Highly crosslinked poly(glycidyl methacrylate-co-divinyl benzene) particles by precipitation polymerization

Crosslinked Bifunctional Particles for the Removal of Bilirubin in Hyperbilirubinemia Cases

This work describes the development of styrene-divinylbenzene (St-DVB) particles with polyethylene glycol methacrylate (PEGMA) and/or glycidyl methacrylate (GMA) brushes for the removal of bilirubin from blood in haemodialyzed patients. Bovine serum albumin (BSA) was immobilized onto the particles using ethyl lactate as a biocompatible solvent, which allowed the immobilization of up to 2 mg BSA/g of particles. The presence of albumin on the particles increased their capacity for bilirubin removal from phosphate-buffered saline (PBS) by 43% compared to particles without albumin. The particles were tested in plasma, finding that St-DVB-GMA-PEGMA particles that had been wetted in ethyl lactate with BSA reduced the concentration of bilirubin in plasma by 53% in less than 30 min. This effect was not observed in particles without BSA. Therefore, the presence of albumin on the particles enabled quick and selective removal of bilirubin from plasma. Overall, the study highlights the potential use of St-DVB particles with PEGMA and/or GMA brushes for bilirubin removal in haemodialyzed patients. The immobilization of albumin onto the particles using ethyl lactate increased their capacity for bilirubin removal and enabled quick and selective removal from plasma.

Functionalization of Poly(styrene-co-methyl methacrylate) Particles for Selective Removal of Bilirubin

Hyperbilirubinemia is one of the main causes of death in patients with severe hepatic problems, which justifies the research for bilirubin removal solutions. In this study, St-MMA particles with PEGMA and/or GMA brushes were synthesized. First, the recipe for St-MMA was optimized and then adapted for PEGMA and GMA incorporation. Different solvents were then assayed to improve the BSA immobilization capacity of the particles. Ethyl lactate proved to be the best solvent, reaching a BSA immobilization capacity improvement of up to 60% for St-MMA-GMA-PEGMA particles. These particles also presented the best results for BR removal from PBS. No significant differences in the final capacity for BR removal from PBS media were observed when BSA was attached to the particles; however, the kinetics were greatly improved, requiring half the time. Finally, St-MMA-GMA-PEGMA particles that were wetted in EL with BSA reduced the bilirubin concentration in plasma from levels that threaten the survival of critical patients to levels close to those of healthy individuals in less than 30 min. On the contrary, particles without BSA were unable to remove bilirubin from plasma. Thus, the attachment of albumin to the particles plays a key role in selectively reducing bilirubin levels.

Epoxidized Block and Statistical Copolymers Reinforced by Organophosphorus-Titanium-Silicon Hybrid Nanoparticles: Morphology and Thermal and Mechanical Properties

Glycidyl methacrylate (GMA) and a mixture of alkyl methacrylates (average chain length of 13 carbons; termed C13MA; derived from vegetable oils) were copolymerized by nitroxide-mediated polymerization to form epoxidized statistical and block copolymers with similar compositions (F GMA ∼0.8), which were further cross-linked by a bio-based diamine. Hybrid plate-like nanoparticles containing organophosphorus-titanium-silicon (PTS) with an average size of ∼130 nm and high decomposition temperature (485 °C) were synthesized via a hydrothermal reaction to serve as additives to simultaneously enhance the thermal and mechanical properties of the blend. Nanocomposites filled with PTS were prepared at different filler-loading levels (0.5, 2, 4 wt %). Transmission electron microscopy (TEM) of the cured block copolymer displayed reaction-induced macrophase-separated domains. TEM also showed an effective dispersion of PTS hybrids in the matrix without intense agglomeration. Thermogravimetric analysis at different heating rates revealed the activation energy of poly (GMA-stat-C13MA) at maximum decomposition increased from 143.5 to 327.2 kJ mol-1 with 4 wt % PTS. Decomposition temperature and char residue improved 12 °C and ∼7 wt %, respectively, and T g increased 12 °C by adding 4 wt % PTS. Targeting various PTS concentrations enabled tuning of the tensile modulus (up to 75%), tensile strength (up to 46%), and storage modulus in both glassy state (up to 59%) and rubbery plateau regions (up to 88%). Oscillatory frequency sweeps indicated that PTS makes the storage modulus frequency dependent, suggesting that the inclusion of the nanoparticles alters the relaxation of the surrounding matrix polymer.

