Ladislav Šoltés

Slovak Academy of Sciences | SAV

Hyaluronan (HA) is a non-sulfated glycosaminoglycan that is present in a variety of body tissues and organs. Hyaluronan has a wide range of biological activities that are frequently influenced by molar mass; however, they also depend greatly on the source, purity, and kind of impurities in hyaluronan. High-molar-mass HA has anti-inflammatory, immun...

The effect of a 10-day-long treatment with taxifolin (TAX, 20 mg/kg/day p.o.) was investigated on spontaneously hypertensive rats (SHRs) with a focus on the vascular functions of isolated femoral arteries and thoracic aortas. TAX reduced blood pressure in SHRs. In femoral arteries, TAX increased acetylcholine-induced relaxation, reduced the maximal...

Medical-grade polymers, i.e., polyvinylchloride and low-density polyethylene (LDPE), were modified by antibacterial compounds through a multistep physicochemical approach. The polymer´s initial surface activation was performed foremost via diffuse coplanar surface barrier discharge plasma. Then, radical graft copolymerization of acrylic acid (AA) t...

We examined the free-radical scavenging capacity of edaravone using the standard spectroscopic methods. Further, the impact of wound dressings composed of chitosan/hyaluronan with the addition of H atom and/or electron donoring edaravone in the absence and presence of laponite, C-nanofibers or silver-plated C-nanofibers was assessed on the healing...

The present study aimed at preparing novel free-radical scavenging and water-soluble compounds derived from gelatin. Specifically, gelatin–syringaldehyde, gelatin–anisaldehyde, and gelatin–vanillin were synthesized and thoroughly studied for their physicochemical properties. In particular, the compounds were characterized by UV-Vis spectroscopy, Fo...

We studied the kinetics of the reaction of N-acetyl-l-cysteine (NAC or RSH) with cupric ions at an equimolar ratio of the reactants in aqueous acid solution (pH 1.4–2) using UV/Vis absorption and circular dichroism (CD) spectroscopies. Cu2+ showed a strong catalytic effect on the 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonate) radical (ABTSr) co...

To date, available review papers related to the electrospinning of biopolymers including polysaccharides for wound healing were focused on summarizing the process conditions for two candidates, namely chitosan and hyaluronic acid. However, most reviews lack the discussion of problems of hyaluronan and chitosan electrospun nanofibers for wound dress...

In the minireview presented here, the authors discuss the evaluation of inhibitory effect of substances in the phases of initiation and propagation of high-molar-mass hyaluronan oxidative degradation. The experimental approach should be considered as original since on using a simple experimental assay it is possible to prove both the so-called “pre...

High levels of hyaluronic acid (HA) in tumors correlate with poor outcomes with several types of cancers due to HA-driven support of adhesion, migration and proliferation of cells. In this study we explored how to enhance the degradation of HA into low-molecular fragments, which cannot prevent the immune system to fight tumor proliferation and meta...

Hyaluronan (HA) is a natural glycosaminoglycan present in many tissues of all vertebrates. HA has various biological functions, which are dependent on its molar mass. High-molar-mass HA has anti-angiogenic, immunosuppressive and anti-inflammatory properties, while low-molar-mass HA has opposite effects. HA has also antioxidative properties, however...

Chitosan, industrially acquired by the alkaline N-deacetylation of chitin, belongs to β-N-acetyl-glucosamine polymers. Another β-polymer is hyaluronan. Chitosan, a biodegradable, non-toxic, bacteriostatic, and fungistatic biopolymer, has numerous applications in medicine. Hyaluronan, one of the major structural components of the extracellular matri...

Chitosan is industrially acquired by the alkaline N-deacetylation of chitin. Chitin belongs to the β-N-acetyl-glucosamine polymers, providing structure, contrary to α-polymers, which supply food with energy. Another β-polymer providing structure is hyaluronan. A lot of studies have been performed on chitosan to explore its industrial use. Since chi...

The chapter deals with the identification of gaseous effluents resulting from the preparation of hybrid adhesive-laser joints. CrNiMo AISI 316 1 mm thick stainless steel was used as the base material (adherend), which was joined by four types of Loctite two-component epoxy adhesives: Hysol 9466, Hysol 9455, Hysol 9492, and Hysol 9497 with D70 weldi...

