High Molecular Weight Hyaluronic Acid Research Articles

A study on the effectiveness of visco-supplementation in osteoarthritis knee

BACKGROUND: Osteoarthritis (OA) is a degenerative disease of synovial joints; recently, it is also termed osteoarthrosis. High-molecular-weight hyaluronic acid (HA) has a better increase in fluid retention within the joint and stronger anti-inflammatory effect. OBJECTIVES: The objective was to assess the efficacy of intra-articular (IA) HA in primary OA of knee joint based on clinical outcome with visual analog score (VAS) and the Western Ontario and McMaster Universities OA Index (WOMAC) score and to determine the safety of IA HA in primary OA of knee joint. SUBJECTS AND METHODS: A single-group, prospective interventional study was conducted from November 2017 to May 2019 in a tertiary care hospital. A total of 36 patients with Grades I and II of Kellegren–Lawrence radiological grading were included in the study. IA injection of HA was given to these patients and were assessed using VAS and WOMAC scores. RESULTS: The mean VAS scores improved from preinjection score of 9.03 ± 0.94 to 2.61 ± 2.15 at 6-month follow-up. In addition, the mean WOMAC scores improved from 81.14 ± 6.43 to 35.81 ± 13.44 at 6-month post-IA HA injection. CONCLUSIONS: This study observed that IA injection of HA is a reliable, productive, efficient, and safe mode of treatment of Grade I and II OA knee, which also delays the disease and reduces the need for surgical intervention.

Synthesis of hyaluronic acid hydrogels by crosslinking the mixture of high-molecular-weight hyaluronic acid and low-molecular-weight hyaluronic acid with 1,4-butanediol diglycidyl ether

High molecular weight hyaluronic acid (HMW-HA) and low molecular weight hyaluronic acid (LMW-HA) were mixed at different ratios and cross-linked with 1,4-butanediol diglycidyl ether (BDDE) to prepare five hyaluronic acid hydrogels A–E. Enzymolysis stability, swelling rate, crosslinking degree, rheological characteristics, BDDE residual rate, surface microstructure, and cytotoxicity of different hydrogels were investigated. The results showed that hydrogel B obtained by 10% HA (w/v, HMW-HA and LMW-HA having a mass ratio of 4 : 1) crosslinking with 1% BDDE (v/v) had stronger in vitro anti-degradation ability, better mechanical properties and lower cytotoxicity than those prepared by mixing in different proportions. Hydrogel B has potential applications in regenerative medicine and tissue engineering.

Combining canine mesenchymal stromal cells and hyaluronic acid for cartilage repair

Cell therapy and tissue engineering have been intensively researched for repair of articular cartilage. In this study, we investigated the chondrogenic potential of canine adipose-derived mesenchymal stromal cells (ASCs) combined to high molecular weight hyaluronic acid (HA) in vitro, and their therapeutic effect in dogs with chronic osteoarthritis (OA) associated with bilateral hip dysplasia. Canine ASCs were characterized after conventional 2D culture or 3D culture in HA, showing adequate immunophenotype, proliferation and trilineage differentiation, as well as chondrogenesis after cultivation in HA. ASC/HA constructs were used to treat 12 dogs with OA, sequentially assigned to control, ASC and ASC/HA groups. Animals were examined for clinical, orthopedic and radiological parameters. Lameness at walk and pain on manipulation were reduced in the ASC group and mainly in the ASC/HA group. Range of motion and detection of crepitus on hip rotation and abduction improved similarly in all groups. For articular edema, muscle atrophy, Norberg angle values and radiographic analyses, there were no variations throughout the period. These results indicate that ASC/HA constructs are safe and may be an effective therapeutic tool in treating canine chronic osteoarthritis, which should be confirmed with larger studies and additional clinical parameters.

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.

