Molecular Weight HA Research Articles

Utility of Authentic 13C‐Labeled Disaccharide to Calibrate Hyaluronan Content Measurements by LC‐MS

ABSTRACTHyaluronan (hyaluronic acid, HA), a key glycosaminoglycan in the extracellular matrix, plays crucial roles in various physiological and pathological processes, including development, tissue hydration, inflammation, and tumor progression. Traditional methods for HA quantification, such as ELISA‐like assays, often have limitations in sensitivity and specificity, particularly for lower molecular weight HA. In this work, we introduce a coupled liquid chromatographic‐tandem mass spectrometric (LC‐MS/MS) method that employs a chemoenzymatically synthesized 13C‐labeled lyase‐derived authentic HA disaccharide calibrant for quantification of HA at the nanogram level. The method was validated against three HA polysaccharides with the sizes of ~33, 210, and 540 kDa. We applied this quantification technique to mouse tissues and plasma from both healthy and acetaminophen‐induced acute liver injury mice. Our data revealed a ~75‐fold increase in HA concentration in the liver of acetaminophen‐injured mice with a concomitant depletion from plasma. Overall, our method offers a robust, universal, and highly sensitive tool for HA analysis in diverse biological samples that will advance the investigation of the roles of this polysaccharide in human disease conditions.

Hyaluronan‐protein interactions: Lilliput revisited

AbstractHyaluronan (HA) is a huge linear polysaccharide composed entirely of a simple repeating disaccharide that has been preserved unchanged since the evolution of vertebrates ~520 million years ago. It is present in all mammalian tissues, being synthesised within the cell membrane and extruded into the extracellular space where it dictates tissue elasticity, hydration and permeability. HA also directs cell behaviour via engagement with cell surface receptors. These properties allow it to mediate diverse functions in a wide range of physiological and pathological processes, including development, mammalian reproduction and inflammation. There is growing evidence that the way in which the HA biopolymer is differentially organised, through its interaction with a repertoire of HA‐binding proteins (HABPs), is key to the diversity of its biological functions. This review summarises current knowledge of HA‐protein interactions and how their diversity may lead to the formation of HA/protein complexes with distinct molecular architectures that in turn underpin different physical properties and receptor‐mediated effects. Potentially controversial areas such the pro‐inflammatory effects of low molecular weight HA fragments and how short HA‐binding peptides modulate HA function are considered from a molecular perspective.

High prevalence of CD44 and its ligand low molecular weight hyaluronan in plasma of HNSCC patients: clinical significance.

This study aims to evaluate the role of cancer stem cell marker, CD44, and its ligand HA as potential molecular biomarker for early detection of HNSCC. The expression profile (mRNA/Protein) of CD44 variants were analysed in primary HNSCC lesions and plasma of the patients. Then, prevalence of HA variants was analysed in plasma of the patients. The mRNA expression of CD44 variants, CD44S and CD44v3, were significantly high in both early (stage I/II) and late (stage III/IV) invasive lesions, with predominant expression of CD44v3 in the late-stage lesions. In plasma of HNSCC patients, increased levels of SolCD44, CD44-ICD and unique 62 KD CD44 variants with respect to standard CD44S were seen, in comparison to their prevalence in plasma of normal individuals. The abundance of CD44-ICD and 62 KD variants were significantly high in plasma of late stage HNSCC patients. Interestingly, significantly high level of low molecular weight HA(LMW HA) with respect to high molecular weight HA(HMW HA) was seen in plasma of HNSCC patients irrespective of clinical stages. On the contrary, high HMW HA level in plasma of normal individuals was seen. The high level of LMW HA in plasma of HNSCC patients might be due to combinatorial effect of increased mRNA expression of HA synthesizing enzyme HAS1/2/3 and HA degrading enzyme HYAL1/2, as seen in the primary HNSCC samples. Thus, our data revealed the importance of specific CD44 and HA variants in plasma of HNSCC patients during its development as potential non-invasive molecular biomarker of the disease.

