muscle injury.

FOXM1 Aptamer-Polyethylenimine Nanoplatform Coated With Hyaluronic Acid And AS1411 Aptamer For Dual-Targeted Delivery of Doxorubicin And Synergistic Treatment of Tumor Cells

The objective of this investigation was to develop a self-assembled, dual-functionalized delivery system that could effectively transport doxorubicin (DOX) to cancer cells through the use of AS1411 aptamer and hyaluronic acid polymer (HA). The ultimate goal is an improved targeting approach for more efficient treatment. The core of this system comprised polyethylenimine (PEI) and FOXM1 aptamer, which was coated by HA. Next, nucleolin targeting aptamers (AS1411) were loaded onto the nanocomplex. Afterward, DOX was added to Aptamers (Apts)-HA-PEI-FOXM1 NPs to create the DOX-AS1411-HA-PEI-FOXM1 NPs for better treatment of cancer cells. The cytotoxic effect of the nanocomplex on L929, 4T1, and A549 cells showed that cell mortality in target cancer cells (4T1 and A549) was considerably enhanced compared to nontarget cells (L929, normal cells). The findings from the flow cytometry analysis and fluorescence imaging demonstrated the cellular absorption of DOX-Apts-HA-PEI-FOXM1 NPs in target cells was significantly enhanced when compared to L929 cells. Furthermore, in vivo antitumor study exhibited that DOX-Apts-HA-PEI-FOXM1 NPs rendered specific tumor accumulation and increasing of the anti-tumor effects.

Clinical Safety and Efficacy Evaluation of a Dissolving Microneedle Patch Having Dual Anti-Wrinkle Effects With Safe and Long-Term Activities.

Anti-aging products are widely used, but the desire for safe and more efficient anti-aging products continues to increase. Dissolving microneedle patches (MNPs) have provided a more efficient transdermal drug delivery solution. MNP is a promising candidate for developing better anti-aging products. To develop a more efficient anti-aging MNP product, we fabricated a dual anti-wrinkle microneedle patch (named DA-MNP) using droplet extension (DEN®) technology and evaluated its skin puncture ability, safety, and efficacy through clinical studies. A DA-MNP comprising hyaluronic acid (HA) polymer backbone, acetyl octapeptide-3, and L-ascorbic acid 2-glucoside and sodium cyclic lysophosphatidic acid was fabricated using DEN® technology. Placebo MNPs comprising only HA were also fabricated. Twenty-four healthy subjects were enrolled in this comparative clinical study. The DA-MNP or placebo MNP was separately applied to the left and right eyes of subjects for overnight. Assessments, including wrinkle improvement, trans-epidermal water loss (TEWL), eye lifting and adverse effects were evaluated at each scheduled visit day for 28 days. The DA-MNP showed mechanical strength enough for puncturing the stratum corneum. Compared to placebo MNP group, the DA-MNP treated group showed an effective eye wrinkles improvement and better anti-aging of skin, with reduced TEWL, enhanced skin elasticity and lifting, and no adverse effects. The present study demonstrated that the fabricated DA-MNP exhibited fast acting on deep wrinkles and enhanced anti-aging efficacy, with no skin safety concern. Thus, this DA-MNP may serve as a new transdermal delivery solution for skin wrinkling and aging.

Pembentukan Hidroksikarbonat Apatit Oleh Pasta Injeksi Bioactive Glass Berbasis Silika Abu Ampas Tebu Dan Penambahan Karageenan Rumput Laut

Root caries is common in the elderly, usually detected late, involving enamel, cementum, and dentin below the cementoenamel junction (CEJ). Remineralisation is used to treat it when cavitation has not occurred. Bioactive glass triggers remineralisation by forming hydroxycarbonate apatite (HCA) at an early stage. Injectable paste preparations are needed to overcome these problems. The use of hyaluronic acid and carrageenan polymers supports the physical and mechanical properties of the paste preparation. The purpose this research to analyse the formation of HCA on the tooth root surface by administering bioactive glass (BAG) injection paste with the addition of seaweed carrageenan. This study was a laboratory experimental study with three research groups, namely treatment group 1 (BAG paste and hyaluronic acid), treatment 2 (BAG paste, hyaluronic acid and carrageenan), and control group (BAG without polymer). All groups were immersed in artificial saliva, incubated at 37oC for six days and then tested by Scanning Electron Microscope (SEM) to see the formation of HCA and FTIR. HCA was quantified by a scoring method according to predetermined score criteria. SEM showed HCA formation in both treatment groups, not the control group. There is HCA formation on the tooth surface by administering BAG injection paste with seaweed carrageenan.

