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In this study, the molecular imprinting method was used to separate enantiomeric forms of chiral antidepressant drug, R,S-citalopram (R,S-CIT) in aqueous solution by CEC system combining the advantages of capillary electrophoresis (CE) and high-performance liquid chromatography (HPLC). For that, an amino acid based molecularly imprinted monolithic capillary column was designed and used as a stationary phase for selective separation of S-citalopram (S-CIT) for the first time. S-CIT was selectively separated from aqueous solution containing the other enantiomeric form of R-CIT, which is same in size and shape to the template molecule. Morphology of the molecularly imprinted (MIP S-CIT) and non-imprinted (NIP S-CIT) monolithic capillary columns was observed by scanning electron microscopy. Imprinting efficiency of MIP S-CIT monolithic capillary column used for selective S-CIT separation was verified by comparing with NIP S-CIT and calculated imprinting factor (I.F:1.81) proved the high selectivity of the MIP S-CIT for S-CIT. Cavities formed for S-CIT form enabled selective (α = 2.08) separation of the target molecule from the other enantiomeric R-CIT form. Separation was achieved in a short period of 10 minutes, with the electrophoretic mobility of 7.68 × 10-6 m2 /Vs for R,S-CIT at pH 7.0 10 mM PB and 50% ACN ratio. The performance of both MIP S-CIT and NIP S-CIT columns was estimated by repeating the R,S-CIT separations with intra-batch and inter-batch studies for reproducibility of retention times of R.S-CITs. Estimated RSD values that are lower than 2% suggest that the monolithic columns separate R,S-CIT enantiomers without losing separation efficiency. This article is protected by copyright. All rights reserved.

WOS:000503065300011 In this study, D,L-ampicillin separation was carried out by ligand exchange-micellar electrokinetic chromatography method using L-Lysine monohydrochloride as a ligand and copper (II) sulfate pentahydrate is a central ion supplier. Isomeric separations were performed using capillary electrophoresis (CE) instrument, in which SDS-L-Lys-Cu+2 micelle complex was used as a pseudostationary phase. The effect of pH, SDS amount, applied electrical field, pressure, organic solvent ratio and ampicillin D,L-ratios were investigated. Fast,inexpensive and sensitive approach for the simultaneous separation of D,L-ampicillin in both aqueous and real antibiotic sample was performed using CE coupled with UV detector. The separation was achieved in a short period of 7 minutes with high-sensitivity andlow-detection limit of 1.25 mu M by the developed SDS-L-Lys-Cu+2 micelle-chiral selector complexes without using any extra process such as imprinting or spacer arms for the immobilization of the ligands.

The ability to detect catecholamines (CAs) and their metabolites is vital to understand the mechanism behind the neuronal diseases. Neurochemistry aims to provide an improved pharmacological, molecular and physiological understanding of complex brain chemistries by analytical techniques. Capillary electrophoresis (CE) is one such analytical technique that enables the study of various chemical species ranging from amino acids and peptides to natural products and drugs. CE can easily adapt the changes in research focus and in recent years remains an applicable technique for investigating neuroscience and single cell neurobiology. The prepared phenylalanine-based hydrophobic monolithic column, Polymethacryloyl-L-phenylalanine [PMAPA], was used as a stationary phase in capillary electrochromatography to separate CAs that are similar in size and shape to each other including dopamine (DA) and norepinephrine (NE) via hydrophobic interactions. Separation carried out in a short period of 17 min was performed with the electrophoretic mobility of 5.54 × 10−6 m2 V−1 s−1 and 7.60 × 10−6 m2 V−1 s−1 for DA and NE, respectively, at pH 7.0, 65% acetonitrile ratio with 100 mbar applied pressure by the developed hydrophobic monolithic column without needing any extra process such as imprinting or spacer arms to immobilize ligands used in separation.

Trietazine was selectively separated from aqueous solution containing the competitor molecule cyanazine, which is similar in size and shape to the template molecule. Structural features of the molecularly imprinted column were figured out by SEM. The influence of the mobile-phase composition, applied electrical field, and pH of the mobile phase on the recognition of trietazine by the imprinted monolithic polymer has been evaluated, and the imprint effect in the trietazine-imprinted monolithic polymer was demonstrated by an imprinting factor. The optimized monolithic column resulted in separation of trietazine from a structurally related competitor molecule, cyanazine. In addition, fast separation was obtained within 6 min by applying higher electrical field, with the electrophoretic mobility of 2.97 × 10(-8) m(2) V(-1) s(-1) at pH 11.0.

