Hyaluronic Acid Solution Research Articles

Crosslinking by Click Chemistry of Hyaluronan Graft Copolymers Involving Resorcinol-Based Cinnamate Derivatives Leading to Gel-like Materials.

The well-known "click chemistry" reaction copper(I)-catalyzed azide-alkyne 1,3-dipolar cycloaddition (CuAAC) was used to transform under very mild conditions hyaluronan-based graft copolymers HA(270)-FA-Pg into the crosslinked derivatives HA(270)-FA-TEGERA-CL and HA(270)-FA-HEGERA-CL. In particular, medium molecular weight (i.e., 270 kDa) hyaluronic acid (HA) grafted at various extents (i.e., 10, 20, and 40%) with fluorogenic ferulic acid (FA) residue bonding propargyl groups were used in the CuAAC reaction with novel azido-terminated crosslinking agents Tri(Ethylene Glycol) Ethyl Resorcinol Acrylate (TEGERA) and Hexa(Ethylene Glycol) Ethyl Resorcinol Acrylate (HEGERA). The resulting HA(270)-FA-TEGERA-CL and HA(270)-FA-HEGERA-CL materials were characterized from the point of view of their structure by performing NMR studies. Moreover, the swelling behavior and rheological features were assessed employing TGA and DSC analysis to evaluate the potential gel-like properties of the resulting crosslinked materials. Despite the 3D crosslinked structure, HA(270)-FA-TEGERA-CL and HA(270)-FA-HEGERA-CL frameworks showed adequate swelling performance, the required shear thinning behavior, and coefficient of friction values close to those of the main commercial HA solutions used as viscosupplements (i.e., 0.20 at 10 mm/s). Furthermore, the presence of a crosslinked structure guaranteed a longer residence time. Indeed, HA(270)-FA-TEGERA-CL-40 and HA(270)-FA-HEGERA-CL-40 after 48 h showed a four times greater enzymatic resistance than the commercial viscosupplements. Based on the promising obtained results, the crosslinked materials are proposed for their potential applicability as novel viscosupplements.

Hyaluronic acid act as drug self-assembly chaperone and co-assembled with celalstrol for ameliorating non-alcoholic steatohepatitis

Nanoformulations of therapeutic drugs with diverse chemical structures are often complex to produce and lack a universal synthesis approach. Herein, we demonstrate that hyaluronic acid (HA) can function as an assembly chaperone, facilitating the formulation of various chemical compounds into nanoparticles without necessitating chemical modification. As a proof of concept, celastrol-HA co-assembled nanoparticles (CHNPs) were synthesized and utilized in the multifactorial treatment of non-alcoholic steatohepatitis (NASH). By simply blending an aqueous solution of HA and celastrol, we achieved the formation of homogeneous, stable, and biocompatible nanoparticles, effectively addressing the critical issues associated with celastrol's poor water solubility and high systemic toxicity. of celastrol. Ex vivo and in vivo experiments demonstrated that CHNPs ameliorated NASH by inhibiting macrophage M1 polarization, reducing liver inflammation and lipid deposition, and improving metabolic disorders. Furthermore, CHNPs reduced systemic toxicity and enhanced the bioavailability of celastrol. The simplicity of the HA-based nanoparticles may facilitate the development of translational nanomedicines.

Effectiveness of a Local Drug Delivery System Based on Antimicrobial Peptides in Early Treatment of Peri-implantitis

ObjectiveTo analyse the effects of titanium implants coated with various antimicrobial peptide (AMP) layers on bacterial growth and early biofilm formation around the implants. MethodsA novel AMP mixture was constructed using Type I collagen, sulfonated succinimide 4- (N-Maleimidylphenyl) butyrate, and AMPs. Titanium discs treated with chitosan and hyaluronic acid solutions were reacted with the AMP mixture to obtain AMP-coated titanium discs. The drug release properties and inhibitory effects on the growth and early biofilm formation of Porphyromonasgingivalis (P. gingivalis) ATCC BAA-308 or Staphylococcus aureus (S. aureus) ATCC 25923 were analysed. ResultsThe antimicrobial activity of the 9-layer AMP-coated titanium discs against P. gingivalis ATCC BAA-308 and S.aureus ATCC 25923 was greatly higher relative to the 3-layer and 6-layer AMP-coated titanium discs (P < .05). The overall optical density and average optical density of titanium discs coated with 6 and 9 layers of AMPs were markedly inferior to those of uncoated titanium discs and discs coated with 3 layers of AMPs (P < .05). The drug release amounts from titanium discs coated with different layers of AMPs increased over time. ConclusionsThe prepared AMP-coated titanium discs effectively inhibit the growth of P. gingivalis and S. aureus, as well as early biofilm formation. The drug-laced discs demonstrate good durability and predictability in drug release, which may be beneficial for long-term therapeutic adoption.

