Polymeric nanoparticle-based electrochemical sensor for the detection of CA 125.

In this paper, Cys-graft-p(HEMA) nanomaterials and a new electrochemical method were developed for determination of CA 125. Cys-graft-p(HEMA) nanomaterials were synthesized with emulsion polymerization method and modified with grafting procedure. It was determined that Cys-graft-p(HEMA) nanomaterials had 50 nm dimension and spherical morphology, and per gram polymeric material contained 0.011 mmol L-cysteine. Electrode surface was prepared step by step for electrochemical analysis with optimization process. Linear determination range was determined as 5-400 U/mL (R= 0.9935). Detection limit (LOD) was calculated as 1.87 U/mL, and quantification limit (LOQ) was determined as 5.62 U/mL. The fabricated sensor system showed good repeatability, accuracy, reality, and storage stability. According to the results obtained, Cys-graft p(HEMA) nanomaterials that is used for the first time in biosensor has the potential to find use in the sector with rapid determination time (10 min), extensive determination range, accuracy of methods. Novelties of this study are rapid analysis, determination range, appropriate of prototype device development, and developing new designed material. Developed material and method can be used in the preliminary diagnosis of the disease and combined with a prototype device that can allow the follow-up of the treatment process in diagnosed patients.

Quercetin adsorption with imprinted polymeric materials.

In this study, molecularly imprinted polymer membranes were synthesized for the recognition and adsorption of quercetin. For this, quercetin imprinted polymeric membranes [p(HEMA-MAH)] (Poly(2-hydroxyethyl methacrylate-co-N-methacryloly-l-histidinemethylester) were synthesized by UV polymerization technique using HEMA and MAH as monomers. Synthesized polymeric membranes were characterized with SEM, FTIR and swelling test. Characterized membranes were used for the direct adsorption of quercetin in a batch system. Quercetin adsorption conditions were optimized by using the quercetin imprinted polymeric membrane by altering the pH, temperature and initial quercetin concentration of the adsorption medium. Effect of adsorption time was also studied for up to 180 min. The optimum pH and temperature was determined between 4.0 and 45 °C. Maximum adsorbed amount of quercetin onto quercetin imprinted poly(HEMA-MAH) membrane was found to be as 299.6 mg/g membrane using the initial quercetin concentration of 2.0 mg/ml. Adsorbed quercetin was desorbed from the polymeric membranes with isopropyl alcohol with desorption yield of 98.3%. and repeated usability of the quercetin imprinted polymeric membranes was fallowed for 7 adsorption/desorption cycles. At the end of the 7th reuse, quercetin adsorption capacity of the quercetin imprinted poly(HEMA-MAH) membranes decreased only about 10%.

Controlled release of curcumin from poly(HEMA-MAPA) membrane.

In this work, poly(HEMA-MAPA) membranes were prepared by UV-polymerization technique. These membranes were characterized by SEM, FTIR, and swelling studies. Synthesized membranes had high porous structure. These membranes were used for controlled release of curcumin which is already used as folk remedy and used as drug for some certain diseases and cancers. Curcumin release was investigated for various pHs and temperatures. Optimum drug release yield was found to be as 70% at pH 7.4 and 37 °C within 2 h period. Time-depended release of curcumin was also investigated and its slow release from the membrane demonstrated within 48 h.

Preparation and characterization of silanized poly(HEMA) nanoparticles for recognition of sugars.

In this study presented, p(HEMA) nanoparticles were synthesized by the emulsion polymerization technique and then activated by a silanization agent, 3-aminopropyltriethoxysilane (APTES). The APTES-functionalized p(HEMA) nanoparticles that were synthesized were characterized by studies using the Zetasizer, FTIR and SEM. The p(HEMA)-APTES nanoparticles were further modified with phenyl boronic acid (PBA), and these boronate affinity nanoparticles were used for the recognition of some sugars such as galactose, fructose and raffinose. The system parameters (temperature and initial sugar concentration) were optimized for maximum sugar adsorption. The maximum amount of galactose, fructose, and raffinose adsorbed were found to be 4334.5 mg/g; 4334.9 and 810.0 mg/g, respectively (at 25°C, in a phosphate buffer of pH 7.0). Considering the results of this study, it can be concluded that these nanoparticles may be used as a new alternative for the specific recognition of sugar.

Boronate affinity nanoparticles for nucleoside separation.

Boronate affinity systems have been recently used for the specific isolation of cis-diol group carrying biomolecules such as glycoproteins, nucleosides, carbohydrates. Nanosized materials have been extremely used for the biotechnological purposes due to their unique properties and their high surface areas. The objective of this presented work was to develop a new boronate affinity system for the nucleoside adsorption. For this purpose, poly(HEMA) nanoparticles were synthesized by using surfactant free emulsion polymerization technique and then functionalized with phenylboronic acid. Synthesized nanoparticles were characterized with FTIR, SEM, and Zeta size analysis. Nucleic acid adsorption experiments were repeated for different medium pH values, for various nucleosides concentrations, for different temperatures and ionic strengths, in order to determine the optimum adsorption conditions. In the light of these studies, it can be concluded that this boronate ligand carrying nanoparticles were very valuable for the separation of nucleosides.

Boronate affinity nanoparticles for RNA isolation.

In this presented paper, boronic acid incorporated poly(HEMA) based nanoparticles were synthesized for RNA adsorption. For this purpose, poly(HEMA) nanoparticles were synthesized by using the surfactant free emulsion polymerization technique. Then, nanoparticles were modified with 3-(2-imidazoline-1-yl)propyl(triethoxysilane) (IMEO) and functionalized with phenylboronic acid (PBA). Prepared nanoparticles were characterized with SEM, FTIR and zeta-size. Optimum RNA adsorption conditions were investigated with different pHs, temperatures and initial RNA concentrations in order to determine the maximum RNA adsorption onto poly(HEMA)-IMEO-PBA nanoparticles. It was also studied that, synthesized nanoparticles could be used for 5 successive reuses and adsorption capacity of the nanoparticles decreased only about 5% at the end of the 5 cycles.