Aeration intensity drives dissolved organic matter transformation and humification during composting by regulating the organics metabolic functions of microbiome

Oxygen levels are critical for composting success and improving humification. Whereas aeration intensity driving the structural heterogeneity and formation mechanism of humus in the dissolved organic matter (DOM) transformation process during kitchen waste with hydrothermal pretreatment composting remains unclear. In this study, the potential mechanisms of aeration intensity on humification were explored by Fourier transform infrared spectroscopy and fluorescence spectroscopy combined with functional microbial prediction analysis. The results showed that moderate aeration intensity (AR0.05, 0.05 L min−1 kg−1 DM) achieved a highly matured fertilizer with a humification index of 0.83 and a humic acid / fulvic acid (HA/FA) of 1.99. Partial least-squares path model demonstrated that environmental factors and humus-like substances were the two most critical factors to improve humification levels. According to the heterogeneous-2DCOS analysis, the biopolymers in DOM were preferentially decomposed into low molecular weight HA precursors through a series of biochemical reaction processes, and then formed the carbon skeleton of HA through condensation reactions, and finally polymerized into complex macromolecular HA. Bugbase analysis showed that AR0.05 treatment reduced 58.52 % of potentially pathogenic bacteria in the thermophilic phase. Moreover, functional bacterial communities in composting systems with AR0.05 were more favorable to drive the organic matter decomposition and HA formation. The mantel test revealed temperature and pH were key drivers in the composition of phenotypic and functional bacterial communities. This study provided unique insights into a deeper understanding of the aeration intensity on the humification pathways of kitchen waste composting.

Binding of different hyaluronan to CD44 mediates distinct cell adhesion dynamics under shear flow.

As a known receptor-ligand pair for mediating cell-cell or cell-extracellular matrix adhesions, cluster of differentiation 44 (CD44)-hyaluronan (HA) interactions are not only determined by molecular weight (MW) diversity of HA, but also are regulated by external physical or mechanical factors. However, the coupling effects of HA MW and shear flow are still unclear. Here, we compared the differences between high molecular weight HA (HHA) and low molecular weight HA (LHA) binding to CD44 under varied shear stresses. The results demonstrated that HHA dominated the binding phase but LHA was in favour of the shear resistance phase, respectively, under shear stress range ≤ 1.0 dyne·cm-2 . This difference was attributed to the high binding strength of the CD44-HHA interaction, as well as the optimal distribution matching between both CD44 and HA sides. Activation of the intracellular signal pathway was sensitive to both HA MW and shear flow. Our findings also indicate that only CD44-HHA interaction under shear stress of 0.2 dyne·cm-2 could significantly enhance the clustering of CD44, as well as induce the increase in both CD44 and CD18 expression. The present study offers the basis for further quantification of the features of CD44-HA interactions and their biological functions.

Composite Hydrogels Based on Cross-Linked Chitosan and Low Molecular Weight Hyaluronic Acid for Tissue Engineering.

The objectives of the study were as follows: (1) to develop two methods for the preparation of macroporous composite chitosan/hyaluronic acid (Ch/HA) hydrogels based on covalently cross-linked Ch and low molecular weight (Mw) HA (5 and 30 kDa); (2) to investigate some properties (swelling and in vitro degradation) and structures of the hydrogels; (3) to evaluate the hydrogels in vitro as potential biodegradable matrices for tissue engineering. Chitosan was cross-linked with either genipin (Gen) or glutaraldehyde (GA). Method 1 allowed the distribution of HA macromolecules within the hydrogel (bulk modification). In Method 2, hyaluronic acid formed a polyelectrolyte complex with Ch over the hydrogel surface (surface modification). By varying compositions of the Ch/HA hydrogels, highly porous interconnected structures (with mean pore sizes of 50-450 μm) were fabricated and studied using confocal laser scanning microscopy (CLSM). Mouse fibroblasts (L929) were cultured in the hydrogels for 7 days. Cell growth and proliferation within the hydrogel samples were studied via MTT-assay. The entrapment of low molecular weight HA was found to result in an enhancement of cell growth in the Ch/HA hydrogels compared to that in the Ch matrices. The Ch/HA hydrogels after bulk modification promoted better cell adhesion, growth and proliferation than the samples prepared by using Method 2 (surface modification).

