Makale Koleksiyonu
Permanent URI for this collection
Recent Submissions
Item Recent developments in subcritical water extraction of industrially important bioactive substances from plants, microorganisms, and organic wastes(Springer, 2024) Aminzai, Mohammad Tahir; Yabalak, Erdal; Akay, Sema; Kayan, BerkantSubcritical water extraction (SBWE) has emerged as one of the most sophisticated green extraction techniques, offering a promising approach for the extraction of bioactive compounds from diverse sources. It holds potential for environmental remediation as well as the production of useful extracts from plant materials, organic wastes, and microorganisms. This review provides a comprehensive analysis of SBWE, focusing on its application to plant materials, microorganisms, and organic wastes. SBWE refers to a process that uses liquid water at temperatures below 374 degrees C and pressures of up to 22.1 MPa, a process that maintains water in a subcritical state, enabling selective extraction of bioactive compounds. Bioactive compounds, such as phenolic compounds, terpenoids, alkaloids, and flavonoids, possess a wide range of physiological and pharmacological activities, including antibacterial, anti-inflammatory, and antioxidant properties. The review details various SBWE applications for extracting these compounds from different matrices: plant materials (seeds, leaves, roots, flowers, and fruits), microorganisms (fungi and algae), and organic wastes (peels, pomace, spent grains, and algal residues). Also, the review discusses the advantages of SBWE over traditional extraction methods, emphasizing its environmental benefits due to the use of non-toxic water as a solvent. SBWE not only enhances extraction efficiency but also reduces extraction time and energy consumption compared to conventional approaches. Besides, it explores the impact of various extraction conditions, including temperature, pressure, and the use of co-solvents, on the efficiency and yield of bioactive compounds. Additionally, it addresses the coupling of SBWE with other techniques to further improve its performance. In conclusion, SBWE stands out as a significant advancement in green extraction technology, with considerable potential for environmental remediation and the production of valuable bioactive extracts. This review highlights the current state of SBWE, its applications, and the ongoing developments in optimizing its efficiency and expanding its industrial applications.Item Enhancing the performance of unitized regenerative proton exchange membrane fuel cells through microwave-synthesized chitosan based nanocomposites(Elsevier, 2024) Yelegen, Nebi; Kümük, Berre; Balun Kayan, Didem; Baran, Talat; Kaplan, YükselThe membrane electrode assembly (MEA) is a core component of unitized regenerative proton exchange membrane fuel cells (UR-PEMFCs). The studies aimed to improve the cell performance and reduce the cost of the MEAs for the widespread adoption of UR-PEMFCs. The present study focuses on modifications of MEA. For this purpose, an innovative nanocomposite electrocatalyst was developed by using a carbon-based support material containing platinum nanoparticles with a diameter of approximately 20–30?nm via microwave synthesis technique. The electrocatalyst was developed by a single-step process, consist of multi-walled carbon nanotubes (MWCNT), graphitic carbon nitride (g-C3N4), chitosan (Chi), and platinum nanoparticles (MWCNT/g-C3N4/Chi/Pt nanocomposite). With the development of this support material, a relatively economical and effective electrocatalyst was obtained by large surface area and using the platinum on this surface at the nano level. The prepared catalyst was applied to commercially available membrane electrode assemblies with an active area of 100?cm2. Single-cell and triple-stack performance tests were conducted, and an increase of 17.13?% in the electrolyzer mode and 16.98?% in the fuel cell mode was achieved in single-cell performance with this applied electrocatalyst. Furthermore, an enhancement of 16.96?% in the electrolyzer mode and 16.81?