Radiolabeling of new generation magnetic poly(HEMA-MAPA) nanoparticles with (131) I and preliminary investigation of its radiopharmaceutical potential using albino Wistar rats.

In this study, N-methacryloyl-l-phenylalanine (MAPA) containing poly(2-hydroxyethylmethacrylate) (HEMA)-based magnetic poly(HEMA-MAPA) nanobeads [mag-poly(HEMA-MAPA)] were radiolabeled with (131) I [(131) I-mag-poly(HEMA-MAPA)], and the radiopharmaceutical potential of (131) I-mag-poly(HEMA-MAPA) was investigated. Quality control studies were carried out by radiochromatographic method to be sure that (131) I binded to mag-poly(HEMA-MAPA) efficiently. In this sense, binding yield of (131) I-mag-poly(HEMA-MAPA) was found to be about 95-100%. In addition to this, optimum radiodination conditions for (131) I-mag-poly(HEMA-MAPA) were determined by thin-layer radiochromatography studies. In addition to thin-layer radiochromatography studies, lipophilicity (partition coefficient) and stability studies for (131) I-mag-poly(HEMA-MAPA) were realized. It was determined that lipophilicities of mag-poly(HEMA-MAPA) and (131) I-mag-poly(HEMA-MAPA) were 0.12 ± 0.01 and 1.79 ± 0.76 according to ACD/logP algorithm program, respectively. Stability of the radiolabeled compound was investigated in time intervals given as 0, 30, 60, 180, and 1440 min. It was found that (131) I-mag-poly(HEMA-MAPA) existed as a stable complex in rat serum within 60 min. After that, biodistribution and scintigraphy studies were carried out by using albino Wistar rats. It was determined that the most important (131) I activity uptake was observed in the breast, the ovary, and the pancreas. Scintigraphy studies well supported biodistribution results.

Silanized polymeric nanoparticles for DNA isolation.

The aim of this study is to prepare silanized polymeric nanoparticles for DNA isolation. Polymeric p(HEMA)-IMEO-PBA nanoparticles around 85.7 nm diameter, was obtained by surfactant free emulsion polymerization for DNA isolation. Synthesized nanoparticles for characterization studies were realized scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and Zeta-size. Surface area, average particle size and size distribution were also performed. The surface area of synthesized silanized polymeric nanoparticles was 2460 m(2)/g. Synthesized polymeric nanoparticles were silanized with 3-(2-imidazoline-1-yl)propyl (triethoxysilane) (IMEO). After that, phenylboronic acid (PBA) which is DNA specific ligand were covalently binded to silanized polymeric nanoparticles. The amount of DNA adsorbed onto the p(HEMA)-IMEO-PBA nanoparticles first increased and then reached a saturation value at around 14.0 mg/mL of DNA concentration. The maximum adsorption was 672.41 mg/g silanized polymeric nanoparticles in the optimum adsorption medium. The maximum DNA adsorption was achieved at 4°C. The overall recovery of DNA was calculated as 95%. In repetitive adsorption-desorption circles, it is observed not being important decrease in DNA adsorption capacities. The results were shown that silanized polymeric nanoparticles can be a good alternative for DNA isolation.

Estrone specific molecularly imprinted polymeric nanospheres: synthesis, characterization and applications for electrochemical sensor development.

The aim of this study is (i) to prepare estrone-imprinted nanospheres (nano-EST-MIPs) and (ii) to integrate them into the electrochemical sensor as a recognition layer. N-methacryloyl-(l)-phenylalanine (MAPA) was chosen as the complexing monomer. Firstly, estrone (EST) was complexed with MAPA and the EST-imprinted poly(2-hyroxyethylmethacrylate-co-N-methacryloyl-(l)-phenylalanine) [EST-imprinted poly(HEMA-MAPA)] nanospheres were synthesized by surfactant- free emulsion polymerization method. The specific surface area of the EST-imprinted poly(HEMA-MAPA) nanospheres was found to be 1275 m2/g with a size of 163.2 nm in diameter. According to the elemental analysis results, the nanospheres contained 95.3 mmole MAPA/g nanosphere. The application of EST specific MIP nanospheres for the development of an electrochemical biosensor was introduced for the first time in our study by using electrochemical impedance spectroscopy (EIS) technique. This nano-MIP based sensor presented a great specificity and selectivity for EST.

Metal-chelating nanopolymers for antibody purification from human plasma.

The purification of immunoglobulin G (IgG) from human plasma was performed by using a novel metal-chelated adsorbent with nano size. The non-porous nanoparticles were produced by surfactant free emulsion polymerization of ethylene glycol dimethacrylate (EDMA) and 2-methacryloylamidohistidine (MAH). Then, Cu(II) ions were chelated on the nanoparticles. The nano-poly(EDMA-MAH) nanoparticles were characterized by Fourier transform infrared, scanning electron microscope, atomic force microscope and elemental analysis. The non-porous nanoparticles were spherical form and have 100-250 nm size distribution. The maximum IgG adsorption capacity of the Cu(II) chelated nanoparticles was found to be 463 mg/g polymer at pH 7.0 in HEPES buffer. Desorption of IgG was performed by 1.0 M NaCl and desorption rate was found to be 97 %. IgG was obtained from human plasma with purity of 94 % (up to 578 mg/g polymer). The non-porous nanoparticles allowed one-step purification of IgG from human plasma.