Bearing Sulfonate Groups Research Articles

Ameliorative antibacterial, anti-inflammatory, and osteogenic activity of sulfonate-bearing polyetheretherketone toward orthopedic and dental implants

Polyetheretherketone (PEEK) has a similar elastic modulus to that of human bone and is considered a promising alternative for biomedical metallic implants. However, the poor antibacterial, anti-inflammatory, and osteogenic activity of bioinert PEEK impedes its clinical use for orthopedic and dental implants. Furthermore, using a single functional strategy to achieve all three biological functions simultaneously is challenging. Previous studies have demonstrated that sulfonate-bearing surfaces have antibacterial activity as well as decreased secretion of pro-inflammatory cytokine TNF-α. Therefore, in this study, sulfonate groups were introduced onto the PEEK surface by a one-step ultraviolet-initiated graft polymerization method. In vitro studies revealed enhanced adhesion, spreading, proliferation, and osteo-differentiation of MC3T3-E1 osteoblasts. Furthermore, the sulfonate-bearing PEEK had anti-inflammatory properties, and antibacterial activity to Escherichia coli and Staphylococcus aureus. Collectively, our findings indicate that PEEK implants bearing sulfonate groups with ameliorative antibacterial, anti-inflammatory, and osteogenic activity have potential clinical applications as orthopedic and dental implants.

Thiol-Poly(Sodium Styrene Sulfonate) (PolyNaSS-SH) Gold Complexes: From a Chemical Design to a One-Step Synthesis of Hybrid Gold Nanoparticles and Their Interaction with Human Proteins.

This study highlights recent advances in the synthesis of nanoconjugates based on gold (Au(III)) complex with a bioactive polymer bearing sulfonate groups called thiol-poly(sodium styrene sulfonate) (PolyNaSS-SH) with various molecular weights (5, 10, and 35 kDa). The three nanomaterials differ substantially in shape and structure. In particular, for PolyNaSS-SH of 35 kDa, we obtained a characteristic core–shell flower shape after chelation of the Au(III) ions and successively reduction with sodium borohydride (NaBH4). The mechanism of formation of the hybrid nanoparticles (PolyNaSS-SH@AuNPs (35 kDa) and their interactions between plasmatic proteins (human serum albumin (HSA), collagen I (Col 1), and fibronectin (Fn)) were deeply studied from a chemical and physical point of view by using several analytical techniques such as Raman spectroscopy, UV–visible, transmission electron microscopy (TEM), 1H NMR, and X-ray photoelectron spectroscopy (XPS).

Zwitterionic and cationic half-sandwich iridium(iii) ruthenium(ii) complexes bearing sulfonate groups: synthesis, characterization and their different biological activities.

Previous studies on the neutral and cationic half-sandwich iridium(iii) and ruthenium(ii) complexes showed that the charge and the substitution pattern of the bidentate ligands, as well as the nature of the accompanying counteranion have a significant effect on their biological activities. In this contribution, a series of zwitterionic and cationic half-sandwich iridium(iii) and ruthenium(ii) complexes containing sulfonate groups have been prepared and characterized. The different locations of counteranions between these two kinds of complexes exert great influence on the cytotoxic activity towards cancer cells. The various possible mechanism of actions (MoAs) of the complexes were determined by flow cytometry. This work has shown for the first time the different biological activities between zwitterionic and cationic half-sandwich complexes.

A Simple Method to Functionalize PCL Surface by Grafting Bioactive Polymers Using UV Irradiation