% in the fuel cell mode was discerned in the UR-PEMFC stack. Beside the experimental studies, a numerical model of the modified membrane properties has been developed and validated through experimental data.Item Synthesis, characterization and anticancer effect of doxorubicin-loaded dual stimuli-responsive smart nanopolymers(Beilstein-Institut, 2024) Acet, Ömür; Kirsanov, Pavel; Acet, Burcu Önal; Halets-Bui, Inessa; Shcharbin, Dzmitry; Cömert, Seyda Ceylan; Odabaşı, MehmetNanopolymers represent a significant group of delivery vehicles for hydrophobic drugs. In particular, dual stimuli-responsive smart polymer nanomaterials might be extremely useful for drug delivery and release. We analyzed the possibility to include the known antitumor drug doxorubicin (DOX), which has antimitotic and antiproliferative effects, in a nanopolymer complex. Thus, doxorubicin-loaded temperature- and pH-sensitive smart nanopolymers (DOX-SNPs) were produced. Characterizations of the synthesized nanostructures were carried out including zeta potential measurements, Fourier-transform infrared spectroscopy, and scanning electron microscopy. The loading capacity of the nanopolymers for DOX was investigated, and encapsulation and release studies were carried out. In a final step, the cytotoxicity of the DOX-nanopolymer complexes against the HeLa cancer cell line at different concentrations and incubation times was studied. The DOX release depended on temperature and pH value of the release medium, with the highest release at pH 6.0 and 41 degrees C. This effect was similar to that observed for the commercial liposomal formulation of doxorubicin Doxil. The obtained results demonstrated that smart nanopolymers can be efficiently used to create new types of doxorubicin-based drugs.Item Enhanced anti-cancer efficacy of hesperidin through smart polymeric nanoparticles targeting prostate cancer(John Wiley and Sons Inc, 2024) Yıldırım, Metin; Acet, Ömür; Önal Acet, Burcu; Karakoç, Veyis; Odabaşı, MehmetThe rapid progress of various nanotechnology tools is currently being utilized in the management of several fatal illnesses, including cancer. Nanopolymers that encapsulate anti-cancer medication present a highly encouraging substitute to traditional therapies, primarily because of their specific targeting and accurate functionality, making them suitable for a variety of uses. Poly(2-hydroxyethyl methacrylate) (pHEMA) is a non-toxic polymer derived from the monomer HEMA, which is known for its toxicity. It can be combined with various other polymers and is associated with minimal immune response. The objective of the current investigation is to produce smart polymeric nanoparticles that are responsive to changes in pH and temperature, and capable of encapsulating hesperidin. These hesperidin-loaded poly(2-Hydroxyethyl methacrylate-N-isopropylacrylamide-Vinyl imidazole) nanoparticles, referred to as HesSNPs, aim to enhance the bioavailability of hesperidin and augment its therapeutic effectiveness in combating prostate cancer. N-isopropylacrylamide and Vinyl imidazole were employed as monomers sensitive to temperature and pH, respectively. Nanopolymers that were synthesized underwent characterization through dynamic light scattering (DLS) analyses, scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR) to analyze particle size and charge, surface morphology, and functional group determinations, respectively. HesSNPs decreased cell viability of DU-145 cells. Flow cytometry analysis revealed that apoptosis is the main mechanism underlying cell death after HesSNPs treatment.Item Poly(n-isopropylacrylamıde) hydrogel incorporatıng squaraine: synthesis, drug delivery and photodynamic properties(Muğla Sıtkı Koçman Üniversitesi Fen Bilimleri Enstitüsü, 2024) Pamuk Algı, Melek; Sarıgöl, RumeysaIn the present work, we describe the fabrication of a thermosensitive hydrogel. To fabricate the hydrogel (Sq1@PNIPAAm), we opted to use biocompatible poly(N-isopropylacrylamide) (PNIPAM) and squaraine dye (Sq1) as the polymer and the crosslinker, respectively. It is noteworthy that Sq1@PNIPAAm can be loaded with fluorescein, and we evaluated the fluorescein release behavior of Sq1@PNIPAAm hydrogel. We noted that on demand sustainable release of fluorescein was feasible upon gradual heating of Sq1@PNIPAAm hydrogel. Furthermore, Sq1@PNIPAAm hydrogels can be used as photosensitizers pertinent to photodynamic