Antioxidant and antimicrobial wound dressings are the most favorable for acute and chronic wounds treatment. Herein, we formulated a multifunctional polyelectrolyte wound dressing membrane on the basis of chitosan (Ch) and hyaluronan (HA) enhanced by phosphatidylcholine dihydroquercetin (PCDQ). Physicochemical properties and microstructures of fabr...

A high-molecular weight hyaluronan is oxidatively degraded by Cu(II) ions and ascorbate—the so called Weissberger biogenic oxidative system—which is one of the most potent generators of reactive oxygen species, namely •OH radicals. Ergothioneine, hercynine, or histidine were loaded into chitosan/hyaluronan composite membranes to examine their effec...

The inflammation of chronic wounds generally causes delaying their healing process. The present work aims to formulate a wound dressing polyelectrolyte membrane based on chitosan (Ch) and sodium hyaluronate (HA) loaded with glutathione (GSH). The membrane types (Ch/HA and Ch/HA/GSH) were examined by Fourier transform infrared spectroscopy (FT-IR)....

Indole derivatives such as isatin (a natural compound), cemtirestat, stobadine, and its derivatives (synthetic compounds) are known to have numerous positive effects on human health due to regulation of oxidative status. The aim of the study was to assess radical scavenging capacities of these compounds and explore their potential protective effect...

Investigation results of wood using Radio-Frequency plasma at reduced presuusre in this chapter has been summarized.

The various wood species oak, beech, maple and ash modified by radio-frequency discharge (RFD) plasma in air atmosphere were studied. The physical and chemical changes were investigated by static contact angles of water and FTIR-ATR spectra measurements for all investigated woods. The results of investigation confirmed the increase in the wood hydr...

Uncontrolled production of oxygen and nitrogen radicals results in oxidative and nitrosative stresses that impair cellular functions and have been regarded as causative common denominators of many pathological processes. In this review, we report on the beneficial effects of molecular hydrogen in scavenging radicals in an artificial system of • OH...

The paper published by Ruczyszky and Liu (2017) reports on the biosynthesis of ergothioneine under both aerobic and anaerobic conditions. We would like to suggest a hypothesis as to what could be the reason that microorganisms on the Earth synthesized ergothioneine under anaerobic conditions.

Ascorbate administered intravenously gives a high plasma concentration of this drug. Clinical trials with pancreatic carcinoma patients revealed their prolonged survival if treated with intravenous ascorbate. On the other hand, high plasma ascorbate concentration leads to severe side effects, such as nephrotoxicity. In the present paper, we advocat...

Two self-associating biopolymers, namely chitosan (Ch) and a high-molar-mass hyaluronan (HA), were used to prepare membranes with the aim to protect and to enhance the healing of injured skin. A mitochondrially-targeted antioxidant—MitoQ—was incorporated into the mixture of biopolymers prior to their self-association. These three-component membrane...

To inhibit reactive oxygen species-induced hyaluronan degradation, protective effects of glutathione, chitosan derivatives (phosphonate chitosan and sulfonated chitosan) individually and in a combination with glutathione were analyzed. A source of reactive oxygen species was cupric ions and ascorbate—the so-called Weissberger’s biogenic oxidative s...

3T3 and VH10 cells were subjected to oxidative damage by hydroxyl radicals generated from Cu(II) ions and ascorbate. The presence of reactive oxygen and nitrogen species in cells was determined using fluorescent dyes. MitoQ—a mitochondrially targeted antioxidant—was examined to prevent cell death and was compared with trolox as a reference standard...

The antioxidant and antimicrobial properties of keratin hydrolysates from acid and from oxidative hydrolyses were studied. For in vitro studies of antioxidant properties of the keratin hydrolysates high-molar-mass hyaluronic acid (HA) that is especially sensitive to the effect of oxidants was used as a substrate. Cu(II) ions and ascorbate-mediated...

Cinnamaldehyde was immobilized to O-amine functionalized chitosan via a coupling reaction. Fourier transform infrared spectroscopy confirmed N-cinnamyl substitution. Wetting analyses demonstrate more hydrophobicity in the N-cinnamyl substituted O-amine functionalized chitosan compared to chitosan or unsubstituted O-amine functionalized chitosan. Th...

Hyaluronan is the major extracellular matrix glycosaminoglycan polymer present in vertebrate tissues, with a molar mass that can reach several megaDaltons. It is particularly prominent in the matrix of tissues undergoing rapid turnover, in fetal tissues, and wherever regeneration and repair are occurring. Hyaluronan has highly varied biological fun...

