| 1. |
- Bagan Navarro, Hector, et al.
(författare)
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Synthesis and characterization of epitope-imprinted polymers for purification of human hemoglobin.
- 2017
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Ingår i: RSC Advances. - 2046-2069. ; 7:66, s. 41705-41712
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Tidskriftsartikel (refereegranskat)abstract
- One promising method to prepare protein-selective polymers is the epitope-imprinting approach, where surface-accessible peptides from a target protein are used as templates to create surface-exposed binding sites on molecularly imprinted polymers (MIPs). However, selection of a suitable peptide target is not always straightforward, and synthesis of peptide on a large scale can be costly. In this work, we developed a new approach that can be used to select peptide epitopes on protein surface to be used as templates to prepare protein-selective MIPs. In this case study, human hemoglobin (Hb) was immobilized on silica nanoparticles and then fragmented by tryptic digestion. The particle-supported peptides were then used as templates to synthesize the Hb-selective MIPs, which were obtained after removal of the silica support and the peptides. The MIPs were tested in equilibrium binding experiments to evaluate their protein separation performance. The new surface imprinted MIPs displayed high selectivity for Hb, and was able to separate different variants of Hb from protein mixtures and crude cell extracts.
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| 2. |
- Bagan Navarro, Hector, et al.
(författare)
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Thermoresponsive Polymer Brushes on Organic Microspheres for Biomolecular Separation and Immobilization
- 2017
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Ingår i: Macromolecular Chemistry and Physics. - : Wiley. - 1022-1352. ; 218:3
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Tidskriftsartikel (refereegranskat)abstract
- A new method is developed to synthesize organic microsphere-supported polymer brushes for affinity separation of saccharides and glycoproteins. In the first step, crosslinked polymer microspheres are synthesized using atom transfer radical polymerization (ATRP). The terminal ATRP initiators on the microspheres are used to graft polymer brushes from propargyl acrylate and N-isopropyl acrylamide. The microsphere-supported polymer brushes are conjugated with an azide-tagged phenylboronic acid to complete the material synthesis. The microsphere-supported, boronic acid-containing polymer brushes are able to bind not only low molecular weight cis-diol compounds but also glycoproteins. The synthetic procedure developed in this work provides a convenient means for preparing all-organic microsphere-supported polymer brushes that have high alkaline stability. Using the surface-attached polymer brushes to immobilize a catalytic glycoprotein (horseradish peroxidase), it is possible to retain on-particle enzyme activity due to the open structure of the polymer brushes and the oriented immobilization. (Figure presented.).
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| 3. |
- Barrera, J., et al.
(författare)
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A new plastic scintillation resin for single-step separation, concentration and measurement of technetium-99
- 2016
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Ingår i: Analytica Chimica Acta. - : Elsevier BV. - 0003-2670. ; 936, s. 259-266
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Tidskriftsartikel (refereegranskat)abstract
- Technetium is a synthetic element with no stable isotopes, produced as waste in nuclear power plants and in cyclotrons used for nuclear medicine. The element has high mobility, in the form of TcO4 −; its determination is therefore important for environmental protection. Technetium is found in low concentrations and therefore common methods for its analysis include long treatments in several steps and require large amounts of reagents for its purification and preconcentration. Plastic scintillation resins (PSresin) are novel materials used to separate, preconcentrate and measure radionuclides in a single step. The objective of this study is to prepare and characterise a PSresin for the preconcentration and measurement of 99Tc. The study first evaluates the reproducibility of the production of PSresins between batches and over time; showing good reproducibility and storage stability. Next, we studied the effect of some common non-radioactive interferences, showing small influences on measurement, and radioactive interferences (36Cl and 238U/234U). 36Cl can be removed by a simple treatment with 0.5 M HCl and 238U/234U can be removed from the column by cleaning with a mixture of 0.1 M HNO3 and 0.1 M HF. In the latter case, a slight change in the morphology of the PSresin caused an increase in detection efficiency. Finally, the PSresin was applied to the measurement of real spiked samples (sea water and urine) with deviations lower than 10% in all cases.
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| 4. |
- Jiang, Lingdong, et al.