Photothermally sensitive gold nanocage augments the antitumor efficiency of immune checkpoint blockade in immune "cold" tumors.

Immune checkpoint blockade (ICB) has revolutionized the therapy landscape of malignancy melanoma. However, the clinical benefits from this regimen remain limited, especially in tumors lacking infiltrated T cells (known as "cold" tumors). Nanoparticle-mediated photothermal therapy (PTT) has demonstrated improved outcomes in the ablation of solid tumors by inducing immunogenic cell death (ICD) and reshaping the tumor immune microenvironment. Therefore, the combination of PTT and ICB is a promising regimen for patients with "cold" tumors. A second near-infrared (NIR-II) light-activated gold nanocomposite AuNC@SiO2@HA with AuNC as a kernel, silica as shell, and hyaluronic acid (HA) polymer as a targeting molecule, was synthesized for PTT. The fabricated AuNC@SiO2@HA nanocomposites underwent various in vitro studies to characterize their physicochemical properties, light absorption spectra, photothermal conversion ability, cellular uptake ability, and bioactivities. The synergistic effect of AuNC@SiO2@HA-mediated PTT and anti-PD-1 immunotherapy was evaluated using a mouse model of immune "cold" melanoma. The tumor-infiltrating T cells were assessed by immunofluorescence staining and flow cytometry. Furthermore, the mechanism of AuNC@SiO2@HA-induced T-cell infiltration was investigated through immunochemistry staining of the ICD-related markers, including HSP70, CRT, and HMGB1. Finally, the safety of AuNC@SiO2@HA nanocomposites was evaluated in vivo. The AuNC@SiO2@HA nanocomposite with absorption covering 1064 nm was successfully synthesized. The nano-system can be effectively delivered into tumor cells, transform the optical energy into thermal energy upon laser irradiation, and induce tumor cell apoptosis in vitro. In an in vivo mouse melanoma model, AuNC@SiO2@HA nanocomposites significantly induced ICD and T-cell infiltration. The combination of AuNC@SiO2@HA and anti-PD-1 antibody synergistically inhibited tumor growth via stimulating robust T lymphocyte immune responses. The combination of AuNC@SiO2@HA-mediated PTT and anti-PD-1 immunotherapy proposed a neoteric strategy for oncotherapy, which efficiently convert the immune "cold" tumors into "hot" ones.

Computational Study of Complex Formation between Hyaluronan Polymers and Polyarginine Peptides at Various Ratios.

Hyaluronic acid, a naturally occurring carbohydrate biopolymer in human tissues, finds wide application in cosmetics, medicine, and material science. Its anionic properties play a crucial role in its interaction with positively charged macromolecules and ions. Among these macromolecules, positively charged arginine molecules or polyarginine peptides demonstrate potential in drug delivery when complexed with hyaluronan. This study aimed to compare and elucidate the results of both experimental and computational investigations on the interactions between hyaluronic acid polymers and polyarginine peptides. Experimental findings revealed that by varying the length of polyarginine peptides and the molar ratio, it is possible to modulate the size, solubility, and stability of hyaluronan-arginine particles. To further explore these interactions, molecular dynamics simulations were conducted to model the complexes formed between hyaluronic acid polymers and arginine peptides. The simulations are considered in different molar ratios and lengths of polyarginine peptides. By analysis of the data, we successfully determined the shape and size of the resulting complexes. Additionally, we identified the primary driving forces behind complex formation and explained the observed variations in peptide interactions with hyaluronan.

"Smart" Matrix Microneedle Patch Made of Self-Crosslinkable and Multifunctional Polymers for Delivering Insulin On-Demand.

A transdermal patch that delivers insulin at high glucose concentrations can offer tremendous advantages to ease the concern of safety and improve the quality of life for people with diabetes. Herein, a novel self-crosslinkable and glucose-responsive polymer-based microneedle patch (MN) is designed to deliver insulin at hyperglycemia. The microneedle patch is made of hyaluronic acid polymers functionalized with dopamine and 4-amino-3-fluorophenylboronic acid (AFBA) that can be quickly crosslinked upon mixing of the polymer solutions in the absence of any chemicalcrosslinking agents or organic solvents. The catechol groups in the dopamine (DA) units form covalent crosslinkages among themselves by auto-oxidation and dynamic crosslink with phenylboronic acid (PBA)via complexation. The reversible crosslinkages between catechol and boronate decrease with increasing glucose concentration leading to higher swelling and faster insulin release at hyperglycemia as compared to euglycemia. Such superior glucose-responsive properties are demonstrated by in vitro analyses and in vivo efficacy studies. The hydrogel polymers also preserve native structure and bioactivity of insulin, attributable to the interaction of hyaluronic acid (HA) with insulin molecules, as revealed by experiments and molecular dynamics simulations. The simplicity in the design and fabrication process, and glucose-responsiveness in insulin delivery impart the matrix microneedle (mMN) patch great potential for clinical translation.