TARGETED TREATMENT OF CHRONIC CYSTITIS USING INTRAVESICAL INSTILLATION OF AN ENCAPSULATED FORM OF HYALURONIC ACID

Introduction. A new approach in the bladder diseases treatment is an intravesical instillation of drugs. However, the low therapeutic effectiveness and painfulness of the instillation procedure are significant limitations of this method. Often, therapy for chronic cystitis comes down to repeated drug instillation into the bladder, which can lead to irritation of the urethral canal and re-infection. Purpose of the study – an approach to the treatment of chronic cystitis by a combination of the local delivery  intravesical instillation, and advanced materials science technologies  emulsion microgels. Materials and methods. Hyaluronic acid (HA) was encapsulated in emulsion microgels based on whey protein isolate. To study the therapeutic effect, experimental animals were divided into 3 groups (5 pieces each): without therapy; with encapsulated HA therapy; with therapy of HA solution. Chronic cystitis modeling was carried out by intraperitoneal administration of a cyclophosphamide solution. For groups of the animals receiving therapy, intravesical instillation of HA in encapsulated and free forms was carried out four times on days 6, 10, 14 and 18 after the initiation of cystitis. The therapy effectiveness was assessed using classical histological analysis. Results. This work demonstrates the effectiveness of chronic cystitis therapy with hyaluronic acid immobilized in mucoadhesive carriers – emulsion microgels. Histological analysis confirmed a significant topical therapeutic effect in animals with intravesical administration of microgels with hyaluronic acid. Conclusions. The proposed strategy combines local delivery and the use of microcontainers containing a drug, which can be successfully used for local therapy of a wide range of bladder diseases.

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.

Comparative fluorophotometric evaluation of the ocular surface retention time of cross-linked and linear hyaluronic acid ocular eye drops on healthy dogs.

Evaluate and compare the retention time on the canine ocular surface of crosslinked hyaluronic acid (X-HA), linear hyaluronic acid (L-HA) and saline solution using fluorescent compounds (fluorescein sodium salt, Alexa Fluor 488 cadaverine and Alexa Fluor 488 maleimide). 0.9% saline solution (SAL) was combined with fluorescein sodium salt. X-HA and L-HA were covalently modified using Alexa Fluor 488 reactive moieties. Eye drops were applied to 70 eyes of 35 dogs that were previously assessed and determined to have a normal ocular surface. Employing a blue light filter (450-490nm), digital images were captured from instillation to 180min. Images were analyzed to assess the percent of the total ocular area covered with green fluorescence at various time points. X-HA exhibited a dual phase behavior: A broad microgel coverage first, followed by accumulation in tear film meniscus and medial canthus in the second phase, remaining in contact with the ocular surface up to 180min. Coverage with L-HA and SAL eye drops quickly migrated to the tear meniscus. No traces of the fluorescent compounds were observed by 45min in eyes treated with SAL solution compound and, by 120min, eyes treated with L-HA. X-HA exhibited a significantly increased ocular surface contact time with the ocular surface compared with L-HA and SAL. Not only could this indicate extended lubrication time but also supports the potential use of this compound as a method for topical sustained-release drug application.

