Ionic Polyurethanes Research Articles

Synthesis, characterization, and surface modification of degradable polar hydrophobic ionic polyurethane nanoparticles for the delivery of therapeutics to vascular tissue

Degradable polar hydrophobic ionic polyurethanes (D-PHI) are an emerging class of biomaterials with particular significance for blood-contacting applications due to their immunomodulatory effects and highly customizable block chemistry. In this manuscript, D-PHI polymer was formulated as a nanoparticle excipient for the first time by inverse emulsion polymerization. The nanoparticles were optimized with consideration of diameter, surface charge, size variability, and yield as a delivery vehicle for a custom vascular therapeutic peptide. A layer-by-layer (LBL) surface modification technique using poly-L-lysine was integrated within the nanoparticle design to optimize therapeutic loading efficiency. Solvent pH played a pivotal role in emulsion micelle formation, LBL polymer secondary structure, and the polymer functional group interactions critical for high therapeutic loading. The resulting nanoparticle platform met target size (200 ± 20 nm), polydispersity (<0.07), and storage stability standards, was nontoxic, and did not affect therapeutic peptide bioactivity in vitro. Surface-modified D-PHI nanoparticles can be reproducibly manufactured at low cost, generating a highly customizable excipient platform suitable for delivery of biomolecular therapeutics. These nanoparticles have potential applications in vascular drug delivery via localized infusion, drug eluting stents, and drug-coated angioplasty balloons. Statement of significanceNanoscale excipients have become critical in the delivery of many therapeutics to enhance drug stability and targeted biodistribution through careful design of nanoparticle composition, surface chemistry, and size. This manuscript describes the development of a nanoparticle excipient derived from an immunomodulatory degradable polar hydrophobic ionic polyurethane, in combination with a layer-by-layer surface modification approach utilizing poly-L-lysine, to transport a mimetic peptide targeting smooth muscle cell migration in vascular disease. The nanoparticle platform draws on the effect of pH to maximize drug loading and tailor particle properties. The low cost and easily reproducible system presents a highly customizable platform that can be adapted for therapeutic delivery across a wide range of clinical indications.

Imidazolium-based ionic polyurethanes with high toughness, tunable healing efficiency and antibacterial activities

Ionic polyurethanes (PUs) with high toughness, fast self-healing ability, antibacterial activity and shape memory behaviors are synthesized.

Mitigation of monocyte driven thrombosis on cobalt chrome surfaces in contact with whole blood by thin film polar/hydrophobic/ionic polyurethane coatings

Monocytes are active at the crossroads between inflammation and coagulation processes since they can secrete pro-inflammatory cytokines and express tissue factor (TF), a major initiator of coagulation. Cobalt-chrome (CoCr), a metal alloy, used as a biomaterial for vascular stents, has been shown to be potentially pro-thrombotic and pro-inflammatory. Research work with a polymer from a family of degradable-polar hydrophobic ionic polyurethanes (D-PHI), called HHHI, has been shown to exhibit anti-inflammatory responses from human monocytes. We have generated multifunctional polyurethane thin films (MPTF) based on the HHHI chemistry, as a thin coating for CoCr and have evaluated the reactivity of blood with MPTF-coated CoCr. The results showed that the coating of CoCr with MPTF derived from HHHI prevents thrombin generation, reduces coagulation activation, and suppresses fibrin formation in whole blood. Activation of monocytes was also suppressed at the surface of MPTF-coated CoCr and specifically the decrease in thrombin generation was accompanied by a significant decrease in TF and pro-inflammatory cytokine levels. Mass spectroscopy of the adsorbed proteins showed lower levels of fibrinogen, fibronectin and complement C3, C4, and C8 when compared to CoCr. We can conclude that MPTFs reduce the pro-thrombotic and pro-inflammatory phenotype of monocytes and macrophages on CoCr, and prevent clotting in whole blood.