Release of adsorbed copper and carbon during Fe(Ⅱ) catalytic conversion of ferrihydrite-humic acid coprecipitation under acidic condition: Mechanism and properties

The mobility of copper (Cu) may be significantly impacted during the conversion of ferrihydrite-humic acid (Fh-HA) coprecipitates. However, the environmental behavior of the adsorbed Cu in Fh-HA coprecipitation and the kinetic process of organic carbon (C) during the Fe(Ⅱ)-catalyzed Fh-HA coprecipitates conversion remains unclear. In this study, a series of Fh-HA coprecipitates with various C/Fe molar ratios were synthesized. Furthermore, the effects of the Fe(Ⅱ) mediated Fh and Fh-HA conversion processes on Cu mobility and carbon release characteristics under acidic condition were investigated. The results show that the specific surface area of Fh-HA is reduced as compared to pure Fh, which impedes the conversion of Fe minerals and increases the release of Cu to the solution. The rate of conversion can be accelerated by increasing the Fe(II) concentration, resulting in the retention of Cu in the mineral structure. As compared to artificial HA, Elliott soil humic acid (ESHA) coprecipitated with Fh resulted in a reduced Cu release. According to results of the fluorescence excitation emission matrix-parallel factor analysis, the "release-resorption" process of carbon occurred during conversion and low molecular weight HA related to the biological activity was the main source of the released organic carbon. The major functional groups were C-O functional groups and phenolic hydroxyl groups, and Cu was involved in the formation of Fe-O-Cu after conversion. The findings of this study provide crucial information for comprehending the biogeochemical process of Cu associated with Fh and Fh-HA coprecipitates.

Chemical analysis of mineral trioxide agregate mixed with hyaluronic acids as an accelerant.

Mineral trioxide aggregate (MTA) has many clinical applications in dentistry; the main drawback is the long setting. The main objective is to investigate and compare the chemical effect of using two commercially available hyaluronic acid hydrogels (HA) instead of distilled water for mixing MTA as an accelerant of setting time. Test materials were divided into three groups; Group 1: (control) mixing MTA with distilled water supplied by the manufacturer; Group 2: mixing MTA with a hybrid cooperative complex of high and low molecular weight HA (Profhilo®); Group 3: mixing MTA with High molecular weight / non-cross-linked HA (Jalupro®). Mixing time, and setting time (initial and final) were determined, Fourier-transform infrared spectroscopy, Energy-dispersive X-ray spectroscopy, Field emission Scanning Electron Microscopy, and X-ray diffraction were performed. mixing time, initial, and final setting time for (MTA + HA) groups were significantly different and lower in comparison to the control group (p < 0.05). This study revealed higher expression of calcium silicate hydrate and calcium hydroxide expression with higher Ca release in the MTA + HA group than the control group. commercially available HA demonstrated better chemical properties when used as a mixing medium for MTA. The Mixing and setting time for MTA + HA group were significantly shorter than those of the control group were. Thus, commercially available HA can be used as a mixing medium for MTA.

Drug Release and Cytotoxicity of Hyaluronic Acid and Zinc Oxide Gels, An In-Vitro Study

ABSTRACT Hyaluronic acid (HA) is a naturally occurring biopolymer, with a remarkable wound healing property. Zinc-oxide non-eugenol is a material widely used for periodontal dressing in dentistry. However, it has been reported that zinc oxide non-eugenol is toxic to osteoblasts and fibroblasts. Hence, the present study aimed to evaluate the drug release and cytotoxicity of HA and zinc-oxide gels. Hydrogels of HA and zinc oxide were formulated with carbopol as a carrier. In vitro drug release was performed by UV spectrophotometry, dialysis, and vial bag methods. Cytotoxicity assessment of HA and zinc-oxide gels was performed in human periodontal ligament fibroblasts (HPdLF) and human gingival fibroblasts (hGFs). An inverted phase-contrast microscope was used to assess the morphological changes. At 24 and 48 hr, HPdLF cells showed the highest viability in 0.1% low molecular weight-HA (LMW-HA) with a median value of 131.9, and hGFs showed the highest viability in 5% LMW-HA with a median of 129.56. The highest viability of HPdLF cells was observed in 5% high molecular weight-HA (HMW-HA), with a median value of 127.11. hGFs showed the highest viability in 1% HMW-HA with a median value of 97.99. Within the limitations of the present study, we concluded that LMW-HA is more efficient than HMW-HA. Both HPdLF and hGF cells showed complete cell morbidity with zinc-oxide hydrogels. Therefore, zinc oxide-based gels in concentrations as low as 9% could be toxic intraorally to soft tissues that harbor gingival and periodontal ligament fibroblasts.