BackgroundPolycaprolactone (PCL) is a biodegradable polymer which is used in tissue engineering applications thanks to its many favorable characteristics. However, PCL surfaces are known as hydrophobic leading to a lack of favorable cell response. To overcome this problem, PCL surfaces will undergo a surface functionalization by grafting bioactive polymers bearing ionic groups. ObjectiveOur laboratory has demonstrated that the grafting of bioactive polymers onto biomaterials can improve cell and antibacterial response. The objective of this work is to functionalize PCL surfaces by the grafting of a bioactive polymer. MethodsThe grafting of an ionic polymer poly(sodium styrene sulfonate) (polyNaSS), using UV irradiation on PCL surfaces was carried out in a two-steps reaction process. PCL surfaces were (1) chemically oxidized in order to allow the formation of (hydro)peroxide species. (2) Then immersed in a sodium styrene sulfonate (NaSS) solution and placed under UV irradiation to induce the decomposition of (hydro)peroxides to form radicals able to initiate the polymerization of the NaSS monomer. Various parameters, such as polymerization time, the effect of the surface activation, lamp power and monomer concentration were investigated in order to optimize the yield of polyNaSS grafting. The amount of polyNaSS grafted onto PCL surfaces was first determined by toluidine blue colorimetric method and characterized by contact angle measurement, Fourier-transform infrared spectra recorded in attenuated total reflection mode (ATR-FTIR), scanning electron microscopy with Oxford energy dispersive spectroscopy (SEM-EDS). ResultsVarious techniques showed that the grafting of ionic polymer polyNaSS bearing sulfonate groups was successful by using radicals from (hydro)peroxides able to initiate the radical polymerization of ionic monomers onto PCL surfaces. ConclusionWe developed a new approach of radical grafting which allows us to successfully graft bioactive polymer polyNaSS covalently to PCL surfaces using UV irradiation.

Superabsorbent hydrogel based on sulfonated-starch for improving water and saline absorbency

The agriculture sectors in many developing countries have been suffering from water shortage and decreasing crop yields. Thus, an increasing interest has been emerged to develop much-needed solutions for a more sustainable management of water resources. Agricultural hydrogel that absorbs many times of its weight in water has been used to distribute into dry regions in order to improve the soil's ability to absorb and retain water.Here, amphoteric superabsorbent hydrogel is prepared by indirect method based on anionic starch bearing sulfonate groups. Anionic starch derivatives were graft-polymerized with acrylonitrile (AN) and hydrolyzed by alkaline by which nitrile groups were converted to hydrophilic functional groups. The hydrolyzed sodium starch sulfate-g-polyacrylonitrile (HSSS-g-PAN) copolymer exhibited improved water and saline absorbencies compared to that of native starch-based hydrogel.The co-polymerization was conducted for 60min polymerization time, 0.75% (wt/wt) ammonium persulfate (APS) associated with sodium bisulfite, SBS, (50% (wt/wt) of APS), 65°C for polymerization temperature and double molar ratio of acrylonitrile to the starch derivatives. The hydrogel based on the sulfonated starch derivatives 1 and 2 showed superior water absorbency for both distilled (250% and 190% respectively) and saline (90% and 70%) solutions over that of the native starch.

Functionalization of New Biocompatible Titanium Alloys with Harmonic Structure Design by Using UV Irradiation

BackgroundTitanium based materials slowly induce the formation of a fibrous layer after several years of implantation, compromising the quality of bone/implant interface and leading progressively to an aseptic loosening of the implants. The functionalization of Titanium based materials by bioactive polymers bearing ionic groups has been shown to be an excellent solution to improve the osseous integration of the implant. ObjectiveOur laboratory has demonstrated that the grafting of bioactive polymers onto biomaterials can improve cell and antibacterial response. The objective of this work is to develop the grafting of a bioactive polymer onto new Titanium alloys of particular structure as named “harmonic structure”. MethodsThe grafting of a bioactive polymer on new Titanium alloys of particular structure named “harmonic structure” was realized in a two-steps reaction process using chemical oxidation and UV irradiation. Titanium alloys samples were (1) oxidized in a mixture of sulfuric acid and hydrogen peroxide allowing the formation of titanium hydroxides and peroxides, (2) then incubated with an aqueous solution of sodium styrene sulfonate and placed under UV irradiation to induce the decomposition of titanium peroxides and the formation of radicals initiating the polymerization of the monomer. Different parameters such as polymerization time and lamp power were studied in order to optimize the yield of poly(sodium styrene sulfonate) grafting. Colorimetric assay, Fourier-transformed infrared spectra recorded in an attenuated total reflection (ATR-FTIR), scanning electron microscopy with Oxford energy dispersive spectroscopy (SEM-EDS) and contact angle measurements were applied to characterize the surfaces. ResultsVarious techniques showed that the grafting of ionic polymers bearing sulfonate groups was successful by using radicals from titanium peroxides able to initiate the radical polymerization of ionic monomers onto new Titanium alloys of particular structure named “harmonic structure”. ConclusionWe have applied the methods used previously in the laboratory in terms of bioactive polymers grafting in particular by UV irradiation onto the surface of new developed titanium alloys with or without harmonic structure. In parallel, a preliminary biological response study to assess toxicity, cell viability, adhesion and morphology on the different titanium alloys functionalized or not by bioactive polymers giving encouraging results.

