Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
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Article Citation - WoS: 15Citation - Scopus: 15Granulation of Hydrometallurgically Synthesized Spinel Lithium Manganese Oxide Using Cross-Linked Chitosan for Lithium Adsorption From Water(Elsevier B.V., 2024) Recepoğlu,Y.K.; Arabacı,B.; Kahvecioğlu,A.; Yüksel,A.A drastic increase in demand for electric vehicles and energy storage systems increases lithium (Li) need as a critical metal for the 21st century. Lithium manganese oxides stand out among inorganic adsorbents because of their high capacity, chemical stability, selectivity, and affordability for lithium recovery from aqueous media. This study investigates using hydrometallurgically synthesized lithium manganese oxide (Li1.6Mn1.6O4) in granular form coated with cross-linked chitosan for lithium recovery from water. Characterization methods such as SEM, FTIR, XRD, and BET reveal the successful synthesis of the composite adsorbent. Granular cross-linked chitosan-coated and delithiated lithium manganese oxide (CTS/HMO) adsorbent demonstrated optimal removal efficiency of 86 % at pH 12 with 4 g/L of adsorbent dosage. The Langmuir isotherm at 25 °C, which showed monolayer adsorption with a maximum capacity of 4.94 mg/g, a better fit for the adsorption behavior of CTS/HMO. Adsorption was endothermic and thermodynamically spontaneous. Lithium adsorption followed the pseudo-first-order kinetic model. © 2024Article Citation - WoS: 52Citation - Scopus: 54Development of Si Doped Nano Hydroxyapatite Reinforced Bilayer Chitosan Nanocomposite Barrier Membranes for Guided Bone Regeneration(Elsevier, 2021) Tamburacı, Sedef; Tıhmınlıoğlu, FundaGuided Bone Regeneration (GBR) is a widely used process for the treatment of periodontal defects to prevent the formation of surrounding soft tissue at the periodontal defect and to provide hard tissue regeneration. Recently GBR designs have focused on the development of resorbable natural polymer-based barrier membranes due to their biodegradability and excellent biocompatibility. The aim of this study is to fabricate a novel bilayer nanocomposite membrane with microporous sublayer composed of chitosan and Si doped nanohydroxyapatite particles (Si-nHap) and chitosan/PEO nanofiber upper layer. Bilayer membrane was designed to prevent epithelial and fibroblastic cell migration and growth impeding bone formation with its upper layer and to support osteogenic cell bioactivity at the defect site with its sublayer. Microporous and nanofiber layers were fabricated by using freeze-drying and electrospinning techniques respectively. The effect of Si-nHap content on the morphological, mechanical and physical properties of the composites were investigated using SEM, AFM, micro-Ct, compression test, water uptake capacity and enzymatic degradation study. Antimicrobial properties of nanocomposite membranes were investigated with tube dilution and disk diffusion methods. In vitro cytotoxicity of bilayer membranes was evaluated. Saos-2 and NIH/3T3 proliferation studies were carried out on each layer. In vitro bioactivity of Saos-2 and NIH/3T3 cells were evaluated with ALP activity and hydroxyproline content respectively. Results showed that Si-nHap incorporation enhanced the mechanical and physical properties as well as controlling biodegradability of the polymer matrix. Besides, Si-nHap loading induced the bioactivity of Saos-2 cells by enhancing cell attachment, spreading and biomineralization on the material surface. Thus, results supported that designed bilayer nanocomposite membranes can be used as a potential biomaterial for guided bone regeneration in periodontal applications.Book Part Citation - Scopus: 6Recent Advances in Chitosan-Based Systems for Delivery of Anticancer Drugs(Springer, 2020) Polat, Mehmet; Polat, HürriyetProblems in transporting drug molecules to tumor sites in required dose or constitution lead to low efficacy and significant side effects. Shielding the drug molecules in micelles, liposomes, or nanoparticles is a major line of investigation to improve chemotherapeutic treatment. Though compatibility for proper envelopment of the drug and timely release at the tumor site are required of such a carrier, protecting its own physicochemical and morphological integrity during transport is another precondition. Because of its superior polymerization capability, biocompatibility, pH dependence, and charging characteristics, chitosan has been in the forefront of potential drug carriers. Numerous synthesis routes for chitosan-based nanocarriers have been suggested to the extent that a search of the literature published since 2000 with the keywords “novel + nano + chitosan” in the title results in 527 articles, indicating the bewildering quality and quantity of the new information. This review was carried out not only to peruse this large amount of work on chitosan-based anticancer drug delivery but also to extract manageable patterns from numerous synthesis routes. The main conclusion is that the synthesis methods suggested in literature can be combined into two main routes, and the degree of hydrophobicity of the drug determines which route should be followed. © Springer Nature Singapore Pte Ltd. 2019.Article Citation - WoS: 43Citation - Scopus: 47Bioactive Diatomite and Poss Silica Cage Reinforced Chitosan/Na-carboxymethyl Cellulose Polyelectrolyte Scaffolds for Hard Tissue Regeneration(Elsevier, 2019) Tamburacı, Sedef; Kimna, Ceren; Tıhmınlıoğlu, FundaRecently, natural polymers are reinforced with silica particles for hard tissue engineering applications to induce bone regeneration. In this study, as two novel bioactive agents, effects of diatomite and polyhedral oligomeric silsesquioxanes (POSS) on chitosan (CS)/Na-carboxymethylcellulose (Na-CMC) polymer blend scaffolds are examined. In addition, the effect of silica reinforcements was compared with Si-substituted nano-hydroxyapatite (Si-Hap) particles. The morphology, physical and chemical structures of the scaffolds were characterized with SEM, liquid displacement, FT-IR, mechanical analysis, swelling and degradation studies. The particle size and the crystal structure of diatomite, POSS and Si-Hap particles were determined with DLS and XRD analyses. In vitro studies were performed to figure out the cytotoxicity, proliferation, ALP activity, osteocalcin production and biomineralization to demonstrate the promising use of natural silica particles in bone regeneration. Freeze-dried scaffolds showed 190-307 mu m pore size range and 61-70% porosity. Both inorganic reinforcements increased the mechanical strength, enhanced the water uptake capacity and fastened the degradation rate. The nanocomposite scaffolds did not show any cytotoxic effect and enhanced the surface mineralization in osteogenic medium. Thus, diatomite and POSS cage structures can be potential reinforcements for nanocomposite design in hard tissue engineering applications.Article Citation - WoS: 17Citation - Scopus: 21Humidity Sensing Properties of Chitosan by Using Quartz Crystal Microbalance Method(American Scientific Publishers, 2012) Havare, A. Kemal; İlgü, Hüseyin; Okur, Salih; Şanlı Mohamed, GülşahHumidity adsorption kinetics of chitosan films was investigated by quartz crystal microbalance (QCM) technique. In this study, chitosan was synthesized from chitin by deacetylation process in 2.0% (v/v) acetic acid solution and then coated on QCM to measure humidity response. The Langmuir model was used to determine the adsorption rates and Gibbs free energy for various relative humidity between 11% and 94%. The average Gibbs free energy for adsorption was obtained as 12.93 kJ/mol. Our reproducible experimental results show that chitosan films are very sensitive to relative humidity changes at room temperature. Copyright © 2012 American Scientific Publishers All rights reserved.