Polymeric Sulfate Research Articles

Polymer-assisted co-axial multi-layered circular ZnO nanodisks

Multi-layered ZnO circular nanodisks were efficiently fabricated using sodium dodecyl sulfate (SDS) and polyvinylpyrrolidone (PVP) polymer by a controlled hydrothermal method. As-prepared ZnO nanostructures were characterized by X-ray powder diffraction, field-emission scanning electron microscopy, and high-resolution transmission electron microscopy. The effect of SDS and PVP polymer on the formation of ZnO multi-layer nanostructures was described in detail. Based on experimental results, a possible mechanism of circular disk formation was proposed. The gas-sensing properties of multi-layered nanodisks were reported for formaldehyde under different concentrations from 5 to 1200ppm at 300°C. A higher response toward formaldehyde was observed, rendering the multi-layered nanostructures a promising gas-sensing material for the on-site detection of formaldehyde.

Sulfated and sulfonated polymers are able to solubilize efficiently the protein aggregates of different nature

The search for new ways to suppress unwanted protein aggregation represents an important problem in modern biochemistry, bioengineering, and even medicine. Recently we succeeded in preventing the aggregation using synthetic polyelectrolytes. The present work describes a new approach to solubilizing pre-formed protein aggregates with sulfated or sulfonated polymers (polysulfoanions). For the first time it was shown that polysulfoanions are capable of solubilizing amorphous and amyloid protein inclusion bodies as well as thermal aggregates. Treatment of prion protein inclusion bodies with sulfonated polymers was shown to cause significant decrease in amyloid structure content, whereas in case of thermal aggregates of glyceraldehyde-3-phosphate dehydrogenase the observed solubilization was accompanied by a partial recovery of enzymatic activity. The suggested approach could be relevant in the task of extracting recombinant proteins from inclusion bodies and also useful in the development of amyloid disease therapy.

Synthesis and anticoagulant activity of polyureas containing sulfated carbohydrates.

Polyurea-based synthetic glycopolymers containing sulfated glucose, mannose, glucosamine, or lactose as pendant groups have been synthesized by step-growth polymerization of hexamethylene diisocyanate and corresponding secondary diamines. The obtained polymers were characterized by gel permeation chromatography, nuclear magnetic resonance spectroscopy, and Fourier transform infrared spectroscopy. The nonsulfated polymers showed similar results to the commercially available biomaterial polyurethane TECOFLEX in a platelet adhesion assay. The average degree of sulfation after reaction with SO3 was calculated from elemental analysis and found to be between three and four −OSO3 groups per saccharide. The blood-compatibility of the synthetic polymers was measured using activated partial thromboplastin time, prothrombin time, thrombin time, anti-IIa, and anti-Xa assays. Activated partial thromboplastin time, prothrombin time, and thrombin time results indicated that the mannose and lactose based polymers had the highest anticoagulant activities among all the sulfated polymers. The mechanism of action of the polymers appears to be mediated via an anti-IIa pathway rather than an anti-Xa pathway.

Heparin-Like Polymers for Potential Inhibition of Bacterial Infection

Sulfated polysaccharides have attained a new recognition in medicine for treatment of human pathogens such as Staphylococcus aureus. By careful protecting group strategy, methacrylate derivatives of sulfated sugars containing various saccharides have been successfully produced. The position of sulfate groups as well as methyl methacrylate was varied to demonstrate the structure-activity relationship (SAR) of the resulting polymers in regards to their multivalent effect on the bacteria inhibition. The preliminary in vitro assay indicated promising inhibition of S. aureus infection in the presence of doubly sulfated polymers and suggests that our sulfated polymers might be a potential candidate to mediate S. aureus internalization.

Heparin-Mimicking Polymer Modified Polyethersulfone Membranes - A Mini Review

Recent studies on the modification of polyethersulfone (PES) membranes using heparin-mimicking polymers are reviewed. The general conception of heparin-mimicking polymersis defined as the syntheticpolymers (including the biopolymer derivates and synthetic sulfated artificial polymers) with similar biologically functionalities as heparin, such as the anticoagulant, growth factor binding, and also disease mediation. In the review, heparin-mimicking polymers is briefly reviewed; then heparin-mimicking polymer modified PES membranes, including blended, coated, and grafted membranes are discussed respectively.