Improving Sorbents for Glycerol Capture in Biodiesel Refinement.

Biodiesel is produced by transesterification of animal fat, vegetable oil, or waste cooking oil with alcohol. After production costs, the economic viability of biodiesel is dependent on what steps are necessary to remove impurities following synthesis and the effectiveness of quality control analysis. Solid-phase extraction offers a potentially advantageous approach in biodiesel processing applications. Nanoporous scaffolds were investigated for adsorption of glycerol, a side product of biodiesel synthesis that is detrimental to engine combustion when present. Materials were synthesized with varying pore wall composition, including ethane and diethylbenzene bridging groups, and sulfonated to promote hydrogen bonding interactions with glycerol. Materials bearing sulfonate groups throughout the scaffold walls as well as those post-synthetically grafted onto the surfaces show notably superior performance for uptake of glycerol. The sorbents are effective when used in biodiesel mixtures, removing greater than 90% of glycerol from a biodiesel preparation.

Poly(3-hydroxyalkanoate) sulfonate: From nanoparticles toward water soluble polyesters

A series of amphiphilic biodegradable polyesters based on short chain lengths, scl-PHAs, or unsaturated medium chain lengths poly(3-hydroxyalkanoate)s, mcl-PHA, bearing sulfonate groups (SO3−) have been synthesized using click chemistry. First, well-defined PHAs oligomers containing alkene or alkyne end groups were prepared by transesterification from natural polyesters using allyl alcohol or propargyl alcohol and by acid-catalyzed methanolysis in the case of unsaturated mcl-PHAs containing vinyl groups on the side chains. Radical mediated thiol–ene or thiol–yne reactions were then used to functionalize all PHAs oligomers using 3-mercapto-1-ethanesulfonate under photochemical initiation. This straightforward and highly efficient modification was confirmed by 1H NMR spectroscopy. The influence of the nature of PHAs and the molar composition of the ionic oligoesters on the self-assembled behavior in aqueous media has been studied. When the molar ratio of sulfonate groups is about 27% the ionic polyester is totally soluble in water for molar masses ranging from 5000 to 223,000gmol−1. Under 27% of sulfonate groups content, particles were obtained with different diameters (118–1746nm), depending on the nature of polyester, and short or medium chain lengths PHAs.

Designing the topology of ion nano-channels in the mesophases of amphiphilic wedge-shaped molecules.

The wedge-shaped amphiphiles bearing sulfonate groups at the tip of the wedge are prone to form ion nano-channels upon exposure to a humid atmosphere. During swelling, water molecules preferentially accumulate in polar regions of the system resulting in the formation of a lyotropic phase. In this work, the details of the structure formation processes occurring upon swelling in water vapour, including determination of the size and topology of the ion nano-channels, are explored. The electron density profiles across the channel are obtained from the fits of the X-ray scattering data with two- and three-phase structural models the applicability of which is critically analysed. The results show that the ion channel size correlates not only with water uptake but also with the molecular architecture such as the structure of the rigid molecular fragment bearing a polar group. These findings can help optimising the ion transport for development of ion-selective membranes.

Role of protein environment and bioactive polymer grafting in the S. epidermidis response to titanium alloy for biomedical applications

Joint implant-related infections, namely by Staphylococci, are a worldwide problem, whose consequences are dramatic. Various methods are studied to fight against these infections. Here, the proposed solution consists in grafting a bioactive polymer on joint implant surfaces in order to allow the control of the interactions with the living system. In this study, sodium styrene sulfonate, bearing sulfonate groups, was grafted on the surface of titanium alloys. Scanning Electron Microscopy, colorimetric method, Fourier-transformed infrared spectroscopy and contact angle measurements were applied to characterize the surfaces. Bacterial adhesion studies were studied on poly(sodium styrene sulfonate) grafted Ti6Al4V and Ti6Al4V surfaces previously adsorbed by proteins involved in the bacteria adhesion process. Fibrinogen and fibronectin were demonstrated to increase staphylococcal adhesion on Ti6Al4V surfaces. Ti6Al4V grafted sodium styrene sulfonate surfaces inhibited the adhesion of Staphylococcus epidermidis in 37% and 13% on pre-adsorbed surfaces with fibrinogen and fibronectin, respectively. The mechanism of the observed inhibiting bacteria adhesion properties is related to the differences of proteic conformations induced by poly(sodium styrene sulfonate) grafting.