Mechanisms of remodeling oral soft tissues (literature review)

Based on the analysis of modern literature, a systematization of information of the soft tissues of the oral cavity remodeling mechanisms after surgical interventions was carried out. Priority area in modern medical practice is the development and use of such methods and drugs that combine maximum safety and high biological activity in relation to body tissues. A number of scientists have proposed and introduced into practical medicine the technology of programmed scar remodeling. According to this technique, injections of antihomotoxic substances directly around the surgical wound are required, which reduce the duration of edema in the tissues. A number of authors have studied the use of a minimally invasive microsurgical method based on fractional laser photothermolysis to initiate the regeneration of gums and oral mucosa. As a result of the study, it was found that microscopic thermal wounds in the form of damage islands surrounded by normal viable tissue contribute to stimulation of regeneration, which leads to complete restoration of the tissue without scar formation. Recently, methods of using directed tissue regeneration have been widely introduced into practice. In this technique, cellular structures are used that increase the activity of regenerative processes - fibroblasts, platelet plasma. Great importance in the processes of regeneration of the oral mucosa has the epidermal growth factor EGF. It is a globular protein, acts like a strong mitogen on cells of endodermal, ectodermal and mesodermal origin. The epidermal factor stimulates cell proliferation and, in combination with other cytokines, is a factor that accelerates wound healing and angiogenesis. For the treatment of patients with periodontal tissue damage, a number of scientists have proposed a method for using an adhesive protective wound cover created with biotechnological high molecular weight hyaluronic acid. Thus, the analysis of literary sources and the systematization of the available information proves the relevance of further studying the features of the mechanisms of remodeling of soft tissues of the oral cavity. Needs of modern maxillofacial surgery requires morphological study for improvement of existing and development of new treatments for patients.

Application of a mechanically responsive, inflammatory macrophage-targeted dual-sensitive hydrogel drug carrier for atherosclerosis

Atherosclerotic lesions create obvious vascular stenosis due to the presence of plaque, and a large number of inflammatory macrophages are enriched in the thrombus. In this study, we develop a composite hydrogel drug delivery system that is capable of both mechanically-sensitive drug release and of targeting inflammatory macrophages at the thrombus. The hydrogel is a high molecular weight hyaluronic acid (HA) modified with glycidyl methacrylate as a hydrogel precursor; a cross-linkable block copolymer (CBC) is used as the drug coating material and a microscopic cross-linking agent. The difference in drug release rate of the composite hydrogel (HACBC) in simulated blood vessels with 0 % and 75 % occlusion was as high as 49.3 %. Under long-term cycling conditions in stenotic vessels, dynamic shear rheometry revealed that the HACBC still maintained the hydrogel properties. However, the micelles were deformed and recombined to produce smaller sized micelles. An in vitro cell culture demonstrated precise targeting of the HACBC to inflammatory macrophages, and our rabbit experiments with simvastatin-coated HACBC confirmed the effective release of simvastatin in the plaque of the drug carrier. Moreover, we demonstrated the precise targeting of HACBC in vivo in apoE-/- mice by using HACBC coated with cy7. The mechanical stress-sensitive and CD44 receptor-targeted dual-response drug delivery system prepared by micellar composite hydrogel is the first application in the field of atherosclerosis, which provides a new method for diagnosing and treating atherosclerosis.

A 3D "In Vitro" Model to Study Hyaluronan Effect in Nasal Epithelial Cell Line Exposed to Double-Stranded RNA Poly(I:C).

Environmental agents, including viral and bacterial infectious agents, are involved in the alteration of physicochemical and biological parameters in the nasal epithelium. Hyaluronan (HA) has an important role in the regulation of tissue healing properties. High molecular weight HA (HMW-HA) shows greater anti-inflammatory responses than medium molecular weight HA (MMW-HA) and low molecular weight HA (LMW-HA). We investigated the effect of HMW-HA, MMW-HA and LMW-HA on the regulation of physicochemical and biological parameters in an “in vitro” model that might mimic viral infections of the nasal epithelium. Human nasal epithelial cell line RPMI2650 was stimulated with double-stranded RNA (dsRNA) Poly(I:C) for 5 days in air-liquid-interface (ALI) culture (3D model of airway tissue). dsRNA Poly(I:C) treatment significantly decreased transepithelial electrical resistance (TEER) in the stratified nasal epithelium of RPMI2650 and increased pH values, rheological parameters (elastic G’ and viscous G’’), and Muc5AC and Muc5B production in the apical wash of ALI culture of RPMI2650 in comparison to untreated cells. RPMI2650 treated with dsRNA Poly(I:C) in the presence of HMW-HA showed lower pH values, Muc5AC and Muc5B production, and rheological parameters, as well as increased TEER values in ALI culture, compared to cells treated with Poly(I:C) alone or pretreated with LMW-HA and MMW-HA. Our 3D “in vitro” model of epithelium suggests that HMW-HA might be a coadjuvant in the pharmacological treatment of viral infections, allowing for the control of some physicochemical and biological properties affecting the epithelial barrier of the nose during infection.