Simvastatin-loaded gelatin-capped polycaprolactone nanoparticles for the post-operative management of breast cancer

Minimal residual disease at the tumor site after surgical ablation is a major cause for tumor recurrence and metastasis. The tropism of circulating tumor cells towards injured areas increases the risk of tumor recurrence. Recent studies have reported the inability of nanocarriers to penetrate the tumor site owing to short systemic half-life, high hydrostatic pressure, and inability to extravasate the tumor tissue. In this work, we developed simvastatin-loaded polycaprolactone - gelatin core-shell nanoparticles (SNP) for post-surgical management of breast cancer (BC). NP-loaded within the hyaluronic acid solution demonstrated shear thinning behavior (n = 0.3089). SNP demonstrated cytotoxic potential in the 2-D cell culture and 3-D tumoroids of MDA-MB-231 cell line in vitro. JC-1 and rhodamine-123 based assays demonstrated the ability of SNP to induce mitochondrial membrane damage. Further, cell cycle analysis revealed that the SNP prevented the progression of cell line from G0/G1 to S-phase. Simvastatin and SNP induced early apoptosis in the MDA-MB-231 cell line. Scratch, invasion, migration, and clonogenic assays demonstrated the ability of SNP to prevent cell invasion and clonal expansion. Immunocytochemistry revealed that both SIM and SNP reduced the expression of anti-apoptotic protein BCL-2 in metastatic cell line. Overall, the developed formulation demonstrates enormous potential for the post-surgery management of BC.

Experience with the use of hyaluronic acid solution (Diart) in the treatment of patients with degenerative-dystrophic diseases of the hip joint

Background. Degenerative-dystrophic diseases of the joints are chronic progressive pathological conditions, accompanied by such features as presence of pain syndrome, impaired functional capacity, muscle weakness, deformation and instability of the joints. The high prevalence of degenerative-dystrophic diseases of the hip joint necessitates the search for optimal non-invasive treatment methods. Objectives. This study aims to analyze the clinical results of intra-articular injections of hyaluronic acid solution (Diart) in the treatment of patients with II–III stages of degenerative-dystrophic diseases of the hip joint. Materials and methods. The clinical results of 30 patients with II–III stages of degenerative-dystrophic diseases of the hip joint were analyzed. The group included 11 (36.67%) males and 19 (63.33%) females. The mean age of group was 61.43±7.98 years. All patients underwent a course of drug therapy using hyaluronic acid solution (Diart), which included 3 intra-articular injections of the drug, which were performed with the 7-day interval. Clinical results were evaluated at the initial visit, at 7, 14, 30 and 90 days after the first injection of Diart by objective examination of patients and analysis of subjective data using the WOMAC questionnaire. Statistical analysis was performed using Statistica 13 software package. Results. The high effectiveness of intra-articular injections of hyaluronic acid (Diart) in the treatment of patients with II-III stages of degenerative-dystrophic diseases of the hip joint and the absence of complications associated with intra-articular injection of the drug have been established. Signs of post-injection sy- novitis, discomfort, swelling or other unpleasant sensations weren’t observed in any of the examined patients. Comparing the results established during remote period, on the 90th day of observation, and indicators determined at the initial visit, we proved a decrease in the intensity of the pain syndrome in the hip joint by 30.35%, in stiffness — by 29.57%, an improvement in the indicators characterizing the functional capacity by 21.34 % and the total values of the WOMAC index — by 27.37%, after a treatment course using Diart. Conclusion. The high efficiency of using intra-articular injections of hyaluronic acid solution (Diart) in the treatment of patients with II–III stages of degen- erative-dystrophic diseases of the hip joint has been proven.

Effect of hyaluronic acid-based viscosupplementation on cartilage material properties

Viscosupplementation by intra-articular injections of hyaluronic acid (HA) is used to treat symptomatic osteoarthritis. Exogenous HA remains in the joint cavity for a short period of time (days) while claimed pain relief period lasts over months. There is a clear lack of understanding of viscosupplementation mechanism of action. Here, we hypothesize that HA penetrates the cartilage and contributes to the restoration of its mechanical quality.Confocal microscopy and bio-indentation were used to confirm HA penetration into cartilage and modulation of cartilage quality. Bio-indentation was performed on rat distal femurs incubated overnight in HA solutions, using phosphate buffered saline (PBS) as control. For this proof-of-concept evaluation, measurements of elastic modulus (MPa) and of maximal force (µN) were recorded before and immediately after exposure with HA, as well as after an additional washout with PBS. Cartilage thickness at the site of indentation was evaluated by contrast enhanced computed tomography with an ionic contrast agent. Indentation depths were located in the upper part of hyaline cartilage. Ostenil®, commercial product containing 1 % HA, induced a decrease in indentation depth in the range of forces influencing the whole cartilage thickness, together with an increase of the elastic modulus. Then, bio-indentation and size distribution of HA chains via SEC-SLS were assessed for a range of commercially available products. The results showed higher modulation of cartilage quality in the presence of 0.25–1 MDa HA chains.The present in vitro study suggests that HA modulates cartilage quality and might thus explain the long-term beneficial effect of viscosupplementation.