therapy (PDT). Our results show that hydrogel possesses favorable biological safety for use in in vitro anticancer studies. In vitro experiments confirmed that Sq1@PNIPAAm hydrogels could kill over 40% of cancer cells. Overall, we have successfully shown that Sq1@PNIPAAm enabled photodynamic therapy. Moreover, fluorescein loading into Sq1@PNIPAAm was possible, and it could be used to successfully accomplish temperature-controlled on-demand release. Given the abundance of low-cost, commercially accessible monomers available for use in hydrogel synthesis, this method offers access to a wide range of functional hydrogels for use in biomedical applications.Item Chemical composition and nutrient profiles of nine red macroalgae species(BioMed Central Ltd, 2024) Yücetepe, Aysun; Kırkın, Celale; Ayar, Eda Nur; Soylukan, Caner; Dikici, Emrah; Özçelik, Beraat; Okudan, Emine ŞükranNine red macroalgae (Amphiroa rigida, Gracilaria bursa-pastoris, Gracilaria gracilis, Grateloupia torture, Jania rubens, Laurencia obtusa, Laurencia pyramidalis, Liagora viscida, and Pterocladiella capillaries) were collected from coastal waters of Türkiye, and their proximate, fatty acid, soluble carbohydrate, and mineral profiles were investigated in the present study. According to the results, the crude protein content of the samples was between 4% and 23.8%, and four of the samples (G. turuturu, L. obtusa, L. pyramidalis, and P. capillacea) contained more than 10% protein. The crude lipid content of all the samples was below 1.6%, and the total carbohydrate content was between 38.3% and 76.9%. The macroalgae samples were generally richer in saturated fatty acids, palmitic acid being the most abundant, whereas G. gracilis had the highest content of unsaturated fatty acids (55.8%). All samples exhibited high contents of myo-inositol or glucose. Also, the samples generally had a good composition of minerals. Still, the heavy metal (i.e., Pb and Cd) content of Gracilaria gracilis was higher (59.6 µg/kg, P < 0.05) than those of the other algae samples. This study provides valuable insight into the chemical composition and fatty acid, mineral, and soluble carbohydrate profiles of Amphiroa rigida, Gracilaria bursa-pastoris, Gracilaria gracilis, Grateloupia turuturu, Jania rubens, Laurencia obtusa, Laurencia pyramidalis, Liagora viscida, and Pterocladiella capillacea from Türkiye.Item Bioisosteric replacement of the carboxylic acid group in Hepatitis-C virus NS5B thumb site II inhibitors: phenylalanine derivatives(Elsevier Masson s.r.l., 2024) Camcı, Merve; Şenol, Halil; Köse, Aytekin; Karaman Mayack, Berin; Alayoubi, Muhammed Moyasar; Karalı, NilgünHepatitis C virus (HCV) is a global health concern and the NS5B RNA-dependent RNA polymerase (RdRp) of HCV is an attractive target for drug discovery due to its role in viral replication. This study focuses on NS5B thumb site II inhibitors, specifically phenylalanine derivatives, and explores bioisosteric replacement and prodrug strategies to overcome limitations associated with carboxylic acid functionality. The synthesized compounds demonstrated antiviral activity, with compound 6d showing the most potent activity with an EC50 value of 3.717 ?M. The hydroxamidine derivatives 7a-d showed EC50 values ranging from 3.9 ?M to 11.3 ?M. However, the acidic heterocyclic derivatives containing the oxadiazolone (8a-d) and oxadiazolethione (9a-d) rings did not exhibit measurable activity. A methylated heterocycle 10b showed a hint of activity at 8.09 ?M. The pivaloyloxymethyl derivatives 11a and 11b did not show antiviral activity. Further studies are warranted to fully understand the effects of these modifications and to explore additional strategies for developing novel therapeutic options for HCV.Item Innovative approach against cancer: Thymoquinone-loaded PHEMA-based magnetic nanoparticles and their effects on MCF-7 breast cancer(Elsevier B.V., 2024) Yıldırım, Metin; Acet, Ömür; Önal Acet, Burcu; Karakoç, Veyis; Odabaşı, MehmetBreast cancer is most common cancer among women in the World. Thymoquinone (TQ) exhibits a wide range of biological activities such as anticancer, antidiabetic, antimicrobial, analgesic, antioxidant, and anti-inflammatory effects. However, its effectiveness in cancer