A Novel NanoMIP-SPR Sensor for the Point-of-Care Diagnosis of Breast Cancer.

Simple, fast, selective, and reliable detection of human epidermal growth factor receptor 2 (HER2) is of utmost importance in the early diagnosis of breast cancer to prevent its high prevalence and mortality. Molecularly imprinted polymers (MIPs), also known as artificial antibodies, have recently been used as a specific tool in cancer diagnosis and therapy. In this study, a miniaturized surface plasmon resonance (SPR)-based sensor was developed using epitope-mediated HER2-nanoMIPs. The nanoMIP receptors were characterized using dynamic light scattering (DLS), zeta potential, Fourier-transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), and fluorescent microscopy. The average size of the nanoMIPs was determined to be 67.5 ± 12.5 nm. The proposed novel SPR sensor provided superior selectivity to HER2 with a detection limit (LOD) of 11.6 pg mL-1 in human serum. The high specificity of the sensor was confirmed by cross-reactivity studies using P53, human serum albumin (HSA), transferrin, and glucose. The sensor preparation steps were successfully characterized by employing cyclic and square wave voltammetry. The nanoMIP-SPR sensor demonstrates great potential for use in the early diagnosis of breast cancer as a robust tool with high sensitivity, selectivity, and specificity.

Magnetic diatomite for pesticide removal from aqueous solution via hydrophobic interactions.

Pesticides are highly hazardous chemicals for the environment and human health and their use in agriculture is constantly increasing. Although 1,1,1-trichloro-2,2-bis(4-chlorophenyl) ethane 4,4'-DDT was banned at developed countries, it is still one of the most dangerous of chemical due to accumulation in the environment. It is known that the toxicity of DDT affects some enzyme systems biochemically. The main motivation of this study is to develop an effective adsorbate for the removal DDT, which was chosen as a model hydrophobic pesticide, out of aqueous systems. For this purpose, the bare diatomite particles were magnetically modified and a hydrophobic ligand attached to enhance its adsorptive and physio-chemical features. Under optimal conditions, a high adsorption capacity, around 120 mg/g with the hydrophobic and magnetic diatomite particles, modification of the diatomite particles reduced average pores diameter whereas surface area and total pore volume increased (around 15-folds). After five consecutive adsorption-desorption cycles, no significant decrease in adsorption capability was observed. The adsorption isotherms (Langmuir, Freundlich, and Flory-Huggins) applied to the data indicated that the adsorption process occurred via monolayer adsorption in an entropy-driven manner. The kinetic data also revealed the quick adsorption process without any diffusion limitations. Graphical Abstract.

Effect of immobilization on the activity of catalase carried by poly(HEMA-GMA) cryogels.

Hydrogen peroxide is converted by catalase to molecular oxygen and water to remove oxidative stress. In this study, catalase immobilization was performed using poly(2-hydroxyethyl methacrylate-glycidyl methacrylate) (poly(HEMA-GMA)) cryogels with different amounts of GMA. Catalase adsorption capacity of 298.7 ±â€¯9.9 mg/g was achieved at the end of 9 h using the poly(HEMA-GMA)-250 cryogel. Kinetic parameters and the inhibitory effects of pesticides such as 4,4'-DDE and 4,4'-DDT on the activity of free and immobilized catalase enzyme were investigated. While the Vmax value of the immobilized enzyme was reduced 4-fold compared to the free enzyme, in the case of the comparison of the KM values, the affinity of the immobilized enzyme was increased by 1.94 times against the substrate. The inhibitory effect of 4,4'-DDT pesticide was found to be higher for the immobilized and free enzyme. NaCl (1 M, pH: 7.0) solution was used for desorption of the adsorbed catalase enzyme. A desorption ratio of 96.45% was achieved. The technique used in this study is promising regarding for the immobilization of catalase enzyme to increase the operational activity. Therefore, poly(HEMA-GMA) cryogels have the potential to be used for immobilization of catalase enzyme in the fields of biology and biochemistry.

Use of nicotinamide decorated polymeric cryogels as heavy metal sweeper.