Designing topical hyaluronic acid technology-Size does matter….

IntroductionHyaluronic acid (HA) plays an important role in cellular and extracellular matrix (ECM) homeostasis. Recent studies demonstrate that low molecular weight (MW) HA has pro‐inflammatory characteristics while high MW HA is considered anti‐inflammatory and regenerative. In formulating a topical HA product, the possibility of creating a focused high MW HA technology was posed, combining external surface high MW HA constituents with active agents promoting fibroblast production of high MW in the depths of the dermis.MethodsHuman dermal fibroblasts and keratinocytes were treated with various agents, and RNA sequencing (RNA‐seq) was conducted to identify genes involved in HA synthesis. HA production by fibroblasts was assessed by collecting the culture supernatant, concentrating the protein, and conducting polyacrylamide gel electrophoresis (PAGE). The gel was stained with Stains‐All to identify bands relative to known HA products of different MWs. Subsequently, the supernatants were treated with hyaluronidase to confirm the bands corresponded to HA.ResultsThe RNA‐seq results revealed a variety of agents upregulated HA‐related genes. However, a potent upregulation of HA synthesis gene was observed by hexapeptide‐11 in the keratinocytes and a newly identified proprietary octapeptide in the fibroblasts. PAGE demonstrated not only robust production of HA by octapeptide, but significantly, the HA produced was ~2 Mega Daltons in size. Octapeptide was the most potent stimulator among the tested agents.ConclusionComprehensive in vitro testing identified a group of active agents that stimulated high MW HA production. This novel approach to HA topical application with exclusively high MW HA production should maximize hydration capacity while encouraging regenerative activity within the ECM. Multi‐center trials are underway.

Real-time metabolic heat-based specific growth rate soft sensor for monitoring and control of high molecular weight hyaluronic acid production by Streptococcus zooepidemicus.

This present investigation addressing the metabolic bottleneck in synthesis of high MW HA by Streptococcus zooepidemicus and illustrates the application of calorimetric fed-batch control of µ at a narrower range. Feedforward (FF) and feedback (FB) control was devised to improve the molecular weight (MW) of HA production by S. zooepidemicus. Metabolic heat measurements (Fermentation calorimetry) were modeled to decipher real-time specific growth rate, [Formula: see text] was looped into the PID circuit, envisaged to control [Formula: see text] to their desired setpoint values 0.05 [Formula: see text], 0.1 [Formula: see text], and 0.15 [Formula: see text] respectively. Similarly, a predetermined exponential feed rate irrespective of real-time µ was carried out in FF strategy. The developed FB strategy established a robust control capable of maintaining the specific growth rate (µ) close to the [Formula: see text] value with a minimal tracking error. Exponential feed rate carried out with a lowest [Formula: see text] of 0.05 [Formula: see text] showed an improved MW of HA to 2.98 MDa and 2.94 MDa for the FF and FB-based control strategies respectively. An optimal HA titer of 4.73g/L was achieved in FF control strategy at [Formula: see text]. Superior control of µ at low [Formula: see text] value was observed to influence HA polymerization positively by yielding an improved MW and desired polydispersity index (PDI) of HA. PID control offers advantage over conventional fed-batch method to synthesize HA at an improved MW. Calorimetric signal-based µ control by PID negates adverse effects due to the secretion of other end products albeit maintaining regular metabolic activities. KEY POINTS: First report to compare HA productivities by feedforward and feedback control strategy. Inherent merits of regulating µ at narrower range were entailed. Relationship between operating µ and HA molecular weight was discussed.