treatment is hindered by its poor bioavailability, attributed to its limited solubility in water. Hence, novel strategies are required to enhance the bioavailability of TQ, which possesses remarkable anticancer characteristics. The aim of this study is to prepare pHEMA-based magnetic nanoparticles carrying TQ (TQ-MNPs) to improve bioavailability, and therapeutic efficacy against breast cancer. For this purpose, TQ-MNPs were synthesized and characterized with Fourier transform infrared spectrophotometer (FTIR), scanning electron microscopy (SEM), dynamic light scattering (DLS), magnetic field using a vibrating sample magnetometer (VSM). The loading capabilities of synthesized magentic nanostructures were evaluated, and release investigations were conducted under experimental conditions that mimic the cellular environment. The findings of the studies indicated that the TQ carrying capacity of MNPs was deemed satisfactory, and the release efficiency was adequate. MNPs and TQ-MNPs showed biocompatibility against HDFa cells. TQ-MNPs showed stronger anti-proliferative activity against MCF-7 breast cancer cells compared to free TQ (p < 0.05). TQ-MNPs induced apoptosis in MCF-7 breast cancer cells.Item Cross-linker engineered poly(hydroxyethyl methacrylate) hydrogel allows photodynamic and photothermal therapies and controlled drug release(Elsevier B.V., 2024) Algı, Melek Pamuk; Sarıgöl, RümeysaHere, we disclose the synthesis of poly(2-hydroxyethyl methacrylate) (PHEMA) hydrogels incorporating a squaraine dye (Sq) as a chemical crosslinker, viz. Sq@PHEMA. Photothermal and photodynamic features of Sq@PHEMA hydrogels are evaluated in detail. It is noteworthy that Sq@PHEMA induces hyperthermia upon irradiation with an 808 nm laser. Furthermore, Sq@PHEMA enables the generation of reactive oxygen species (ROS) upon irradiation with red light. To our delight, Sq@PHEMA hydrogels can be used as efficient dual photosensitizers pertinent to both PDT and PTT simultaneously. Finally, the hydrogels are loaded with methotrexate (MTX) to investigate controlled drug release behavior. It is noted that Sq@PHEMA hydrogels are promising candidates as drug delivery systems since on-demand MTX release is feasible upon irradiation. In sItem Luminescent carbon dots endowed with selective recognition of the carcinoid tumor biomarkers in biological fluids(Elsevier Ltd, 2024) Algı, Fatih; Pamuk Algı, Melek; Sonkaya, Ömer; Ocakçı, ŞeymaBiomarkers are commonly used in both basic research and clinical practice as diagnostic tools. Particularly, cancer biomarkers can be applied to the early detection and diagnosis or screening the tumors. Of special note, malignant tumors can release serotonin (5-hydroxytryptamine, 5-HT). In fact, 5-HT is an excellent biomarker for carcinoid tumors since its level in blood plasma is hardly affected by other parameters. Moreover, secretion of 5-HT gives rise to elevated levels of 5-hydroxyindole-3-acetic acid (HIAA), the major metabolite of 5-HT, in urine samples of the patients with carcinoid tumors. 5-HT and HIAA are regarded as eligible biomarkers, of which concentrations in blood plasma and urine samples can be utilized for prognosis, and early diagnosis of carcinoid syndrome. Here, we unveil the facile synthesis and characterization of new Tb(III)-doped carbon dots (CDs) in the present work. Strikingly, CDs exhibited superior features for sensing 5-HT and HIAA. It is of worth to note that the Tb(III)-doped CDs induce phosphorescent response to both 5-HT and HIAA in water. Limit of detections (LODs) for 5-HT and HIAA were found to be 0.44 nM and 0.49 nM, respectively. Remarkably, these are the lowest reported values for luminescent systems to date. Moreover, CDs were utilized as chemosensors for 5-HT and HIAA in simulated blood plasma and synthetic urine samples, respectively. To this purpose, extensive luminescence measurements were performed. Accordingly, the obtained results attested that CDs were promising chemosensors for the detection of both 5-HT and HIAA in simulated blood plasma and synthetic urine samples, respectively. Last but not least, we successfully demonstrate that Tb(III)-doped CDs can be used for the detection of 5-HT in artificial cerebrospinal fluid as well as in conditions