The Role of the Conformational Profile of Polysaccharides on Skin Penetration: The Case of Hyaluronan and Its Sulfates

The literature data suggest the capacity of biomacromolecules to permeate the human skin, even though such a transdermal permeation appears to be governed by physicochemical parameters which are significantly different compared to those ruling the skin permeation of small molecules. On these grounds, the present study was undertaken to investigate the in vitro diffusion properties through the human epidermis of hyaluronic acid and their sulfates. Low- and medium-molecular-weight hyaluronic acids and the corresponding derivatives at two degrees of sulfation were then tested. In vitro studies evidenced that the sulfated polymers permeate better than the corresponding hyaluronic acid, despite their vastly greater polarity, while the observed permeation markedly decreases when increasing the polymer's molecular weight regardless of the sulfation degree. Using a fluorescent-labeled polysaccharide, it was also evidenced that hyaluronans have a great affinity for corneocytes and likely cross the stratum corneum mainly through a transcellular route. The molecular-dynamics study revealed how the observed permeations for the investigated polysaccharides can be rationalized by monitoring their conformational profiles, since the permeation was found to be directly related to their capacity to assume extended and flexible conformations.

Enhancing the intestinal absorption of low molecular weight chondroitin sulfate by conjugation with α-linolenic acid and the transport mechanism of the conjugates

The purpose of this report was to demonstrate the effect of amphiphilic polysaccharides-based self-assembling micelles on enhancing the oral absorption of low molecular weight chondroitin sulfate (LMCS) in vitro and in vivo, and identify the transepithelial transport mechanism of LMCS micelles across the intestinal barrier. α-Linolenic acid-low molecular weight chondroitin sulfate polymers(α-LNA-LMCS) were successfully synthesized, and characterized by FTIR, (1)HNMR, TGA/DSC, TEM, laser light scattering and zeta potential. The significant oral absorption enhancement and elimination half-life (t₁/₂) extension of LNA-LMCS2 in rats were evidenced by intragastric administration in comparison with CS and LMCS. Caco-2 transport studies demonstrated that the apparent permeability coefficient (Papp) of LNA-LMCS2 was significantly higher than that of CS and LMCS (p<0.001), and no significant effects on the overall integrity of the monolayer were observed during the transport process. In addition, α-LNA-LMCS micelles accumulated around the cell membrane and intercellular space observed by confocal laser scanning microscope (CLSM). Furthermore, evident alterations in the F-actin cytoskeleton were detected by CLSM observation following the treatment of the cell monolayers with α-LNA-LMCS micelles, which further certified the capacity of α-LNA-LMCS micelles to open the intercellular tight junctions rather than disrupt the overall integrity of the monolayer. Therefore, LNA-LMCS2 with low cytotoxicity and high bioavailability might be a promising substitute for CS in clinical use, such as treating osteoarthritis, atherosclerosis, etc.

Hydrolysis of cellulose catalyzed by sulfonated poly(styrene-co-divinylbenzene) in the ionic liquid 1-n-butyl-3-methylimidazolium bromide

The hydrolysis of cellulose catalyzed by sulfonated poly(styrene-co-divinylbenzene) (SPS–DVB) was carried out in the ionic liquid 1-n-butyl-3-methylimidazolium bromide (BMIMBr), in which the reaction medium BMIMBr and sulfate polymer catalyst can be recovered. The influence of the amount of catalyst, water and ionic liquid, reaction conditions including reaction time and temperature was investigated in detail. The recovery of BMIMBr was performed based on using Aliquat 336 and naphthalene-2-boronic acid to extract the sugar derived from the hydrolysis of cellulose, and it was reused without further treatment. It was found that ionic liquid possessed excellent stability, and the conversion of cellulose almost kept constant during the recycles. The fresh and recovered sulfonated catalysts were characterized by means of TGA and IR, and the recovered catalyst was reused with/without treatment with acid. The catalytic activity almost kept constant in the case of regenerating by sulphuric acid prior to reuse, but a significant loss of activity was observed without regeneration. The results revealed that there may be an ion exchange process between the acidic sites of sulfonated catalyst and ionic liquid during the hydrolysis of cellulose.

