Chemistry / Kimya
Permanent URI for this collectionhttps://hdl.handle.net/11147/4072
Browse
406 results
Search Results
Article Citation - WoS: 3Citation - Scopus: 3Roadmap on Multifunctional Materials for Drug Delivery(IOP Publishing, 2024) Nottelet, Benjamin; Buwalda, Sytze; van Nostrum, Cornelus F.; Zhao, Xiaofei; Deng, Chao; Zhong, Zhiyuan; Cheah, Ernest; Kehr, Nermin SedaThis Roadmap on drug delivery aims to cover some of the most recent advances in the field of materials for drug delivery systems (DDSs) and emphasizes the role that multifunctional materials play in advancing the performance of modern DDSs in the context of the most current challenges presented. The Roadmap is comprised of multiple sections, each of which introduces the status of the field, the current and future challenges faced, and a perspective of the required advances necessary for biomaterial science to tackle these challenges. It is our hope that this collective vision will contribute to the initiation of conversation and collaboration across all areas of multifunctional materials for DDSs. We stress that this article is not meant to be a fully comprehensive review but rather an up-to-date snapshot of different areas of research, with a minimal number of references that focus upon the very latest research developments.Article Citation - WoS: 17Citation - Scopus: 15Antiproliferative and Apoptotic Effects of Olive Leaf Extract Microcapsules on Mcf-7 and A549 Cancer Cells(American Chemical Society, 2023) Bal, Yıldız; Sürmeli, Yusuf; Şanlı Mohamed, GülşahAlginate microcapsules are a talented means for the delivery of broad curative biomacromolecules. In this study, we immobilized olive leaf extract (OLE) by calcium alginate (CA) and chitosan-coated CA (CCA) and characterized the OLE-loaded CA and CCA. The cytotoxic effect, the cell cycle arrest, and the apoptotic effect of OLE and its microcapsules were investigated against breast adenocarcinoma (MCF-7) and lung carcinoma (A549). As a result, the loading capacity of OLE-CA and OLE-CCA was found to be 80 and 99%, respectively, in optimal conditions. Also, OLE-CA and OLE-CCA were characterized by unique FTIR peaks and morphological display relative to the empty CCA microcapsules. The cytotoxicity analysis showed that the IC50 values of OLE-CA and OLE-CCA were determined to be 312 and 0.94 μg mL-1 against A549, respectively, whereas these were found to be 865.4 and 425.5 μg mL-1 for MCF-7 cells. On the other hand, the OLE microcapsules did not possess in any concentration of cytotoxic influence on the BEAS 2B healthy cell line. Also, the exposure of OLE-CCA to MCF-7 and A549 resulted in the arrest of more MCF-7 and A549 cells at the G0/G1 phase compared to the OLE. A549 and MCF-7 cells were predominantly found in the late apoptosis phase and necrosis phase, respectively. Optical microscopy images confirmed that OLE microcapsules were more effective against MCF-7 and A549 than free OLE. The present work suggested that the OLE microcapsules might be administered as nutrition supplements for cancer therapy. © 2023 The Authors. Published by American Chemical Society.Article Citation - WoS: 2Citation - Scopus: 2Gas Phase Fragmentation Behavior of Proline in Macrocyclic B7 Ions(American Chemical Society, 2023) Taşoğlu, Çağdaş; Arslanoğlu, Alper; Yalçın, TalatThefragmentation characteristics of b (7) ionsproduced from proline-containing heptapeptides have been studiedin detail. The study has utilized the following C-terminally amidatedmodel peptides: PA(6), APA(5), A(2)PA(4), A(3)PA(3), A(4)PA(2), A(5)PA, A(6)P, PYAGFLV, PAGFLVY, PGFLVYA, PFLVYAG,PLVYAGF, PVYAGFL, YPAGFLV, YAPGFLV, YAGPFLV, YAGFPLV, YAGFLPV, YAGFLVP,PYAFLVG, PVLFYAG, A(2)PXA(3), and