mimicking the environment within secretory vesicles where 5-HT is stored. To the best of our knowledge, this is the first example of CDs which can induce remarkable phosphorescent response to 5-HT and HIAA in biological fluids.Item Highly efficient and reusable Pd nanoparticles decorated on a novel Schiff base polymer for reduction of nitroarenes and Suzuki coupling reactions(Elsevier, 2024) Yılmaz Baran, NurayEnvironmental pollutants such as nitroarenes which released from several factories threaten flora, fauna and human life. Therefore, removal of these toxic substances from waste waters is of significance. Catalytic systems involving metal nanoparticles are effective to reduce hazardous nitroarenes and to fabricate biaryls, which are significant for pharmaceutical and natural product industries, via cross coupling reactions. The current research was conducted to produce a quick, highly efficient, simply recoverable and reusable nanocatalyst (Pd NPs@P(2- FAN)) involving Pd nanoparticles (Pd NPs) immobilized on a novel Schiff base polymer, Poly(2-((furan-2- ylmethylene)amino)-5-nitrophenol) (P(2-FAN)) for reduction of several toxic nitroarenes to harmless and useful organic molecules in water and fabrication of useful biaryls via Suzuki coupling (SC) reactions. UV–Vis, FTIR, TGA, XRD, FE-SEM and EDS techniques were used for characterizations of the synthesized materials. Then, catalytic performance of the produced Pd NPs@P(2-FAN) was examined in reduction of 2-nitroaniline, 4- nitroaniline, 4-nitrophenol, 4-nitro-o-phenylenediamine. Pd NPs@P(2-FAN) was reduced all these hazardous nitroarenes in water in very short time (between 30 and 85 s) with only 3 mg nanocatalyst using NaBH4. Moreover, Pd NPs@P(2-FAN) accomplished the fabrication of several biaryls via SC reactions using the microwave irradiation method in a solventless medium. This resulted in excellent reaction yields (99 %) with a very low catalyst amount (0.006 mol%) and a rapid reaction time (6 min). Additionally, performed reusability test results displayed that the nanocatalyst was simply recoverable and repeatedly reusable for successive six and eight cycles for reduction of nitroarenes and production of biaryls, respectively.Item Pd@Na-CMC/g-C3N4: A nanostructured catalyst system based on sodium carboxymethyl cellulose/graphitic carbon nitride hydrogel beads and its performance in the treatment of organic and inorganic pollutants in water(Elsevier, 2024) Yılmaz Baran, Nuray; Çalışkan, Melike; Kızılbulut, Nurcan; Baran, TalatThe chemical reduction of organic or inorganic water contaminants is very important for both human health and pollution control. However, challenges still persist in preparing catalysts for chemical reduction, and there is a need for the development of inexpensive, easily synthesized, and effective catalyst systems. In this study, we have synthesized a new palladium nanocatalyst supported on the composite hydrogel beads composed of sodium carboxymethyl cellulose (Na-CMC) and graphitic carbon nitride (g-C3N4). The Pd@Na-CMC/g-C3N4 composite was fully characterized using FE-SEM, XRD, EDS, TEM, and EDS mapping analysis, confirming its successful preparation at the nano-scale. Pd@Na-CMC/g-C3N4 was utilized to reduce various nitroaromatics such as 4-nitrophenol (4-NP), 2-nitrophenol (2-NA), 4-nitroaniline (4-NA), 4-nitro-o-phenylenediamine (4-NPDA), and organic dyes including methylene blue (MB), methyl orange (MO), Rhodamine B (RhB), as well as potassium hexacyanoferrate(III) (K3[Fe(CN)6]), which is the inorganic contaminant. While Pd@Na-CMC/g-C3N4 completely reduced nitroaromatics within 65–120?s at 1?×?10?4?M concentration, organic dyes within 0–60?s at 1?