DMTMM-mediated synthesis of norbornene-modified hyaluronic acid polymers to probe cell-hydrogel interactions

Synthesis of chemically modified hyaluronic acid (HA) polymers has enabled the fabrication of hydrogels, such as norbornene-modified HA (NorHA) hydrogels that can provide tunable mechanical properties. However, current protocols for the synthesis of NorHA polymers rely on the use of dimethyl sulfoxide (DMSO), a solvent that is cost-intensive and requires extensive dialysis to be removed. To address this limitation, we developed an organic solvent-free NorHA synthesis protocol based on the triazine derivative 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride (DMTMM) which enables control over the degree of substituted norbornene groups and hydrogel mechanical properties. Our study further demonstrates the incorporation of enzymatically degradable crosslinkers to fabricate NorHA hydrogels as an in vitro platform to tune cell spreading and nascent protein deposition towards their use in tissue engineering and regenerative medicine.

A multifunctional nanoaggregate‐based system for detection of rheumatoid arthritis via Optoacoustic/NIR‐II fluorescent imaging and therapy via inhibiting JAK‐STAT/NF‐κB/NLRP3 pathways

AbstractRheumatoid arthritis (RA) is a debilitating autoimmune disease that causes chronic pain and serious complications, presenting a significant challenge to treat. Promising approaches for treating RA involve signaling pathways modulation and targeted therapy. To this end, a multifunctional nanosystem, TPC‐U@HAT, has been designed for RA therapy, featuring multitargeting, dual‐stimuli response, and on‐demand drug release capabilities. TPC‐U@HAT is composed of a probe/prodrug TPC, a JAK1 kinase inhibitor upadacitinib, and the drug carrier HAT. TPC is composed of an aggregation‐induced emission (AIE)‐active NIR‐II chromophore TPY and an NF‐κB/NLRP3 inhibitor caffeic acid phenethyl ester (CAPE), connected via boronic ester bond which serves as the reactive‐oxygen‐species‐responsive linker. The carrier, HAT, is created by grafting bone‐targeting alendronate and hydrophobic tocopheryl succinate onto hyaluronic acid chains, which can encapsulate TPC and upadacitinib to form TPC‐U@HAT. Upon intravenous injection into mice, TPC‐U@HAT accumulates at inflamed lesions of RA through both active and passive targeting, and the overexpressed hyaluronidase and H2O2 therein cleave the hyaluronic acid polymer chains and boronate bonds, respectively. This generates an AIE‐active chromophore for detection and therapeutic evaluation of RA via both optoacoustic imaging and NIR‐II fluorescent imaging and concomitantly releases CAPE and upadacitinib to exert efficacious therapy by inhibiting NF‐κB/NLRP3 and JAK‐STAT pathways.

The effect of manipulating glucuronic acid biosynthetic pathway in Bacillus subtilis strain on hyaluronic acid production

Hyaluronic acid (HA), composed of glucuronic acid (GlcUA) and N-acetyl glucoseamine (GlcNAc), is a versatile biopolymer with high commercial value and innumerous physiological roles and pharmaceutical applications. The hasA gene has main role in HA biosynthesis by Streptococcus strain as a natural producer. The hasB and hasC genes are also mediate GlcUA precursor biosynthesis. In the present study, S. equisimilis hasA gene; B. subtilis tuaD and gtaB genes for GlcUA precursors enhancement, and vgb gene coding bacterial hemoglobin as an oxygen provider were used to construct the B. subtilis strain for HA production. RBSHA (hasA), RBSHA2 (hasA/tuaD/gtaB), and RBSHA3 (hasA/tuaD/gtaB/vgb) strains were developed and confirmed through genotype and phenotype analysis. After HA production and purification, FTIR spectroscopy confirmed the produced HA structures. HA assay showed the highest HA titer for RBSHA3 (2.1 ± 0.18 mg/ml) and then RBSHA2 (1.9 ± 0.03 mg/ml), and RBSHA (0.6 ± 0.14 mg/ml). Statistical analysis indicated there is no significant difference in HA titer between RBSHA2 and RBSHA3 strains (p-value > 0.05), however, these strains produced HA approximately 4-fold higher than that of RBSHA strain. Agarose gel electrophoresis showed the same molecular weight (< 30 kDa) of produced HA by strains. Dynamic light scattering (DLS) revealed all HA polymers had a relatively low polydispersity index (PDI < 0.5). These findings demonstrate the successful GlcUA biosynthetic pathway engineering strategy in improving HA yield by recombinant B. subtilis, metabolically-robust, and industrially potential strain.