A BIOCHEMICAL STUDY OF THE EFFECT OF HIGH MOLECULAR WEIGHT HYALURONIC ACID IN MANAGEMENT OF TEMPOROMANDIBULAR JOINT OSTEOARTHRITIS IN RATS

INTRODUCTION: Osteoarthritis is one of the most common degenerative diseases affecting the joints. Adjuvant- induced arthritis (AIA) is an experimental model of polyarthritis which has been widely used for preclinical testing of several anti-arthritic agents and investigating the pathogenesis of arthritis. A modified model of AIA was used in this study, where the disease was induced in one joint. Hyaluronic acid deals with the degenerative effects of arthritis from 3 different aspects: mechanically by maintaining lubrication, metabolically by providing nutritional materials to the articular disc and biologically by decreasing inflammatory effects. OBJECTIVES: to study the biochemical actions of high molecular weight hyaluronic acid (HMWHA) in management of temporomandibular joint (TMJ) adjuvant induced arthritis by detecting matrix metalloproteinase-3 (MMP3) concentration in TMJ tissue extract. MATERIALS AND METHODS: 14 male albino rats were divided into 2 equal groups and in each group a split mouth design was used. •Study I: Arthritis was induced in 7 animals through a single intra-articular injection of Complete Freund's Adjuvant (CFA) in the left TMJs. (50µl) •Study II: Arthritis was induced in the other 7 animals through a single intra-articular injection of CFA and treated with an intra-articular injection of HMWHA into their left TMJs, once a week for total of three injections. 7 animals were sacrificed on day 7 of the disease while the other 7 animals were sacrificed one week after the last injection of HMWHA. Elisa test was performed to detect MMP 3 which is considered as a biomarker of the disease progression RESULTS: The concentration of MMP-3 of study I (diseased group) on day 7 was found to be significantly higher than that of study II (treated group) on day 28. CONCLUSIONS: High molecular weight hyaluronic acid is capable of management of osteoarthritic TMJs.

Effect of high molecular weight hyaluronic acid in treatment of osteoarthritic temporomandibular joints of rats

ObjectiveThe aim of this study was to determine the histological and biochemical effects of high molecular weight hyaluronic acid on experimentally induced osteoarthritic changes in male rat temporomandibular joint (TMJ). DesignIn this in-vivo study, 36 male albino rats were divided into 3 groups; control non-injected, disease and treatment group. Osteoarthritis was induced using a single intra-articular injection of Complete Freund’s adjuvant (CFA) (50 μl). High molecular weight hyaluronic acid (HMWHA) was injected intra-articularly once a week, for a total of 3 injections. TMJ tissue samples were dissected from control, disease and treatment groups for biochemical analysis using ELISA test to detect the levels of matrix metalloproteinase-3 (MMP-3) on day 28. Histological examination was done using Hematoxylin &eosin, Mallory’s trichrome and Alcian blue stains. Data was analyzed using Kruskal-Wallis test followed by Dunn-Sidek method, with a 5 % significance level. ResultsTreatment group showed regaining of the normal histological features of the TMJ and decreased levels of MMP-3 when compared to disease group. ConclusionsThese findings may suggest that HMWHA plays a role in the management of CFA-induced osteoarthritic cartilage lesions.

Human vitreous concentrations of citicoline following topical application of citicoline 2% ophthalmic solution.