Synthesis, Characterization and Physicomechanical Properties of Novel Water-based Biodegradable Polyurethane Dispersion

Novel water-based biodegradable polyurethane dispersions with an aim to develop environmentally friendly materials, including medicine, various industries, have been prepared in this study. Biodegradable ionic polyurethanes (IPU) were synthesized based on polyols from renewable resources, such as castor oil (CO), in the presence of a polyester polyol and polyethylene glycol (PEG) with hydrophilic property and 1,6-hexamethylene diisocyanate. 1,4-Butanediol and dibutyltin dilaurate, were used as a chain extender and catalyst, respectively. The comprehensive investigations of the structure and properties of five types of synthesized polyurethanes demonstrated biodegradability relationship of these polyurethanes with their structure and composition. In this research effects of different types and content of polyols on biodegradability and physico mechanical properties of prepared PUDs were investigated. The structure, properties and physico mechanical and application behavior of mentioned materials were characterized by 1H NMR, FTIR spectroscopy, thermogravimetric analysis (TG/DTG) and dynamic mechanical thermal analysis (DMTA). The adhesion properties were measured by pull off test as well. Particle size was measured by dynamic light scattering (DLS) methods. The biodegradability of prepared polyurethane dispersions was confirmed by water uptake, hydrolytic and enzymatic degradation in phosphate buffer saline (PBS) with lipase enzyme in PBS. Results showed that by the incorporation of natural components into the polymer chain, adjusting of hydrophilic and hydrolytic liability properties of soft segments and especial relevant designs, useful polyurethane can be synthesized with desirable property of biodegradability and dispersion stability. Except for one sample, other samples were decomposed totally in enzymatic media.

Carboxylic Acid Ionic Modification of Castor‐Oil‐Based Polyurethanes Bearing Amine Groups: Chemically Tunable Physical Properties and Recyclability

AbstractA family of supramolecular side‐chain ionic polyurethanes (PUs) is synthesized by a simple method using polyurethanes with tertiary amines as pendant groups, and carboxylic acids. The resulting polyurethanes contain diethyl ammonium and carboxylate moieties that are bonded by a combination of ionic and hydrogen bonds. The self‐assembling process is observed by Fourier‐transform infrared spectroscopy‐attenuated total reflection (FTIR‐ATR) and nuclear magnetic resonance (NMR) spectroscopy. The synthesized polyurethanes are characterized by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Rheological, dielectric, and mechanical properties are investigated, and it is found that the tunability of the properties depends on the acid functionality and the chain length. Dynamic viscoelastic tests reveal a rapid and complete thermal reversibility, which opens the door to studying the recyclability of the samples.

Temperature responsive PEG-based polyurethanes “à la carte”

Temperature responsive polymers able to alter their chemical or physical properties have been extensively investigated. Most of these polymers have an alkane polymer backbone with only carbon-carbon bonds. In this sense, the design of thermoresponsive polymers not only with sharp transition temperatures but also possessing hydrolizable linkages such as esters, carbonates or urethanes in the main backbone are highly desired. Here we show a library of thermoresponsive cationic and anionic polyurethanes synthesized by copolymerization of isophorone diisocyanate with poly(ethylene glycol) and ionic diols. These polyurethanes exhibit lower critical solution temperatures (LCST) that can be easily tuned from 20 °C to 60 °C by altering the polyurethane composition. Our findings show that LCST temperature could be reduced by the using poly(ethylene glycol) of lower molecular weight and/or increasing the hydrophobicity of the employed ionic diol. We also demonstrated that the thermoresponsive behavior could be translated to hydrogels based on those ionic polyurethanes. These “a la carte” thermoresponsive polyurethanes materials present a great potential in the biomedical field due to the presence of hydrolizable linkages in the main polymer backbone.

