Kazım Köse

Polyethyleneimine assisted-two-step polymerization to develop surface imprinted cryogels for lysozyme purification.

Surface imprinting strategy is one of the promising approaches to synthesize plastic antibodies while overcoming the problems in the protein imprinting research. In this study, we focused our attentions on developing two-step polymerization to imprint on the bare surface employing polyethyleneimine (PEI) assisted-coordination of template molecules, lysozyme. For this aim, we firstly synthesized poly(2-hydroxyethyl methacrylate-glycidyl methacrylate), poly(HEMA-GMA) cryogels as a bare structure. Then, we immobilized PEI onto the cryogels through the addition reaction between GMA and PEI molecules. After that, we determined the amount of free amine (NH2) groups of PEI molecules, subsequently immobilized methacrylate functionalities onto the half of them and another half was used to chelate Cu(II) ions as a mediator between template, lysozyme and PEI groups. After the characterization of the materials developed by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and the micro-computed tomography (μCT), we optimized the lysozyme adsorption conditions from aqueous solution. Before performing lysozyme purification from chicken egg white, we evaluated the effects of pH, interaction time, the initial lysozyme concentration, temperature and ionic strength on the lysozyme adsorption. Moreover, the selectivity of surface imprinted cryogels was examined against cytochrome c and bovine serum albumin (BSA) as the competitors. Finally, the mathematical modeling, which was applied to describe the adsorption process, showed that the experimental data is very well-fitted to the Langmuir adsorption isotherm.

Poly(hydroxyethyl methacrylate) based magnetic nanoparticles for lysozyme purification from chicken egg white.

Abstract The purpose of this article is to synthesize poly(hydroxyethyl methacrylate-N-methacryloyl-(L)-tryptophan) [mPHEMATrp] magnetic nanoparticles for lysozyme purification from chicken egg white. mPHEMATrp nanoparticles (38 nm in diameter) were synthesized by surfactant-free emulsion polymerization. Specific surface area of the mPHEMATrp nanoparticles was calculated to be 896 m2/g. Elemental analysis of mPHEMATrp nanoparticles was estimated in the range of 5.7–48.3 µmol MATrp/g. The maximum lysozyme adsorption capacity of the mPHEMATrp nanoparticles was 376.1 mg/g. The mPHEMATrp nanoparticles could be used five times without decreasing the lysozyme adsorption capacity significantly. The results indicate that the mPHEMATrp nanoparticles promise high selectivity for lysozyme purification.

PolyAdenine cryogels for fast and effective RNA purification.

Cryogels are used effectively for many diverse applications in a variety of fields. The isolation or purification of RNA, one of the potential utilizations for cryogels, is crucial due to their vital roles such as encoding, decoding, transcription and translation, and gene expression. RNA principally exists within every living thing, but their tendency to denaturation easily is still the most challenging issue. Herein, we aimed to develop adenine incorporated polymeric cryogels as an alternative sorbent for cost-friendly and fast RNA purification with high capacity. For this goal, we synthesized the polymerizable derivative of adenine called as adenine methacrylate (AdeM) through the substitution reaction between adenine and methacryloyl chloride. Then, 2-hydroxyethyl methacrylate (HEMA)-based cryogels were prepared in a partially frozen aqueous medium by copolymerization of monomers, AdeM, and HEMA. The cryogels were characterized by using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), surface area measurements, thermogravimetric analysis (TGA), and swelling tests. RNA adsorption experiments were performed via batch system while varying different conditions including pH, initial RNA concentration, temperature, and interaction time. We achieved high RNA adsorption capacity of cryogels, with the swelling ratio around 510%, as 11.86mg/g. The cryogels might be reused at least five times without significant decrease in adsorption capacity.

PolyGuanine methacrylate cryogels for ribonucleic acid purification

The isolation and purification of ribonucleic acid have attracted attention recently for the understanding of the functions in detail because of the necessity for the treatment of genetic diseases. In this study, guanine-incorporated polymeric cryogels were developed to obtain highly purified ribonucleic acid. The satisfactory purification performance was achieved with the guanine-incorporated poly (2-hydroxyethyl methacrylate-guanine methacrylate) cryogels. The most crucial advantages to use guanine as a functional monomer are to obtain a real natural interaction between guanine on the polymeric material and cytosine on the ribonucleic acid. Moreover, using cryogel with a highly porous structure and high swelling ratio provide advantages of getting more water within the structure to get more analyte to interact. The characterization of cryogels has proved the success of the synthesis and the perfect natural interaction to be taken place between the ligand (guanine methacrylate) and the cytosine in the ribonucleic acid molecules. Although the pores within the structure of cryogels are small, they provide efficient and fast adsorption. The chromatographic separation performance was investigated for different conditions (pH, temperature etc.). The desorption ratio and reusability were also analyzed at the end of the five adsorption-desorption cycles with no significant changes.

Adsorption of Victoria Blue R (VBR) dye on magnetic microparticles containing Fe(II)–Co(II) double salt

AbstractMagnetic microparticles have many applications in various areas today. The aim of this study was to develop hydrophobic magnetic microparticles as an alternative to traditional methods for high capacity and low cost removal of Victoria Blue R (VBR), which is valuable for industry and commercial, from wastewater and to determine the VBR adsorption ability of this adsorbent. Fe(II)–Co(II) double salt incorporated magnetic poly(2-hydroxyethyl methacrylate-N-methacryloyl-l-tryptophan) [m-poly(HEMA-MATrp)] microparticles were synthesized and used as adsorbent. These microparticles were synthesized in aqueous dispersion medium via microemulsion polymerization using MATrp and HEMA monomers. Magnetic hydrophobic microparticles were characterized via Fourier transform infrared spectroscopy, scanning electron microscopy, and vibrating sample magnetometer. Adsorption experiments were conducted for different conditions (pH, interaction time, amount of microparticles, temperature, and ionic strength) in batch ...