Cross-Linking Strategies for Fluorine-Containing Polymer Coatings for Durable Resistant Water- and Oil-Repellency

Functional coatings for application on surfaces are of growing interest. Especially in the textile industry, durable water and oil repellent finishes are of special demand for implementation in the outdoor sector, but also as safety-protection clothes against oil or chemicals. Such oil and chemical repellent textiles can be achieved by coating surfaces with fluoropolymers. As many concerns exist regarding (per)fluorinated polymers due to their high persistence and accumulation capacity in the environment, a durable and resistant coating is essential also during the washing processes of textiles. Within the present study, different strategies are examined for a durable resistant cross-linking of a novel fluoropolymer on the surface of fibers. The monomer 2-((1,1,2-trifluoro-2-(perfluoropropoxy)ethyl)thio)ethyl acrylate, whose fluorinated side-chain is degradable by treatment with ozone, was used for this purpose. The polymers were synthesized via free radical polymerization in emulsion, and different amounts of cross-linking reagents were copolymerized. The final polymer dispersions were applied to cellulose fibers and the cross-linking was induced thermally or by irradiation with UV-light. In order to investigate the cross-linking efficiency, tensile elongation studies were carried out. In addition, multiple washing processes of the fibers were performed and the polymer loss during washing, as well as the effects on oil and water repellency were investigated. The cross-linking strategy paves the way to a durable fluoropolymer-based functional coating and the polymers are expected to provide a promising and sustainable alternative to functional coatings.

3D Printing of Covalent Functionalized Graphene Oxide Nanocomposite via Stereolithography

A major challenge for many industries wanting to adopt 3D printing technologies for rapid prototyping, customized parts, and low-volume manufacturing depends on the availability and functionality of the input materials to suit specific requirements. A well-studied nanofiller because of its distinct properties and wide range of applications, graphene oxide (GO) proves to be a good choice in the development of new materials. However, as a filler in a polymer matrix, GO has its own unique set of problems enough to make certain constraints in achieving an optimum reinforcement in the targeted polymer matrix. The need for a matrix-filler interaction is critical because reinforcement occurs only when the external load applied to the material can be successfully transmitted from the matrix to the filler, which will only happen if the interfacial adhesion between the matrix and the filler is strong. This study demonstrates the synthesis of the covalently linked GO-methacrylate (MA) nanocomposite materials through 3D printing via stereolithography (SL). Spectral analysis using Fourier-transform infrared confirms the successful functionalization of GO and ascertains the presence of the functionalized GO (fGO) in the 3D-printed nanocomposite specimens. Likewise, further validation using thermogravimetric analysis and differential scanning calorimetry also affirms the formation of fGO for use as a functional filler, activating a stronger interfacial bonding with the MA polymer. Excellent attributes of GO will become futile because of premature fracturing of the material simply because of an oversight to consider robustness during the early stages of design. Hence, different mechanical and thermal properties of the new 3D-printed MA-fGO nanocomposite material are characterized and presented in the discussion. This work demonstrates the first successful 3D printing of the functionalized GO nanocomposite via SL, forming a complex structure with consistently high fidelity and enhanced material properties with potential for various industrial applications.

Simultaneous Determination and Investigation of Nine Fungicides in Fruits Using Diethylenetriamine-Functional Magnetic Core-Shell Polymer Modified Graphene Oxide as an Efficient Adsorbent Coupled to UPLC-HRMS