Cryogels are synthetic polymers used in adsorption experiments in recent years. Because of their macropores, they provide an excellent advantage as an adsorbent in continuous and batch adsorption processes. In this study, nicotinamide (NAA) decorated poly(2-hydroxyethyl methacrylate-glycidyl methacrylate), poly(HEMA-GMA), cryogels were synthesized. Heavy metal adsorption was carried out in wastewater obtained from six different sources in Çorum, Turkey. This study has a novelty regarding the application, i.e., it is the first time to use a polymeric adsorbent for the removal of 15 different heavy metal at the same time without any competition (despite the fact that there is a competition between the metals, the only thing is the removal regarding the purpose the study) as a heavy metal sweeper. Inductively coupled plasma-mass spectrometer (ICP-MS) was used for the determination of the initial amount of heavy metal in the wastewater samples. Adsorption studies were performed using poly(HEMA-GMA) and NAA-decorated poly(HEMA-GMA) cryogel to see the effect of NAA decoration. Higher adsorption capacity was achieved using NAA decorated poly(HEMA-GMA) cryogel. The total heavy metal amount adsorbed from six different sources was about 686 and 387 mg for poly(HEMA-GMA)-NAA and poly(HEMA-GMA) cryogels, respectively. The highest heavy metal adsorption value was obtained in the wastewater from source 2, and Zn (II) was the heavy metal adsorbed most for both cryogel. Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), thermal, surface area, elemental, and computerized microtomography (µCT) analyses were used for the characterization of cryogels.

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.

Efficient polymeric material for separation of human hemoglobin.

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.

Polychelated cryogels: hemoglobin adsorption from human blood.

The separation and purification methods are extremely important for the hemoglobin (Hb) which is a crucial biomolecule. The adsorption technique is popular among these methods and the cryogels have been used quite much due to their macropores and interconnected flow channels. In this study, the Hb adsorption onto the Cu(II) immobilized poly(2-hydroxyethyl methacrylate-glycidyl methacrylate), poly(HEMA-GMA)-Cu(II), cryogels was investigated under different conditions (pH, interaction time, initial Hb concentration, temperature and ionic strength) to optimize adsorption conditions. The swelling test, Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscope (SEM), surface area (BET), elemental and ICP-OES analysis were performed for the characterization of cryogels. Polyethyleneimine (PEI) molecule was used as a Cu(II)-chelating ligand. The Hb adsorption capacity of cryogels was determined as 193.8 mg Hb/g cryogel. The isolation of Hb from human blood was also studied under optimum adsorption conditions determined and the Hb (124.5 mg/g cryogel) was isolated. The adsorption model was investigated in the light of Langmuir and Freundlich adsorption isotherm models and it was determined to be more appropriate to the Langmuir adsorption isotherm model.

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

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.

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.

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.

Fe(II)-Co(II) Double Salt Incorporated Magnetic Hydrophobic Microparticles for Invertase Adsorption.

Invertase (ß-fructofuranoside fructohydrolase, EC 3.2.1.26) is an enzyme widely used in the food industry. Its main function is the formation of glucose and fructose through hydrolysis of sucrose. For the separation and purification of this commercially important enzyme from aqueous solutions, magnetic poly(2-hydroxyethyl methacrylate-N-methacryloyl-L-tryptophan), m-poly(HEMA-MATrp) microparticles were developed. Magnetic properties of microparticles are provided using ferromagnetic Fe(II)-Co(II) double salt. Characterization studies of magnetic microparticles were conducted via vibrating sample magnetometer (VSM), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM) analysis. Specific surface area of magnetic microparticles is 6.75 m(2)/g. Because of all experiments performed in this study, the adsorption capability of magnetic microparticles was optimized by variation of different conditions (pH, interaction time, initial invertase concentration, temperature, and ionic strength) and maximum adsorption capacity was determined as 992.64 mg invertase/g magnetic microparticles.

Purification, characterization, and investigation of in vitro inhibition by metals of paraoxonase from different sheep breeds.

Paraoxonase (PON) was purified and characterized from the Merino and Kivircik sheep's blood serums by a two-step procedure using ammonium sulphate precipitation and Sepharose-4B-L-tyrosine-1-napthylamine hydrophobic interaction chromatography for the first time. On SDS-polyacyrilamide gel electrophoresis, purified human serum paraoxonase yielded a single band of 66 kDa on SDS-PAGE. The KM and Vmax were 0.482 mM and 41.348 U/mL.dak for Merino PON enzyme, 0.153 mM and 70.289 U/mL.dak for Kivircik PON, respectively. The effect of Mn(2+) , Hg(2+) , Co(2+) , Cd(2+) , Ni(2+) and Cu(2+) heavy metals on purified Merino and Kivircik serum PON in vitro was determined.