(författare)
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Nanohybrid polymer brushes on silica for bioseparation
- 2016
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Ingår i: Journal of Materials Chemistry. B. - : Royal Society of Chemistry (RSC). - 2050-7518 .- 2050-750X. ; 4:19, s. 3247-3256
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Tidskriftsartikel (refereegranskat)abstract
- Boronic acid based affinity materials are of great importance for effective enrichment of biomolecules containing a cis-diol structure, for example glycoproteins. In this work, we developed a new pH- and temperature-responsive boronate affinity material for effective separation of glycoproteins. A nanohybrid material composed of silica cores and flexible polymer brushes, denoted as Si@poly(NIPAm-co-GMA)@APBA, was prepared via surface-initiated atom transfer radical polymerization (SI-ATRP) in combination with Cu(i)-catalyzed azide-alkyne cycloaddition (CuAAC) click reaction. The size, morphology and composition of the obtained nanohybrid were characterized by dynamic light scattering (DLS), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), elemental analysis and thermogravimetric analysis (TGA). The density of polymer brushes on the surface of silica nanoparticles was determined to be 0.7 molecules per nm2. The maximum binding capacities of the nanohybrid Si@poly(NIPAm-co-GMA)@APBA for ovalbumin (OVA) and horseradish peroxidase (HRP) were determined to be 87.6 mg g-1 and 22.8 mg g-1, respectively. Glycoprotein binding on the nanohybrid could be controlled by varying the pH of the binding buffer. By increasing the temperature from 20 °C to 35 °C, glycoprotein binding onto the nanohybrid was decreased. This new pH- and temperature-responsive nanohybrid will be useful for a number of biotechnological and biomedical applications, for example, for protein separation and drug delivery.
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| 5. |
- Lluch, E., et al.
(författare)
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Analysis of 210Pb in water samples with plastic scintillation resins
- 2016
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Ingår i: Analytica Chimica Acta. - : Elsevier BV. - 0003-2670. ; 940, s. 38-45
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Tidskriftsartikel (refereegranskat)abstract
- 210Pb is a radioactive lead isotope present in the environment as member of the 238U decay chain. Since it is a relatively long-lived radionuclide (T1/2 = 22.2 years), its analysis is of interest in radiation protection and the geochronology of sediments and artwork. Here, we present a method for analysing 210Pb using plastic scintillation resins (PSresins) packaged in solid-phase extraction columns (SPE cartridge). The advantages of this method are its selectivity, the low limit of detection, as well as reductions in the amount of time and reagents required for analysis and the quantity of waste generated. The PSresins used in this study were composed of a selective extractant (4′,4″(5″)-Di-tert-butyldicyclohexano-18-crown-6 in 1-octanol) covering the surface of plastic scintillation microspheres. Once the amount of extractant (1:1/4) and medium of separation (2 M HNO3) were optimised, PSresins in SPE cartridges were calibrated with a standard solution of 210Pb. 210Pb could be fully separated from its daughters, 210Bi and 210Po, with a recovery value of 91(3)% and detection efficiency of 44(3)%. Three spiked water samples (one underground and two river water samples) were analysed in triplicates with deviations lower than 10%, demonstrating the validity of the PS resin method for 210Pb analysis.
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| 6. |
- Santiago, Luz Mary, et al.
(författare)
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Production of polystyrene-based scintillation microspheres for the measurement of radioactivity by spray-drying
- 2016
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Ingår i: Journal of Radioanalytical and Nuclear Chemistry. - : Springer Science and Business Media LLC. - 0236-5731 .- 1588-2780. ; 308:3, s. 789-799
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Tidskriftsartikel (refereegranskat)abstract
- The use of plastic scintillation microspheres (PSm) is an innovative technique for measuring the radioactivity of beta-emitting radionuclides. PSm can be produced via different methods; none of which has been assayed at the industrial scale. In the present paper, we evaluate the production of PSm by spray-drying on an industrial scale. Our results indicate that fluorescent solutes were indeed encapsulated within polystyrene producing spherical particles of 10 μm in diameter. Detection efficiencies for the measurement of 3H and 14C were 3–5 % and 60–75 %, respectively. These efficiencies are comparable to those of PSm produced via other methods.
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