Identification of hyaluronic acid in seized samples by Hypercarb chromatography-high resolution mass spectrometry.

Hyaluronic acid (HA) has been commonly used to treat osteoarthritis and joint injuries in horses and dogs since the 1970s. HA is a polysaccharide made up of alternating N-acetyl-d-glucosamine and d-glucuronic acid residues, with polymeric molecules achieving molecular weights as high as 20 MDa. High molecular weight HA forms a viscous hydrogel when dissolved in water, making HA solutions distinct from most other pharmaceutical preparations. Clear viscous solutions are often encountered during stable and kennel inspections, but in the absence of an analytical method, it is not possible to identify if these substances contain HA or other unknown compounds. This paper presents a simple method for the identification of HA in seized materials based on chemical hydrolysis followed by Hypercarb chromatography and MS/MS analysis.

P-195 Euploid embryo transfer in a hyaluronic acid-enriched media results in a higher ongoing pregnancy rate than euploid embryo transfer in media not containing hyaluronic acid

Abstract Study question Will using a hyaluronan-rich transfer medium increase the ongoing pregnancy rate and live birth rate when transferring euploid embryos cultivated in a dry incubator? Summary answer Transferring euploid embryos in a media with high concentrations of hyaluronic acid increases the ongoing pregnancy rate compared with media with no hyaluronic acid. What is known already Cochrane Review found that solutions with high concentrations of hyaluronic acid increase the chance of live birth by adding probably 1 additional live birth for every 14 embryos transferred in a high-concentration hyaluronic acid solution for patients aged 27 to 35. A study involving 85 frozen embryo transfer cycles showed a positive effect of high concentrations of hyaluronic acid on the results of transfer of morphologically poor euploid blastocysts. Previous studies were conducted in humidified incubators where hyaluronic acid-rich media was equilibrated without oil overlay. Our clinic uses dry incubators, necessitating oil overlay with all media, including hyaluronic acid-rich media. Study design, size, duration A randomized prospective study involving 255 patients aged 19-44 undergoing a transfer of a single euploid embryo between June 2023 and November 2023. Patients were randomly assigned to the study and control groups. Blastocysts were incubated after thawing for 3 hours either in a hyaluronic acid-enriched medium or in a medium without hyaluronic acid. Participants/materials, setting, methods Embryos underwent PGT-A at the blastocyst stage on either day 5 or day 6, using the EmbryoMap method. Trophectoderm biopsy was performed using the Flicking technique without a laser. 5-7 cells were removed for analysis. Blastocysts were vitrified following biopsy. Hyaluronic acid-enriched media was equilibrated for 16-18 hours in a 5%O2 6%CO2 atmosphere in a well of 4-well culture dish under oil overlay (600 microliters of media and 500 microliters of oil). Main results and the role of chance In this ongoing study, 127 transfers of euploid blastocysts in a hyaluronic acid-rich media resulted in 70 ongoing pregnancies, with a 55.1% ongoing pregnancy rate. In comparison, 128 transfers of euploid blastocysts in a media with no hyaluronic acid resulted in 65 ongoing pregnancies, with a 50.8% ongoing pregnancy rate. The relative improvement in the ongoing pregnancy rate is 8.5%. Our data suggests that using a hyaluronic acid-rich medium for the transfer of euploid blastocysts of good morphology can improve clinical pregnancy rates, although the effect is less dramatic than was shown in a 2023 study by Nakagawa et al. for morphologically poor euploid blastocysts, where more than twofold increase in clinical pregnancy rates was detected. Limitations, reasons for caution Specific media equilibration protocol is required for the incubation and transfer of embryos in a hyaluronan-rich transfer medium for IVF clinics utilizing dry incubators. Further research is required to confirm results and to establish whether transferring embryos in hyaluronic acid-enriched media increases the live birth rate after euploid embryo transfer. Wider implications of the findings Our results show that it is feasible to use a hyaluronic acid-enriched medium in a dry incubator with an oil overlay and that using it according to described protocol could increase the ongoing pregnancy rate after a single euploid blastocyst transfer. Trial registration number not applicable

Intravesical Instillation of Hyaluronic Acid With Epidermal Growth Factor for Restoring Urothelial Denudation and Alleviating Oxidative Stress in Lipopolysaccharide-Induced Interstitial Cystitis of Rats.