In this study, diethylenetriamine-functional magnetic core-shell polymer modified graphene oxide (DETA-MPs-GO) was prepared via precipitation polymerization and amidation reaction, and it was characterized by transmission electron microscopy (TEM), Fourier-transformed infrared spectroscopy (FTIR), and X-ray diffractometer (XRD). Subsequently, a magnetic solid-phase extraction (MSPE) procedure was applied to the as-synthesized DETA-MPs-GO for the detection of nine fungicides in fruit samples, prior to ultra-performance liquid chromatography-high resolution mass spectrometry (UPLC-HRMS). The homogenized fruit samples, spiked with D-labelled internal standards, were firstly extracted by 5 mL of acetonitrile twice and then purified by DETA-MPs-GO adsorbents. The optimization of the adsorption and elution conditions of DETA-MPs-GO toward fungicides was carried out to attain a satisfactory adsorption performance and desorption efficiency. The adsorption mechanism was carefully investigated, and the results revealed that a synergistic adsorption mechanism, including hydrogen bond and a π-π stacking interaction, was confirmed. Moreover, the limits of quantitation (LOQs) of the proposed approach were in the range of 0.01 to 0.30 μg/kg under the optimum conditions. The average recoveries at three spiking levels were 84.9% to 105.2%, with relative standard deviations (RSDs) varying from 0.8% to 8.2% (n = 6). The developed method was successfully utilized for the screening and detection of fungicides in 81 fruit samples purchased from markets. A detailed survey was carried out about the concentration distribution, types of fungicides, and combined use of fungicides in different fruits.

Molecularly imprinted polymer microspheres prepared by Pickering emulsion polymerization for selective solid-phase extraction of eight bisphenols from human urine samples

The bisphenol A (BPA) imprinted polymer microspheres were prepared by simple Pickering emulsion polymerization. Compared to traditional bulk polymerization, both high yields of polymer and good control of particle sizes were achieved. The characterization results of scanning electron microscopy and nitrogen adsorption-desorption measurements showed that the obtained molecularly imprinted polymer microsphere (MIPMS) particles possessed regular spherical shape, narrow diameter distribution (30-60 μm), a specific surface area (S(BET)) of 281.26 m(2) g(-1) and a total pore volume (V(t)) of 0.459 cm(3) g(-1). Good specific adsorption capacity for BPA was obtained in the sorption experiment and good class selectivity for BPA and its seven structural analogs (bisphenol F, bisphenol B, bisphenol E, bisphenol AF, bisphenol S, bisphenol AP and bisphenol Z) was demonstrated by the chromatographic evaluation experiment. The MIPMS as solid-phase extraction (SPE) packing material was then evaluated for extraction and clean-up of these bisphenols (BPs) from human urine samples. An accurate and sensitive analytical method based on the MIPMS-SPE coupled with HPLC-DAD has been successfully established for simultaneous determination of eight BPs from human urine samples with detection limits of 1.2-2.2 ng mL(-1). The recoveries of BPs for urine samples at two spiking levels (100 and 500 ng mL(-1) for each BP) were in the range of 81.3-106.7% with RSD values below 8.3%.

Facile Synthesis of Magnetic Copolymer Microspheres Based on Poly(glycidyl methacrylate-co-N-isopropylacrylamide)/Fe3O4by Suspension Photopolymerization

Magnetic copolymer based on poly(glycidyl methacrylate-co-N-isopropylacrylamide) microspheres was prepared by 2,2-dimethoxy-2-phenylacetophenone- (DMPP-) photo initiated and poly(vinyl alcohol)- (PVA-) stabilized single step suspension photopolymerization. The effect of chemical interaction, morphology, and thermal properties by adding 0.1% w/v Fe3O4in the copolymer was investigated. Infrared analysis (FTIR) showed that (C=C) band disappeared after copolymerization, indicating that the magnetic copolymer microspheres were successfully synthesized and two important bands at 908 cm−1and 1550 cm−1appear. These are associated with the epoxy group stretching of GMA and secondary amide (N–H/C–H) deformation vibration of NIPAAm in magnetic microspheres. The X-ray diffraction (XRD) result proved the incorporation of Fe3O4nanoparticles with copolymer microspheres as peak of Fe3O4was observed. Morphology study revealed that magnetic copolymer exhibited uniform spheres and smoother appearance when entrapped with Fe3O4nanoparticles. The lowest percentage of Fe3O4nanoparticles leached from the copolymer microspheres was obtained at pH 7. Finally, thermal property of the copolymer microspheres was improved by adding a small amount of Fe3O4nanoparticles that has been shown from the thermogram.