×?10?5?M concentration, and K3[Fe(CN)6] within 90?s at 0.002?M concentration in water at room temperature. Rate constant values (kapp) of 4-NP, 2-NA, 4-NA, 4-NPDA, MO, RhB, and K3[Fe(CN)6] were calculated to be 0.0085?s?1, 0.012?s?1, 0.016?s?1, 0.01?s?1, 0.013?s?1, 0.021?s?1, and 0.015?s?1, respectively. Additionally, the Pd@Na-CMC/g-C3N4 displayed high stability and even after four consecutive runs, it was able to reduce 4-NP and MO without any significant loss in its performance.Item Palladium nanoparticles anchored on NiO particles-modified micro-size chitosan spheres: A promising, active, and retrievable catalyst system for treatment of environmental pollutants(Elsevier, 2024) Erdoğan, Afife Nur; Baran, TalatEfficient treatment of toxic organic pollutants in water/wastewater by using innovative, cost efficient, and simple technologies has recently become an important issue worldwide. Remediation of these pollutants with chemical reduction in the presence of a nano-sized catalyst and a reducing agent is one of the most useful methodologies. In the present study, we have designed a promising heterogeneous catalyst system (Pd@CS-NiO) by easy and efficient stabilization of palladium nanoparticles on the surface of microspheres composed of chitosan (CS)-NiO particles (CS-NiO) for the reduction of organic pollutants. The nano-structure of the developed Pd@CS-NiO was successfully validated using FE-SEM, XRD, EDS, TEM, and FTIR/ATR and its particles size was determined as 10 nm. The catalytic power of Pd@CS-NiO was then assessed in the reduction of 4-nitro-o-phenylenediamine (4-NPDA), 4-nitrophenol (4-NP), 4-nitroaniline (4-NA), 2-nitroaniline (2-NA), and some organic dyes, namely methylene blue (MB), methyl orange (MO), and rhodamine B (RhB) in aqueous medium at room temperature. The reductions were thoroughly studied spectro-photometrically. The tests displayed that the synthesized Pd@CS-NiO was a highly active and useful catalyst that reduced these pollutants in 0-145 s. Moreover, the rate constants for 2-NA, 4-NP, 4-NA, 4-NPDA, MO, and RhB were found to be 0.017 s-1, 0.011 s-1, 0.006 s-1, 0.013 s-1, 0.023 s-1, and 0.03 s-1, respectively. Moreover, the recycling test indicated that Pd@CS-NiO may be recovered easily thanks to its micro size nature and could be used up to seven steps, confirming its practical application potential.Item Molecular imprinted polymers: important advances in biochemistry, biomedical and biotechnology(Springer Science and Business Media Deutschland GmbH, 2024) Önal Acet, Burcu; İnanan, Tülden; Salieva, Kalipa; Borkoev, Bakyt; Odabaşı, Mehmet; Acet, ÖmürMolecularly imprinted polymers (MIPs) are handmade receptors that mimic the binding of natural antibodies. In other words, MIPs can selectively bind to the target molecule and qualify as bio-inspired synthetic materials. Today, MIPs are used extensively and are being developed further for biological applications. High cost and time consuming techniques are compelling factors for the field of biochemistry, biomedicine and biotechnology (3B), and there is an urgent need for an alternative, cheap, easy to produce, fast and effective method in these fields. MIPs stand out as a promising way for this purpose. MIPs have superiorities such as specific recognition specificity, excellent sensitivity selectivity and reusability. From this point of view, we examined MIP-related drug delivery studies, cell recognition, enzyme applications, in vivo applications, and applications for some important biomolecules. The aim of this review is to compile the utilizations, advantages, important developments and future expectations of MIPs for the fields of 3B.Item Preparation and application of naringenin imprinted cryogel membranes for selectively separation of naringenin from natural environment(Springer Science and Business Media Deutschland GmbH, 2024) Demirtaş, Emel; Odabaşı, MehmetNaringenin imprinted cryogel membranes (Nar-ICMs) were constructed for the selective separation of naringenin from the natural media. Acrylamide was used as functional monomer, while 2-hydroxyethyl methacrylate was used as co-monomer. Nar-ICMs were subjected to some characterization analyses, e.g., contact angle measurement, swelling tests, FTIR and SEM. Selectivity studies of Nar-ICMs were carried out both in aqueous media and natural orange juice. In selectivity studies, gallic and caffeic acid molecules were used as competitor agents due to their structural similarity to naringenin. Some results obtained as follows: Contact angle values for Nar-ICMs and non-imprinted cryogel membranes (non-ICMs) were found to be 58.5° and 71.8°, respectively. The maximum adsorption capacities of Nar-ICMs and non-ICMs for naringenin were found to be 66.5 and 14 mg/g, respectively at an initial concentration of 2 mg/mL. The