An investigation of proton conductivity of nanocomposite membranes based on sulfated nano-titania and polymer

Abstract The synthesis and physicochemical properties of the nanocomposite polymer electrolyte membranes were investigated throughout this work. The materials were prepared via two different approaches where in the first, a binary system was produced by mixing of poly(1-vinyl 1,2,4-triazole) (P(VTri))/sulfated nanotitania (TS) and poly(vinylphosphonic acid) (P(VPA))/sulfated nanotitania (TS) composites. In the second, ternary nano-composite membranes including P(VTri)/TS/P(VPA) were produced at several compositions to get P(VTri)–TS–P(VPA)x where x designates the molar ratio of the polymer repeating units and sulfated nanotitania ratio. The complex structure of the polymers as well as the interaction of functional nano-particles with the matrix were investigated by FT-IR spectroscopy. TGA results verified that the presence of sulfated nanotitania and P(VTri) in the complex polymer electrolytes suppressed the formation of phosphonic acid anhydrides and thermal stability increased up to approximately 300 °C. The DSC results indicate that the Tg of the materials shifts to lower temperatures as P(VPA) content increases. SEM results showed the homogeneity of the nanocomposite membrane systems. Proton conductivity of the membranes was also measured at the anhydrous state. The conductivity of P(VTri)–TSP(VPA)4 is found to be 0.003 (S cm− 1) at 150 °C. The sulfated nanotitania particles in the composite membranes improved the thermal and mechanical properties and enhanced the proton conductivity.

Reversed-phase ion-pair ultra-high-performance-liquid chromatography–mass spectrometry for fingerprinting low-molecular-weight heparins

Heparin is a complex mixture of sulfated linear carbohydrate polymers. It is widely used as an antithrombotic drug, though it has been shown to have a myriad of additional biological activities. Heparin is often partially depolymerized in order to decrease the average molecular weight, as it has been shown that low molecular weight heparins (LMWH) possess more desirable pharmacokinetic and pharmacodynamic properties than unfractionated heparin (UFH). Due to the prevalence of LMWHs in the market and the emerging availability of generic LMWH products, it is important that analytical methods be developed to ensure the drug quality. This work explores the use of tributylamine (TrBA), dibutylamine (DBA), and pentylamine (PTA) as ion-pairing reagents in conjunction with acetonitrile and methanol modified mobile phases for reversed-phase ion-pairing ultraperformance liquid chromatography coupled to mass spectrometry (RPIP-UPLC–MS) for fingerprint analysis of LMWH preparations. RPIP-UPLC–MS fingerprints are presented and compared for tinzaparinand enoxaparin.

Simple and rapid removal of the interference in gangliosides extracted from HPTLC spot on MALDI-TOF MS analysis

Extraction of thin-layer chromatography (TLC) spot with organic solvents is one of the convenient methods for glycolipid isolation from crude samples, but other background contaminants are also co-extracted during this process. Calcium sulfate (gypsum), starch and synthetic polymers are commonly used as binders in TLC plates, and the co-extracted synthetic polymers usually interfere with further structural analyses, especially in analysis by mass spectrometry (MS). Several column chromatographic processes are therefore used to purify these extracts. However, the purification processes are time consuming and suffer from sample loss. In our previous study, we established a method for detergent removal from glycolipids in a detergent-resistant membrane microdomain (DRM). The procedure is based on selective detergent extraction, in which the sample is dried in a glass tube, followed by washing with non-polar organic solvents, 1,2-dichloroethane (DCE). In this study, we have attempted to apply this method for the background removal from gangliosides and glycosylinositolphosphoceramides extracted from high performance TLC (HPTLC) spots. After DCE washing, these glycolipids were detected by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) MS, and it was found that DCE washing could effectively remove HPTLC backgrounds.

