Esra Maltas

Novel humic acid-bonded magnetite nanoparticles for protein immobilization

The present paper is the first report that introduces (i) a useful methodology for chemical immobilization of humic acid (HA) to aminopropyltriethoxysilane-functionalized magnetite iron oxide nanoparticles (APS-MNPs) and (ii) human serum albumin (HSA) binding to the obtained material (HA-APS-MNPs). The newly prepared magnetite nanoparticle was characterized by using Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and elemental analysis. Results indicated that surface modification of the bare magnetite nanoparticles (MNPs) with aminopropyltriethoxysilane (APS) and HA was successfully performed. The protein binding studies that were evaluated in batch mode exhibited that HA-APS-MNPs could be efficiently used as a substrate for the binding of HSA from aqueous solutions. Usually, recovery values higher than 90% were found to be feasible by HA-APS-MNPs, while that value was around 2% and 70% in the cases of MNPs and APS-MNPs, respectively. Hence, the capacity of MNPs was found to be significantly improved by immobilization of HA. Furthermore, thermal degradation of HA-APS-MNPs and HSA bonded HA-APS-MNPs was evaluated in terms of the Horowitz-Metzger equation in order to determine kinetic parameters for thermal decomposition. Activation energies calculated for HA-APS-MNPs (20.74 kJmol(-1)) and HSA bonded HA-APS-MNPs (33.42 kJmol(-1)) implied chemical immobilization of HA to APS-MNPs, and tight interactions between HA and HA-APS-MNPs.

Immobilization and characterization of hemoglobin on modified sporopollenin surfaces

Hemoglobin was covalently immobilized onto modified sporopollenin surface with different functional groups by chemical reactions to enhance binding ability of protein. In this study, the influence of various silane linker molecules on the capacity of protein binding was studied. For this purpose, activated sporopollenin was modified by 3-aminopropyltriethoxysilane (APTS), 3-chloropropyltrimethoxysilane (CPTS) and (3-glycidyloxypropyl)trimethoxysilane (GPTS). Hemoglobin (Hb) was immobilized on modified sporopollenin surfaces in phosphate buffer saline solution (PBS, pH 7.4) at 4°C. Results showed that GPTS modified sporopollenin surfaces resulted in the highest binding capacity for Hb. Micro porosity of samples was observed through scanning electron microscopy (SEM) and thermal behavior of the samples were studied with thermogravimetric analysis (TGA) within a temperature range: 25-900°C. TGA studies demonstrated the advantages of silane modification for high temperature applications and illustrated differences of the structures due to the different tail groups.

Synthesis and Application of Novel Magnetite Nanoparticle Based Azacrown Ether for Protein Recognition

AbstractThis article is the first report showing the human serum albumin (HSA) binding studies by using a new magnetite nanoparticle containing azacrown ether moieties via solid-liquid extraction process. The structure of the newly prepared magnetite nanoparticle was clarified by using attenuated total reflectance (ATR) infrared spectroscopy, scanning electron microscopy (SEM), UV-vis and elemental analysis. Analytic results indicated that modification of the surface of the magnetite nanoparticles with azacrown ether derivative was successfully carried out. The protein binding studies exhibited that the modified magnetite nanoparticles could be efficiently used for the binding of the human serum albumin (HSA) in aqueous solutions via non-covalent interaction between crown ether cavity and amino group of the protein.

Development of doxorubicin loading platform based albumin-sporopollenin as drug carrier

Albumin is thought as an drug carrier for doxorubicin (DOX). The binding of doxorubicin to albumin was studied on the surface of sporopolleninin (SP) to produce a new drug system based natural materials. Human serum albumin (HSA) was immobilized on SPIONs in 20 mM Tris buffer, 7.4 of pH. Data showed that binding amount of HSA has been found to be as 285.53 µg to the 25 mg of Sporopolleninin which also bounded 319.76 µM of DOX. Binding of protein and drug to Sp were clarified by SEM, EDX and FT-IR analysis.

Fluorimetric Analysis of Aluminum in Diluted Hemodialysis Solutions by Using a Novel Schiff Base

A spectrofluorimetric method has been developed for trace amount of aluminum(III) by using a novel Schiff base, N,N′-bis(salicylidene)-1,4-diaminobuthane (BUTAS), and 4-methyl-2-aminophenol (OAP). Since the aluminum complexes are generally fluorescent, aluminum(III) increases the fluorescence intensity of BUTAS-OAP by formation of Al-BUTAS-OAP complex. The fluorescence of the complex is measured at an excitation wavelength of 410 nm with an emission at 526 nm. Aluminum(III) can be detected within a concentration limit of 0.11–1.62 ppb and the lowest detection limit being 0.07 ppb. The proposed method was applied to diluted hemodialysis solution and spectrofluorimetric data was compared with data of standard pharmacopoeia method.

Development of New Fluorescent Dyes by Using Amine Modified Nanoparticles for Immunostaining

Fluorescent labeling of DNA was studied by using two newly synthesized ligands, which are 4-(2-hydroxybenzylidinamino) benzoic acid (PHBA) and 4-(2-hydroxybenzylidinamino) phthalic acid (PHPA). Their binding capacity to calf-thymus DNA was determined on functionalized superparamagnetic iron oxide nanoparticles (SPIONs). 23.1 µg of DNA was immobilized on 25 mg of nanoparticles. Binding capacity of fluorescent ligands to DNA-APTS-SPIONs was also found as 2.36 µM for PHBA and 1.97 for PHPA at 25 mg of the nanoparticles. Binding of the DNA to the ligands were examined by scanning electron microscopy, transmission electron microscopy, infrared spectroscopy, and confocal microscopy.

Comparison of winter and summer canola (Brassica napus) genotypes in Turkey.

We examined genetic relationships between canola (Brassica napus) genotypes cultivated in winter and spring in Turkey. Genomic DNA was isolated from the seeds by two modified CTAB protocols: EZ1 nucleic acid isolation method and a commercial kit (Dneasy Plant Mini Kit, Qiagen). Diversity and genetic relationships in the genotypes were analyzed with RAPD markers; 156 reliable bands were found for both genotypes, of which 24% were polymorphic. Fifteen primers gave at least one consistent polymorphic band. The dendogram developed by pooling data of RAPD analysis of summer and winter genotypes had similar patterns. This technique allowed us to examine the relationship between canola genotypes.

Antioxidant Activity and Fatty Acid Compositions of Arum Dioscoridis Extracts

In this study, we investigated the antioxidant activity of the extracts of Arum dioscoridis grown in Turkey. The antioxidant activity of the methanolic and acetone extracts from Arum dioscoridis seed was measured by various assays including ferric reducing antioxidant power, cupric reducing antioxidant capacity, scavenging activity of hydrogen peroxide and metal chelating capacity. The methanolic extract showed higher antioxidant activity with 85.4±2.1%. Fatty acid compositions of the methanolic and acetone extracts of Arum dioscoridis were analysed. Data suggested that Arum dioscoridis grown in Turkey may be importance source as natural antioxidant.