| 1. |
- Bagan Navarro, Hector, et al.
(författare)
-
Synthesis and characterization of epitope-imprinted polymers for purification of human hemoglobin.
- 2017
-
Ingår i: RSC Advances. - 2046-2069. ; 7:66, s. 41705-41712
-
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.
|
|
| 2. |
- Jiang, Lingdong, et al.
(författare)
-
Nanohybrid polymer brushes on silica for bioseparation
- 2016
-
Ingår i: Journal of Materials Chemistry. B. - : Royal Society of Chemistry (RSC). - 2050-7518 .- 2050-750X. ; 4:19, s. 3247-3256
-
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.
|
|
| 3. |
- Kamra, Tripta, et al.
(författare)
-
Implementation of Molecularly Imprinted Polymer Beads for Surface Enhanced Raman Detection
- 2015
-
Ingår i: Analytical Chemistry. - : American Chemical Society (ACS). - 1520-6882 .- 0003-2700. ; 87:10, s. 5056-5061
-
Tidskriftsartikel (refereegranskat)abstract
- Molecularly imprinted polymers (MIPs) have a predesigned molecular recognition capability that can be used to build robust chemical sensors. MIP-based chemical sensors allow label-free detection and are particularly interesting due to their simple operation. In this work we report the use of thiol-terminated MIP microspheres to construct surfaces for detection of a model organic analyte, nicotine, by surface enhanced Raman scattering (SERS). The nicotine-imprinted microspheres are synthesized by RAFT precipitation polymerization and converted into thiol-terminated microspheres through aminolysis. The thiol groups on the MIP surface allow the microspheres to be immobilized on a gold-coated substrate. Three different strategies are investigated to achieve surface enhanced Raman scattering in the vicinity of the imprinted sites: (1) direct sputtering of gold nanoparticles, (2) immobilization of gold colloids through the MIPs thiol groups, and (3) trapping of the MIP microspheres in a patterned SERS substrate. For the first time we show that large MIP microspheres can be turned into selective SERS surfaces through the three different approaches of assembly. The MIP-based sensing surfaces are used to detect nicotine to demonstrate the proof of concept. As synthesis and surface functionalization of MIP microspheres and nanoparticles are well established, the methods reported in this work are handy and efficient for constructing label-free chemical sensors, in particular for those based on SERS detection.
|
|
| 4. |
- Kujawska, Małgorzata, et al.
(författare)
-
Synthesis of naproxen-imprinted polymer using Pickering emulsion polymerization
- 2018
-
Ingår i: Journal of Molecular Recognition. - : Wiley. - 0952-3499. ; 31:3, s. 2626-2626
-
Tidskriftsartikel (refereegranskat)abstract
- For the last decades, molecular imprinting is developing intensively, especially in the case of the application of new imprinting techniques. In this work, for the first time, a Pickering emulsion polymerization was used to synthesize the S-naproxen-imprinted polymer spheres following a noncovalent protocol. To enhance the knowledge about imprinting process using mentioned technique, thorough analysis of the synthesis process was performed. Optimization of polymerization conditions included the selection of functional monomer, cross-linking agent, type of porogen, surfactant, and the choice of appropriate amount of the template and porogen. Prepared materials were characterized using scanning electron microscopy and nitrogen adsorption. To study the binding properties, the sorption studies, including adsorption isotherms and competitive binding, were performed. Investigation of the effect of the functional monomer on the selective recognition of S-naproxen showed that the interactions between the template molecule and 4-vinylpyridine resulted in the best recognizing ability. Moreover, the synthesis with application of ethylene glycol dimethacrylae as a cross-linker, toluene as a porogen, and Tween 20 as an additional emulsion stabilizer gave the most desired result. The optimal ratio of the porogen to monomers mixture was 0.1, due to the fact that the increase of the porogen volume resulted in the significant increase of nonspecific uptake. In addition, the tenfold molar excess of functional monomer relative to the template turned out to be optimal. Subsequent binding studies demonstrated that the material synthesized using optimized polymerization conditions consists of imprinted sites that are sensitive for the S-naproxen.
|
|
| 5. |
- Shen, Xiantao, et al.