Porous-based biomaterials for tissue engineering and drug delivery applications

Porous-based biomaterials for tissue engineering and drug delivery applications

Marine algae sulfated polysaccharides for tissue engineering and drug delivery approaches

Biomedical field is constantly requesting for new biomaterials, with innovative properties. Natural polymers appear as materials of election for this goal due to their biocompatibility and biodegradability. In particular, materials found in marine environment are of great interest since the chemical and biological diversity found in this environment is almost uncountable and continuously growing with the research in deeper waters. Moreover, there is also a slower risk of these materials to pose illnesses to humans.In particular, sulfated polysaccharides can be found in marine environment, in different algae species. These polysaccharides don’t have equivalent in the terrestrial plants and resembles the chemical and biological properties of mammalian glycosaminoglycans. In this perspective, are receiving growing interest for application on health-related fields. On this review, we will focus on the biomedical applications of marine algae sulfated polymers, in particular on the development of innovative systems for tissue engineering and drug delivery approaches.

Phosphorus, copper and zinc in solid and liquid fractions from full-scale and laboratory-separated pig slurry

Pig slurry separation is a slurry treatment technique that can reduce excess loads of P, Cu and Zn to the arable land. This study investigated the effects of different commercial and laboratory separation treatments for pig slurry on P, Cu and Zn distribution into solid and liquid fractions. Solid and liquid separation fractions were collected from two commercial separators installed on the farm. Five different separation treatments were performed (polymer flocculation and drainage; coagulation with iron sulphate addition and polymer flocculation and drainage; ozonation and centrifugation; centrifugation only; and natural sedimentation) on sow and suckling piglet raw slurry. Particle size fractionation was performed on raw slurry and all separation fractions by sequential wet sieving and P, Cu and Zn concentrations were then measured in the particle size classes. Dry matter and total P, Cu and Zn were separated with higher efficiency when chemical pretreatments with flocculants and coagulants were introduced before mechanical separation at both commercial and laboratory scale. When solid fractions are utilized as crop fertilizer (primarily as P fertilizer), the loads of Cu and Zn to the soils are not markedly different than the loads applied with raw slurry. When liquid fractions are used as crop fertilizer (primarily as N fertilizer), the loads of Cu and Zn are markedly lower than those supplied with raw slurry. The loads of Cu and Zn introduced to the soil were lowest on application of the liquid fraction produced by optimized separation treatments that included flocculation and coagulation.

Biochemical and Structural Characterization of the Complex Agarolytic Enzyme System from the Marine Bacterium Zobellia galactanivorans

Zobellia galactanivorans is an emerging model bacterium for the bioconversion of algal biomass. Notably, this marine Bacteroidetes possesses a complex agarolytic system comprising four β-agarases and five β-porphyranases, all belonging to the glycoside hydrolase family 16. Although β-agarases are specific for the neutral agarobiose moieties, the recently discovered β-porphyranases degrade the sulfated polymers found in various quantities in natural agars. Here, we report the biochemical and structural comparison of five β-porphyranases and β-agarases from Z. galactanivorans. The respective degradation patterns of two β-porphyranases and three β-agarases are analyzed by their action on defined hybrid oligosaccharides. In light of the high resolution crystal structures, the biochemical results allowed a detailed mapping of substrate specificities along the active site groove of the enzymes. Although PorA displays a strict requirement for C6-sulfate in the -2- and +1-binding subsites, PorB tolerates the presence of 3-6-anhydro-l-galactose in subsite -2. Both enzymes do not accept methylation of the galactose unit in the -1 subsite. The β-agarase AgaD requires at least four consecutive agarose units (DP8) and is highly intolerant to modifications, whereas for AgaB oligosaccharides containing C6-sulfate groups at the -4, +1, and +3 positions are still degraded. Together with a transcriptional analysis of the expression of these enzymes, the structural and biochemical results allow proposition of a model scheme for the agarolytic system of Z. galactanivorans.

Room-Temperature Fluorescence Lifetime of Pseudoisocyanine (PIC) J Excitons with Various Aggregate Morphologies in Relation to Microcavity Polariton Formation

The results of room-temperature fluorescence lifetime measurements are reported for the excitation of J aggregates (Js) of pseudoisocyanine chloride (PIC-Cl) prepared in potassium polyvinyl sulfate (PVS) polymer thin films, their aqueous solutions, and NaCl aqueous solutions. Variations of the microscopic morphologies of the aggregates were investigated. The results show that fluorescence decay features correlated to the morphology change. The observed fluorescence lifetime and quantum efficiency of PIC J aggregates (PIC-Js) in a NaCl aqueous solution were 310 ps and 28%, respectively. The lifetime of the fibril-shaped macroaggregates prepared in PVS thin films was below the instrumental time resolution of 5 ps, and the efficiency decreased to below 3%. The results indicate that PIC-Js prepared with PVS polymers have an increased nonradiative contribution to the excitation deactivation process. In particular, macro-Js with isolated fibril-shaped structures revealed nonradiative pathway(s) that are closely associated to the specific packaging morphology of the constituent meso-Js. The possibility of a destructive effect on the formation of cavity-polaritons is also discussed.