A(2)XPA(3) (where X = C, D, F, G, L, V, and Y, respectively). The resultshave shown that b (7) ions undergo head-to-tailcyclization and form a macrocyclic structure. Under the collision-induceddissociation (CID) condition, it generates nondirect sequence ionsregardless of the position of the proline and the neighboring aminoacid residues. This study highlights the unusual and unique fragmentationbehavior of proline-containing heptapeptides. Following the head-to-tailcyclization, the ring opens up and places the proline residue in theN-terminal position while forming a regular oxazolone form of b (2) ions for all peptide series. Then, the fragmentationreaction pathway is followed by the elimination of proline with itsC-terminal neighbor residue as an oxazolone (e.g., PXoxa) for all proline-containing peptide series.Article Citation - WoS: 2Citation - Scopus: 6Immobilization of Olive Leaf Extract With Chitosan Nanoparticles as an Adjunct To Enhance Cytotoxicity(American Chemical Society, 2023) Özdamar, Burcu; Sürmeli, Yusuf; Şanlı Mohamed, GülşahWe immobilized the olive leaf extract (OLE) with chitosannanoparticles(CNPs) by optimizing the effect of various immobilization conditions,and OLE-loaded CNPs (OLE-CNPs) were then elaborately characterizedphysicochemically by scanning electron microscopy (SEM), Fourier transforminfrared (FT-IR) spectroscopy, dynamic light scattering (DLS), andatomic force microscopy (AFM). Under optimal conditions, CNPs wereable to accommodate the OLE with a loading capacity of 97.5%. Theresulting OLE-CNPs had a spherical morphology, and their average diameterwas approximately 100 nm. The cytotoxic influence, cell cycle distribution,and apoptosis stage of OLE and OLE-CNPs were analyzed on lung carcinoma(A549) and breast adenocarcinoma (MCF-7) cell lines. In an in vitrocytotoxic assay, IC50 values of OLE-CNPs were determinedto be 540 & mu;g/mL for A549 and 810 & mu;g/mL for MCF-7. Thetreatment of both A549 and MCF-7 with OLE-CNPs caused the highestcell arrest in G0/G1 in a dose-independent manner. OLE-CNPs affectedcell cycle distribution in a manner different from free OLE treatmentin both cancer cells. A549 and MCF-7 cells were predominantly foundin the late apoptosis and necrosis phases, respectively, upon treatmentof 1000 & mu;M OLE-CNPs. Our results suggest that CNPs enhance theutility of OLEs as nutraceuticals in cancer and that OLE-CNPs canbe utilized as an adjunct to cancer therapy.Conference Object Citation - WoS: 3Citation - Scopus: 3Halloysite Nanotube Loaded Polyamide Nanocomposites: Structural, Morphological, Mechanical, Thermal and Processing Behaviors(American Institute of Physics, 2023) Akar, Alinda Öykü; Yıldız, Ümit Hakan; Tayfun, ÜmitIn this study, the polyamide 6 (PA) matrix was reinforced with the purified, fine ground and amino-silane treated halloysite nanotubes (HNT) at different concentrations. The preparation of composites was carried out using a lab-scale twin-screw micro-compounder with loading ratios at 0.5, 1, 3, and 20% by weight, and the test samples were prepared by the injection-molding process. According to mechanical test results, additions of HNT to the PA matrix caused slight improvements in tensile strength and Youngs' modulus parameters. The optimum concentrations for all of the additives used were estimated by comparison of mechanical test data. The addition of aminosilane-modified HNT resulted in a higher impact performance at high loading levels up to 3% concentrations. Further addition of HNT caused a reduction in the mechanical parameters of composites. Thermal studies revealed that the glass transition temperature of PA shifted to higher values