PurposeTo evaluate the presence and concentration of citicoline and its metabolites (choline, cytidine and uridine) in the vitreous body in human eyes after topical application of an ophthalmic solution of citicoline 2%, in vivo.MethodsTwenty-one subjects affected by epiretinal membrane with surgical indication for pars-plana vitrectomy underwent treatment with 1 drop 3 times/day of a solution of citicoline 2%, 0.2% high molecular weight hyaluronic acid and 0.01% benzalkonium chloride (OMK1, Omikron Italia s.r.l., Rome, Italy) 14 days before surgery and 2 hours prior to surgery. Five additional patients served as controls and received an OMK1 vehicle solution without citicoline. The vitreous samples were taken at the beginning of the pars-plana vitrectomy and analyzed for qualitative/quantitative determination of vitreous concentration of citicoline and its metabolites by means of high performance liquid chromatography.ResultsThe overall mean concentration of citicoline in patients treated with citicoline 2% solution was 406.72 ± 52.99 μg/mL, while the mean concentration of choline, cytidine and uridine was 180.88 ± 41.49 μg/mL, 44.45 ± 10.19 μg/mL and 330.41 ± 75.8 μg/mL, respectively. The concentration of citicoline in phakic eyes (n = 13, 366.61 ± 129.61 μg/mL) was lower compared to that found in pseudophakic eyes (n = 8, 435.89 ± 131.42 μg/mL) and the difference was not statistically significant. The concentration of citicoline in the control eyes was 45.66 ± 26.36 μg/mL, while the concentration of choline, cytidine and uridine were 17.21 ± 9.93 μg/mL, 6.24 ± 3.6 μg/mL and 172.80 ± 99.76 μg/mL, respectively.ConclusionCiticoline can reach the human vitreous in high concentration when administered in ophthalmic solution. This evidence contributes to the build-up of the pyramid of the evidences required for determining the role of citicoline administered in ophthalmic formulation in retinal and optic nerve neurodegenerative diseases.

Key Factors for A One-Pot Enzyme Cascade Synthesis of High Molecular Weight Hyaluronic Acid.

In the last decades, interest in medical or cosmetic applications of hyaluronic acid (HA) has increased. Size and dispersity are key characteristics of biological function. In contrast to extraction from animal tissue or bacterial fermentation, enzymatic in vitro synthesis is the choice to produce defined HA. Here we present a one-pot enzyme cascade with six enzymes for the synthesis of HA from the cheap monosaccharides glucuronic acid (GlcA) and N-acetylglucosamine (GlcNAc). The combination of two enzyme modules, providing the precursors UDP–GlcA and UDP–GlcNAc, respectively, with hyaluronan synthase from Pasteurella multocida (PmHAS), was optimized to meet the kinetic requirements of PmHAS for high HA productivity and molecular weight. The Mg2+ concentration and the pH value were found as key factors. The HA product can be tailored by different conditions: 25 mM Mg2+ and 2-[4-(2-hydroxyethyl)piperazin-1-yl]ethanesulfonic acid (HEPES)-NaOH pH 8 result into an HA product with high Mw HA (1.55 MDa) and low dispersity (1.05). Whereas with 15 mM Mg2+ and HEPES–NaOH pH 8.5, we reached the highest HA concentration (2.7 g/L) with a yield of 86.3%. Our comprehensive data set lays the basis for larger scale enzymatic HA synthesis.

MECHANISMS OF LONGEVITY: LESSONS FROM LONG-LIVED MAMMALS

Animals have evolved a dramatic diversity of aging rates with lifespans ranging from 2 years to 200 years. This natural diversity of lifespan can be exploited to understand the mechanisms of longevity and develop anti-aging interventions. Our goal is to identify mechanisms that allow such exceptionally long-lived animals to live long and healthy lives and then use these mechanisms to benefit human health. Naked mole rat is the longest-lived rodent with the maximum lifespan of 32 years. We discovered that the mechanism of longevity and cancer resistance in the naked mole rat mediated by high molecular weight hyaluronan. I will discuss the mouse model we generated that mimics the naked mole rat and shows increased healthspan and lifespan. I will also the role of SIRT6 in mediating longevity across mammals and in human centenarians by improving DNA repair and silencing transposable elements.