To investigate the efficacy of an intravesical instillation of hyaluronic acid (HA) combined with epidermal growth factor (EGF) for the treatment of interstitial cystitis (IC) using a lipopolysaccharide (LPS)-induced IC animal model. A total of 24 female Sprague-Dawley rats were randomized to 4 groups: sham control, IC, HA, and treatment (HA/ EGF) groups. A polyethylene-50 tube was placed inside the bladder of each animal. IC was induced by twice-weekly instillations of LPS for 3 weeks, which resulted in chronic injury of the urothelium. Animals in the sham control group only received saline instillation. Treatment solutions of HA and HA/EGF were given on days 0, 7, and 14 after IC induction (400 μL of HA in a concentration of 0.4 mg/0.5 mL and 400 μL of NewEpi, a commercialized HA/EGF mixture containing 2 μg of EGF and 0.4 mg of sodium hyaluronate). Animals were sacrificed on day 21 for further examinations. The HA/EGF group showed visible improvement in hematuria with a significant reduction of red blood cells in the urine compared to the HA group. Histological examination revealed that HA/EGF treatment reversed the abnormalities developed in IC, including infiltration of inflammatory cells, irregular re-epithelialization, and fibrotic tissue. Moreover, HA/ EGF significantly reduced the levels of proinflammation cytokines (tumor necrosis factor-α, interleukin [IL]-6, and IL-1β) and substantially lowered the elevated oxidative stress biomarker malondialdehyde, yet restored the levels of antioxidant enzymes glutathione peroxidase and superoxide dismutase, with superior results than HA treatment. Cystometry studies indicated that HA/EGF significantly prolonged intercontraction interval and increased micturition volume. HA/EGF has been demonstrated as a more effective treatment for enhancing the urothelium lining and reducing inflammatory changes to alleviate clinical symptoms associated with IC in rats, compared to HA alone.

Preparation and Physicochemical Evaluation of Eye Drop Formulation Based on Hyaluronic Acid and Vitamin B12

Background Dry eye disease is a common age-related disease in the world. Vitamin B12 is an essential factor in maintaining eye health and has antioxidant properties that protect the surface of the eye from damage caused by harmful factors, such as reactive oxygen species. Hyaluronic acid polymer is also similar to natural eye tears with its biocompatibility and physical properties. This polymer is one of the important components of the extracellular matrix. Objective Due to the lack of formulations containing the combination of vitamin B12 and hyaluronic acid in the country and the appropriate effects of these two compounds for dry eyes, this study formulates and analyzes the stability of eye drop formulation based on hyaluronic acid and vitamin B12. Methods First, the formulation of hyaluronic acid and vitamin B12 solution with borate buffer was prepared and the stability of vitamin B12 was evaluated. Next, the physicochemical properties of the prepared formulations were evaluated and a sterile ophthalmic solution was prepared from the selected formulations under aseptic conditions. Finally, by choosing the final formulation, accelerated stability was achieved. Results Accelerated studies after six months showed that the amount of vitamin B12 and its ultraviolet absorption did not decrease, and the physicochemical properties, such as solution pH, color, and viscosity did not change. Conclusion This formulation could be a good candidate for industrial production and long-term stability studies are recommended.

Organization of hyaluronic acid molecules in solutions

The organization of hyaluronic acid (HA) solutions was investigated by small angle neutron scattering (SANS). It was demonstrated that HA formed clusters greater than several hundred nanometers. The SANS response revealed a weak correlation peak, corresponding to ordering over a distance scale of about 80 nm. At higher wave vectors, the SANS response indicated the presence of rod-like structures. Addition of calcium ions only weakly affects the structure of the HA solution, but significantly reduces its osmotic pressure. The osmotic component of the SANS response is in good agreement with the intensity obtained from direct osmotic pressure measurements. The results are consistent with the rigid structure of the HA molecule.Graphical abstract

Collagen-Mesenchymal Stem Cell Microspheres Embedded in Hyaluronic Acid Solutions as Biphasic Stem Niche Delivery Systems for Pulmonary Differentiation.