Investigation of synovial fluid lubricants and inflammatory cytokines in the horse: a comparison of recombinant equine interleukin 1 beta-induced synovitis and joint lavage models

BackgroundLameness is a debilitating condition in equine athletes that leads to more performance limitation and loss of use than any other medical condition. There are a limited number of non-terminal experimental models that can be used to study early inflammatory and synovial fluid biophysical changes that occur in the equine joint. Here, we compare the well-established carpal IL-1β-induced synovitis model to a tarsal intra-articular lavage model, focusing on serial changes in synovial fluid inflammatory cytokines/chemokines and the synovial fluid lubricating molecules lubricin/proteoglycan 4 and hyaluronic acid. The objectives of this study were to evaluate clinical signs; synovial membrane and synovial fluid inflammation; and synovial fluid lubricants and biophysical properties in response to carpal IL-1β synovitis and tarsal intra-articular lavage.ResultsHyaluronic acid (HA) concentrations, especially high molecular weight HA, and synovial fluid viscosity decreased after both synovitis and lavage interventions. Synovial fluid lubricin concentrations increased 17–20-fold for both synovitis and lavage models, with similar changes in both affected and contralateral joints, suggesting that repeated arthrocentesis alone resulted in elevated synovial fluid lubricin concentrations. Synovitis resulted in a more severe inflammatory response based on clinical signs (temperature, heart rate, respiratory rate, lameness and joint effusion) and clinicopathological and biochemical parameters (white blood cell count, total protein, prostaglandin E2, sulfated glycosaminoglycans, tumor necrosis factor-α and CC chemokine ligands − 2, − 3, − 5 and − 11) as compared to lavage.ConclusionsSynovial fluid lubricin increased in response to IL-1β synovitis and joint lavage but also as a result of repeated arthrocentesis. Frequent repeated arthrocentesis is associated with inflammatory changes, including increased sulfated glycosaminoglycan concentrations and decreased hyaluronic acid concentrations. Synovitis results in more significant inflammatory changes than joint lavage. Our data suggests that synovial fluid lubricin, TNF-α, CCL2, CCL3, CCL5, CCL11 and sGAG may be useful biomarkers for synovitis and post-lavage joint inflammation. Caution should be exercised when performing repeated arthrocentesis clinically or in experimental studies due to the inflammatory response and loss of HA and synovial fluid viscosity.

The efficacy of intra-articular HYADD4-G injection in the treatment of femoroacetabular impingement: results at one year follow up

Objective Femoroacetabular impingement (FAI) is a condition that has been increasingly recognized as a source of hip pain and a possible risk factor to early development of hip osteoarthritis (OA). To our knowledge, the use of HA in the treatment of femoroacetabular FAI has been investigated only by two studies, both using a high molecular weight HA. The aim of this study was to evaluate the efficacy of two weekly injections of an hexadecylamide derivative of HA (HYADD4-G, HYMOVIS, Fidia Farmaceutici) in FAI. Methods All patients received two weekly intra-articular injections of Hymovis at baseline and after 7 days. Clinical and functional assessments were performed at baseline and was repeated after 1, 3, 6 and 12 months. Functional measures included visual analogue scale (VAS) for pain, Harris Hip score (HHS), Lequesne Index (LI), Tegner activity level scale (TALS) and monthly consumption of nonsteroidal anti-inflammatory drugs (NSAIDs). Results Twenty-one hips (19 patients, 2 bilateral cases) were treated. The variables VAS, HHS as well as Lequesne improved significantly from T0 to T4 (at 12 months) with the best improvement between T0 and T1. At the same time, a reduction in NSAIDs monthly intake was registered. On the other hand, a significant improvement in Tegner scale was not observed. No adverse events were registered. Conclusion This study states that one cycle of HYADD4-G could be a safe and effective treatment in patients with FAI, showing significative results in term of pain control as well as hip functionality and quality of life up to 1 year.

Controlled conversion of sodium hyaluronate into low-molecular-weight polymers without additives using high-temperature water and fast-heating-rates

In this work, molecular weight reduction of the polysaccharide biopolymer, sodium hyaluronate (NaHA), was obtained without added chemicals or catalysts using high temperature water (180 to 260) °C, fast-heating-rates (417 to 750) °C∙s−1 and short reaction times (< 18 s) in a flow reactor. Results show that hydrothermal treatment of NaHA with fast-heating-rates convert the substrate into low molecular weight oligomers with minimal byproduct formation. A kinetic model assuming random depolymerization provided data correlation and allowed estimation of molecular weight reductions. Mechanism of NaHA decomposition in high temperature water with fast-heating rates seems to be related to initial disentanglement of NaHA random coils through convective (turbulent) mixing and shear that minimizes heterogenous decomposition. Evidence for the mechanism includes lack of significant furan byproducts (fast-heating), clear product solutions and model applicability. Fast-heating with high temperature water allows selective conversion of high molecular weight NaHA into low molecular weight HA fragments without chemical modification, catalysts or additives.