Antibacterial effect of novel synthesized sulfated β-cyclodextrin crosslinked cotton fabric and its improved antibacterial activities with ZnO, TiO2 and Ag nanoparticles coating

Sulfated β-cyclodextrin was synthesized from sulfonation of β-cyclodextrin and sulfated polymer was crosslinked with cotton fabric using ethylenediaminetetraacetic acid as crosslinker. ZnO, TiO2 and Ag nanoparticles were prepared and characterized by XRD, UV, DLS, SEM and PSA. The prepared nanoparticles were coated on crosslinked cotton fabric. The crosslinking and nanoparticles coating effects of cotton fabrics were studied by FTIR and SEM analysis. The antibacterial test was done against gram positive Staphylococcus aureus and gram negative Escherichia coli bacterium.

A comprehensive study on the size exclusion chromatography of kappa‐carrageenan for the identification of after‐peaks

AbstractAqueous size exclusion chromatography (SEC) of polysaccharides in general and carrageenans in particular is complicated by a number of factors. The chromatograms of carrageenans which are sulfated anionic natural polymers contain a number of after‐peaks depending on the occlusion, adsorption, or association of various ionic species either naturally present or evolved during their processing. A systematic SEC analysis of after‐peaks appearing in the chromatograms was made to identify the species responsible for their formation. The five after‐peaks constantly appearing in the aqueous (0.1M NaNO3) SEC of kappa‐carrageenan are attributed to sulfate, chloride, and nitrate anions whereas the first three and the fourth are due to divalent cations, mostly, and the fifth appears to result from the unknown impurities. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

Polymer-liposome nanoparticles obtained by the electrostatic bio-adsorption of natural polymers onto soybean lecithin liposomes

This work is focused on the formulation of polymer-liposome nanoparticles based on the electrostatic bio-adsorption of natural polymers onto soybean lecithin liposomes, with potential as novel delivery system for macromolecules, such as proteins. The building up of the polymer-liposome nanoparticles was achieved through the alternating bio-adsorption of natural cationic (chitosan) and neutral (dextran) or anionic (dextran sulphate or alginate) polymer layers on a core composed by anionic nanosized soybean lecithin liposomes. The electrostatic bio-adsorption of natural polymers succeeded in building nanosized, spherical, monodisperse and stable polymer-liposome nanoparticles with cumulative sizes between 357.3 nm ± 25.3 nm and 498.2 nm ± 69.6 nm and surface charges (ζ-potential) between –30.66 mV ± 1.55 mV and –26.74 mV ± 1.04 mV for the liposomal systems composed by alternating layers of chitosan and dextran sulphate or alginate, respectively. Natural-polymer-liposome nanoparticles offer good properties for encapsulation on its liposomal aqueous core and sustained release of a model protein, BSA, in vitro.

Sulfated β-d-mannan from green seaweed Codium vermilara

β-(1→4)-d-Mannans constitute the major component of the cell wall of seaweeds of the genus Codium and replace cellulose as the major fibrillar component. They were found as major constituents of the hot water extracts of green seaweed Codium vermilara. By anion exchange chromatography of the first hot water extract, a pure sulfated mannan with a molar ratio carbohydrates:sulfate of 2.7:1 was isolated. The sulfate groups are linked to C-2 of 23% of the mannose units, while most of these units are not substituted. This degree of sulfation would explain the higher solubility of the polymer, compared to that of the non-sulfated fibrillar mannan. Taking into account that the fibrillar polysaccharides form two external layers in the cell wall, while the sulfated polymers are forming an amorphous central layer, it is postulated that these sulfated mannans could act as an interphase region between the neutral and acidic layers.