Cell therapy has the potential to become a feasible solution for several diseases, such as those related to the lungs and airways, considering the more beneficial intratracheal administration route. However, in lung diseases, an impaired pulmonary extracellular matrix (ECM) precludes injury resolution with a faulty engraftment of mesenchymal stem cells (MSCs) at the lung level. Furthermore, a shielding strategy to avoid cell damage as well as cell loss due to backflow through the injection path is required. Here, an approach to deliver cells encapsulated in a biomimetic stem niche is used, in which the interplay between cells and physiological lung ECM constituents, such as collagen and hyaluronic acid (HA), can occur. To this aim, a biphasic delivery system based on MSCs encapsulated in collagen microspheres (mCOLLs) without chemical modification and embedded in an injectable HA solution has been developed. Such biphasic delivery systems can both increase the mucoadhesive properties at the site of interest and improve cell viability and pulmonary differentiation. Rheological results showed a similar viscosity at high shear rates compared to the MSC suspension used in intratracheal administration. The size of the mCOLLs can be controlled, resulting in a lower value of 200 μm, suitable for delivery in alveolar sacs. Biological results showed that mCOLLs maintained good cell viability, and when they were suspended in lung medium implemented with low molecular weight HA, the differentiation ability of the MSCs was further enhanced compared to their differentiation ability in only lung medium. Overall, the results showed that this strategy has the potential to improve the delivery and viability of MSCs, along with their differentiation ability, in the pulmonary lineage.

Stretchable hydrogels of chitosan/hyaluronic acid induced by polyelectrolyte complexation around neutral pH

In this work, we propose the formation of stretchable hydrogels at neutral pH from the physical crosslinking of chitosan (CS) and hyaluronic acid (HA) by polyelectrolyte complexation. A mixture of CS (Mw ≈ 600 kg/mol, degree of acetylation ≈ 50 %) solution and HA (Mw ≈ 77 kg/mol) solution was prepared with an excess of salts screening the electrostatic interactions CS/HA. In a controlled manner, the polyelectrolyte complexation was induced through the progressive dialysis of the salted polymer mixture against a sodium acetate solution (AcONa, 0.01 M) for 7 days. Depending on [HA], various materials were obtained: viscous solutions at [HA] = 0.75 % (w/v); hydrogels at [HA] = 1.50–2.24 % (w/v) with Young modulus of 14 kPa and stretchable to 200 %. The small angle X-ray scattering characterization of the hydrogels revealed a multiscale organization related to the conformation of the polymers induced by the physical interactions. The dialysis process with AcONa was optimized by adding a dialysis step against a zinc acetate solution containing Zn2+. The combination of polyelectrolyte complexation between CS/HA and metal complexation between Zn2+ and the polymers led to an enhancement of the hydrogel stretchability up to 400 %.

Accurate prediction of hyaluronic acid concentration under temperature perturbations using near-infrared spectroscopy and deep learning

Accurate prediction of the concentration of a large number of hyaluronic acid (HA) samples under temperature perturbations can facilitate the rapid determination of HA’s appropriate applications. Near-infrared (NIR) spectroscopy analysis combined with deep learning presents an effective solution to this challenge, with current research in this area being scarce. Initially, we introduced a novel feature fusion method based on an intersection strategy and used two-dimensional correlation spectroscopy (2DCOS) and Aquaphotomics to interpret the interaction information in HA solutions reflected by the fused features. Subsequently, we created an innovative, multi-strategy improved Walrus Optimization Algorithm (MIWaOA) for parameter optimization of the deep extreme learning machine (DELM). The final constructed MIWaOA-DELM model demonstrated superior performance compared to partial least squares (PLS), extreme learning machine (ELM), DELM, and WaOA-DELM models. The results of this study can provide a reference for the quantitative analysis of biomacromolecules in complex systems.

A Wood-Derived Periosteum for Spatiotemporal Drug Release: Boosting Bone Repair through Anisotropic Structure and Multiple Functions.