qmax and Kd values of the high-affinity binding sites of the obtained Scatchard plot were found to be 0.126 mmol/g (34.4 mg/g) and 0.16 mM (1.6.10–4 M), respectively. The selectivity of Nar-ICMs for naringenin was found as 1.99 and 2.26 times high when compared to gallic and caffeic acids, respectively. The adsorption of naringenin from natural orange juice with Nar-ICMs was found to be 843 µg/g.Item Biopolymeric Composite Columns for Improving Water Quality in a Freshwater Stream Receiving Wastewater Treatment Plant Effluents(Springer, 2024) Akpınar, Şahin; Gürbüz, Fatma; Özcan, Samet; Odabaşı, MehmetInefficiently treated wastewater, which contains a high concentration of pollutants, is hazardous when it is mixed with the clean water of rivers and lakes. Nitrate in particular is a major global problem that leads to eutrophication and poses a threat to both aquatic ecosystems and human health. To address this issue, this work assessed the efficiency of polymeric cryogel (PC) and biopolymer (EPS)-blended composites (EPS@PC) in removing nitrates. Tests were also conducted to quantify the decrease in phosphate, chloride ions, and chemical oxygen demand (COD) in real water samples taken from the Ankara stream, which receives effluents from both urban (UWTP) and industrial (IWTP) wastewater treatment plants. Five different columns with varying adsorptive properties were prepared, some of which were combined with iron. The EPS-@PC-C5 column demonstrated the highest adsorption ratio for nitrate removal compared to the other tested columns. The EPS@PC-C5 achieved a high removal efficiency of 126.38 mg nitrate/g and showed COD reduction ranging from 60.2 to 94.1%. The removal ratio of chloride concentration varied between 56.0 and 75.7%, while the removal of phosphates ranged from 87 to 99%. Columns composed of EPS (EPS@PC) with both negatively and positively charged ligands are dependable and suitable options for water remediation.Item Sn-based chi-rGO/SnO2 Nanocomposite as an Efficient Electrocatalyst for CO2 Reduction to Formate(John Wiley and Sons Inc, 2024) Rende, Kumru; Kayan, Didem Balun; Çolakerol Arslan, Leyla; Ergenekon, PınarDesigning efficient and cost-effective electrocatalysts in simple ways is very important for energy efficiency. In this sense, nano-sized materials have been extensively utilized for the development of efficient electrodes for electrochemical CO2 reduction. In the present study, we have developed a Sn/chitosan-reduced graphene oxide (chi-rGO)/SnO2 composite electrode via only electrochemical techniques and tested it for electrochemical reduction of CO2 to formate. A bare Sn plate was modified with a reduced graphene oxide layer in the presence of chitosan to get a stable Sn/chi-rGO composite structure and to get more active sites, thus an efficient reduction process was performed. The surface of the Sn/chi-rGO composite was further modified by SnO2 nanoparticles via the potentiostatic electrodeposition method at a fixed applied potential of ?0.6 V for varying periods. The calculated double-layer capacitance (Cdl) of the Sn/chi-rGO/SnO2 electrode was about 80 times larger than the bare Sn plate implying that the coexistence of SnO2 nanoparticles on the (chi-rGO) structure enhanced the electrochemically active sites. The maximum Faradaic efficiency was recorded as 88 % towards the production of formate at an average current density of ?7.36 mAcm?2 at ?1.8 V. Electrochemical measurements and the stability test revealed that the resultant Sn/chi-rGO/SnO2 composite structure behaves as a potential electrode material for efficient CO2 conversion to formate.The study presents a simple and low-cost electrode preparation procedure including only electrochemical techniques which can be conducted within a very short time and without using extra energy and chemicals/additives.Item Identification of hCA I, hCA II, AChE and BChE Inhibitory Properties of Some Norcantharimide Derivatives; Molecular Docking, SAR and in silico ADME Studies(John Wiley and Sons Inc, 2024) Polat Köse, Leyla; Köse, Aytekin(3aR,4S,7R,7aS)-2-Alkyl/aryl-3a,4,7,7a-tetrahydro-1H-4,7-epoxyisoindole-1,3(2H)-diones, which are norcantharimide derivatives, were synthesized and their effects on carbonic anhydrase I (hCA