Ionic Polyurethanes as a New Family of Poly(ionic liquid)s for Efficient CO2 Capture

Carbon dioxide (CO2) levels are continuously growing, and CO2 is believed to be a significant contributor to global warming and climate change. Therefore, there is a great interest in the development of highly efficient technologies to curb CO2 emissions of current energy sources. In this context to combat such issues, poly(ionic liquid)s (PILs) offer an extremely versatile and tunable platform to fabricate a wide variety of sorbents for CO2 capture. To date, the majority of poly(ionic liquid)s studied for CO2 capture is related to carbochain polymers (acrylate and styrene polyelectrolytes), while it is generally accepted that polymers with more basic backbones such as amides, urethanes or amidoxines can considerably enhance the CO2 absorption capacity. Thus, a series of novel high molecular weight (Mn = (3.4–21.0) × 104) ionic polyurethanes (PUs) have been prepared using four different ionic diols based on ammonium, quinuclidinium, diquinuclidinium and imidazolium cations. Furthermore, a range of ionic P...

1,2,3-Triazolium-based linear ionic polyurethanes

We report the synthesis and detailed characterization of a series of ionic polyurethanes issued from the polyaddition of a 1,2,3-triazolium-functionalized diol monomer having a bis(trifluoromethylsulfonyl)imide counter-anion with four aliphatic, cycloaliphatic or aromatic commercial diisocyanates.

Деградуючі іономерні поліуретани на основі рослинної олії та полісахариду: отримання та властивості

Деградуючі іономерні поліуретани на основі рослинної олії та полісахариду: отримання та властивості

A robust super-tough biodegradable elastomer engineered by supramolecular ionic interactions

Alginate-based supramolecular ionic polyurethanes (ASPUs) as mechanically tunable biomaterials with high strength and toughness in both dry and hydrated states are developed under metal-free conditions. The Young's modulus and tensile strength of ASPUs are tuned from 30 to 100 MPa, and 20 to 50 MPa, respectively. Interestingly, the ASPUs exhibit a small hysteresis loop, minimal loss of tensile strength and minimal creep deformation after 100 repetitive cycles which makes them of use for engineering of load-bearing tissues. This is the first report that describes a linear PU can resist a large number of cyclic stresses without significant stretching. These bio-based elastomers engineered by ionic interactions are biocompatible and biodegradable. The ASPUs demonstrate a similar in vivo degradation rate compared to polycaprolactone (PCL). These biomaterials also demonstrate a rapid self-healing and recovery after rupture, and have a linear biodegradation profile. Furthermore, histological examination of subcutaneous transplanted ASPUs after five months reveals low immunological response and low fibrosis.

Interaction of a block-co-polymeric biomaterial with immunoglobulin G modulates human monocytes towards a non-inflammatory phenotype