Existing artificial periostea face many challenges, including difficult-to-replicate anisotropy in mechanics and structure, poor tissue adhesion, and neglected synergistic angiogenesis and osteogenesis. Here, inspired by natural wood (NW), a wood-derived elastic artificial periosteum is developed to mimic the structure and functions of natural periosteum, which combines an elastic wood (EW) skeleton, a polydopamine (PDA)binder layer, and layer-by-layer (LBL) biofunctional layers. Specifically, EW derived from NW is utilized as the anisotropic skeleton of artificial periosteum to guide cell directional behaviors, moreover, it also shows a similar elastic modulus and flexibility to natural periosteum. To further enhance its synergistic angiogenesis and osteogenesis, surface LBL biofunctional layers are designed to serve as spatiotemporal release platforms to achieve sequential and long-term release of pamidronate disodium (PDS) and deferoxamine (DFO), which are pre-encapsulated in chitosan (CS) and hyaluronic acid (HA) solutions, respectively. Furthermore, the combined effect of PDAcoating and LBL biofunctional layers enables the periosteum to tightly adhere to damaged bone tissue. More importantly, this novel artificial periosteum can boost angiogenesis and bone formation in vitro and in vivo. This study opens up a new path for biomimetic design of artificial periosteum, and provides a feasible clinical strategy for bone repair.

Computer-guided versus conventional arthrocentesis in treatment of anterior disc displacement of temporomandibular joint

Objectives This study aimed to compare computer-guided arthrocentesis with conventional double puncture technique in the treatment of anterior disc displacement with reduction of the temporomandibular joint. Patient and methods 16 adult patients were included in the study and were divided into two equal groups: group I: treated with guided arthrocentesis using ringer’s lactate solution and injection of hyaluronic acid, group II: treated with conventional double puncture technique of arthrocentesis using ringer’s lactate solution and injection of hyaluronic acid. Patients were evaluated clinically and radiographically preoperatively and postoperatively: clinically for evaluation of pain intensity, maximal mouth opening, and clicking at 1 week and 2 weeks and 1, 2, 3, and 6 months. Radiographically by MRI imaging at 3 and 6 months to determine any changes in the disc position and inflammatory changes within the joint. Results 16 patients (13 females and 3 males), their ages ranged from 17 to 35 years the results of the clinical data including pain intensity, maximal mouth opening, and clicking presented with significant improvements of all outcomes from preoperative to 6 months postoperatively for group I when compared with group II. Radiographically MRI after 3 and 6 months presented with no changes in the disc condyle relationship. Conclusion Arthrocentesis is a useful minimally invasive technique in the treatment of anterior disc displacement with reduction. It plays a role in decreasing joint pain and improving its function and by making arthrocentesis computer-guided this makes the procedures more accurate, safe, less painful, and time-saving and preventing postoperative complications.

Development of a Cissus quadrangularis-Doped Extracellular Matrix and a Hyaluronic Acid-Incorporated Scaffold for Periodontal Regeneration: An In Vitro Study.

The study aimed to analyze whether adding Cissus quadrangularis (CQ) extract and the extracellular matrix of ovine tendon (TENDON) increases the regenerative potential of mesenchymal stem cells produced in hyaluronic acid (HA) scaffolds for tenogenesis. Fifty grams of powdered CQ was mixed with 250 mL of ethanol to prepare the extract. Two grams of hyaluronic acid powder was added to 100 mL of distilled water to make the HA solution. The ovine tendon was decellularized using a mixture of 10% phosphate-buffered saline (PBS), sodium dodecyl sulfate (SDS), and Triton-X. The hydrogel samples were prepared by mixing the extracellular matrix of tendon, HA, and CQ, after which they were divided into study groups such as HA, HA + CQ, HA + TENDON, and HA + CQ + TENDON. Scanning electron microscopy (SEM) analysis, swelling analysis, differentiation analysis, compression test, compatibility assay, and tenogenesis assay were later conducted. The morphology of the samples was analyzed using SEM. Low levels of swelling of the hydrogels were observed. Cells were found to be viable and showed good differentiation and tenogenesis. Optimal compression levels were observed, and the properties of the prepared hydrogels were satisfactory. The results suggest that the addition of CQ considerably increases the tenogenic potential of the extracellular matrix/HA scaffold. Hence, it can be used as a regenerative material for periodontal tissue regeneration.