after HNT mineral inclusions. Thermo-mechanical results showed that storage moduli of PA exhibited improvement with an increase in HNT content. The distributions of HNT clay into the PA phase were visualized with SEM images. Based on these observations, a high level of dispersion homogeneity was achieved for lower filling ratios. According to melt-flow and force measurements, composites filled with 20% of HNT displayed a remarkable increase in exerted force during melt-blending. © 2023 Author(s).Editorial Citation - WoS: 1Citation - Scopus: 1Editorial: Biomaterial Applications in Soft Tissue Engineering and Replacement(Frontiers Media S.A., 2023) Hornyak, Istvan; Jedlovszky-Hajdu, Angela; Kehr, SedaThe research related to the application of biomaterials encompasses a large area within the field of tissue engineering and regenerative medicine (TERM), and this Research Topic was dedicated to the versatile possibilities in the use of biomaterials. The sum of 10 manuscripts were submitted to this Research Topic and six were selected for this Research Topic with the contribution of 35 authors, Four of the accepted manuscripts were original research articles and two were review articlesReview Citation - WoS: 116Citation - Scopus: 125Salivary Biomarkers: Novel Noninvasive Tools To Diagnose Chronic Inflammation(Springer, 2023) Dongiovanni, Paola; Meroni, Marica; Casati, Sara; Goldoni, Riccardo; Thomaz, Douglas Vieira; Kehr, Nermin Seda; Galimberti, DanielaSeveral chronic disorders including type 2 diabetes (T2D), obesity, heart disease and cancer are preceded by a state of chronic low-grade inflammation. Biomarkers for the early assessment of chronic disorders encompass acute phase proteins (APP), cytokines and chemokines, pro-inflammatory enzymes, lipids and oxidative stress mediators. These substances enter saliva through the blood flow and, in some cases, there is a close relation between their salivary and serum concentration. Saliva can be easily collected and stored with non-invasive and cost-saving procedures, and it is emerging the concept to use it for the detection of inflammatory biomarkers. To this purpose, the present review aims to discuss the advantages and challenges of using standard and cutting-edge techniques to discover salivary biomarkers which may be used in diagnosis/therapy of several chronic diseases with inflammatory consequences with the pursuit to possibly replace conventional paths with detectable soluble mediators in saliva. Specifically, the review describes the procedures used for saliva collection, the standard approaches for the measurement of salivary biomarkers and the novel methodological strategies such as biosensors to improve the quality of care for chronically affected patients.Article Citation - WoS: 41Citation - Scopus: 44Ultralong-Life Quinone-Based Porous Organic Polymer Cathode for High-Performance Aqueous Zinc-Ion Batteries(American Chemical Society, 2023) Büyükçakır, Onur; Yüksel, Recep; Begar, Ferit; Erdoğmuş, Mustafa; Arsakay, Madi; Lee, Sun Hwa; Kim, Sang OukWe synthesized and studied a redox-active quinone-basedporousorganic polymer (rPOP) and found ultralong cycle life: it is a promisingorganic cathode for aqueous zinc-ion batteries (ZIBs). It has highphysicochemical stability and enhanced intrinsic conductivity fromits fused-aromatic conjugated skeleton. rPOP's high porosityallows for efficient Zn2+ infiltration through the poresduring charging-discharging cycles and contributes to the efficientutilization of redox-active quinone units. It delivers a specificcapacity of 120 mAh g(-1) at a current density of0.1 A g(-1) with a flat and long discharge plateau,which is critically important to provide