Sulfonate groups grafted on Ti6Al4V favor MC3T3-E1 cell performance in serum free medium conditions

Ten years ago, we synthesized “bioactive model polymers” bearing sulfonate groups and proposed a mechanism of their modulation effect at different steps of the cell response. Then, we set up the grafting of polymers bearing sulfonate on Ti6Al4V surfaces by a grafting “from” technique making sure of the creation of covalent bonds between the grafted polymer and the Ti6Al4V surface. We have checked and confirmed the positive effect of grafted sulfonate groups on the osteoblastic cell response in vivo and in vitro but we did not elucidate the mechanism. The aim of this basic work consists first in investigating the role of sulfonate groups in the presence and in the absence of proteins at early stages of the osteointegration process on poly(sodium styrene sulfonate) poly(NaSS) grafted and ungrafted Ti6Al4V surfaces, in vitro. To understand the role of poly(NaSS) grafted chains on osteoblast-like cell response and to confirm/elucidate the importance of fetal bovine serum (FBS) proteins in the culture medium, MC3T3-E1 cells were seeded onto poly(NaSS) grafted and non-grafted Ti6Al4V surfaces. Cultures were carried out in a complete (10% FBS) and in a non-complete medium (without FBS). Cell viability assay, cell attachment number and cell adhesion strength were followed up to 3days of culture. The presence of proteins enhanced cell growth and development whatever the surface and the presence of sulfonate groups enhanced the cell attachment even in the absence of proteins, which suggests and confirms that the sulfonate groups can modify the activity of cells such as the secretion of binding proteins. Statistical differences were found in the attachment strength tests on poly(NaSS) grafted and ungrafted surfaces and showed that the sulfonate groups play an important role in the cell resistance to shear stress.

Le greffage radicalaire de polymères bioactifs sur le titane pour prévenir l’infection sur prothèse articulaire

During implantation of a total hip prosthesis (PTH), many interactions will develop at the interface bone–implant to achieve ultimately the healing of the host tissue. In a few cases (∼2%), a microbial colonization occurs, whose consequences are dramatic. The nature of the surface of materials can improve the host response and prevent infection. Studies in LBPS show that the “bioactive” polymers bearing sulfonate groups are able to inhibit bacterial adhesion. In this study, sodium styrene sulfonate, bearing sulfonate groups, was grafted on the surface of titanium alloys, which is the material of total hip replacement. It was shown that the TA6V grafted sodium styrene sulfonate, inhibits the adhesion of Staphylococcus aureus (methycillin-resistant strain).

Zeta potential of particle bilayers on mica: A streaming potential study

The streaming potential of mica covered by bilayers of latex particles was measured using the parallel-plate channel cell. The size of the first latex (A500) bearing amidine charged groups was 503nm and the second latex (L800) bearing sulfonate groups was 810nm (at pH 5.5 and an ionic strength of 10−2M). The A500 latex exhibited an isoelectric point at pH 10.5, whereas the L800 latex was strongly negative at all pH. Mica sheets were precovered first by the A500 latex particles under diffusion transport conditions. The coverage of this supporting layer was regulated between 0.02 and 0.5 by changing the bulk concentration of latex and the deposition time. Then, the second layer of the L800 latex of regulated coverage up to 0.55 was deposited under the diffusion transport. The coverage of particles and their distributions in both layers were determined by a direct enumeration of particles by optical microscopy under wet conditions and by AFM. It was shown that the structure of the L800 particle layers and the maximum coverage were in accordance with theoretical simulations performed according to the random sequential adsorption (RSA) model. After forming bilayers of desired composition and structure, streaming potential measurements were carried out. The influence of the mica substrate, the supporting layer coverage, and its zeta potential on the apparent zeta potential of bilayers was systematically studied. It was established that for a bilayer coverage exceeding 0.20, the net zeta potential became independent of the substrate and the supporting layer zeta potentials. Then, the asymptotic values of the zeta potential of the bilayer approach 1/2=0.71 of the bulk zeta potential of the particles forming the external (second) layer. This behavior was interpreted theoretically in terms of the electrokinetic model derived previously for monolayers. It was also concluded that results obtained in this work can be exploited for interpretation of polyelectrolyte film formation in the layer by layer (LbL) processes and protein adsorption pertinent to the antigen/antibody interactions.