Antioxidants may have a positive effect on human health since they can protect human body against deterioration by reactive oxygen species (ROS). Chitosan has many promising properties as nontoxic, biocompatible, biodegradable, antimicrobial and recently antioxidant properties. Most of reports on the antioxidant activity of chitosan are based on ab...

Kinetics of reduction of the stable radical cation derived from 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS) in reaction with the anti-rheumatic drug bucillamine (BUC) and two reference thiols – cysteine (Cys) and glutathione (GSH) was followed spectrophotometrically in acidic medium with 10-fold molar excess of the reductant. Deca...

Objective: Venlafaxine (VLF) was examined as a potential donor of H atom(s) to scavenge hydroxyl and peroxy-type radicals generated under aerobic conditions by catalytic oxidation of ascorbate with Cu2+ ions. Kinetics of the electron-donor property of VLF was investigated by standard ABTS and DPPH assays. Electron paramagnetic resonance measuremen...

In this study, new cinnamyl chitosan schiff base was evaluated as antioxidant material. Antioxidant activity was measured by two different popular methods (uninhibited/inhibited hyaluronan degradation and decolorization of ABTS methods). the results show decrease the hydrogen donation behavior of chitosan after coupling with cinnamaldehyde, in the...

Since chitosan and its amino-, cinnamo- or cinnamo-amino- derivatives are acid-soluble, the effect of acetic acid on hyaluronan (HA) macromolecules degraded by Cu(II) ions and ascorbate was examined to produce reactive oxygen species (ROS). Further, the effects of glutathione (GSH), chitosan and its derivatives, added individually or in combination...

The surface treatment of steel is frequently used in many industrial applications. The nitrooxidation of steel is one of noconventional method of the surface treatment, which can to improve the mechanical properties, fatigue characteristics and corrosion resistance of steel. New method of steel surface pre-treatment has a major influence for improv...

The ability to protect hyaluronic acid (HA) from oxidative degradation by cupric ions and ascorbate (production of OH and peroxy-type radicals) during acute phase joint inflammation has been investigated using the following drugs: tiopronin, captopril, and levamisole. Radical scavenging activity, i.e. the propensity for donation of electrons was as...

Potential protective effects of elderberry (Sambucus nigra) extracts against oxidative degradation of hyaluronan (HA) were detected in vitro. To induce free-radical-mediated HA degradation, Weissberger’s biogenic oxidative system, which mimics the situation of acute inflammation, was applied. Time- and dose-dependent changes of dynamic viscosity of...

Joining of steel sheets treated by the process of nitrooxidation represents an interesting technical as well as technological problem. The fusion welding methods with high energy concentration, e.g. laser beam welding are one of the possible options, however even with high effort of minimising the surface layer deterioration, it's not possible to c...

Hyaluronan (HA) molecules were exposed to free radical-mediated degradation performed by the reaction mixture Cu(II) and ascorbate, the so-called Weissberger biogenic oxidative system, which mimics the situation of acute inflammation. To achieve protection of HA from degradation, herbal extracts such as Agrimonia herba, Cynare folium, and Ligustri...

To assess protective effects of the tara (Caesalpinia spinosa) extract against hyaluronan (HA) degradation evoked by cupric ions and ascorbate. Uninhibited/inhibited HA degradation was assayed by a decrease in dynamic viscosity of the HA solutions, whereas as a method rotational viscometry was used. To determine radical scavenging capacity of the t...

The bucillamine effect on free-radical-mediated degradation of high-molar-mass hyaluronan (HA) has been elucidated. As HA fragmentation is expected to decrease its dynamic viscosity, rotational viscometry was applied to follow the oxidative HA degradation. Non-isothermal chemiluminometry, thermogravimetry, differential scanning calorimetry, and siz...

. Currently the reinforcement of steel surface treatment is widely used in variousindustries, especially in the automobile. The paper discusses the new economical methods ofprocessing the steel surface, which can significantly improve the properties of the metal.Key words: steel surface, сhemical modification, mechanical properties of the material,...

Oxidative stress and the resulting damage to cellular and extracellular components has been observed in a variety of degenerative processes, including degenerative joint disorders, where high-molar-mass hyaluronan (HA) is often found to be massively degraded. The present study sought to test the hypothesis that dithiols are more effective in protec...