Monocyte interactions with implanted biomaterials can contribute significantly to the ability of a biomaterial to support tissue integration and wound healing, as opposed to a chronic pro-inflammatory foreign body reaction, provided the materials are designed to do so. However, there are few biomaterials available designed to regulate immune cell response with the intention of reducing the pro-inflammatory activation state. Material chemistry is a powerful tool for regulating protein and cell interactions that can be incorporated into surfaces while maintaining desired mechanical properties. The aspects of material chemistry that can support monocyte activation away from a pro-inflammatory state are still poorly understood. Protein adsorption is a key initial event that transforms the surface of a biomedical device into a biological substrate that will govern subsequent cellular interactions. In this study, the chemistry of degradable block polyurethanes, termed degradable polar hydrophobic ionic (D-PHI) polyurethanes, were studied for their unique interactions with bound immunoglobulin G (IgG), a pro-inflammatory protein that supports monocyte–biomaterial interactions. The specific immunological active sites of the polyurethane-adsorbed protein were compared with IgG’s adsorbed state on a homopolymeric material with surface chemistry conducive to cell interactions, e.g. tissue culture polystyrene (TCPS). IgG-coated TCPS supported sustained monocyte adhesion and enhanced monocyte spreading, effects not observed with IgG-coated PU. The degradable PU was subsequently shown to reduce the number of exposed IgG-Fab sites following pre-adsorption vs. IgG adsorbed to TCPS, with antibody inhibition experiments demonstrating that Fab-site exposure appears to dominate monocyte–biomaterial interactions. Minor changes in chemical segments within the PU molecular chains were subsequently investigated for their influence on directing IgG interactions towards reducing pro-inflammatory activity. A reduction in chemical heterogeneity within the PU, without significant differences in other material properties known to regulate monocyte response, was shown to increase Fab exposure and subsequently led to monocyte interactions similar to those observed for IgG-coated TCPS. These results infer that reduced IgG-Fab site exposure can be directed by material chemistry to attenuate pro-inflammatory monocyte interactions with biomaterial surfaces, and identify the chemical features of polymeric biomaterial design responsible for this process. Statement of SignificanceThere is currently limited understanding of material design features that can regulate protein–material interactions in order to prevent adverse inflammatory responses to implanted biomaterials. In this paper, monocyte interactions with biomaterials (specifically a block co-polymeric degradable polyurethane [D-PHI] and tissue culture polystyrene [TCPS]) were investigated as a function of their interactions with adsorbed immunoglobulin G (IgG). D-PHI was shown to attenuate IgG-induced monocyte retention and spreading by reducing IgG-Fab site exposure upon adsorption relative to TCPS. Aspects of D-PHI chemistry important in regulating Fab site exposure were determined. This study thus identifies features of biomaterials, using D-PHI as a case study, which can contribute to the development of new immunomodulatory biomaterial design.

Деградируемые иономерные полиуретаны на основе экзополисахарида ксантана

Деградируемые иономерные полиуретаны на основе экзополисахарида ксантана

Preparation of Two Novel Ionic Electroconductive Polyurethanes Functionalized with the Backbone of Ionic Liquid

The facile synthesis of two new Ionic electroconductive polyurethanes with the framework of ionic liquids, i.e., PUR-T: synthesized with isocyanate TDI; PUR-H: synthesized with isocyanate HDL, are described. Their structures and properties were characterized by Fourier transform infrared spectroscopy (FTIR), thermal gravimetric analysis (TGA), Differential scanning calorimetry (DSC) and the surface resistance meter. The effects of the different kinds of isocyanate on electrical conductivity of PUR were also investigated. It was found that their electrical conductivity can be optimized by changing the reaction temperature. The PUR-H, which exhibits an electrical conductivity of 1.0×104 Ω surface resistance, could be obtained in high yield, up to 65% at 90 oC for 12h.

Synthesis of imidazolium-functionalized ionic polyurethane and formation of CdTe quantum dot-polyurethane nanocomposites

A series of positively charged imidazolium-functionalized ionic polyurethanes (IPUs) were prepared in one-step polymerization process by polymerization of presynthesized short-chain imidazolium-based ionic diol, polyethylene glycols with different molecular weights as long-chain diols, and toluylene-2,4-diisocyanate. The structures of IPUs are confirmed by 1H NMR analysis, and the thermogravimetric analysis measurement indicates that the IPUs have high degradation temperature. Fluorescent nanocrystal–polymer composites CdTe–IPU can be prepared conveniently, by the electrostatic interaction between positively charged IPUs and the negatively charged aqueous CdTe quantum dots (QDs). UV–vis absorption and photoluminescence spectra indicate the photochemical stability and strong fluorescent emission of CdTe–IPU composites. The quantum yields (QYs) of the composites are high and basically restore the QYs of the pure QDs. In addition, the transmission electron microscopy photographs show that the QDs in composites are uniform (about 3 nm in diameter) and monodisperse. The obtained nanocomposites are powder or elastomers with good film building. The casted CdTe–IPU films are transparent under visible light, and the colors of the composites and their films are vivid under a UV lamp. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011