One-step activation, purification, and stabilization of lipase enzyme were performed by using composite hydrophobic support at low ionic strength with increased surface area during embedding process. A novel hydrophobic poly(hydroxyethylmethacrylate) [PHEMA] based, poly(glycidyl methacrylate-N-methacryloly-(L)-tryptophan) [PGMATrp] bead embedded composite cryogel membrane having specific surface area of 195 m(2)/g was used as hydrophobic matrix for adsorption of commercial Candida Rugosa lipase in a continuous system. PGMATrp embedded PHEMA cryogel membrane with 60-100 mu m pore size was obtained by dispersion polymerization of GMA and MATrp to form PGMATrp beads followed by embedding of PGMATrp to HEMA via APS and TEMED redox pair. The introduction of hydrophobic MATrp monomer into bead structure aiming to increase interaction between lipase and composite membrane was estimated using nitrogen stoichiometry of elemental analysis and found to be 239 mu mol/g of polymer. Hydophobicity increment due to embedding process was confirmed by measuring contact angle, it was found 42 degrees and 48.4 degrees for the PHEMA and PHEMA/PGMATrp composite cryogel respectively. Some parameters i.e. pH, flow-rate, protein concentration, temperature, salt type and ionic intensity were evaluated on the adsorption capacity in a continuous system. Fast protein liquid chromatography (FPLC) studies were performed for specific adsorption of lipase onto the PHEMA/PGMATrp embedded composite cryogel membrane. (C) 2015 Elsevier B.V. All rights reserved.

The use of molecular imprinted polymers (MIPs), which provides a means for preparing stationary phases with predetermined selectivity for a target molecule in capillary electrochromatography (CEC), is attractive because it combines selectivity, higher separation efficiency and shorter analysis time. A bisphenol A (BPA)-imprinted monolithic capillary BPA/PMAPA column was synthesized for the selective separation of bisphenol A (BPA) from aqueous solutions containing the competitor molecule phenol (PH), which is similar in size and shape to the template molecule. BPA-imprinted monolithic column was prepared in the presence of the template molecule, BPA, which results in the formation of recognition cavities complementary to the template molecule, after the removal of template molecule. An amino acid based monomer, N-methacryloyl-L-phenyl alanine (MAPA), was used as the functional monomer. The new stationary phase contains both charged and hydrophobic groups originating from MAPA monomer, which behaves as both an electroosmotic flow (EOF) supplier and a hydrophobic matrix. The MAPA containing BPA imprinted column behaves as a mixed mode stationary phase, as ion exchanger and hydrophobic matrix depending on the pH of the medium. Scanning electron microscopy was used to identify the structural features of the molecular imprinted column. MIP column performance was evaluated by the electrochromatographic separation of alkylbenzenes. The novelty of this work originated from dual separation mechanism shown by MAPA, which has the ability to form both hydrophobic and electrostatic interactions by the charged and hydrophobic groups of phenylalanine amino acid. This new column with mixed-mode characteristics was then used successfully as the stationary phase in CEC for the selective separation of BPA in MIP systems.

A dopamine-imprinted monolithic column was prepared and used in capillary electrochromatography as stationary phase for the first time. Dopamine was selectively separated from aqueous solution containing the competitor molecule norepinephrine, which is similar in size and shape to the template molecule. Morphology of the dopamine-imprinted column was observed by scanning electron microscopy. The influence of the organic solvent content of mobile phase, applied pressure and pH of the mobile phase on the recognition of dopamine by the imprinted monolithic column has been evaluated, and the imprinting effect in the dopamine-imprinted monolithic polymer was verified. Developed dopamine-imprinted monolithic column resulted in excellent separation of dopamine from structurally related competitor molecule, norepinephrine. Separation was achieved in a short period of 10 min, with the electrophoretic mobility of 5.81x10(-5)m(2)V(-1)s(-1) at pH 5.0 and 500mbar pressure.

A molecularly imprinted composite cryogel (MICC) was prepared for depletion of hemoglobin from human blood prior to use in proteome applications. Poly(hydroxyethyl methacrylate) based MICC was prepared with high gel fraction yields up to 90%, and characterized by Fourier transform infrared spectrophotometer, scanning electron microscopy, swelling studies, flow dynamics and surface area measurements. MICC exhibited a high binding capacity and selectivity for hemoglobin in the presence of immunoglobulin G, albumin and myoglobin. MICC column was successfully applied in fast protein liquid chromatography system for selective depletion of hemoglobin for human blood. The depletion ratio was highly increased by embedding microspheres into the cryogel (93.2%). Finally, MICC can be reused many times with no apparent decrease in hemoglobin adsorption capacity. Copyright © 2014 John Wiley & Sons, Ltd.