A multistep physicochemical approach making use of plasma technology combined with wet chemistry has fueled considerable interest in delivery of surface-active antiadherence materials. In the first step of the approach, concerning an inherent lack of befitting functional groups on pristine substrate, plasma treatment at low temperature and atmosphe...

A new physicochemical method of polymer surface modification using the plasma technology combined with wet chemistry has fueled considerable interest in delivery of surface-active antiadherence materials. In the first step of the approach, concerning an inherent lack of befitting functional groups on pristine substrate, plasma treatment at low temp...

Mineral waters from Bardejovske Kupele spa are natural, strongly mineralized, with healing effects. They are classified as hydrocarbonic - containing chloride and sodium - carbonic, cold, hypotonic, with a relatively high boric acid content. Potential anti-oxidative effects of curative waters from Bardejovske Kupele were investigated against the hy...

Several sorts of block polyimide based copolymers, namely poly(imide-co-siloxane) (PIS) block copolymers containing siloxane blocks in their polymer backbone have been investigated. In comparison with pure polyimides the PIS block copolymers possess some improvements, e.g. enhanced solubility, low moisture sorption, and their surface reaches the hi...

Five hexahydropyridoindoles, namely stobadine, SM1dM9dM10, SME1i-ProC2, SM1M3EC2, and SMe1EC2, in the form of mono- or dihydrochloride salts, were tested to act as an H atom donor as well as an electron donor. The H atom donating properties of the substances were examined by rotational viscometry - an assay based on hyaluronan free-radical degradat...

High-molar-mass hyaluronan (HA) was used as a model biomacromolecule to study its in vitro oxidative damage. The main aim of the present study was to test Aloe Vera Freedom drinking gel and one of its components, methylsulfonylmethane, for their ability to protect HA from oxidative degradation. The secondary objective was to monitor the blood gluco...

Objectives: Hyaluronan (HA), one of the main components of extracellular matrix, is a glycosaminoglycan composed of repeating disaccharide units of N-acetyl-d-glucosamine and d-glucuronic acid linked by β-(1→4) and β-(1→3) glycoside bonds. High-molar-mass HA was used as a model for studying its oxidative degradation. In the present paper protectiv...

Fourier-transform infrared spectroscopy and non-isothermal methods—chemiluminometry, differential scanning calorimetry, and differential thermogravimetry—were used to characterize potential structural changes of thiol-modified hyaluronans. Degradative conditions tested via rotational viscometry were first initiated applying oxidative Weissberger’s...

Stobadine·2HCl and its two hydrophilic derivatives SM1dM9dM10·2HCl and SME1i-ProC2·HCl were tested in the function of antioxidants on hyaluronan (HA) degradation induced by the Weissberger oxidative system [ascorbate plus Cu(II)]. As a primary method, rotational viscometry was applied, where the substance tested was added before or 1 h after the in...

Based on our previous findings, the present study has focused on free-radical-mediated degradation of the synovial biopolymer hyaluronan. The degradation was induced in vitro by the Weissberger's system comprising ascorbate plus cupric ions in the presence of oxygen, representing a model of the early phase of acute synovial joint inflammation. The...

High-molecular-weight hyaluronan (HA) samples were exposed to free-radical chain-degradation reactions induced by ascorbate in the presence of Cu(II) ions - the so-called Weissberger's oxidative system. The concentrations of both reactants [ascorbate, Cu(II)] were comparable to those that may occur during an early stage of the acute phase of joint...

Glycosaminoglycans Hyaluronic Acid/Hyaluronan – Structure, Occurrence Hyaluronan Synthases Enzymatic Catabolism of Hyaluronan Oxidative Degradation of Hyaluronan Hyaluronan Degradation under Inflammatory Conditions Interaction of Hyaluronan with Proteins and Inflammatory Mediators Hyaluronan and Its Derivatives in Use Concluding Remarks

Current understanding on the role of peroxynitrite in etiology and pathogenesis of some human diseases, such as cardio-vascular diseases, stroke, cancer, inflammation, neurodegenerative disorders, diabetes mellitus and diabetic complications has recently led to intensive investigation of peroxynitrite involvement in physiology and pathophysiology....

The potential anti- or pro-oxidative effects of a disease-modifying antirheumatic drug, aurothiomalate, to protect high-molar-mass hyaluronan against radical degradation were investigated along with L-glutathione - tested in similar functions. Hyaluronan degradation was induced by the oxidative system Cu(II) plus ascorbate known as the Weissberger'...