Chemical Modification of the Surface of a Sulfonated Membrane by Formation of a Sulfonamide Bond

This paper describes a novel approach for the surface modification of a cation-exchange membrane, bearing sulfonate groups, by a cationic layer. The modification procedure involved the chlorosulfonation of the sulfonate groups of the base membrane with thionyl chloride, followed by a reaction with a diamine to yield a sulfonamide bond and a terminal amine. The latter could be quaternized by reaction with methyl iodide or protonated by soaking in acidic media. The membranes were characterized in detail by attenuated total reflectance Fourier transform infrared and X-ray photoelectron spectroscopies as well as elemental analysis to confirm that the above reactions occurred. The selectivity of these membranes toward the electrochemically assisted transport of protons versus Zn2+ metallic cations was determined during an electrodialysis in a two-compartment electrochemical cell. The data indicate a significant decrease of the transport of the metallic cations following modification of the membrane with the cationic layer. The later allows for the transport of protons from the catholyte to the anolyte compartment with much improved selectivity since the divalent cations are excluded from the membrane due to the electrostatic barrier of the cationic layer.

Alumina interaction with AMPS–MPEG random copolymers: I. Adsorption and electrokinetic behavior

Adsorption of brush copolymers, bearing sulfonate groups and polyethylene glycol segments, on to alumina particles in suspension in water has been investigated. Study of the adsorption isotherms revealed that the copolymers displayed a strong affinity for the surface of the alumina regardless of the fraction of ionic groups on the polymer. For poly(ethylene glycol) content greater than 50%, the adsorption isotherms revealed an initial adsorption plateau followed by a second one. The shape of the adsorption isotherms was interpreted in terms of the polymer configuration at the solid-to-liquid interface. The effects of the pH and the ionic force on adsorption were studied and connected to the effects of interaction between chain segments at the surface of the alumina particles. Changes in the electrokinetic properties of the alumina particles after addition of the copolymers were investigated by following the zeta potential of particles as a function of pH. In the presence of the copolymer continuous shift of the isoelectric point IEP to a more acidic values was observed. Beyond a certain concentration the zeta potential remained negative regardless of the pH.

Chemical Modification of a Sulfonated Membrane with a Cationic Polyaniline Layer to Improve its Permselectivity

The surface of a cation-exchange membrane (Neosepta) bearing sulfonate groups was modified by a thin polyaniline layer to produce a thin positively charged layer at its surface. This modification induces a slight modification of the surface morphology as evidenced by scanning electron microscopy and a decrease in ion exchange capacity. The presence of the polyaniline layer was confirmed by X-ray photoelectron spectroscopy. The selectivity of the modified and unmodified membranes toward protons vs. metallic cations such as Zn 2 + and Cu 2 + were determined after electrodialysis in a two-compartment electrochemical cell. The data indicate that the transport of the metallic cations is decreased significantly following the modification of the membrane with the cationic polyaniline layer. The latter allows the transport of protons from the catholyte to the anolyte compartment with a much improved selectivity since the divalent cations are excluded from the membrane due to the electrostatic barrier created by the thin protonated polyaniline layer.

Novel alkyl-modified anionic siloxanes as pseudostationary phases for electrokinetic chromatography: II. Selectivity studied by linear solvation energy relationships.