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

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

Delivery of quercetin for breast cancer and targeting potentiation via hyaluronic nano-micelles

Quercetin (QT) is a very effective anticancer drug in combating breast cancer. However, it has several disadvantages such as poor water solubility, low bioavailability and low targeting, which seriously restrict its clinical application. In this work, amphiphilic hyaluronic acid polymers (dHAD) were synthesized by grafting dodecylamine to hyaluronic acid (HA). The dHAD self-assembles with QT to form drug-carrying micelles (dHAD-QT). The dHAD-QT micelles possessed excellent drug-loading capacities (75.9 %) for QT and showed significantly improved CD44 targeting compared with unmodified HA. dHAD-QT micelles exhibited high cytotoxicity and apoptosis-inducing abilities, which were ascribed to the pH-sensitive dHAD-QT micelles accomplishing rapid drug release of QT under low pH condition. Importantly, in vivo experiments showed that dHAD-QT effectively inhibited tumor growth in tumor-bearing mice, with a tumor inhibition rate of 91.8 %. Furthermore, dHAD-QT prolonged the survival time of tumor-bearing mice and reduced the toxicity of the drug to normal tissues. These findings indicate that the designed dHAD-QT micelles have promising potential as efficient nano-drugs for breast cancer treatment.

PH-responsive Sulfated Hyaluronic Acid Nanoparticles Targeting Tumor Cells and CAFs for the Treatment of Breast Cancer.

Tumor metastasis is a main cause of death in patients with breast cancer. The cross-talk between cancer-associated fibroblasts (CAFs) and tumor cells plays an important role in promoting tumor invasion and metastasis. It is important to develop a novel delivery system to inhibit tumor development by simultaneously targeting both CAFs and tumor cells. The main objective of this research was to prepare nanoparticles to inhibit tumor proliferation and migration by blocking the cross-talk of tumor-CAFs. Additionally, a novel "MCF- 7+NIH/3T3" mixed cell model was established to mimic the tumor microenvironment (TME). In this study, the pH-responsive nanoparticles (MIF/DOX-sul-HA NPs) based on sulfated hyaluronic acid (sul-HA) polymers were prepared for co-delivery of doxorubicin (DOX) and mifepristone (MIF). The effects of anti-proliferation and anti-metastasis of MIF/DOX-sul-HA NPs were investigated both in vitro and in vivo. The results showed that MIF/DOX-sul-HA NPs were nearly spherical in shape with narrow particle size distribution and pH-responsive drug release, and could be taken up by both MCF-7 and NIH/3T3 cells. Compared with MCF-7 cells alone, the anti-tumor effect of single DOX was weak in the "MCF-7+NIH/3T3" mixed cell model. MIF/DOX-sul-HA NPs exhibited strong effects of anti-proliferation and anti-metastasis than the free single drug. The sul-HA nanoparticles for co-delivery of DOX and MIF could be a promising combined therapy strategy for the treatment of breast cancer.

Design and characterization of adipose-derived mesenchymal stem cell loaded alginate/pullulan/hyaluronic acid hydrogel scaffold for wound healing applications

Recently, significant attention has been focused on the progression of skin equivalents to facilitate faster wound healing and thereby skin restoration. The main aim of this study was the design and characterization of a novel polysaccharide-based hydrogel scaffold by using alginate, pullulan, and hyaluronic acid polymers to provide an appropriate microenvironment to deliver Adipose-derived mesenchymal Stem Cells (ASC) in order to promote wound healing in an animal model. Characterization of synthesized hydrogel was done by using a field emission scanning electron microscope (FE-SEM), Fourier Transform-Infrared spectroscopy (FT-IR), and Differential Scanning Calorimetry (DSC). Also, contact angle analysis, the swelling and mechanical tests were performed. As a result of in vitro studies, cells can be attached, alive, and migrate through the prepared hydrogel scaffold. Finally, the therapeutic effect of the cell-seeded hydrogels was tested in the full-thickness animal wound model. Based on obtained results, the hydrogel-ASC treatment improved the healing process and accelerated wound closure.