The immobilized metal-affinity chromatography (IMAC) has gained significant interest as a widespread separation and purification tool for therapeutic proteins, nucleic acids and other biological molecules. The enormous potential of IMAC for proteins with natural surface exposed-histidine residues and for recombinant proteins with histidine clusters. Cryogels as monolithic materials have recently been proposed as promising chromatographic adsorbents for the separation of biomolecules in downstream processing. In the present study, IMAC cryogels have been synthesized and utilized for the adsorption and separation of immunoglobulin G (IgG) from IgG solution and whole human plasma. For this purpose, Cu(II)-ions were coupled to poly(hydroxyethyl methacrylate) PHEMA using poly(ethylene imine) (PEI) as the chelating ligand. In this study the cryogels formation optimized by the varied proportion of PEI from 1% to 15% along with different amounts of Cu (II) as chelating metal. The prepared cryogels were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, and thermogravimetric analysis. The [PHEMA/PEI]-Cu(II) cryogels were assayed for their capability to bind the human IgG from aqueous solutions. The IMAC cryogels were found to have high affinity toward human IgG. The adsorption of human IgG was investigated onto the PHEMA/PEI cryogels with (10% PEI) and the concentration of Cu (II) varied as 10, 50,100 and 150 mg/L. The separation of human IgG was achieved in one purification step at pH 7.4. The maximum adsorption capacity was observed at the [PHEMA/PEI]-Cu(II) (10% PEI) with 72.28 mg/g of human IgG. The purification efficiency and human IgG purity were investigated by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). (C) 2016 Elsevier B.V. All rights reserved.

WOS: 000276436300007, A new generation of molecularly imprinted macroporous hydrogels, so-called cryogels, were prepared for depletion of hemoglobin from human blood. Hb-PHEMAH cryogels were prepared with gel fraction yields up to 90%, and its morphology and porosity were characterized by FTIR, SEM, swelling studies, flow dynamics and surface area measurements. Selective binding experiments were performed in the presence of competitive PHEMAH cryogel exhibited a high binding capacity and selectivity for Hb in the presence of Myb and BSA. The selectivity of Hb-PHEMAH cryogel for Hb was confirmed by HPLC. Hb depletion from blood hemolysate was also studied using SDS-PAGE. Hb-PHE-MAH cryogel can be reused many times with no apparent decrease in Hb adsorption capacity.

WOS: 000257442900022, Supermacroporous poly(2-hydroxyethyl methacrylate) [poly(HEMA)]-based monolithic cryogel column was prepared by radical cryocopolymerization of HEMA with N-methacryloyl-L-histidine methyl ester (MAH) as functional comonomer and N,N'-methylene-bisacrylamide (MBAAm) as crosslinker directly in a plastic syringe for affinity purification of lysozyme from chicken egg white. The monolithic cryogel containing a continuous polymeric matrix having interconnected pores of 10-50 mu m size was loaded with Zn2+ ions to form the metal chelate with poly(HEMA-MAH) cryogel. Poly(HEMA-MAH) cryogel was characterized by swelling studies, FTIR, scanning electron microscopy, and elemental analysis. The equilibrium swelling degree of the poly(HEMA-MAH) monolithic cryogel was 5.62 g H2O/g cryogel. Poly(HEMA-MAH) cryogel containing 45.8 mu mol MAH/g was used in the adsorption/desorption of lysozyme from aqueous solutions. The nonspecific adsorption of lysozyme was very low (7.5 mg/g). The maximum amount of lysozyme adsorption from aqueous solution in phosphate buffer was 209 mg/g at pH 7.0. It was observed that lysozyme could be repeatedly adsorbed and desorbed with the poly (HEMA-MAH) cyogel without significant loss of adsorption capacity. (C) 2008 Wiley Periodicals, Inc.

We have synthesized PVA/PEI monolithic cryogel columns chelated with Cu2+ ions as a model adsorbent, which is capable of binding haemoglobin (Hb) from human blood. The goal of this study is to perform the depletion of Hb via a single and easy process to be useful in proteomic studies. PVA/PEI-Cu2+ cryogel columns were subjected to adsorption studies of Hb from both aqueous solution and human plasma to evaluate the extent of interaction between cryogel columns and Hb. The effects of experimental parameters, such as pH, Hb equilibrium concentration, adsorption time, temperature, and ionic strength, on Hb adsorption capacity were investigated.

WOS: 000376136500005, PubMed: 26772759, In this study, we aimed to prepare the metal chelate affinity cryogels for the hemoglobin (Hb) depletion. Poly(2-hydroxyethyl methacrylate) (PHEMA) cryogels were selected as base matrix because of their blood compatibility, osmotic, chemical, and mechanical stability. Cryogels are also useful when working with the viscous samples such as blood, because of their interconnected macroporous structure. Iminodiacetic acid (IDA), the chelating agent, was covalently coupled with PHEMA cryogels after activation with the epichlorohydrin and then the Ni(II) ions were chelated to the IDA-bound cryogels. The depletion of the Hb from hemolysate was shown by SDS-PAGE.