Browsing by Author "Tural, Bilsen"

Now showing 1 - 7 of 7

Citation - WoS: 7
Citation - Scopus: 17
Adsorptive Performance of Magnetic Nano-Biosorbent for Binary Dyes and Investigation of Comparative Biosorption
(Springer international Publishing Ag, 2019) Tarhan, Tuba; Tural, Bilsen; Boga, Kenan; Tural, Servet
The individual and competitive biosorption capacities of Metanil Yellow (MY) and Reactive Black 5 (RB5) by glutaraldehyde cross-linked magnetic chitosan nanoparticles (GMCNs) were studied. Competitive biosorption of the MY and RB5 dyes by the GMCNs has never been reported previously. Fourier transform infrared technique has been used to show the biosorbed MY and RB5 dyes onto GMCNs. During the studies, various essential factors influencing the biosorption, like adsorbate concentration, pH of the solution and contact time have been monitored.The equilibrium was achieved within 17 h for single dyes and 3 h for binary mixture at pH 3. The biosorption capacities were 620 mg/g for dye MY and 2549 mg/g for dye RB5 at pH 3, 30 degrees C. The second-order kinetic model has good compatibility with the dynamical biosorption behavior of a single dye and binary mixture. In order to study the competition biosorption of the RB5 and MY dyes in mixture solutions, the intraparticle diffusion model was used. Competition biosorption through analysis of the intraparticle diffusion model apparently favored the RB5 dye more than the MY dye on the GMCNs in mixture solutions. The biosorbent was regenerated efficiently through the alkaline solution and was then reused ten times for biosorption-desorption cycles.
ANTİ-KANSER İLAÇ YÜKLENMİŞ MANYETİK O-KARBOKSİ METİL KİTOSAN NANOKOMPOZİTİN SİTOTOKSİSİTE ÇALIŞMALRI
(2019) Tarhan, Tuba; Tural, Bilsen; Tural, Servet
Günümüzde kanser kemoterapisinin en önemli sorunlarına çözüm bulmak için nanoboyutta ilaç taşıyıcı sistemler geliştirilmiştir. Nanoboyuttaki kontrollü ilaç taşıma sistemleri tümör hedeflenmesine olanak sağlamıştır. Nanotaşıyıcılar arasından, biyouyumlu polimer kaplı süperparamanyetik nanoparçacıklar dışardan uygulanan manyetik alan ile istenilen bölgeye hedeflenebilme özelliklerine sahiptirler. Bu sayede ilaç hedeflenen bölgeye güvenli bir şekilde taşınabilmektedir. Bu çalışmada daha önce sentez ve karakterizasyonu yapılmış Manyetik O-Karboksimetil Kitosan nanokompozitine anti kanser ilaç olan Topotekan yükleme çalışmaları yapılmış olup, burada topotekan yüklü manyetik O-Karboksimetil Kitosan nanokompozitinin prostat kanseri Du145 ve sağlıklı insan prostat PNT1A hücre hattı üzerine sitotoksisite çalışmaları yapılmış ve sonuçları değerlendirilmiştir. Anahtar Kelimeler: Polimer Kaplı Süperparamanyetik Nanokompozit, Topotekan, Sitotoksisite, DU145 ve PNT1A
Competitive Biosorption of Azo-Dyes in Aqueous Solution on Magnetic Biosorbent Nanoparticles
(2018) Tarhan, Tuba; Tural, Bilsen; Tural, Servet
Abstract— In this study, glutaraldehyde cross-linked magnetic chitosan nanoparticles (GMCNs) were prepared through crosslinking modification of magnetic chitosan nanoparticles (MCNs) using glutaraldehyde as crosslinker that exhibited excellent adsorption performance Reactive Black 5 (RB5) and Metanil Yellow (MY) in dyes mixture solution. The characterization of synthesized GMCNs was performed by fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), dynamic light scattering (DLS), scanning electron microscopy (SEM) and vibrating sample magnetometry (VSM) analyses. Adsorption characteristics of dyes mixture solution on to GMCNs have been studied and results indicated that the adsorption capacities were affected by initial dye concentrations and contact time. The adsorption of dyes mixture solution experiments were well fitted the pseudo-second-order reaction. The technique used in this study offers a convenient and economical method for the preparation of nanoparticles, which can facilitate a higher adsorption capacity and thus more efficient adsorption of dyes in an aqueous solution compared with nature or other synthetic materials Keywords— Azo Dye, Biosorption, Biosorption isotherm, Biosorption kinetics, Magnetic Biosorbent
Citation - WoS: 18
Citation - Scopus: 19
Newly Synthesized Multifunctional Biopolymer Coated Magnetic Core/Shell Fe3O4@Au Nanoparticles for Evaluation of L-asparaginase Immobilization
(SpringerLink, 2022) Tarhan, Tuba; Dik, Gamze; Ulu, Ahmet; Tural, Bilsen; Tural, Servet; Ateş, Burhan
The immobilization strategy can promote greater enzyme utilization in applications by improving the overall stability and reusability of the enzyme. In this work, the L-asparaginase (L-ASNase) obtained from Escherichia coli was chosen as a model enzyme and immobilized onto the Fe3O4@Au-carboxymethyl chitosan (CMC) magnetic nanoparticles (MNPs) through adsorption. TEM, SEM, FT-IR, XRD, EDS, and TGA analyses were performed to examine the structure with and without L-ASNase. The yield of immobilized L-ASNase on Fe3O4@Au-CMC was found to be 68%. The biochemical properties such as optimum pH, optimum temperature, reusability, and thermal stability of the Fe3O4@Au-CMC/L-ASNase were comprehensively investigated. For instance, Fe3O4@Au-CMC/L-ASNase reached maximum activity at pH 7.0 and the optimum temperature was found to be 50 °C. The noticeably lower Ea value of the Fe3O4@Au-CMC/L-ASNase revealed the enhanced catalytic activity of this enzyme after immobilization. The Km and Vmax values were 3.27 ± 0.48 mM, and 51.54 ± 0.51 μmol min−1 for Fe3O4@Au-CMC/L-ASNase, respectively, which means good substrate affinity. The Fe3O4@Au-CMC/L-ASNase retained 65% of its initial activity even after 90 min at 60 °C. Moreover, it maintained more than 75% of its original activity after 10 cycles, indicating its excellent reusability. The results obtained suggested that this investigation highlights the use of MNPs as a support for the development of more economical and sustainable immobilized enzyme systems