Hyaluronic acid oligosaccharide-modified collagen nanofibers as vascular tissue-engineered scaffold for promoting endothelial cell proliferation

Hyaluronic acid oligosaccharides (oHAs) have shown promising results in promoting vascular endothelial cell (EC) proliferation and endothelialization. To engineered develop tissue scaffold for promoting EC proliferation and vessel endothelialization, different sizes of oHAs were prepared and grafted onto collagen to improve the biological properties of the synthesized materials, especially in angiogenesis. Firstly, oHAs were successfully prepared and conjugated with collagen to construct glycosylated collagens by reductive amination. The glycosylated collagens were then electrospun into various nanofibrous structures and their morphology and hemocompatibility, as well as EC responses on these nanofibrous scaffolds, were studied to evaluate the potential for vascular tissue engineering. The results showed that the nanofibrous scaffolds grafted by oHAs promoted EC proliferation whereas high molecular weight HA inhibited proliferation. The scaffolds had no detectable degree of hemolysis and coagulation, suggesting their promise as engineered vascular tissue scaffolds.

Temporomandibular joint dysfunction – sequential infiltration protocol of sodium hyaluronate at different molecular weights

Introduction: The temporomandibular dysfunction (TMD) it’s a collective expression that encompasses clinical alterations in chewing muscles, temporomandibular joints (TMJ), and/or associated estructures. The viscosuplementation (VS) is a minimally invasive technique which consistis of intra-articular injection of sodium hyaluronate (SH) for the improvement of lubrification and joint biomechanics and elimination or decrease of pain. The aim of this study was to evaluate, through a series of cases, the efficacy of a viscosupplementation protocol with SH in different molecular weights, in the signs and syntptoms of joint TMJ and in patients’quality of life [1–3]. Materials and methods: this study was approved by the Ethics Committee of Universidade Federal de Minas Gerais, Belo Horizonte, Brazil (CAAE-24911314.3.0000.5149) and registered in the Brazilian Registry of Clinical Trials (RBR-6759yz). Is a case series that describes the efficacy of a viscosupplementation protocol in intra-articular temporomandibular disorders. Ten patients with a diagnosis of disc displacement and/or osteoarthritis according to the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) were submitted to four monthly injections of low or medium molecular weight HA. Pain, mandibular function, image analysis by tomography and magnetic resonance, and quality of life were assessed at baseline and follow-ups (1 and 6 months). Results: Pain, jaw range-of-motion, mandibular function, and quality of life improved at follow-up evaluations. Osteoarthritis changes decreased, and 20% of patients improved mandibular head excursion after treatment. Resolution of effusion and improvement in disc morphology were observed for most patients. This viscosupplementation protocol reduced pain and symptoms associated with internal derangement of temporomandibular joint, improved quality of life, and showed benefits from both low and medium molecular weight HA in alternate cycles. Discussion and conclusions: These results suggest the effectiveness of the VS protocol in the control and relief of the signs and symptoms of TMD, and the great therapeutic potential of this technique.

Targeted deletion of HYBID (hyaluronan binding protein involved in hyaluronan depolymerization/ KIAA1199/CEMIP) decreases dendritic spine density in the dentate gyrus through hyaluronan accumulation

HYBID (hyaluronan binding protein involved in hyaluronan [HA] depolymerization, KIAA1199/CEMIP) is a key player in HA depolymerization of the skin fibroblasts, arthritic synovial fibroblasts, and brain. Our previous study demonstrated that Hybid knock-out (KO) mice showed spatial memorial impairment, which is accompanied by the accumulation of high molecular weight HA in the hippocampus. However, the mechanism underlying cognitive impairment by Hybid deficiency remains unclear. In the present study, we examined the HA distribution patterns in the brains of wild-type (WT) and Hybid KO mice by HA staining using HA binding protein, and found that in Hybid KO mice, HA is accumulated and doublecortin-positive immature neurons are significantly decreased in the dentate gyrus of the hippocampus, where Hybid mRNA is highly expressed in WT mice. The Golgi-Cox staining demonstrated that the dendritic spine density is significantly decreased in the dentate gyrus granule cells in Hybid KO mice. These results suggest that Hybid-mediated HA degradation is critical for the synaptic formation process by contributing to cognitive functions, such as learning and memory, in the mouse brain.