Anionic, water-soluble siloxane polymers modified with different lengths of alkyl chains have very different selectivity than sodium dodecyl sulfate (SDS) micelles when used as pseudostationary phases in electrokinetic chromatography. The siloxanes in this study are random copolymers with side chains bearing sulfonate groups and alkyl groups (C8, C12, or C18), with the proportion of alkyl groups between 10 and 25% of the total. The differences in selectivity have been studied by linear solvation energy relationships (LSERs). The siloxanes in general have been found to be more cohesive, less polar, more able to interact with solutes through n- and pi-electrons, and more able to accept hydrogen bonds than SDS micelles, while the ability to act as hydrogen bond donors is not significantly different than SDS micelles. In addition, the performance in a pH 7.0 Tris buffer has been investigated and the siloxanes were found to have higher methylene selectivities and more variable electrophoretic mobilities than in borate buffers.

Stable Entrapment of Small Molecules Bearing Sulfonate Groups in Multilayer Assemblies

A way to realize the stable entrapment of small molecules bearing sulfonate groups in the multilayer assemblies was reported. First, the sulfonate-containing small molecules were alternately assembled with photoreactive polycation diazo resins (DAR) to form electrostatically held multilayer films. Then these films were exposed under UV irradiation to form covalently attached ones due to the in situ photoreaction between diazonium and sulfonate goups. In this way, the stability of the small molecules in the multilayer was improved to some extent. When these film assemblies were covered with additional layers of photoactive diazo resins/poly(4-styrene sulfonate) films, the stability of the films could be improved further. By making full use of the incompleteness of the reaction between DAR and small molecules, good permeability of the film could be realized, which guarantees these kinds of films in finding potential application in chemically modified electrodes in which films with both stability and permeability are required. These kinds of films were characterized in detail by UV−vis spectroscopy, cyclic voltammetry, X-ray diffraction measurements, and solvent etching experiments.

Entropic origin of the sulfonate groups’ electrostatic assistance in the complexation of quaternary ammonium cations by water soluble calix[4]arenes

The inclusion of symmetrical tetramethylammonium cation (TEMA) by the water soluble calixarene hosts 1–8 was studied at neutral pH by 1H NMR spectroscopy and compared with that of the ditopic trimethylanilinium cation (TMA). The hosts blocked in the cone conformation and bearing sulfonate groups at the upper rim (2, 3, 5, 7 and 8) bind selectively the aromatic portion of TMA, whereas compound 4 which lacks sulfonate groups interacts only with the charged head group of TMA. The conformationally mobile compound 1 and the partial cone calixarene 6 include TMA cation in an unselective fashion. TEMA is complexed by hosts 1–7, but not by the tetraether-tetrasulfonate receptor 8. The binding constants for all the systems, as determined by 1H NMR spectroscopy, show that inclusion is favoured by the presence of the sulfonate groups and that the complexes of the conformationally mobile receptor 1 with both guests are more stable. The thermodynamic parameters of inclusion determined by direct calorimetry for 2–TEMA and 4–TEMA systems show that in both cases the inclusion process is enthalpically driven and that the greater stability constant observed for 2–TEMA with respect to that of 4–TEMA mainly results from a less unfavourable entropic contribution, suggesting that in the 2–TEMA complex the charged sulfonate groups cause a better desolvation of the host–guest system upon inclusion.

Platelet adhesion and activation on an amphoteric chitosan derivative bearing sulfonate groups

To improve blood compatibility of chitosan, a linear cationic polymer of d-glucosamine, we have synthesized an amphoteric derivative containing sulfonate functional groups. Unlike chitosan which is soluble only in acidic pH (<5.0), the sulfonated derivative was soluble over a wide pH range. Elemental analysis of N-sulfofurfuryl chitosan showed 5.20% sulfur content and the degree of substitution analysis confirmed 23.4% sulfofurfuryl substitution. Wide-scan electron spectroscope for chemical analysis (ESCA) showed the presence of sulfur (3.30%) and sodium (6.00%) on N-sulfofurfuryl chitosan surface. High resolution S2p spectra was entirely due to the - S -0- functional moiety of the sulfonate residues. As compared with an average of more than 73.0 platelets per 25 000 μm 2 on unmodified chitosan, only 4.50 platelets were present on the sulfonated chitosan derivative. The extent of platelet activation was also significantly reduced on the N-sulfofurfuryl chitosan surface. N-sulfofurfuryl chitosan, an amphoteric watersoluble derivative, does appear to possess non-thrombogenic properties and may be suitable for some blood-contacting applications.