Transdermal transport of collagen and hyaluronic acid using water in oil microemulsion.

Collagen and hyaluronic acid (HA) are biopolymers that affect the appearance and condition of the skin. Delivery of these compounds into the skin is highly challenging since have a number of disadvantageous properties, such as high molecular weight and hydrophilicity. Here, we evaluated the transdermal penetration of low and high molecular weight collagen and HA from microemulsions. A number of microemulsion formulations, differing in the content of polymers and surfactants (i.e. penetration promoters), were used for the permeation study. In addition, a correlation was made between the composition of these microemulsions and the polymers transport efficiency. The results indicate that, microemulsions enable transdermal permeation of collagen and HA. The concentration of polymers and the solubilization capacity of microemulsions had the greatest influence on the permeation. Surprisingly, the molecular weight of polymers and the content of other components affected the size of microemulsion particles, and thus these parameters had an indirect influence on the permeation process. This study demonstrated therefore the potential therapeutic use of microemulsion with collagen and HA in improving and regenerating the barrier of aged or diseased skin.

Evaluation of the inflammatory response to two intra-articular hyaluronic acid formulations in normal equine joints.

Intra-articular (IA) hyaluronic acid (HA) is commonly used to treat equine arthritis. Inflammatory response or "joint flare" is a recognized potential side effect. However, the incidence and severity of inflammation following IA HA injection in horses is not well documented. This study compared the effects of two IA HA formulations of different molecular weight (MW) and a saline control on clinical signs and synovial fluid markers of inflammation in normal equine joints. Eight adult horses each had three healthy fetlock joints randomly assigned to treatment with either 1.4 mega Dalton HA, 0.8 mega Dalton HA or saline control once weekly for three weeks. Clinical evaluation and synovial fluid analysis were performed by blinded assessors. Outcomes of interest were lameness score, joint effusion score and synovial fluid white cell count and differential, total protein, viscosity and serum amyloid A. Joints injected with HA developed significant mild-to-moderate inflammatory responses often associated with lameness and joint effusion compared with saline control joints. The higher MW HA formulation elicited a significantly greater inflammatory response than the lower MW HA after the first injection. In HA injected joints, viscosity remained poor for the entire study. Both IA HA formulations in this study induced an inflammatory response in healthy equine joints. This may have implications for the use of HA in equine joints. The findings in this study are limited to the two HA formulations used. Further investigation of different HA formulations and the use of HA in normal and arthritic equine joints iswarranted.

Improved Clinical Outcomes After Arthroscopic Microfracture in Isolated Medial Talar Osteochondral Lesions with a Single Injection of High Molecular Weight Hyaluronic Acid

Objective: To investigate the efficacy of a single intra-articular injection of high molecular weight hyaluronic acid (HMW-HA) for treating isolated medial osteochondral lesions (OCLs) of the talus following arthroscopic microfracture. Methods: A total of 39 patients, treated between 2014–2017 for medial OCLs of the talus, were enrolled in the study. Patients were split into two groups: group 1, consisting of 18 patients who received a single of 4 ml of HMW-HA (22 mg/ml) injection following microfracture; and group 2, consisting of 21 patients who underwent microfracture but did not receive an injection. Functional and clinical outcomes were assessed at baseline, 6 months, and at a final follow-up using a visual analogue scale (VAS) and the American Orthopaedic Foot and Ankle Society Ankle-Hindfoot Scale (AOFAS). Results: The mean AOFAS score increased in groups 1 and 2, from 45.61±14.71 to 95.11±5.02 (p=0.0001) and 41.81±13.83 to 90.29±7.43 (p=0.0001), respectively. Similarly, the mean VAS score decreased in groups 1 and 2 from 8.72±1.23 to 2.11±1.45 (p=0.0001) and 9.05±0.80 to 3.67±2.22 (p=0.0001), respectively. In addition, the mean AOFAS score in group 1 was higher than in group 2 (p=0.025) at the final follow-up, and the mean VAS score in group 1 was lower than that of group 2 (p=0.0001, p=0.015, respectively) at 6 months postoperatively and the final follow-up. Conclusions: Although both treatments for isolated medial OCL of the talus were associated with a decrease in pain and less loss of function, single-dose HMW -HA injection following arthroscopic microfracture was significantly more effective .