Use of telechelic cis-1,4-polyisoprene cationomers in the synthesis of antibacterial ionic polyurethanes and copolyurethanes bearing ammonium groups

New crosslinked ionic polyurethanes and copolyurethanes were yielded by reaction of telechelic cis-1,4-oligoisoprenes, bearing a variable number of ammonium and hydroxy groups, with isocyanurate of isophorone diisocyanate (I-IPDI). Aiming for a comparative study, polyurethane elastomers based on non-ionic telechelic oligomers were also synthesized. Thermo-mechanical behavior and crosslinking density of these three families of materials were investigated by DMTA and swelling test, respectively. Surface properties were examined by static contact angle measurements and AFM imaging. The bactericidal activity of the polymers was investigated by enumerating living Pseudomonas aeruginosa on material surfaces and on water suspensions. The number of attached living bacteria was found to depend on the chemical structure of the material and on the contact time between the microorganisms and the surface. An exclusive bactericidal activity was obtained with the ionic copolyurethane family. Materials with weak crosslinking density were found to release bactericidal moieties. The abilities of the polymers to prevent bacterial growth were examined through zone of inhibition experiments against P. aeruginosa, which shown a bacteriostatical effect for each synthesized material. These experiments were not sufficiently sensitive to detect the leaching of bactericidal moieties from the materials with weak crosslinking density. When the zone of inhibition experiments was performed on more sensitive bacteria, namely Staphylococcus epidermidis, the leaching of bactericidal moieties as well as bacteriostatic effect was detected. This work demonstrates the potentiality for making functional biomaterials from natural rubber, a renewable resource.

Synthesis of ionic polyurethanes with pyrene rings: Spectral properties and fluorescence quenching study

AbstractHydrophilic ionic polyurethanes with 4‐chloromethylphenylcarbamoyl‐1‐oxymethylpyrene located on the quaternary ammonium structure from a polymer based on poly(ethylene glycol), isophorone diisocyanate, and N‐methyldiethanolamine were prepared by a quaternization reaction, in which the amount of pyrene covalently attached to the polymeric backbone ranged from 1.14 to 19.82 mmol of fluorophore/100 g of polymer. It was interesting to compare the photoluminescence of the pyrene polyurethane carrying a few mole percent of pyrene moieties with that of a third polymer resulting from its subsequent quaternization with benzyl chloride up to a concentration of ionic groups as in the latter (quaternization degree = 14.15%). The process of excimer formation between the pyrene molecules attached to the ionic polyurethane was investigated in tetrahydrofuran (THF), dimethylformamide, film, and THF/H2O to illustrate the expected differences in the polymer behavior compared with that of the starting pyrene derivative. The formation of aggregates or core–shell micelles was sustained by the fluorescence data, which indicated the existence of pyrene units in the ground state of the molecule, giving rise thus to an explanation for the high excimer‐to‐monomer intensity ratio. The fluorescence decay of pyrene polyurethanes in the presence of various concentrations of nitrobenzene used as a quencher was analyzed too when the fluorescence quenching in the polymer solution normally followed Stern–Volmer kinetics. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 3945–3956, 2005

Study on the Gas Permeability of Nickel(II) Polyurethane Complexes

AbstractIonic polyurethanes (PUs) were prepared from hydroxyl‐terminated polybutadiene (HTPB) and 4,4′‐dicyclohexylmethane diisocyanate (H12MDI) by a two‐stage method. The ionic group was introduced by adding 4,8‐diazaundecanediamide (L‐2,3,2) as the chain extender of which the tertiary amines and carbonyl groups were complexed with nickel ions. It was found that the binding of hard segments and the flexibility of soft segments had subtle effects on the gas permeability. The effects of hard segment content and the amount of nickel ion on the gas permeability and morphological properties were investigated. Fourier transform infrared (FTIR) spectroscopy was utilized to identify the segregation between hard and soft segments and structure change, which affect the transport properties. The hydrogen bonding index (HBI), frequency difference, and shift as a measure of the phase segregation and the average strength of the interpolymer hydrogen bonds were utilized to study the intermolecular interaction and transport property of the prepared PUs. The oxygen and nitrogen permeabilities of membranes were determined by using gas permeability analyzer. The results of FTIR, differential scanning calorimetry and thermogravimetric analysis measurements explain the complexation and, hence, the gas permeability.