Citation - WoS: 26
Citation - Scopus: 24
Removal of hazardous azo dye Metanil Yellow from aqueous solution by cross-linked magnetic biosorbent; equilibrium and kinetic studies
(Taylor & Francis Online, 2016) Tural, Servet; Tarhan, Tuba; Tural, Bilsen
In this study, glutaraldehyde cross-linked magnetic chitosan nanoparticles (GMCNs) were prepared through cross-linking modification of magnetic chitosan nanoparticles using glutaraldehyde as a cross-linker that exhibited excellent Metanil Yellow (MY) adsorption performance. The characterization of the GMCNs was performed by Fourier transform infrared spectroscopy, transmission electronmicroscopy, scanning electron microscopy, dynamic light scattering, and vibrating sample magnetometry analyses. Adsorption characteristics of MY from aqueous solution onto GMCNs have been studied. During the studies, various essential factors influencing the adsorption, like adsorbate concentration, amount of adsorbent, pH of the solution, and contact time have been monitored. The equilibrium was achieved within 17 h at pH 4, and the adsorption data obeyed the Langmuir equation with a maximum adsorption capacity of 625 mg/g and a Langmuir adsorption equilibrium constant of 5.2 × 10−4 dm3/mg at 25°C. The adsorption kinetics of MY at different initial dye concentrations was evaluated by the first-order and second-order models. The kinetic studies of MY adsorption showed that the adsorption process followed a second-order kinetic model. Furthermore, the GMCNs can be regenerated and reused through dye desorption in alkaline solution at pH 10. Adsorption results for reusability were 100, 93, and 65%, respectively, for three repeats.
Citation - WoS: 12
Citation - Scopus: 14
Synthesis and Characterization of New Branched Magnetic Nanocomposite for Loading and Release of Topotecan Anti-Cancer Drug
(Springer international Publishing Ag, 2019) Tarhan, Tuba; Tural, Bilsen; Tural, Servet
The purpose of this study is to synthesize the new branched magnetic nanocomposite to carry the therapeutic agents and bio-macromolecules. Although topotecan (TPT) has significant antitumor activity to lung, ovarian, breast, pancreas, and stomach cancers, lactone ring opening causes a reduction in cytotoxic activity and severe side effects in physiological conditions. In order to contribute to the removal of the handicap (lactone ring opening), magnetic dextran branched with N alpha N alpha-Bis (carboxymethyl)-l-lysine hydrate (NTA) nanoparticles (MD3) were prepared. The characterization of the resulting MD3 material was done by using multi-pronged analyses. The stability and release of TPT with synthesized and characterized new material of the MD3 was studied using various essential factors like concentration, dosage, pH, and time. The entrapment efficiency and loading capacity of TPT onto MD3 was calculated as 32.2% and 1.44 mg/g, respectively, at pH 5. Release studies were performed with drug-loaded MD3 at different pH values. It was seen that the best release was obtained at the cancerous site pH. Initial drug concentration was measured as 0.118 mM. The loaded drug concentration was calculated as 0.0380 mM at pH 5 and 0.00092 mM of drug was released after 90 min at pH 5.8. Percentage released of drug was found as 2.42% during 90 min.
Citation - WoS: 42
Citation - Scopus: 42
Synthesis of novel magnetic nano-sorbent functionalized with N-methyl-D-glucamine by click chemistry and removal of boron with magnetic separation method
(ACADEMIC PRESS INC ELSEVIER SCIENCE, 2018) Tural, Servet; Ece, Mehmet Sakir; Tural, Bilsen
Click chemistry refers to a group of reactions that are fast, simple to use, easy to purify, versatile, regiospecific, and give high product yields. Therefore, a novel, efficient magnetic nano-sorbent based on N-methyl-D-glucamine attached to magnetic nanoparticles was prepared using click coupling method. Its boron sorption capacity was compared with N-methyl-D-glucamine direct attached nano-sorbent. The characterization of the magnetic sorbents was investigated by several techniques such as X-ray diffraction, scanning electron microscope, transmission electron microscope, dynamic light scattering, thermogravimetric analysis, Fourier transform infrared spectrophotometer, and vibrating sample magnetometer. The boron sorption capacity of sorbents was compared by studying various essential factors influencing the sorption, like sorbate concentration, sorbents dosage, pH of the solution, and contact time. Langmuir and Freundlich and Dubinin-Radushkevich adsorption isotherms models were applied. Percent removal and sorption capacities efficiencies of sorbents obtained with direct and click coupling are found to be 49.5%, 98.7% and 6.68 mg/g, 13.44 mg/g respectively. Both sorbents have been found to be compatible with Langmuir isotherm, and the boron sorption kinetics conforms to the pseudo second order kinetics. The reusability study of sorbents was carried out five times for boron sorption and desorption.