Mucoadhesive properties of liquid lipid nanocapsules enhanced by hyaluronic acid

In the field of drug delivery, nanoparticles (NPs) offer important advantages such as drug protection and solubilization, increased bioavailability, prolonged blood circulation time or sustained drug delivery. Regarding patients’ quality of life, the oral route is the most convenient, but developing oral therapies is a great challenge because of the physiological barriers to overcome. NPs can protect the active compound from the digestive process, but they need to diffuse through the mucus layer and be absorbed by the intestinal epithelium. Interaction between NPs and mucus can be promoted by the mucoadhesive properties of polysaccharide hyaluronic acid (HA). In this work, the interaction between mucin and liquid lipid nanocapsules loaded with Coumarin 153 and coated with HA of different molecular weights, has been evaluated by dynamic light scattering and by fluorimetric techniques, providing new insights in the investigation of this interaction. Hydrodynamic radius and ζ-potential data evidence that mucin and HA interact even at low mucin concentrations, and suggest that a layer of mucin is formed around the particles. FRET analysis, static fluorescence spectroscopy, anisotropy studies and time-resolved fluorescence further confirmed this interaction, allowed determination of binding constants and disclosed the different behaviour of low and high molecular weight HA.

Pilot, Open and Non-controlled Trial to Assess the Objective Parameters which Correlate Knee Mobility with Pain Reduction in Patients Affected by Knee Osteoarthritis and Treated with Oral Hyaluronic Acid

The study was in preparation for a future randomized clinical trial (RCT) with oral hyaluronic acid (HA) in knee osteoarthritis. Its purpose was to evaluate the feasibility of i) ultrasonography (US) and range of motion (ROM) parameters as objective measurements to correlate the improvement of knee mobility with its pain reduction; ii) the planned recruitment monthly rate to estimate the resources for the main study. In addition, it should give by US, ROM, visual analogue scale (VAS) and KOOS questionnaire, preliminary data on efficacy. This open-label pilot trial was performed in an orthopedic clinic (Timisoara, Romania). Male and female subjects (from 50 to 70 years) diagnosed with symptomatic OA of the knee with i) mild joint discomfort for at least 6 months, ii) Kellgren/Lawrence score 2 by X-ray, iii) pain for at least 15 of the 30 previous days, were included. Exclusion criteria were: inflammatory arthritic condition; oral corticosteroids within 4 weeks; intra-articular injections of HA or corticosteroids within 3 months; anti-inflammatory or chondroprotective drugs within 2 weeks. Following protocol, 8 patients administered for 8 weeks Syalox� 300 Plus (River Pharma, Italy) a product based on HA of high molecular weight. US parameters improved from baseline, even if no statistically significant differences were found. ROM and VAS (at rest, on moving and on pressing) values improved significantly at week 4 and 8 in comparison with baseline. The correlation between objective improvement of knee mobility and subjective pain reduction was documented. The enrolment rate was 8 patients/month. The KOOS subscales scores evidenced statistically significant differences during the study. No adverse event. US and ROM can be used as objective measurements to correlate improvement of knee mobility with pain reduction. The recruitment capability evidenced a realistic estimation of time and budget for the main study. Preliminary data on efficacy using objective measurements (US, ROM) and subjective parameters (VAS, KOOS questionnaire) showed significant improvements and will be used for sample size calculation in the main study.