New ways of supplementary or combinatory therapy of rheumatoid arthritis (RA) are of great importance. The aim is to find an additive to classical RA therapy with natural molecules without side effects possessing anti-inflammatory and anti-oxidative properties. In this study we investigated the anti-oxidative and anti-inflammatory properties of the...

This study presents the results of antioxidative and pro-oxidative efficacy of cysteamine and D-penicillamine (D-pen) in comparison to L-glutathione (L-GSH) on high-molar-mass hyaluronan (HA) degradation by cupric ions plus ascorbic acid. The substance tested was applied in the degradative system cupric ions plus ascorbate: (i) before the reaction...

Comparison of the effectiveness of antioxidant activity of three thiol compounds, D-penicillamine, reduced L-glutathione, and 1,4-dithioerythritol, expressed as a radical-scavenging capacity based on the two independent methods, namely a decolorization 2,2'-azinobis[3-ethylbenzothiazoline-6-sulfonic acid] assay and a rotational viscometry, is repor...

Protective effects of manganese(II) chloride on hyaluronan degradation by oxidative system ascorbate plus cupric chloride The degradation of several high-molar-mass hyaluronan samples was investigated in the presence of ascorbic acid itself and further by an oxidative system composed of ascorbic acid plus transition metal ions, i.e. Fe(II) or Cu(II...

Reactive oxygen species, which are generated during the oxygen metabolism, participate in physiological catabolism of native high-molar-mass hyaluronan within the joint synovial fluid. It is very plausible that the microenvironment of the oxidativereductive hyaluronan degradation under physiological conditions is closely to bone cartilages. Yet at...

High-molar-mass hyaluronan (HA) degradation was initiated by two oxidative systems, i.e. ascorbate plus Fe(II) ions and ascorbate plus Cu(II) ions. By using the method of rotational viscometry, we observed dose-dependent degradation of HA by the above mentioned oxidative systems, which however differed in the reaction kinetics. The effects of two b...

Hyaluronan-degrading enzymes in synovial fluid, if any, is extremely low. Thus, the high rate of this glycosaminoglycan turnover in synovial fluid, around 12 hours, should result from a cause different from enzymatic catabolism. An alternative and plausible mechanism is that of oxidative-reductive degradation of the biopolymer chains by a combined...

The paper deals with adhesive and mechanical properties study of nanocomposites based on ethylene-acrylic acid copolymer during aluminium bonding. The main objective was to describe the changes of co-polymer properties during increasing of the nanofiller's concentration. Based on executed experiments it was found out, that the properties of tested...

One of the very complex structures in the vertebrates is the joint. The main component of the joint is the synovial fluid with its high-molar-mass glycosaminoglycan hyaluronan, which turnover is approximately twelve hours. Since the synovial fluid does not contain any hyaluronidases, the fast hyaluronan catabolism is caused primarily by reductive-o...

Pro- and anti-oxidative effects of two thiol compounds, d-penicillamine and reduced l-glutathione, on the kinetics of degradation of high-molar-mass hyaluronan samples were monitored via rotational viscometry. The degradation was induced under aerobic condition by the so-called Weissberger′s system [ascorbate plus Cu(II)]. Electron paramagnetic res...

magnified image Pro‐ and anti‐oxidative effects of an anti‐rheumatoid drug, D ‐penicillamine ( D ‐PN), on the kinetics of high‐molar‐mass hyaluronan (HA) degradation were monitored using the method of rotational viscometry. The degradation of the dissolved HA macromolecules was attained by applying the Weissberger 's system comprising ascorbic acid...

magnified image This study compares the radical scavenging capacity of high‐molar‐mass hyaluronan (HA) using standardized methods applying 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) radicals and 2,2′‐azinobis[3‐ethylbenzthiazoline sulfonate] (ABTS) radical cations as oxidants. Additionally, spin‐trapping technique combined with electron paramagnetic reso...

Hyaluronan (hyaluronic acid, HA) is a linear naturally occurring polysaccharide formed from repeating disaccharide units of N-acetyl-D-glucosamine and D-glucuronate. Despite its relatively simple structure, HA is an extraordinarily versatile glycosaminoglycan currently receiving attention across a wide front of research areas. It has a very high mo...