(författare)
-
Molecular imprinting of protein in Pickering emulsion.
- 2012
-
Ingår i: Chemical Communications. - : Royal Society of Chemistry (RSC). - 1364-548X .- 1359-7345. ; 48:66, s. 8198-8200
-
Tidskriftsartikel (refereegranskat)abstract
- A new strategy of molecular imprinting to prepare spherical hydrogels via water-in-oil Pickering emulsion polymerization was developed. The imprinted hydrogels exhibited fast adsorption kinetics and significant selectivity for the target protein.
|
|
| 6. |
- Zhang, Ka, et al.
(författare)
-
Characterization of protein-protein interactions in recombinant hemoglobin producing escherichia coli cells using molecularly imprinted polymers
- 2017
-
Ingår i: Advances in Experimental Medicine and Biology. - Cham : Springer International Publishing. - 0065-2598. ; 977, s. 367-373
-
Tidskriftsartikel (refereegranskat)abstract
- The worldwide blood shortage has generated demands for alternatives to transfusible human blood. One such important option is based on recombinant hemoglobin-based oxygen carriers (rHBOCs). Most efforts have been focused on various E. coli based production systems. One of the key challenges in these systems is to devise an efficient and economical protein production strategy involving selection of suitable host cell and Hb variant, growth conditions and media engineering. Hb also influences the heterologous host cell metabolism and therefore the identification of modified protein-protein interactions is critical for optimizing Hb production. In this study, molecularly imprinted polymers (MIPs) directed against Hb were used to identify the human Hb protein interaction network in E. coli. One E. coli host protein, glyceraldehyde 3-phosphate dehydrogenase (GAPDH), interacted strongly with Hb, especially fetal Hb (HbF).
|
|
| 7. |
- Zhang, Ka, et al.
(författare)
-
Chromatographic separation of hemoglobin variants using robust molecularly imprinted polymers
- 2019
-
Ingår i: Talanta. - : Elsevier BV. - 1873-3573 .- 0039-9140. ; 199, s. 27-31
-
Tidskriftsartikel (refereegranskat)abstract
- Devising a robust, efficient and cost effective hemoglobin (Hb) purification strategy is one of the key challenges in the development of Hb-based blood substitutes. The aim of this study was to use molecularly imprinted polymers (MIPs) as a novel and efficient chromatographic resin to selectively recognize and purify different Hb variants. The results showed that the Hb-MIP material developed here could selectively recognize and purify various Hb directly from either crude E. coli extracts or human body fluids, such as blood plasma and cerebrospinal fluid (CSF), in one-step. The dynamic binding capacity at 10% breakthrough was around 7.4 mg mL−1resin for adult Hb (HbA) and fetal Hb (HbF). This chromatographic material also allowed identification of changes related to amino acid substitutions on the Hb protein surface. For instance, when an additional lysine residue was introduced, the HbA αY42K mutant eluted later in an Hb-MIP column than wildtype HbA. Additional negative charges on the protein surface, such as aspartate, mitigated the interaction between the protein and imprinted polymers, and therefore an αA19D-αA12D HbF mutant eluted earlier, at −2.7 column volumes compared to wildtype HbF.
|
|
| 8. |
- Zhou, Tongchang, et al.
(författare)
-
Molecularly imprinted polymer beads for nicotine recognition prepared by RAFT precipitation polymerization: a step forward towards multi-functionalities
- 2014
-
Ingår i: RSC Advances. - : Royal Society of Chemistry (RSC). - 2046-2069. ; 4:57, s. 30292-30299
-
Tidskriftsartikel (refereegranskat)abstract
- A nicotine imprinted polymer was synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization using methacrylic acid (MAA) as a functional monomer. The resulting molecularly imprinted polymers were monodispersed beads with an average diameter of 1.55 mu m. The molecular selectivity of the imprinted polymer beads was evaluated by studying the uptake of nicotine and its structural analogs by the polymer beads. Equilibrium binding results indicate that the amount of nicotine bound to the imprinted polymer beads is significantly higher than that bound to the non-imprinted polymer in both acetonitrile and in a mixture of acetonitrile and water. The RAFT reagent present on the surface of the polymer beads allowed straightforward grafting of hydrophilic polymer brushes on the particle surface. In addition to the demonstrated molecular selectivity and the straightforward surface modification of the imprinted polymer beads, we also show that the dithioester end groups on the surface of the polymer beads can be converted into new thiol groups without sacrificing the specific molecular recognition. Through the new terminal thiol groups, a fluorescent dye was conveniently conjugated to the imprinted polymer beads via Michael addition reaction. The living characteristic of RAFT and the versatile thiol groups that can be derived from the RAFT reagent provide many new possibilities for realizing multi-functionalities for molecularly imprinted polymers.