Evaluation of KI-67, Apoptosis, and Hyaluronic Acid in Grading Retinoblastoma

Hyaluronic acid (HA) is a glycosaminoglycan with a straight-chain polymer arrangement defined as the extracellular matrix constituent. High molecular weight HA has normal physicochemical, biological, and physiological properties whereas low molecular weight has the property of angiogenesis, inflammation, and suppresses apoptosis. This study occupied the samples of 35 paraffin block from poorly and well differentiated retinoblastoma tissue and 8 normal retinal block which have been collected for 4 years from 2010-2013 at Dr. Soetomo Hospital, Surabaya, Indonesia. Afterwards, the paraffin blocks were immunohistochemically examined for HA staining, expression of cell proliferation (Ki-67), and cell apoptosis to determine intratumoral aggressiveness of retinoblastoma. HA on poorly differentiated retinoblastoma stain with a high immunostaining of 76.2%, while well differentiated retinoblastoma on the highest HA staining was revealed to be at moderate level of 64.3%, and not appear in normal retina. In poorly differentiated retinoblastoma, the location of most HA stain is in the cell cytoplasm (87.5%). In the well differentiated retinoblastoma, the HA immunostaning mainly occurred in the cell membrane (73.7%). Histopathological retinoblastoma grading showed a significant correlation (p <0.01) towards several variables of HA immunostaining, Ki-67, and cell apoptosis. In addition, the histopathological retinoblastoma grading also revealed a significant correlation (p <0.01) towards the location of HA staining (cell membrane and cytoplasm). Both stainings are also play role in retinoblastoma differentiation. The malignancy of retinoblastoma can be proven by the increased HA staining at cytoplasm in poorly differentiated and associated with increased of cell proliferation along with decreased apoptosis.

Corrigendum to "Effect of High, Medium, and Low Molecular Weight Hyaluronan on Inflammation and Oxidative Stress in an In Vitro Model of Human Nasal Epithelial Cells".

[This corrects the article DOI: 10.1155/2016/8727289.].

Hyaluronic acid as a macromolecular crowding agent for production of cell-derived matrices

Cell-derived matrices (CDMs) provide an exogenous source of human extracellular matrix (ECM), with applications as cell delivery vehicles, substrate coatings for cell attachment and differentiation, and as biomaterial scaffolds. However, commercial application of CDMs has been hindered due to the prolonged culture time required for sufficient ECM accumulation. One approach to increasing matrix deposition in vitro is macromolecular crowding (MMC), which is a biophysical phenomenon that limits the diffusion of ECM precursor proteins, resulting in increased ECM accumulation at the cell layer. Hyaluronic acid (HA), a natural MMC highly expressed in vivo during fetal development, has been shown to play a role in ECM production, but has not been investigated as a macromolecule for increasing cell-mediated ECM deposition in vitro.In the current study, we hypothesized that HA can act as a MMC, and increase cell-mediated ECM production. Human dermal fibroblasts were cultured for 3, 7, or 14 days with 0%, 0.05%, or 0.5% high molecular weight HA. Ficoll 70/400 was used as a positive control. SDS-PAGE, Sircol, and hydroxyproline assays indicated that 0.05% HA-treated cultures had significantly higher mean collagen deposition at 14 days, whereas Ficoll 70/400-treated cultures had significantly lower collagen production compared to the HA and untreated controls. However, fluorescent immunostaining of ECM proteins and quantification of mean gray values did not indicate statistically significant differences in ECM production in HA or Ficoll 70/400-treated cultures compared to untreated controls. Raman imaging (a marker-free spectral imaging method) indicated that HA increased ECM deposition in human dermal fibroblasts. These results are consistent with decreases in CDM stiffness observed in Ficoll 70/400-treated cultures by atomic force microscopy. Overall, these results indicate that there are macromolecule- and cell type- dependent effects on matrix assembly, turnover, and stiffness in cell-derived matrices. Statement of SignificanceCell-derived matrices (CDMs) are versatile biomaterials with many regenerative medicine applications, including as cell and drug delivery vehicles and scaffolds for wound healing and tissue regeneration. While CDMs have several advantages, their commercialization has been limited due to the prolonged culture time required to achieve CDM synthesis in vitro. In this study, we explored the use of hyaluronic acid (HA) as a macromolecular crowder in human fibroblast cell cultures to support production of CDM biomaterials. Successful application of macromolecular crowding will allow development of human cell-derived, xeno-free biomaterials that re-capitulate the native human tissue microenvironment.