Soft hydrazone crosslinked hyaluronan- and alginate-based hydrogels as 3D supportive matrices for human pluripotent stem cell-derived neuronal cells

Regenerative medicine, especially cell therapy combined with a supportive biomaterial scaffold, is considered to be a potential treatment for various deficits in humans. Here, we have produced and investigated the detailed properties of injectable hydrazone crosslinked hyaluronan-polyvinyl alcohol (HA-PVA) and alginate-polyvinyl alcohol (AL-PVA) hydrogels to be used as a supportive biomaterial for 3D neural cell cultures. To the best of our knowledge, this is the first time the polymerization and properties of hydrazone crosslinked AL-PVA hydrogel have been reported. The effect of the degree of substitution and molecular weight of the polymer components as well as the polymer concentration of the hydrogel on the swelling, degradation and mechanical properties of the hydrogels is reported. Furthermore, we studied the effect of the above parameters on the growth of human pluripotent stem cell-derived neuronal cells. The most neural cell supportive HA-PVA hydrogel was composed of high molecular weight HA component with brain-mimicking mechanical properties and decreased polymer concentration. AL-PVA hydrogel, with stiffness quite similar to brain tissue, was also shown to be similarly supportive. Neuronal spreading and 3D network formation was enhanced inside the softest hydrogels.

Double printing of hyaluronic acid/poly(glycidol) hybrid hydrogels with poly(ε-caprolactone) for MSC chondrogenesis

This study investigates the use of allyl-functionalized poly(glycidol)s (P(AGE-co-G)) as a cytocompatible cross-linker for thiol-functionalized hyaluronic acid (HA-SH) and the optimization of this hybrid hydrogel as bioink for 3D bioprinting. The chemical cross-linking of gels with 10 wt.% overall polymer concentration was achieved by a UV-induced radical thiol-ene coupling between the thiol and allyl groups. The addition of unmodified high molecular weight HA (1.36 MDa) enabled the rheology to be tuned for extrusion-based bioprinting. The incorporation of additional HA resulted in hydrogels with a lower Young’s modulus and a higher swelling ratio, especially in the first 24 h, but a comparable equilibrium swelling for all gels after 24 h. Embedding of human and equine mesenchymal stem cells (MSCs) in the gels and subsequent in vitro culture showed promising chondrogenic differentiation after 21 d for cells from both origins. Moreover, cells could be printed with these gels, and embedded hMSCs showed good cell survival for at least 21 d in culture. To achieve mechanically stable and robust constructs for the envisioned application in articular cartilage, the formulations were adjusted for double printing with thermoplastic poly(ε-caprolactone) (PCL).

Hyaluronic Acid Intra-Articular Injections in Patients Affected by Moderate to Severe Glenohumeral Osteoarthritis: A Prospective Randomized Study.

Purpose The aim of this study was to evaluate the efficacy and safety of intra-articular injection treatment with high molecular weight HA (Hyalubrix, 30 mg/2 mL, molecular weight > 1,500 kDa) in patients affected by moderate to severe glenohumeral osteoarthritis (OA). Methods Seventy-eight patients, affected by shoulder OA grade II–IV were randomized in two groups. Patients included in case group were treated with three intra-articular injections of HA and a specific physiotherapy program, whereas patients included in the control group received the only physical therapy. The follow-up examination was 6 months for both groups. The evaluation of functional status of treated shoulder, range of motion, and pain was performed before treatment and at the final follow-up examination by means of the Constant score. The safety evaluation of the treatment was also performed recording any adverse events. Results Statistical analysis revealed a significant difference ( p < 0.05) between the two groups in terms of pain reduction and improvement in the activities of daily living. In particular, case group subjects affected by grade III and IV OA had a significant improvement in the Constant score (18.2 ± 5.4 and 19.2 ± 5.9, respectively). Conclusion This study showed that the combination of intra-articular injection of hyaluronic acid (Hyalubrix, 30 mg/2 mL) with physical therapy program was more effective in comparison with the only physical therapy in reducing pain in patients affected by glenohumeral OA. Level of Evidence Level II, randomized controlled study.