Bioinspired surface modification of poly(2-hydroxyethyl methacrylate) based microbeads via oxidative polymerization of dopamine.

Surface modification of support materials is crucial for improving their selectivities and biocompatibilities in bioaffinity applications. However, conventional modification techniques including chemical or physical conjugations mostly suffer from limitations of their multistep and complicated procedures, surface denaturations, batch-to-batch inconsistencies, and insufficient surface conjugations. In this study, we demonstrate a simple yet effective bioinspired approach for the surface modification of poly(2-hydroxyethyl methacrylate) [PHEMA] based bioaffinity adsorbents through oxidative polymerization of dopamine. The magnetic (mPHEMA) and non-magnetic (PHEMA) polymeric microbeads were fabricated by suspension polymerization technique. Surface modification of obtained microbeads was then carried out by using dopamine molecules under alkaline conditions. The polydopamine (PDOPA) coated microbeads were further employed as a bioaffinity absorbent targeted for immunoglobulin G (IgG) molecules. The effects of pH, temperature, protein concentration and ionic strength on the IgG adsorption process have been investigated. We found that PDOPA coated microbeads display dramatically higher IgG adsorption capacities when compared with their un-modified forms. Adsorption capacities also increased with increasing temperature. Monolayer Langmuir adsorption model can be thought more applicable for these adsorbent systems.

Efficient polymeric material for separation of human hemoglobin

Abstract In this study, negatively charged acrylic acid was used as a functional ligand to synthesise net-poly(2-hydroxyethyl methacrylate-co-acrylic acid) microparticles for the removal of hemoglobin having a positively charged Fe2+ ion in the core, as an alternative to conventional techniques to achieve a cost effective high-capacity purification. The characterization of microparticles was performed via Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, atomic force microscopy, the Brunauer – Emmett – Teller surface area analysis, and swelling test methods. Optimum adsorption conditions such as pH, initial hemoglobin concentration, temperature, and interaction time were studied batch wise. The highest adsorption capacity of microparticles was observed at pH 7.4 as 1276.4 mg hemoglobin/g polymer. The reusability of microparticles was also promising with ∼5% decrease in the adsorption capacity at the end of the five adsorption-desorption cycles.

Affinity purification lipase from wheat germ: comparison of hydrophobic and metal chelation effect

Abstract Cryogels are used quite a lot nowadays for adsorption studies as synthetic adsorbents. In this study, lipase enzyme (obtained from Candida cylindracea) adsorption capacity of poly(2-hydroxyethyl methacrylate-N-methacryloyl-L-tryptophan), poly(HEMA-MATrp), and Cu(II) ions immobilized poly(HEMA-MATrp), poly(HEMA-MATrp)-Cu(II), cryogel membranes were synthesized to determine and compare the adsorption behavior of lipase enzyme. In this regard, the effect of pH, interaction time, lipase initial concentration, temperature and ionic strength on the adsorption capacity of these membranes was investigated. Maximum lipase enzyme adsorption capacities of poly(HEMA-MATrp) and poly(HEMA-MATrp)-Cu(II) cryogel membranes were determined as 166.4 mg/g and 196.4 mg/g, respectively.

Synthesis and characterization of Ag+-decorated poly(glycidyl methacrylate) microparticle design for the adsorption of nucleic acids

In this study, we report on the adsorption of RNA and DNA molecules by exploiting the high binding affinity of these nucleic acids to Ag+ ions anchored on magnetic poly(glycidyl methacrylate) (PGMA) microparticles. PGMA microparticles were synthesized and modified with nicotinamide which enabled to anchor Ag+ ions on the surface. The successful preparation of PGMA was confirmed by the presence of characteristic FTIR peaks. The ESR results showed that the incorporation of FeNi salt to the polymeric structure provided a magnetic property to the microparticles. The amount of nicotinamide and Ag+ ions used to modify the surface of the particles were found to be 1.79 wt% and 52.6 mg Ag/g microparticle, respectively. The high affinity of nucleic acids to Ag+ ions were exploited for the adsorption studies. At the optimum working conditions, the adsorption capacity of microparticles was found to be 40.1 and 11.48 mg nucleic acid/g microparticle for RNA and DNA, respectively. Our study indicated that the use of novel Ag+-decorated magnetic PGMA particles can be successfully employed as adsorbents for fast, easy, and cost-friendly adsorption of nucleic acids with high purity as well as high in quantity.

Poly(HEMA-co-AA) microparticles for removal of aluminum: The reason for Alzheimer's

ABSTRACT Aluminum is one of the most toxic metals causing a variety of neurologic diseases, especially Alzheimers disease. It is impossible to avoid contact with aluminum because of its existence in food to medications. Therefore, removal of aluminum from the blood or wastewater is urgently important. The cost-effective and easy-to-prepare adsorbents are needed to get efficient aluminum removal. For that purpose, the poly(2-hydroxyethylmethacrylate-co-acrylic acid), poly(HEMA-co-AA), microparticles was synthesized to remove aluminum in a very short interaction time. The achievement of the desired polymeric structure was confirmed via Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM) and transmission electron microscope (TEM), etc. Additionally, particle features such as swelling ratio, size, and surface area were determined. The microparticles synthesized in this study have been determined with very good adsorption capacity even in small aluminum concentrations.