|
|
| 9. |
- Zhou, Tongchang, et al.
(författare)
-
Molecularly Imprinted Polymer Beads Prepared by Pickering Emulsion Polymerization for Steroid Recognition
- 2014
-
Ingår i: Journal of Applied Polymer Science. - : Wiley. - 1097-4628 .- 0021-8995. ; 131:1, s. 39606-39606
-
Tidskriftsartikel (refereegranskat)abstract
- Pickering emulsion polymerization was used to synthesize molecularly imprinted polymer beads for the selective recognition of 17-beta-estradiol under aqueous conditions. Scanning electron microscopy analysis indicated that the imprinted polymer beads had a small diameter with a narrow size distribution (18.9 +/- 2.3 mu m). The reduction in particle size achieved in this study was attributed to the altered polarity of the stabilizing nanoparticles used in the Pickering emulsion. The imprinted polymer beads could be used directly in water and showed a high binding affinity for the template molecule, 17-beta-estradiol, and its structural analogs. These water-compatible polymer beads could be used as affinity adsorbents for the extraction and analysis of low-abundance steroid compounds in aqueous samples. (C) 2013 Wiley Periodicals, Inc.
|
|
| 10. |
- Zhou, Tongchang
(författare)
-
Molecularly Imprinted Polymer Beads-Synthesis, Evaluation and Applications
- 2016
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Molecularly imprinted polymers (MIPs) are artificial receptors designed for the selective recognition of template molecules. These polymers have been applied in analytical separations, as chemical sensors and in drug delivery system due to their low cost and high stability. In recent years MIP beads, especially those with good selectivity in aqueous solution, have become attractive as they can be potentially used as selective adsorbents for the solid phase extraction (SPE) and chromatographic separation of various target molecules.The aim of this thesis was to investigate and improve the synthetic methods for the preparation of MIP beads, especially those that can be used in aqueous solution. In the first section, Pickering emulsion is utilized to synthesize water-compatible MIP beads. Scanning electron microscopy (SEM) was used to characterize the morphology and surface structure of the particles. As water-soluble monomers were employed during the imprinting process, the MIP beads had a hydrophilic surface and showed high compatibility with aqueousconditions. Additionally, the MIP beads exhibit high selectivity and specificity to template in aqueous solution. Both organic compounds and macromolecules were used as templates separately and MIP beads with specific bindingsites were successfully obtained. The method developed in this thesis has a general applicability and offers a potential approach to synthesize polymer beads for bioseparation and wastewater treatments.Another focus of this thesis was the preparation of multifunctional materials based on MIP beads for the purpose of different applications. Reversible addition-fragmentation chain transfer (RAFT) precipitation polymerization wasused to prepare monodisperse beads with RAFT reagents located on their surfaces, which allowed for the straightforward grafting of polymer brushes, or can be converted into new functional groups for further modification. The specific molecular recognition of the beads was not sacrificed during the aminolysis process, and different functionalities were introduced to the MIP beads under mild conditions. The thiol groups introduced onto the MIP surface allowed the MIP beads to be immobilized on a gold-coated substrate, such that these MIP based sensing surfaces were used for the detection of nicotine by surface enhanced Raman scattering (SERS).The Pickering emulsion systems provide an efficient method with which to prepare water-compatible MIP beads that have high selectivity under aqueous conditions. Further functional materials and new applications can beexpected upon the combination of Pickering emulsion systems with more controllable synthetic chemistry. The RAFT polymerization method, in particular, has a general applicability and introduces new possibilities for the development of other functional materials and devices.
|
|