I) and II (hCA II), acetylcholinesterase (AChE), and butyrylcholinesterase (BChE) inhibitory activity were investigated. For enzyme activity studies, hCA I and II isoenzymes purified from human erythrocytes and the commercially available enzymes AChE and BChE, which are both markers and significantly affect the known symptoms of Alzheimer's disease, were used. The two derivatives exerted efficient inhibition with IC50=4.530 nM (Ki=4.483) and 4.426 nM (Ki=4.696) against hCA I and with IC50=3.825 nM (Ki=3.854) and 3.457 nM (Ki=3.292) against hCA II, respectively. The another two derivatives exerted considerable inhibition with IC50=0.526 nM (Ki=0.224) and 0.575 nM (Ki=0.292) against AChE and with IC50=0.135 nM (Ki=0.057) and IC50=0.180 nM (Ki=0.070) against BChE, respectively. The compounds showed activity at the nanomolar level. These remarkable inhibition results were compared with those of standard inhibitors (acetazolamide for hCA I and II and tacrine for AChE and BChE) of each enzyme, reported, and graphed. In addition, molecular docking studies were carried out by in silico methods and the structure–activity relationship was discussed. The poses of compound 4 c are presented along with the ligand–receptor interaction against all metabolic enzymes.Item Revolution in Cancer Treatment: How Are Intelligently Designed Nanostructures Changing the Game(Multidisciplinary Digital Publishing Institute (MDPI), 2024) Gül, Désirée; Önal Acet, Burcu; Lu, Qiang; Stauber, Roland H.; Odabaşı, MehmetNanoparticles (NPs) are extremely important tools to overcome the limitations imposed by therapeutic agents and effectively overcome biological barriers. Smart designed/tuned nanostructures can be extremely effective for cancer treatment. The selection and design of nanostructures and the adjustment of size and surface properties are extremely important, especially for some precision treatments and drug delivery (DD). By designing specific methods, an important era can be opened in the biomedical field for personalized and precise treatment. Here, we focus on advances in the selection and design of nanostructures, as well as on how the structure and shape, size, charge, and surface properties of nanostructures in biological fluids (BFs) can be affected. We discussed the applications of specialized nanostructures in the therapy of head and neck cancer (HNC), which is a difficult and aggressive type of cancer to treat, to give an impetus for novel treatment approaches in this field. We also comprehensively touched on the shortcomings, current trends, and future perspectives when using nanostructures in the treatment of cancer.Item A Review for Uncovering the “Protein-Nanoparticle Alliance”: Implications of the Protein Corona for Biomedical Applications(Multidisciplinary Digital Publishing Institute (MDPI), 2024) Önal Acet, Burcu; Gül, Désirée; Stauber, Roland H.; Odabaşı, Mehmet; Acet, ÖmürUnderstanding both the physicochemical and biological interactions of nanoparticles is mandatory for the biomedical application of nanomaterials. By binding proteins, nanoparticles acquire new surface identities in biological fluids, the protein corona. Various studies have revealed the dynamic structure and nano–bio interactions of the protein corona. The binding of proteins not only imparts new surface identities to nanoparticles in biological fluids but also significantly influences their bioactivity, stability, and targeting specificity. Interestingly, recent endeavors have been undertaken to harness the potential of the protein corona instead of evading its presence. Exploitation of this ‘protein–nanoparticle alliance’ has significant potential to change the field of nanomedicine. Here, we present a thorough examination of the latest research on protein corona, encompassing its formation, dynamics, recent developments, and diverse bioapplications. Furthermore, we also aim to explore the interactions at the nano–bio interface, paving the way for innovative strategies to advance the application potential of the protein corona. By addressing challenges and promises in controlling protein corona formation, this review provides insights into the evolving landscape of the ‘protein–nanoparticle alliance’ and highlights emerging.