Photo-active collagen systems with controlled triple helix architecture

The design of photo-active collagen systems is presented as a basis for establishing biomimetic materials with varied network architecture and programmable macroscopic properties. Following in-house isolation of type I collagen, reaction with vinyl-bearing compounds of varied backbone rigidity, i.e. 4-vinylbenzyl chloride (4VBC) and glycidyl methacrylate (GMA), was carried out. TNBS colorimetric assay, 1H-NMR and ATR-FTIR confirmed covalent and tunable functionalization of collagen lysines. Depending on the type and extent of functionalization, controlled stability and thermal denaturation of triple helices were observed via circular dichroism (CD), whereby the hydrogen-bonding capability of introduced moieties was shown to play a major role. Full gel formation was observed following photo-activation of functionalized collagen solutions. The presence of a covalent network only slightly affected collagen triple helix conformation (as observed by WAXS and ATR-FTIR), confirming the structural organization of functionalized collagen precursors. Photo-activated hydrogels demonstrated an increased denaturation temperature (DSC) with respect to native collagen, suggesting that the formation of the covalent network successfully stabilized collagen triple helices. Moreover, biocompatibility and mechanical competence of obtained hydrogels were successfully demonstrated under physiologically-relevant conditions. These results demonstrate that this novel synthetic approach enabled the formation of biocompatible collagen systems with defined network architecture and programmable macroscopic properties, which can only partially be obtained with current synthetic methods.

Reactive magnetic poly(divinylbenzene-co-glycidyl methacrylate) colloidal particles for specific antigen detection using microcontact printing technique

Epoxy-functionalized magnetic poly(divinylbenzene-co-glycidyl methacrylate) colloidal particles (mPDGs) were prepared by co-polymerization of 1,4-divinylbenzene and glycidyl methacrylate monomers. The reaction was conducted by batch emulsion polymerization in the presence of an oil in water magnetic emulsion as a seed. The chemical composition, morphology, iron oxide content, magnetic properties, particle size and colloidal stability of the prepared magnetic polymer particles were characterized using Fourier transform infrared spectroscopy, transmission electron microscopy, thermal gravimetric analysis, vibrating sample magnetometry, dynamic light scattering, and zeta potential determination, respectively. The prepared mPDGs were immobilized on a self-assembled monolayer of 3-aminopropyltriethoxysilane (APTES)/octadecyltrichlorosilane (OTS), which were patterned on glass using microcontact printing technique, forming mPDGs-APTES/OTS reactive surface. This construction (mPDGs-APTES/OTS) was used as a solid support for immunoassay. The immobilized magnetic particles were bioconjugated with monoclonal anti-human IL-10 antibody to provide specific and selective recognition sites for the recombinant human IL-10 protein (antigen). Fluorescence microscopic examination was carried out to follow this immunoassay using fluorescently labeled anti-human IL-10 antibody. The results obtained proved the successful use of mPDGs-APTES/OTS microcontact printed surfaces in an immunoassay, which can be exploited and integrated into microsystems in order to elaborate medical devices (e.g. biosensors) which could provide rapid analysis at high sensitivity with low volumes of analyte.

Preparation of anti-CD4 monoclonal antibody-conjugated magnetic poly(glycidyl methacrylate) particles and their application on CD4+ lymphocyte separation

Novel immunomagnetic particles have been prepared for separation of CD4(+) lymphocytes. The magnetic nanoparticles with a diameter of approximately 5-6 nm were first synthesized by co-precipitation from ferrous and ferric iron solutions and subsequently encapsulated with poly(glycidyl methacrylate) (PGMA) by precipitation polymerization. Monoclonal antibody specific to CD4 molecules expressed on CD4(+) lymphocytes was conjugated to the surface of magnetic PGMA particles through covalent bonding between epoxide functional groups on the particle surface and primary amine groups of the antibodies. The generated immunomagnetic particles have successfully separated CD4(+) lymphocytes from whole blood with over 95% purity. The results indicated that these particles can be employed for cell separation and provide a strong potential to be applied in various biomedical applications including diagnosis, and monitoring of human diseases.