Synthesis, characterization and platelet adhesion studies of novel ion-containing aliphatic polyurethanes

Two novel ion-containing aliphatic polyurethanes based on 4,4′-methylene dicyclohexyl diisocyanate (H 12MDI), polytetramethyl oxide (PTMO) were synthesized using either sulfonated or carboxylated chain extender. The nonionic polyurethane chain extended with 1,4-butanediol, which is denoted as H–M–BD, was synthesized. Pellethane ®, a biomedical-grade polyurethane, was also studied for comparison. The polymer's bulk, surface, and platelet-contacting properties were studied using Fourier transform infrared spectrophotometry, differential scanning calorimetry, water absorption analysis, electron spectroscopy for chemical analysis, static contact angle analysis, and in vitro platelet adhesion experiments. The effects of ion incorporation on the morphology, surface properties and blood compatibility are discussed. Unlike MDI-based Pellethane ®, all H 12MDI-based polyurethanes are not composed of crystalline hard segment domain but are amorphous. The ionic polyurethanes exhibit a smaller fraction of hydrogen-bonded carbonyl groups, poorer phase separation, smaller fraction of PTMO residing at the surface, and smaller contact angle; however, significant higher water absorption value than H–M–BD and Pellethane ®. The in vitro platelet adhesion experiments indicated that ion incorporation, especially for carboxylate, significantly reduced the number and the degree of activation of the adherent platelets.

Syntheses and characterizations of soft‐segment ionic polyurethanes

Novel soft-segment ionic polyurethane (linear and crosslinking) have been prepared based up on sodium sulfonate–side chains poly(ethylene oxide) (SPEO). SPEO was synthesized by grafting the sodium sulfonate onto the chain of poly(ethylene oxide) with molecular weights of 400, 600, 800, and 1000. The SPEO and the ionic polyurethane were characterized by elemental analysis, 1H-NMR, 13C-NMR, gel permeation chromatography, and impedance analysis. The effect of plasticizer on the ionic conductivity of the polyurethane was also investigated. These solid polymer electrolytes possess a higher ionic conductivity (about 10−6 S/cm at room temperature) than the corresponding sulfonated hard-segment polyurethane electrolytes. The presence of the hydroxyl group in the electrolyte tends to lower the ionic conductivity. Crosslinking of polyurethane results in the enhancement of the dimensional stability, while maintaining the same level of the ionic conductivity. © 1999 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 37: 837–845, 1999

Syntheses and characterizations of soft-segment ionic polyurethanes

Novel soft-segment ionic polyurethane (linear and crosslinking) have been prepared based up on sodium sulfonate-side chains poly(ethylene oxide) (SPEO). SPEO was synthesized by grafting the sodium sulfonate onto the chain of poly(ethylene oxide) with molecular weights of 400, 600, 800, and 1000. The SPEO and the ionic polyure- thane were characterized by elemental analysis, 1 H-NMR, 13 C-NMR, gel permeation chromatography, and impedance analysis. The effect of plasticizer on the ionic conduc- tivity of the polyurethane was also investigated. These solid polymer electrolytes possess a higher ionic conductivity (about 10 26 S/cm at room temperature) than the corresponding sulfonated hard-segment polyurethane electrolytes. The presence of the hydroxyl group in the electrolyte tends to lower the ionic conductivity. Crosslinking of polyurethane results in the enhancement of the dimensional stability, while maintain- ing the same level of the ionic conductivity. © 1999 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 37: 837- 845, 1999