a stable voltage output.It provides ultralong cycle life at a current density of 1.0 A g(-1) for 1000 and at 2.0 A g(-1) for 30 000cycles, with initial capacity retention of 95 and 66%, respectively.The co-insertion (Zn2+ and H+) charge storagemechanism was investigated using various electrochemical measurementsand ex/in situ structural characterization techniques, and is explainedherein. These findings contribute to a better understanding of thestructure-property relationship for rPOP and open a new avenuefor new organic cathode materials for high-performance next-generationaqueous batteries.Research Project Üstüniletken MgB2 tellerin üretimi ve karakterizasyonu(TÜBİTAK - Türkiye Bilimsel ve Teknolojik Araştırma Kurumu, 2005) Okur, Salih; Özyüzer, Lütfi; Abukay, Doğan; Emirdağ, Mehtap; Tanoğlu, Metin; Eğilmez, MehmetMgB2 alaşımının 39 K lik Tc kritik sıcaklığına sahip bir üstüniletken olduğunun 2001 de keşfedilmesi çok iyi üstüniletken olduğu bilinen NbTi ve NbsSn malzemelerinin yanısıra uygulamaya daha yakın yeni bir üstüniletken malzeme olma ümidini de artırmıştır. O günden bu güne MgB2 üstüniletken tellerin üretilmesi konusunda çok etkileyici bir aşama kaydedilmiştir. Daha yüksek kritik akım yoğunluğuna ulaşmak için gerekli parametrelerin araştırılması konusunda birkaç teknik geliştirilmiştir. Bunların arasında 'tüp içinde toz ' (TIT) adı verilen metot diğerlerine göre daha pratik ve ümit verici gözükmektedir. Bazı metal ve alaşımların TIT işleminde kılıf malzeme olarak kullanılmaya uygun bulunmuştur. Bunlardan demir ve alaşımları kısmen MgB2 özelliğini bozmadığı gibi manyetik ekranlama yaparak dış manyetik alanların kritik akım üzerindeki yan etkilerini azaltarak daha yüksek değerlere ulaşılmıştır. TIT yöntemi ile MgB2 üretimi sırasında iki farklı teknik vardır. Birisinde reaktif MgB2 tozlar kulanılırken diğerinde belli kimyasal oranlarda karıştırılmış reaktif olmayan Mg+2B tozları kullanılmaktadır. Daha sonra bu tozlar reaksiyon yapmayan bir tüp veya kapsül içine kapatılıp 900 ile 1000 °C civarında belirli bir süre tavlanmaktadır. Bu yöntem ile Demir kılıflı MgB2 üstüniletken tellerinden 15 K de 10 A/cm civarında bir Jc kritik akım yoğunluğuna ulaşılmıştır. Bu projede ilk adım olarak borik asitten M&B2 elde edilmiş ve elde edilen MgB2 in yapısını XRD ve SEM EDX mikroskopu ile karakterize edilmiştir. Uygun bir saflığa sahip MgB2 e ulaşıldığında elektriksel ve manyetik özellikleri pellet haline getirilip incelenmiştir, ikinci adımda ise üretilen MgB2 tozlarından üstüniletken MgB2 tel ve teyplerin TIT yöntemi ile üretilmiştir ve Cu, Fe, ve paslanmaz çelik gibi MgB2 ile etkileşmeyen malzemeler kılıf olarak kullanılanarak üretilmeye çalışılmış ve bu üstüniletken MgB2 tellerin özdirenç ve manyetik alana bağlı olarak kritik akım (Jc) karakteristiğinin sıcaklığa bağımlılığı incelenmiştir.Research Project Paladyum N-heterokarben kompleksleri içeren zeolitlerin Heck ve Suzuki tepkimelerinde katalizör olarak kullanılması(TÜBİTAK - Türkiye Bilimsel ve Teknolojik Araştırma Kurumu, 2006) Artok, Levent; Aksın, Özge; Bulut, Hatice; Durgun, GülaySilika bağlı Pd-N-heterosiklik karben kompleksleri ve paladyum yüklü silika bağlı imidazolinyum tuzlan bromoarenlerin Mizoroki-Heck tepkimelerinde yüksek aktivite göstermiştir. Tepkimeler liganddan ayrılan Pd tarafından katalizlenmiştir. Tepkime sonunda Pd silika yüzeyine çökelerek tekrar kazanılmıştır. Pd yüklü NaY zeolit bromoarenlerin Suzuki tepkimelerinde yüksek TOF aktivitesi göstermiştir. Katalizörün aktiflik göstermesi için ortamda suyun bulunması elzemdir. Katalizör kloroarenler için de aktivite göstermiştir. Ancak tepkime ortamında suyun bulunması katalizör aktivitesine olumsuz etki göstermiştir.